Dissertations / Theses on the topic 'Syndrome of the device'

An electronically-controlled positive-displacement bellows-type air pump has been developed in the Bio-medical Engineering Laboratory for the treatment of adult Sleep Apnea Syndrome (SAS). An electronically-controlled positive-displacement pump has been employed in order to eliminate the pressure regulator and accompanying noise of present therapeutic devices. The positive-displacement pump is found to quietly and effectively provide the required airway pressures for the treatment of adult Sleep Apnea Syndrome. New developments in the reduction of the size and noise levels of current therapeutic devices, however, preclude mass production of the bellows-type pump because of its size disadvantage. The custom nasal mask and exhalation valve, control system, pressure-monitoring alarm system, and the controlled humidifier of the positive-displacement pump should be incorporated within the present fanâ type Nasal Continuous Positive Airway Pressure (NCPAP) system to provide quieter, more comfortable, and safer NCPAP therapy. Before the design and development of the positive displacement NCPAP pump is detailed in this thesis, however, the problem of adult Sleep Apnea Syndrome is introduced, available therapies are investigated, and the current NCPAP therapy system is examined.

Master of Science

A 53 year-old male presented with a one-day history of a swollen arm and dull, aching pain in the right upper extremity. The patient reported commencing exercising daily over the prior week with a modified, oscillating dumbbell; commonly referred to as a Shake Weight. Imaging revealed an occlusive thrombus in the right axillary, proximal brachial and basilic veins. The patient was treated with a 24-hour tPA infusion followed by mechanical thrombectomy, balloon angioplasty, and stent placement for a residual thrombus and stenosis. The patient was discharged the following day on warfarin and aspirin. This is the first report of effort-induced thrombosis of the upper extremity following the use of a modified, oscillating dumbbell. Due to the growing popularity of modified dumbbells and the possible risk for axillary vein thrombosis, consideration should be made to caution consumers of this potential complication.

名古屋大学博士学位論文 学位の種類:博士（医療技術学）（課程） 学位授与年月日:平成19年3月23日
"Daytime polysomnography and portable recording device for diagnosis and CPAP therapy in patients with obstructive sleep apnea syndrome" Sleep and Breathing, v.11, n.2 (2007) pp.109-115 を、博士論文として提出したもの。

Le syndrome d’apnée obstructive du sommeil affecte 6% à 17% de la population adulte. Le traitement de référence est la ventilation nocturne par une pression positive continue (PPC) fixe ou autopilotée afin de maintenir les voies aériennes ouvertes. L’efficacité de traitement des PPC autopilotées dépend des algorithmes et technologies pour détecter et qualifier les événements respiratoiresDes bancs d’essai ont été créés pour évaluer les PPC autopilotées en conditions comparables, en simulant des scénarios respiratoires composés de chaînes répétitives d’événements respiratoires. Les profils respiratoires simulés par les bancs d’essai précédents sont standardisés et simplifiés par rapport au profil respiratoire du patient.Pour tendre vers des essais plus réalistes, un nouveau banc d’essai physiologique permettant de reproduire automatiquement les profiles respiratoires à partir des données polygraphiques a été créé pendant cette thèse. Il a été validé en évaluant la simulation de scénarios respiratoires de différents phénotypes issus de 12 patients.Via ce banc d’essai, la précision de l’index d’apnée-hypopnée (IAH) résiduel fourni par PPC a été évalué, en comparant les IAH déterminés par 4 dispositifs de PPC (AirSense 10, DreamStation Auto, S.Box et Prisma 20A) avec ceux de polygraphie. Les résultats ont permis de quantifier les différences d’IAH afin d’aider les médecin à en tenir compte
Obstructive sleep apnea syndrome affects 6% to 17% of adult population. The reference treatment is nocturnal ventilation via an either fixed or auto-titrating positive airway pressure (APAP) to maintain upper airway (UA) open. Treatment efficiency of APAP depends greatly on algorithms and technologies used for detecting and characterizing disordered breathing events (linked to UA obstruction or central command).Bench tests have been developed to evaluate APAP devices under the same conditions, by simulating respiratory scenarios composed of a repetitive string of several disordered breathing events registered from apneic patients or artificially designed.Therefore, breathing profiles simulated on benches are standardized and simplified, in comparison with patients’. To improve this disadvantage, a new physiological bench, which enables reproducing automatically a specific patient breathing profile from its polygraph recordings, has been created. It has been validated by simulating various breathing profiles issuing from 12 patients of different pathological phenotypes.Through this new bench, the accuracy of residual apnea hypopnea indices (AHI) determined by 4 APAP devices (AirSense 10, DreamStation Auto, S.Box and Prisma 20A) has also been investigated in comparison with polygraph scorings. The results would help physicians in clinical practice thanks to the quantification of AHI discrepancies between manufacturers

The overarching theme of the thesis was to investigate the association between smart device use and computer vision syndrome. The initial study designed and developed the Open Field Tear film Analyser (OFTA) enabling a continuous, real-time assessment of the tear film and blink characteristics during smart device use. The monocular OFTA prototype was validated and showed good intra- and inter-observer repeatability relative to the Oculus Keratograph 5M and Bausch and Lomb one position keratometer. Subsequently, tear osmolarity following engagement with reading and gaming tasks on smart device and paper platforms was investigated. Discrete measures of osmolarity pre- and post-engagement with the tasks were obtained with the TearLab osmometer; osmolarity values differed between platforms when participants were engaged in a gaming task but no such difference was observed with the reading task. In addition, the influence of repeated measurements on tear osmolarity was also explored. To simulate the habitual binocular viewing conditions normally associated with smart device use, the binocular OFTA was developed. The device was used to assess the tear film and blink characteristics whilst engaging with reading and gaming tasks on smart device and paper platforms. The results revealed differences in blink characteristics and non-invasive tear break up time between the different platforms and tasks assessed. In addition, the thesis also reports on an investigation examining the real-time accommodative response to various targets displayed on smart devices using an open-field autorefractor with a Badal lens system adaptation. The results showed that accommodative latency, accommodative lag, mean velocity of accommodation, speed of disaccommodation and mean velocity of disaccommodation varied across the different platforms. Through the use of validated subjective questionnaires and smartphone apps, the relationship between duration of smartphone use and symptoms of dry eye were examined. The findings of this study demonstrated that longer duration of smartphone and personal computer use were associated with higher risk of dry eyes as indicated by subjective questionnaire outcomes.

Die vorliegende Untersuchung stellt sich die folgenden Fragen: Welchen Stand hat die Entwicklung von mechanischen Kreislaufunterstützungssystemen für Kinder, worin unterscheiden sich die eingesetzten Verfahren? Wie beeinflusst der Blutkontakt mit Fremdmaterial das Kapillarleck beim Kind? Welche Erfahrungen gibt es mit dem pulsatilen Ventrikelunterstützungssystem Berlin Heart beim Kind, welche Schwierigkeiten und Nebenwirkungen sind für das Kindesalter spezifisch? Wann profitieren Kinder von einer mechanischen Kreislaufunterstützung? Die bei Kindern am häufigsten eingesetzten Verfahren, Herzlungenmaschine (HLM), extrakorporale Membranoxygenierung (ECMO) und pneumatisch pulsatiles ventrikuläres Assist device (VAD) unterscheiden sich in Technik, Indikation, Nebenwirkung und möglicher Einsatzdauer erheblich. Die HLM dient der intraoperativen Kreislaufunterstützung. ECMO haben wir seit 1990 zur mittelfristigen Kreislaufunterstützung bei mehr als 70 Kindern für eine Dauer von ein bis zwei, selten bis zu drei Wochen eingesetzt. Mit VAD''s haben wir seit 1990 bei 56 Kindern die Herzfunktion teils monatelang ersetzt. Es bestehen multiple Unterschiede bei dem Einsatz von VAD zwischen Säuglingen, Kindern und Erwachsenen sowohl in der Indikation, Physiologie, Technik, Antikoagulation, der Familienbetreuung und hinsichtlich der Komplikationen. Bei jeder mechanischen Kreislaufunterstützung aktiviert der Fremdflächenkontakt des Blutes das Kontaktsystem, zu dem Gerinnungs- und Komplementsystem gehören. Klinische Äquivalente sind Thrombosen, Thrombozytenverlust und Kapillarleck. Insbesondere Säuglinge neigen zu diesen Komplikationen, weil das Verhältnis von Blutvolumen zu Fremdfläche ungünstig ist und der kontaktabhängige alternative Weg der Komplementaktivierung im jungen Alter vorherrscht. - Wir untersuchten prospektiv den prä- und postoperativen Verlauf von Kontakt- und Komplementsystem (C1q, C3, C4, C1-Inhibitor, Faktor B, Faktor XIIa) bei 11 herzoperierten Säuglingen ohne und 24 Säuglingen mit HLM. Es konnte nachgewiesen werden, dass obwohl bei allen Kindern eine Komplementaktivierung vorhanden war, diese signifikant ausgeprägter in der HLM-Gruppe stattfand. Die Kontaktaktivierung (Faktor XIIa, Präkallikrein) ließ sich nur in der HLM-Gruppe nachweisen, so dass belegt war, dass es nicht die Anästhesie oder die Operation an sich, sondern die HLM ist, die die inflammatorische Reaktion hervorruft. - Bei 27 mit HLM operierten Säuglingen untersuchten wir prospektiv die CLS-Entstehung und die Komplement- und Kontaktaktivierung. Bei den 10 Kindern, die im späteren Verlauf ein Kapillarlecksyndrom (CLS) entwickelten, waren bereits 30 Minuten nach HLM-Beginn die C1-INH-Konzentration und -Aktivität niedriger und Faktor XIIa, C3a und C5a höher als bei den 17 Kindern, die später kein CLS entwickelten. Die Aktivierung korrelierte mit dem Alter der Kinder und der HLM-Zeit, nicht mit der Tiefe der Hypothermie. - Retrospektiv untersuchten wir 28 Kinder (6 Tage - 16 Jahre alt), bei denen im terminalen Herzversagen nach Reanimation die Herzfunktion mit dem parakorporalen pneumatischen VAD Berlin Heart 1-98 Tage lang unterstützt wurde. Zwölf dieser Kinder wurden unter laufender Reanimation mit Herzdruckmassage in den Operationssaal gebracht. 13 Patienten erreichten eine Herztransplantation, 3 Kinder wurden mit dem eigenen Herzen vom System entwöhnt. 12 Kinder starben am System, Todesursachen waren Schock, Multiorganversagen, Sepsis und Blutungen. - Bei 95 herztransplantierten Kindern untersuchten wir retrospektiv die Verläufe in Abhängigkeit davon, ob die Kinder (I) vor der Transplantation in relativ stabilem Zustand zuhause waren (n=33), ob sie (II) kritisch krank hospitalisiert waren (n= 44), oder ob sie (III) nach Reanimation mit einem VAD kreislaufunterstützt wurden (n=18, Dauer 4-111 Tage). Die Überlebensraten nach 1Mo/1J/5J betrugen in Gruppe I 88/88/80 %, Gruppe II 88/82/79 %, Gruppe III 72/72/72 %. Der frühpostoperative Verlauf nach Transplantation war bei Gruppe III nur wenig komplizierter, was den Erfolg der Transplantation nicht minderte. - Retrospektiv untersuchten wir den Verlauf von 4 Kindern mit schwerer Myokarditis, die bei kardiogenem Schock mit biventrikulärem VAD kreislaufunterstützt wurden. Das schockbedingte Multiorganversagen und die Thrombozytopenie bildete sich während der Unterstützung mit dem VAD zurück. Drei Kinder konnten nach Erholung des Myokards vom VAD entwöhnt werden, eines wurde erfolgreich transplantiert. - Ausserdem untersuchten wir den Verlauf von 84 Kindern, die wegen Kardiomyopathie auf der Intensivstation behandelt wurden. Von den 69 (= 82 %), bei denen eine kreislaufstützende medikamentöse Therapie ausreichend war, konnten 32 herztransplantiert werden, 36 besserten sich und wurden nach Hause entlassen und ein Kind verstarb akut. Fünfzehn der 84 Kinder (= 18 %) ließen sich nicht stabilisieren und erhielten nach Reanimation eine mechanische Kreislaufunterstützung mit VAD (Dauer 1 – 98 Tage). Von diesen konnten 12 transplantiert werden. Die in dieser Habilitationsschrift ausgeführten Arbeiten haben weiterführende Fragestellungen und Grenzbereiche des mechanischen Kreislaufersatzes im Kindesalter aufgezeigt und neue Therapiestrategien dargestellt. Dadurch ist es möglich, die Überlebenschancen von Kindern mit terminalem Herzversagen erheblich zu verbessern. Sei es durch Zeitgewinn bis zur Erholung des Myokards oder zum Organangebot auf der HTx-Warteliste. Durch den Zeitgewinn, den die VAD`s den zur HTx gelisteten Kindern bieten, brauchen zur Transplantation freigegebene Kinderherzen seltener verworfen werden, mehr Kinder können überleben und die Ausnutzung der angebotenen Organe gelingt besser.
This scientific work addresses the following questions: what is the state of the art in mechanical circulatory support (MCS) in infants and children? How do the different techniques differ? How does mechanical circulatory support influence the systemic inflammatory response after cardiac surgery? What are the indications for use of the pneumatic pulsatile ventricular support system Berlin Heart in children and what do our experience and the results of its use show? The MCS systems most often used for children of all ages are cardiopulmonary bypass (CPB), extracorporeal membrane oxygenation (ECMO), centrifugal pumps and the pneumatic pulsatile ventricular assist device (VAD). These systems vary in indications, results, side effects and potential supporting time. CPB is used to replace the circulation during cardiac surgery. ECMO has been used in our hospital since 1990 for circulatory support in cases of cardiac failure and of pulmonary failure and has been applied in more than 70 children over a period of 1 to 3 weeks. The VAD (Berlin Heart) has been used since 1990 in 56 children for long-term support, when the heart function had to be supported for up to several months. In VAD use there are multiple differences in indication, physiology, underlying disease, technique, anticoagulation and complications between infants, children and adults. In every case of MCS there is contact and complement activation as a reaction of the blood to foreign surfaces, resulting in capillary leak and activation of coagulation and anticoagulation systems with the risk of thrombosis or bleeding. In particular, young infants are prone to systemic inflammatory response in the form of capillary leak. In a prospective study we compared the complement activation after cardiac operations with or without CPB in 35 infants and measured serially the complement function and concentrations or activity of C1q, C3, C4, C1 esterase inhibitor, factor B, the activated split product C3a, prekallikrein and factor XIIa of the contact system. We found that complement activation occurs in all infants but is significantly higher in the group with CPB. Contact activation occurred only in patients who undergo CPB. Thus, the inflammatory response is caused by the use of a CPB circuit and to a lesser degree by surgical procedures and anesthesia. In 27 infants with CPB surgery we prospectively investigated the early clinical parameters that predict the development of capillary leak syndrome (CLS) and examined the relationship between CLS and complement and contact activation and C1 esterase inhibitor during and after bypass. We found that contact and complement activation occurs during CPB and contributes to CLS more frequently in infants of a younger age and with a prolonged bypass time. This activation and decrease in C1 esterase inhibitor was strongly expressed in the CLS group. Although MCS in intractable heart failure in children has normally been limited to centrifugal pumps and ECMO, we implanted 28 children with the pediatric sized pulsatile air-driven Berlin Heart VAD. Our aim was to keep the children alive and allow recovery from shock sequeale until later transplantation or myocardial recovery. Twelve children were brought to the operating room under cardiac massage. In total 12 children died on the system, but thirteen children were transplanted and three were sucessfully weaned from the system. Acute myocarditis appears to be a promising precondition for complete recovery during VAD support and in patients with cardiomyopathy support until transplantation is the goal for the future. We reviewed the course of 95 children who had undergone heart transplantation in our center to investigate whether previous VAD support has an impact on long-term outcome after transplantation. Three groups were compared and we found that bridging to transplantation with a pulsatile pneumatic VAD is a safe procedure in pediatric patients. After transplantation the overall survival rate is 86 % at 1 month, 82 % at 1 year and 75 % at 5 years. The survival of children previously supported with a VAD is similar to that of patients who were bridged with inotropes or who awaited heart transplantation electively. In 4 children with fulminant myocarditis and cardiogenic shock in whom all aggressive medical treatment failed we found that artificial replacement of the heart with complete unloading was followed by total recovery; 3 patients were successfully weaned from the device. No patient died and heart transplantation was necessary in only one child. Retrospectively we examined the course of 84 children who were treated at the ICU, presenting severe cardiac failure due to cardiomyopathy. In 15 of them medical treatment failed and the disease progressed so rapidly that they would have died during the waiting period before a suitable donor organ was found. After resuscitation these 15 children were supported with a VAD. Only 3 died during the waiting period and 12 (80%) underwent later heart transplantation. Progress has been rapid towards individualized choice of mechanical circulatory support systems for children of different ages and with different indications. With the Berlin Heart VAD prolonged circulatory support until myocardial recovery or until heart transplantation is effective in children and infants. It offers time to restore organ function, allows extubation, mobilization and neurological examination and increases the chances for successful transplantation. It can be used with low device-related morbidity and satisfactory results especially in the myocarditis and the cardiomyopathy groups. Complete recovery from secondary organ dysfunction should be achieved before heart transplantation is considered. We expect not only that children with end-stage heart failure will benefit from long-term VAD support, but also that fewer organs from young donors will be lost. Of particular importance is our experience with myocardial recovery in children with acute myocarditis in whom the devices could be explanted.

L’État de droit peut se définir comme un système institutionnel dans lequel la puissance publique est soumise au droit. Cette notion, a été redéfinie au début du vingtième siècle par Hans Kelsen comme : « un État dans lequel les normes juridiques sont hiérarchisées de telle sorte que sa puissance s’en trouve limitée ». Un tel système qui pose la soumission des patients à la règle, présuppose outre la légitimité de ses agents, la traduction objective de la normativité qui en est issue. Pour autant il appert de l’observation des dispositifs qui en résultent, des anomalies structurelles et fonctionnelles dont les effets cliniques constitutifs d’un syndrome, pointent les dysfonctionnements d’un espace juridictionnel essentiellement abandonné aux individualités. En conséquence, les interactions entre les agents et les patients (justiciables, défendeurs, demandeurs) ne sauraient être dissociées de l’analyse de ces manifestations spécifiques au droit continental, notamment français contemporain. C’est donc, après avoir procédé à l’identification du syndrome et à l’analyse du « concept dispositif », fait le constat d’un paradoxe régulatoire constant et relevé les signes cliniques des affections, que nous en avons déduis les vecteurs. Toutefois, le constat qui en est résulté conduisait, soit à considérer le phénomène inéluctable et à l’intégrer, soit à en rechercher les causes originelles et les voies susceptibles d’en atténuer les effets. Par suite, c’est à l’aune d’un paradigme constant, propre au droit continental, qu’après avoir relevé les effets et identifié les causes des affections ainsi révélées par le syndrome du dispositif, que nous avons imaginé le concept de résidualisme. Partant, après en avoir aperçu tant les fondements que la stratégie, nous en avons recherché les premières pistes susceptibles d’en réduire la portée et de conduire à l’élaboration d’un dispositif « assisté », visant tant à obtenir l’adhésion effective des agents et des patients, qu’à décharger le juge d’une responsabilité normative qui n’est pas la sienne
The two bodies of the judge and the syndrome of the device: study on the causes of the normative incompleteness, legal scope and its other consequences in contemporary French continental law.The rule of law can be defined as an institutional system in which the public authority is subject to the law. This notion has been redefined in the early twentieth century by Hans Kelsen as: "a State in which legal standards are prioritized so that its power is limited. Such a system that asks patients to the rule submission, presupposes the legitimacy of its agents, in addition to objective translation of normativity which from. So far it appears from the observation devices resulting, structural and functional abnormalities with the constituent clinical effects of a syndrome, that point the dysfunctions of a jurisdictional space essentially abandoned to individualities. As a result, the interactions between agents and patients (litigants, defendants, plaintiffs) cannot be separated from the analysis of these events specific to the continental law, including contemporary french. It is therefore, after identification of the syndrome and the analysis of the 'system concept', made the observation that for a constant regulatory paradox and noted the clinical signs of disease, that we examined the vectors. However, the observation that resulted was driving, consider the inevitable and to integrate it, either search for the original causes and ways to mitigate the effects. Accordingly, it is in the light of a paradigm of constant, clean to the continental law, after having noted the effects and identified the causes of disease as revealed by the syndrome of the device, we have created the concept of residualism. Therefore, after to have seen both the foundations that the strategy we sought in the first tracks likely to reduce the scope and lead to the development of a "guided" device, both aiming to get effective accession of agents and of the patients, to unload the judge of a normative responsibility is not hers

A. 1 Background The need to assess safety as well as clinical and economic effectiveness of health care innovations and thus prioritise health care provision, created the need for structured health technology assessment (HTA) programs [Gafni et al. 1993b; Henshall et al. 1997; Stevens et al. 20041. Sleep apnoea hypopnoea syndrome (SAHS) affects 2-4% of the adult population [Young et al. 1993] who are disabled by daytime dysfunction [Hardinge et al. 1995; Johns 1993b; Mitler 1993; Sauter et al. 200l and a heightened mortality and morbidity [Greenberg et al. 1995; Kiely et al. 2000; Peker et al. 1999; Sanner et al. 1997; Tremel et al. 1999; Wilcox et al. 1998; Moruzzi et al 1999; Malone et al. 1991]. The advent of continuous positive airway pressure devices (CPAP) [Sullivan et al 1981] made it possible to treat safely, patients over a wider spectrum of disease severity [Borak et al. 1996; Mar et al. 2003; Engleman et al 1997a], yet its diffusion and adoption appears to follow a heterogenous pattern. A. 2 Study design A retrospective case-control study of 603 SAHS patients was followed by a prospective, randomised, parallel group trial (RCT) of CPAP compared to lifestyle intervention (including weight reduction and sleep hygiene strategy) comparing clinical, health related quality of life (HRQL) and cost-utility ratios (CUR). The final study is a qualitative survey assessing the factors influencing the diffusion and adoption of CPAP among 303 Primary care trusts (PCT) and 261 Respiratory physicians in the UYA. 3 Results SAHS patients had a (5x) higher risk of death and (2x) of hypertension, compared to controls. Among 71 SAHS patients in the RCT, those on CPAP demonstrated greater clinical effectiveness (sleep latency, apnoea hypopnoea index, excessive daytime sleepiness & neuropsychiatriefunction) and HRQL (social functioning, mental health & energylvitality) compared to lifestyle intervention. Utilities improved on CPAP and the CUR were lower (E'716-E2027 vs. F-326444243). The diffusion survey demonstrated that the characteristics of CPAP as an innovation, would favour its adoption compared to alternative therapies, except in patient tolerability (PCT respondents). However there appeared to be no regular system for the diffusion of innovation knowledge within the NHS and hindrances in SAHS management due to deficiencies in resources, specialists and facilities. A. 4 Conclusions The results presented in this thesis provide a logical framework for the assessment of the progression of an innovation from the stage of establishing the clinical burden of disease and treatment needs, to its adoption and may help identify potentially modifiable factors in slow diffusion scenarios.

This study examined the effect on reading performance of a controversial treatment for a dysfunction of visual perception known as Scotopic sensitivity/lrlen Syndrome. The treatment, referred to as spectral modification, involved the use of colored transparent overlays for reading by four elementary school children in their actual school environments. The diagnostic, prescriptive and remediation procedures used in this study were originally developed by Helen Irlen, a California psychologist and researcher. Irlen conceptualized Scotopic Sensitivity Syndrome as a difficulty in visual processing of the printed page when perceived through full spectrum light. Spectral modification techniques were considered controversial in that they were employed prior to scientific validation of the syndrome. Previous research used pre-test/post-test experimental designs to test the effect of spectral modification on reading performance. The research problem addressed here was that the technique had not been systematically examined over time in the school setting, and from the practitioner's point of view. Sample selection involved pre-screening and screening phases. The pre-screening procedures of teacher recommendation and file review resulted in a pool of 26 children who were screened with the Irlen Differential Perceptual Interview Survey. Four subjects were selected who were in separate school settings, who demonstrated Irlen Syndrome to a significant extent, and whose profiles did not present variables which would compromise their participation. These four underwent comprehensive vision evaluations as a preliminary assessment procedure. A four-strand single-subject experimental design was used to generate data on subjects' rate and accuracy of oral reading, and comprehension of silent reading. Performance changes during experimental reading trials varied between the four, although three subjects exhibited positive performance change on one indicator. A supporting procedure was that subjects were pre and post-tested on the three performance indicators. Post-test results corroborated the changes demonstrated by three subjects Interview formats were employed to obtain qualitative data from teachers, parents, and the subjects themselves. Recommendations for practitioners intending to implement spectral modification techniques were generated from this data.

A população idosa possui alta prevalência de edentulismo e, conseqüentemente, é afetada pelos problemas a ele associados. A perda da dimensão vertical de oclusão (DVO) é um destes problemas que compromete, entre outros fatores, o desempenho do sistema estomatognático. Logo, doenças relacionadas ao colapso da musculatura da via aérea superior (VAS), como a síndrome da apnéia obstrutiva do sono (SAOS), tornam-se enfermidades relevantes para pacientes nesta faixa etária. Sendo assim, medidas terapêuticas eficazes e de baixo custo, como a utilização de aparelhos intraorais (AIOs) para liberação do fluxo aéreo, podem ser empregadas contribuindo para a qualidade do sono destes pacientes. O objetivo deste estudo foi avaliar parâmetros subjetivos e objetivos do sono, em 10 pacientes idosos portadores de Próteses totais (PTs) bimaxilares, após a utilização de novas PTs confeccionadas no Programa Envelhecer Sorrindo e após o uso de dois AIOs: um dispositivo intraoral (DIO), especialmente desenvolvido para aumentar a DVO sem provocar avanço mandibular, e um aparelho de avanço mandibular (AAM). Para isso, questionários de rastreamento da qualidade do sono e polissonografias (PSGs) foram realizados, em quatro momentos distintos: sem as PTs, com as PTs, com o DIO e com o AAM. Foram realizadas, também, telerradiografias em norma lateral (TNL) dos pacientes com as PTs, com o DIO e com o AAM a fim de avaliar alterações no diâmetro da VAS e o posicionamento mandibular nesses três momentos. Concluiu-se que, o AAM testado promove maior porcentagem de sono no estágio 1, podendo contribuir para a melhora na qualidade subjetiva do sono dos pacientes, uma vez que ajudou a diminuir o tempo necessário para iniciar o sono, além de facilitar a manutenção do estado de vigília.
There is a high prevalence of edentulism and problems associated to it in the elderly population. A decrease in vertical dimension of occlusion (VDO) is one of these problems that may compromise the stomatognathic system. Therefore, it is important to investigate diseases related to upper airway (UA) musculature collapse, such as the syndrome of obstructive sleep apnea (OSAS). Therapeutic measures of low cost and high efficacy, such as intraoral appliances (IAs) to release the air flow may be employed, contributing to patients sleep quality. The aim of this study was to evaluate subjective and objective sleep parameters in 10 elderly patients who wore maxilar and mandibular complete dentures (CD). The analyses were performed after the use of a new pair of CD and after using two IAs: an intraoral device (ID), especially developed to increase the VDO without causing mandibular advance, and a mandibular advance device (MAD). For this purpose, questionnaires and polysomnography (PSG) were performed in four distinct stages: patients not wearing CD, wearing CD, wearing ID and wearing MAD. In addition, lateral cephalograms (LC) of patients wearing FD, wearing ID and wearing MAD were performed to assess changes in UAs diameter and in the mandibular positioning. It was concluded that the MAD tested promotes higher percentage of stage 1 sleep and and may contribute to the improvement in patients subjective sleep quality, as it helped to decrease the time needed to fall asleep, and facilitate the maintenance of wakefulness.

Wearable assistive robotics have the potential to address an unmet medical need of reducing disability in individuals with chronic hand impairments due to neurological trauma. Despite myriad prior works, few patients have seen the benefits of such devices. Following application experience with tendon-actuated soft robotic gloves and a collaborator's orthosis with novel flat-spring actuators, we identified two common assumptions regarding hand orthosis design. The first was reliance on incomplete studies of grasping forces during activities of daily living as a basis for design criteria, leading to poor optimization. The second was a neglect of increases in muscle tone following neurological trauma, rendering most devices non-applicable to a large subset of the population. To address these gaps, we measured joint torques during activities of daily living with able-bodied subjects using dexterity representative of orthosis-aided motion. Next, we measured assistive torques needed to extend the fingers of individuals with increased flexor tone following TBI. Finally, we applied this knowledge to design a cable actuated orthosis for assisting finger extension, providing a basis for future work focused on an under-represented subgroup of patients.

Antalet neuropsykiatriska diagnoser och antal personer som diagnostiseras har ökat de senaste året. Diagnostiseringen kan dock ha djupare betydelse och bidra till stigmatisering och utanförskap, men samtidigt medföra stöd och ge identitet och samhörighet. En förhållandevis ny och omdebatterad diagnos är Asperger syndrom (hädanefter refereras som AS). Diagnosen ströks 2003 och ingår numera i autismspektrumsyndrom. AS-begreppet används dock ändå och alltfler personer växer upp och/eller identifierar sig med diagnosen. Jämförelsevis få studier söker fånga individers upplevelser och därför försöker denna studie undersöka hur personer med AS-diagnos själv beskriver sin upplevelse. Syftet med denna studie var således att beskriva upplevelsen av att ha en AS-diagnos i relation till identitet och självbild kopplat till normalitet/avvikelse. Ett kvalitativt tillvägagångssätt, baserat på semistrukturerad intervjuer, har använts. Fem personer med AS-diagnos över 18 år i södra Sverige intervjuades; resultaten analyserades med hjälp av tematisk analys. Fyra huvudkategorier identifierades: (1) Att få och att ha AS (upplevelser, känslor och vad AS betyder för individen); (2) att kamouflera, passera och framträda (informanternas upplevelse av sin skillnad, de svårigheter som AS kan medföra samt de ansträngningar de gör för att övervinna dessa); (3) mötet med okunskapen – att leva i fördomarnas paradis (den betydelse okunskapen om AS-diagnosen har för informanterna och hur detta kommer till uttryck och får för konsekvenser för identitet/självbild i form av att samhället betraktar personer med AS-diagnos som annorlunda och avvikande); och (4) att leva i en slags marginal av normalitet, i gränslandet mellan avvikande och normal (informanternas upplevelse av att inte riktigt passa in i vare sig normalitetsmallen eller funktionshindermallen). Att ha en AS-diagnos är alltså komplext och mångfacetterat.
The number of neuropsychiatric diagnoses and the number of persons being diagnosed have increased during recent years. To receive a diagnosis may, however, have a deeper meaning, e.g. stigmatisation and alienation, but also increased societal support, and an identity and a sense of belonging. One such diagnosis is Asperger’s Syndrome (henceforth referred to as AS). However, both the diagnosis per se, and diagnostics, have remained highly debated, and since 2003 AS has been omitted, instead included in the overall Autism Spectrum Syndrome. The AS concept is, however, still in use, and an increasing number of persons are growing up and identify with having AS. But, the question remains what it actually means for a person to have AS. Comparatively few studies have focused the individual experience of AS, fewer yet concerning self-image/identity, normality/deviation in relation to AS. Hence, the aim of this study was to describe the experience of having AS concerning identity and self-image in terms of normality/deviation. A qualitative method was used; data gathered with semi-structured interviews with five persons with AS, and over 18 years of age, living in southern Sweden. Results were analysed thematically, and fell into four main categories: (1) Getting AS (or to receive, and have AS), including reaction upon learning of the diagnosis, and experiences and emotions connected to the individual meaning of the diagnosis); (2) camouflaging, passing and showing, i.e. the ways in which the individual deal with self-consciousness surrounding questions of being different, but also worries of what difficulties they can experience, and how to overcome these issues; (3) meeting ignorance, i.e. how the general state of ignorance and preconceptions concerning Asperger syndrome affects the individual, how such aspects manifest, and how they may affect self-image and identity; and (4) living on the margins of normalcy, to live in on the border between abnormal and normal, and to not fit in, neither with societal norms of normality, nor concepts of disability. Hence, based on the overall results of the study, it was concluded that having AS is a multi-faceted and complex experience.

The current study evaluates the effectiveness of a Brain-Computer Interface (BCI) system that operates by detecting a P300 elicited by one of four randomly presented stimuli (i.e., YES, NO, PASS, END). Two groups of participants were tested. The first group included three ALS patients that varied in degree of disability, but all retained the ability to communicate; the second group included three Non-ALS controls. Each participant participated in ten experimental sessions during a period of approximately 6 weeks. Sessions were conducted either at the participant's home or in the lab. During each run the participant's task was to attend to one stimulus and disregard the other three. Stimuli were presented auditorily, visually, or in both modes. Additionally, on each run, the experimenter would either tell the participant which stimulus to focus on, or ask the participant a question and the participant would focus on the correct "YES/NO" answer to the question. Overall, for each participant, the ERPs elicited by the target stimuli could be discriminated from the non-target stimuli; however, less variability was observed in the Non-ALS group. Comparing across sessions, the within session variability was lower than across session variability. In addition, waveform morphology varied as a function of the presentation mode, but not in a similar pattern for each participant. Offline and simulated online classification algorithms conducted using step-wise discriminant analysis produced results suggesting the potential for online classification performance at levels acceptable for communication. Future investigations will begin to focus on testing online classification performance with real-time feedback, and continuing to examine stimulus properties to determine how to maximize P300 amplitude for individual users.

O avançar da idade é reconhecidamente um fator de risco para a Síndrome da Apneia Obstrutiva do Sono (SAOS). O motivo dessa constatação está associado à diminuição do tônus da musculatura orofaringeana e à redução da Dimensão Vertical de Oclusão (DVO), esta última atribuída às perdas dentárias. A abordagem odontológica, no tratamento da SAOS, refere-se ao uso de Aparelho de Avanço Mandibular (AAM), que impede a obstrução, parcial ou total, da passagem do ar pela via respiratória alta, durante o sono. Os pacientes desdentados, no entanto, têm sido negligenciados, nos estudos atualmente realizados. Pelo exposto, este trabalho objetivou avaliar os efeitos do tratamento em variáveis polissonográficas, ronco, sonolência, qualidade do sono e ainda os efeitos colaterais pelo uso do AAM titulável, em pacientes idosos e desdentados portadadores de SAOS. A metodologia envolveu inicialmente, cinquenta pacientes, dos quais dezesseis realizaram polissonografia de noite inteira, com gravação do ronco, por meio de um Roncômetro, visando investigação objetiva do sono. Analisaram-se subjetivamente frequência e intensidade do ronco, por questionários. A Escala Visual Analógica de Ronco (EVAR), aplicada ao parceiro de quarto, permitiu, igualmente, que fosse avaliada a intensidade desse sintoma. A sonolência diurna foi quantificada pela Escala de Sonolência de Epworth e a qualidade do sono, pelo Índice de Qualidade do Sono de Pittsburgh. Confecção individualizada dos AAMs respeitou os princípios biológicos relativos à DVO. Durante uma semana após a instalação, os pacientes utilizavam o AMM sem qualquer avanço mandibular, visando redução de quaisquer desconfortos. Subsequentemente, o protocolo estabelecia titulação gradual e progressiva (30%, 50% e 70%) do aparelho. Transposta a etapa de adaptação, após um período superior a quinze dias, as avaliações iniciais foram repetidas Os efeitos colaterais pelo uso do AAM e adesão ao tratamento foram investigados, a partir de questionários. Doze pacientes completaram o estudo (83,3% mulheres), sendo a media de idade 68 anos e índice de massa corporal médio de 28,3 kg/m2. Os resultados permitiram observar reduções significantes no índice de dessaturação de O2 (17,710,1 eventos/h, p=0,05) e índice de apneia (3,10,9 eventos/h, p=0,02). O uso do AAM evidenciou também diminuições na latência do sono REM, movimentos períodicos de perna, saturação mínima de O2, índice de apneia e hipopneia, na posição supina (p>0,05). O estudo objetivo do ronco apontou redução de 49,522,6 eventos/h (p=0,07). Além do mais, as avaliações subjetivas de frequência (p=0,024) e intensidade (p=0,007) do ronco, EVAR (p=0,003), qualidade do sono (p=0,008), efeitos colaterais e adesão ao AAM foram estatisticamente significantes. Foi possível concluir pela eficácia do tratamento sobre algumas variáveis polissonográficas estudadas, parâmetros subjetivos do ronco e qualidade do sono. Ademais, os sintomas relatados, pelo uso do AAM, reduziram-se ao longo do tempo, o que permitiu, com vantagem, que houvesse maior adesão ao tratamento por parte dos pacientes inseridos nesta pesquisa.
Aging process is well known as a risky factor to Obstructive Sleep Apnea Syndrome (OSAS). Concomitant with this process, the reduction of orofacial and pharyngeal musculature tone, as well as the decrease of Vertical Occlusion Dimension (VOD), the latter attributed to tooth loss, have been considered as probable causal agents involved in OSAS pathogenesis. The Dentistry approach for OSAS treatment is commonly related to the use of Mandibular Advancement Devices (MAD), which could prevent partial or complete upper airway obstruction during sleep. However, this treatment has been scarcely used in toothless patients. The aim of this study was to assess the effects of a titratable MAD in polysomnographic (PSG) variables, snoring, sleepiness, sleep quality and side effects, in edentulous elderly patients with OSAS. Sixteen out of fifty patients assessed have been selected and have undergone an overnight polysomnographic study. Snoring was recorded by using suitable equipment, so that an objective assessment of sleep patterns could be made. The frequency and intensity of snoring have also been subjectively assessed by means of questionnaires. The Snoring Visual Analogic Scale (SVAS), posed to a bed partner, was also assessed to evaluate snoring intensity. Excessive daytime sleepiness and the quality of sleep have also been investigated by Epworth Sleepiness Scale and Pittsburgh Sleep Quality Index, respectively. The patients went through the whole process for individually manufacturing of the MAD following the biological principles of the VDO. A week after using the MAD, at 0% of mandibular advancement, the patients were invited to return in order to undergo a new evaluation according to their adaptation to MAD. Subsequently, a titration protocol was gradually established at 30%, 50% and 70% for mandibular advancement. After a period of at least fifteen days, which should correspond to an adjustment of patients to their devices, the same initial assessment procedures were repeated. The MAD collateral effects as well as the treatment acceptance have been investigated through questionnaires. Twelve patients (83,3% females) completed the study, with an average age of 68 years, body mass index of 28,3 kg/m2. The results showed a significant reduction in O2 desaturation index (17,710,1 event/h, p=0,05) and also in AI (3,10,9 events/h, p=0,02). The use of the MAD also represented reductions in the latency to REM sleep, periodical leg movements, minimum O2 saturation, apnea and hypopnea index (AHI) in supine position (p>0,05). The objective assessment of snoring showed a reduction, with no statistical relevance of the Snoring Index (49,522,6 events per hour of recording, p=0,07). The subjective assessment of frequency (p=0,024) and intensity of snoring (p=0,007), EVAR (p=0,003), sleep quality (p=0,008) and the MAD collateral effects as well as the treatment acceptance were also statistically significant. We observed that the OSAS treatment with MAD was effective in some polysomnografic variables studied as well as in the subjective parameters of snoring and sleep quality in edentulous elderly patients. The reported symptoms due to MAD use decreased over the time.

Since wireless communication has become a standard feature in the daily life, smartphones and tablets among other things are integrated with the Bluetooth technology. While in some parts of the day wireless communication can be used for searching the internet and share information on social networks without the need of having a secure connection, there are some other parts where the security might become of high importance. When the technology gets integrated in companies the security problem becomes more evident. This is because when the radio signals spread in the medium they can be accessed by anyone that is in reach in the network and the information that was sent may not be intended for everyone. To secure the network from unintended users becomes important when handling fragile information, which companies may deal with daily.  This paper gives an introduction on which security features and techniques that already exist in some personal area networks. From this it has been clear that a security feature could be implemented on the baseband layer of Bluetooth to increase the secrecy during the transmission since at the moment security is only implemented on higher layers using encryption algorithms.  This paper proposes a conceptual idea of improving the secrecy in the network by using a wiretap code that is implemented before the error-correction coding in the Bluetooth's baseband. By disabling the ARQ scheme in Bluetooth one can modulate the channel as a Packet Erasure Channel that will lose packet with a certain probability. By using a nested code structure, the message can then be securely sent by using a higher rate than what the eavesdropper can recover due to the amount of errors the received signal will have. The performance of the concept is evaluated with the secrecy throughput, secrecy outage and the leakage.

Syfte: Syftet med den här studien var att jämföra Digital Eye Strain-symptom mellan läsning på papper och mobiltelefon. Att undersöka om det som tidigare studier har visat i skillnad mellan läsning på papper och en datorskärm även gäller mobiltelefoner och hur mycket våra ögon påverkas när det gäller ansträngning, trötthet och andra ögonrelaterade symptom.  Metod: Deltagarna (n=16) fick läsa i 20 minuter tyst, antingen på papper eller en smartphone-skärm. Avståndet fick de själva bestämma. De läste samma bok med samma typsnitt och storlek på båda medierna. Direkt efter de hade läst i 20 minuter fick de fylla i ett frågeformulär som bestod av tio frågor kring deras upplevda ögonsymptom under uppgiften. Resultat: Studien visade på signifikanta skillnader i medelvärdet mellan papper och mobiltelefon på tre av symptomen: suddig syn vid tittande på texten (p=0,016), ansträngda ögon (p=0,023) samt trötta ögon (p=0,015). I alla tre fallen var symptompoängen högre efter läsning på mobilskärm än efter läsning på papper. Det fanns ingen signifikant skillnad mellan de övriga sju symptomen. Det var även en signifikant skillnad i läsavstånd med ett betydligt mindre avstånd till mobiltelefonen än till pappret. Slutsats: Studien visar att symptomen efter användning av mobiltelefon upplevs som svårare än efter läsning på papper. De tre symptom som skilde sig signifikant var alla högre efter läsning på mobilskärmen.
Purpose: The purpose of this study was to compare Digital Eye Strain DES-symptoms after reading on a printed hardcopy versus a smartphone. To understand if results obtained from earlier studies that have showed DES when reading in from computer also applies to smartphones. Methods: 16 participants in the study were asked to read a Swedish book quietly for 20 minutes, either on a hardcopy or on a smartphone. The participants were told to use their normal working distance while reading from book or smartphone. They read the same book with the same textsize and font in both conditions. Directly after reading the participants completed a written questionnaire that consisted of ten questions about their level of ocular discomfort during the task.   Results: This study showed significant differences in mean symptom scores between printed hardcopy and smartphone on three of the symptoms; blurred vision while viewing the text (p=0,016), eyestrain (0,023) and tired eyes (0,015). In all three cases the symptoms were higher during smartphone use. No significant differences were found between the other seven symptoms. There were a significant difference in reading distance, smartphone were held closer than the hardcopy. Conclusion: This study shows that the symptoms after smartphone use is perceived as more severe than after reading on a hardcopy. The three symptoms that showed a significant difference were all higher after smartphone use.

Thesis (M.S. in Systems Engineering)--Naval Postgraduate School, December 2004.
Thesis advisor(s): Singh Gurminder, John Gibson. Includes bibliographical references (p. 65-66). Also available online.

Content caching at mobile user devices (UDs) utilizing device to device (D2D) communication has recently been proposed as an exiting and innovative technology to offload network data traffic and enhance the performance of mobile networks, in terms of latency, throughput, energy consumption, and so on. In this thesis, a novel method of content delivery using multiple devices to single device (MDSD) communication through D2D links is presented. In this method, the Zipf distribution with exponent shape parameter is adopted to model the content caching popularity for the analysis of the achievable signal to interference plus noise ratio (SINR). In order to investigate the advantage of the proposed MDSD method, firstly, a closed-form expression of the outage probability is theoretically derived for a single D2D communication to evaluate the success of content delivery to the reference UD. Secondly, the expression of the outage probability for MDSD communication is derived, where the outage probability is analysed as a function of content caching popularity, the density of UDs, and the size of cooperative area. The research work is further extended to address the frequency reuse among different UDs in one cell, where a frequency band factor is introduced, and the optimal radius of the cooperative area is introduced and analysed. The analytical results, validated by the simulation results, show that the outage probability decreases drastically when the popularity of the content increases, or the radius of the cooperative area increases. Using the given closed-form expression of the outage probability, the area spectral efficiency (ASE) of the system is presented. Furthermore, the results show that as the frequency band factor increases, the outage probability decreases, as well as the ASE decreases. Finally, it is shown that the MDSD outperforms the single D2D-based method.

This thesis identifies and addresses two barriers to the adoption of Long Term Evolution (LTE) Device-to-Device (D2D) communication enabled smart grid applications in out of core network coverage regions. The first barrier is the lack of accessible simulation software for engineers to develop and test the feasibility of their D2D LTE enabled smart grid application designs. The second barrier is the lack of a distributed resource allocation algorithm for LTE D2D communications that has been tailored to the needs of smart grid applications. A solution was proposed to the first barrier in the form of a simulator constructed in Matlab/Simulink used to simulate power systems and the underlying communication system, i.e., D2D communication protocol stack of Long Term Evolution (LTE). The simulator is built using Matlab's LTE System Toolbox, SimEvents, and Simscape Power Systems in addition to an in-house developed interface software to facilitate D2D communications in smart grid applications. To test the simulator, a simple fault location, isolation, and restoration (FLISR) application was implemented using the simulator to show that the LTE message timing is consistent with the relay signaling in the power system. A solution was proposed to the second barrier in the form of a multi-agent Q-learning based resource allocation algorithm that allows Long Term Evolution (LTE) enabled device-to-device (D2D) communication agents to generate orthogonal transmission schedules outside of network coverage. This algorithm reduces packet drop rates (PDR) in distributed D2D communication networks to meet the quality of service requirements of microgrid communications. The PDR and latency performance of the proposed algorithm was compared to the existing random self-allocation mechanism introduced under the Third Generation Partnership Project's LTE Release 12. The proposed algorithm outperformed the LTE algorithm for all tested scenarios, demonstrating 20-40% absolute reductions in PDR and 10-20 ms reductions in latency for all microgrid applications.

Systemic inflammation involves a complex array of cytokines that can result in organ dysfunction. Mortality remains high despite the vast amount of research conducted to find an effective biomarker. The cause of systemic inflammation can be broad and non-specific; therefore, this research investigates using transendothelial electrical resistance (TEER) measurements to better define systemic inflammatory response syndrome (SIRS)/sepsis within a patient. Results show a difference in TEER measurements between healthy individuals and SIRS-rated patients. This research also displays correlations between TEER measurements and biomarkers currently studied with systemic inflammation (tumor necrosis factor-α, C- reactive protein, procalcitonin). Furthermore, this research also presents the groundwork for developing a microfluidic cell-based biosensor using low temperature co-fired ceramic materials. An LTCC TEER-based microfluidic device has the potential to aid in a more effective treatment strategy for patients and potentially save lives.

Au cours du traitement du syndrome d’apnées obstructives du sommeil (SAOS) par pression positive continue (PPC), les fuites non-intentionnelles sont un des effets indésirables les plus fréquents mais leur étiologie est mal comprise. Les objectifs de cette thèse étaient d’identifier les facteurs déterminants des fuites non-intentionnelles au cours du traitement du SAOS par PPC et de proposer des stratégies pour le choix du masque et la gestion des fuites.Dans notre revue de la littérature, nous avons arbitrairement classifié les déterminants potentiels à l’origine de fuites non-intentionnelles en deux catégories. 1) les déterminants non évolutifs au cours de la nuit : l’obstruction nasale, l’âge, un indice de masse corporel élevé, une distribution centrale des masses adipeuses et le genre masculin étaient des déterminants potentiels des fuites non-intentionnelles. Le masque naso-buccal était également associé à des fuites non-intentionnelles plus élevées que le masque nasal ; et 2) les déterminants évolutifs au cours du sommeil tels que les stades de sommeil, la position, l’ouverture buccale. Nous avons étudié ces déterminants évolutifs dans une population de 74 patients SAOS traités par PPC auto-pilotée : l’ouverture buccale, le niveau de pression de la PPC, la position du sujet et le sommeil paradoxal contribuaient au risque de fuite non-intentionnelle. Nous avons également mis en évidence que le masque naso-buccal réduisait le risque de fuite non-intentionnelle en cas d’ouverture buccale et au cours du sommeil paradoxal. Puisque le niveau de pression est un déterminant des fuites non-intentionnelles, nous avons évalué par une analyse ancillaire d’un essai randomisé contrôlé, si le mode de PPC (fixe versus autopiloté) pouvait contribuer aux fuites : nous n’avons pas montré d’association entre le mode et le niveau de fuites après 4 mois de traitement. Le mode PPC n’influençait pas le type de masque utilisé par les patients. Enfin, au cours d’une étude prospective incluant de 214 patients, nous avons évalué l’intérêt du questionnaire Nasal Obstruction Syndrom Evaluation (NOSE) comme outil pour guider le choix du masque. Un score NOSE > 50/100 à l’initiation de la PPC était indépendamment associé à l’utilisation d’un masque naso-buccal après 4 mois de traitement. Ce score est un outil simple pour évaluer objectivement les symptômes d’obstruction nasale et faciliter le choix de l’interface la plus appropriée. En conclusion, au cours de cette thèse nous avons développé une méthode innovante d’analyse des déterminants des fuites non-intentionnelles dont l’application clinique pourrait permettre la mise en place des stratégies de corrections individualisées des fuites. Cela devra faire l’objet d’une évaluation prospective, tout comme l’intérêt clinique de l’utilisation en routine du score NOSE pour guide le choix du masque.Mots clés : syndrome d’apnées obstructives du sommeil, pression positive continue, fuites, masque, interface, obstruction nasale, sommeil
Continuous Positive Airway Pressure (CPAP) is the first-line treatment for moderate to severe Obstructive Sleep Apnea (OSA) syndrome. Unintentional leakage and its annoying consequences are the most frequently reported adverse effects. However, the causes of unintentional leaks are poorly understood. This thesis aimed at identifying the determining factors of unintentional leaks during CPAP treatment in OSA and developping innovative strategies for the selection of masks and leaks management.In our systematic review we have arbitrarily split the potential determining factors of leaks into two categories: 1) the non evolving factors overnight: nasal obstruction, age, high body mass index, central fat distribution and male sex were potential contributing factors associated with unintentional leakage. The oronasal mask was associated with higher unintentional leaks than the nasal mask; and 2) the evolving factors overnight such as sleep stages, body position, mouth opening and CPAP level. We studied these evolving factors in 74 OSA patients treated with auto-adjusting CPAP: mouth opening, CPAP level, body position and REM sleep were independently associated with an increased risk of unintentional leakage. We also highlighted that oronasal masks reduced the risk of unintentional leaks in cases of mouth opening and REM sleep. Since the CPAP level is a determining factor of leakage we evaluated through an ancillary analysis of a randomised controlled trial whether the type of CPAP (fixed versus auto-adjusting) could contribute to leakage. In this study, there was no effect of type of CPAP on leaks or the type of interface used after 4 month of treatment. Finally, in 214 patients, we prospectively evaluated the relevance of the Nasal Obstruction Syndrom Evaluation (NOSE) score as a simple decision-making tool to guide the choice of mask during CPAP initiation. A NOSE score > 50/100 at the initiation was independently associated with the use of an oronasal mask at 4 month. This score could be a simple tool for the objective assessment of nasal obstruction related to symptoms, facilitating the choice of an appropriate interface. As a conclusion, during this thesis we have developed a novel methodology to characterise and analyse the overnight determinants of unintentional leakage. Its clinical application could lead to individualised corrective measures of leaks. Further studies are needed to prospectively validate this model, as well as the clinical relevance of the NOSE score to guide the choice of mask in daily practice

The steep growth in the mobile data traffic has gained a lot of attention in recent years. This growth is mainly the result of emerging applications, multimedia services, and revolutions in the device technology. With current deployments and radio resources, operators will not be able to cope with the growing demands. Consequently, there is a need to either provide new resources or increase the efficiency of what is available. Proposed solutions for accommodating growing data traffic are based on improvements in three dimensions: efficient use of radio resources especially the spectrum, technology advancements, and densifying the current infrastructure. In this thesis, we focus on the spectrum dimension. Providing more spectrum is a long-term process. However, increasing the spectrum usage and efficiency can be put rapidly in practice. We discuss potential solutions in the area of spectrum sharing. Among enabling technologies to facilitate spectrum sharing, we consider the cognitive radio and device-to-device (D2D) communications. In order to gain from sharing the spectrum, systems need to somehow deal with extra sources of interference. In the first part of the thesis, we consider a primary-secondary sharing model in cognitive radio networks. We employ the cooperative communication method in order to facilitate the access of the secondary system to the licensed spectrum of the primary system, and therefore increase the spectrum usage. The cooperation between the two systems is formed provided that it is beneficial for the primary system. In this way, the primary users' quality-of-service can be preserved while at the same time the secondary users can access the spectrum. This cooperative approach prevents both systems from concurrent transmissions. As a consequence, the need for interference control techniques are eliminated. We evaluate different models and transmission schemes and optimize the corresponding parameters to quantify the gain resulting from cooperative spectrum sharing. In the second part of the thesis, we consider spectrum sharing within one system between different types of users. This is done in the context of D2D communications where close proximity users can transmit directly to each other. For this type of communications, either dedicated resources are allocated or resources of the cellular users are reused. We first study the feasibility of cooperation between D2D and cellular users and identify the scenarios where it can be beneficial. Then we take on a challenging problem which guarantees the gain from the D2D communication, namely the mode selection. For this problem, we characterize the decision criteria that determines if D2D communication is gainful. Next, we focus on the problem of interference in D2D communications underlaying cellular networks, where the same spectrum is reused in the spatial domain. In such scenarios, the potential gain is determined by how the interference is managed, which in turn depends on the amount of available information at the base station. The more information is required, the more signaling is needed. In this part of the thesis, we address the trade-off between the signaling overhead and the performance of the system and propose a novel approach for interference control which requires very little information on the D2D users.

QC 20140509

With the ever growing demands of power and bandwidth by users, energy and spectral efficiency emanated as key criteria for designing future wireless networks. Therefore, in this thesis energy harvesting (EH) aided device-to-device (D2D) communication is designed for improving both the key design criteria, which is an intricate journey from the realm of individual analysis of EH and D2D communication to that of amalgamating the two techniques. Specifically, with the widespread use of energy hungry smart devices, these devices become dis-functional due to outage of batteries, which can be avoided by introduction of EH capability at these nodes. In this context, an energy efficient successive relaying based network is conceived using rechargeable source and relay nodes having limited buffers for both their energy and data storage. An optimal and sub-optimal transmission policies are designed for the maximisation of the network throughput with non-causal knowledge of energy arrivals by the deadline. On the other hand, for exploiting the spectrum efficiently, D2D communication is invoked which brings in new interference scenarios that may be circumvented by incorporating fractional frequency reuse (FFR) or soft frequency reuse (SFR) in OFDMA cellular networks. By carefully considering the downlink resource reuse of the D2D links, beneficial frequency allocation schemes are proposed, when the macrocell has employed FFR or SFR. The coverage probability and the capacity of D2D links are analytically derived under the proposed schemes. It is imperative to integrate the benefits of EH and D2D communication aided systems for creating unparalleled opportunities in emerging applications. Therefore, a system is designed that comprises of EH aided D2D links relying on downlink resource reuse with the goal of maximizing the sum-rate of the D2D links, without degrading the quality of service (QoS) requirement of the MUs. A pair of joint resource block and power allocation algorithms are proposed for the D2D links, when there is non-causal (off-line) and causal (on-line) knowledge of the EH profiles at the D2D transmitters. For the sake of further accentuating design flexibility and alleviating the demands of increased spectral resources, previously designed EH aided D2D communication is investigated in conjunction with heterogeneous network (HetNet). An algorithmic solution is proposed with the aim of maximising the sum-rate of these D2D links in the downlink of two-tier HetNet without unduly degrading MU’s throughput, when two tiers share spectrum under following regimes: (a) orthogonal, (b) co-channel and (c) the proposed coorthogonal. Low complexity heuristic methods are also proposed, which demonstrate that the optimization of the D2D-MU matching is indeed crucial for the system considered.

La communication device-to-device (D2D) est un nouvel aspect prometteur dans les réseaux LTE-Advanced. Elle est mise en place pour permettre une détection efficace et une communication de proximité entre mobiles. Grâce aux capacités D2D, les mobiles de proximité sont capables de se détecter entre eux en utilisant la technologie radio LTE et de communiquer entre eux via un lien direct. Cette thèse porte sur la conception, la coordination et les tests d'un réseau hybride avec la technologie D2D et les communications cellulaires. Les exigences de conception et les choix des fonctions dans la couche physique et MAC qui permettent la détection D2D et la communication reposant sur les réseaux LTE sont analysés. De plus, une stratégie de planification centralisée dans la station de base est proposée afin de coordonner les communications de données D2D en liaison descendante pour le réseau LTE FDD. Cette stratégie de planification combine de multiple techniques telles que le mode de sélection, l'allocation des ressources et d'énergie, afin d'améliorer les performances des utilisateurs dans une cellule. Enfin, les performances des communications de données D2D reposant sur le système LTE sont mesurées à partir d'un simulateur, au niveau système, avec un scénario comportant de multiples liens de communication
Device-to-device (D2D) communication is a promising new feature in LTE-Advanced networks. It is brought up to enable efficient discovery and communication between proximate devices. With D2D capability, devices in physical proximity could be able to discover each other using LTE radio technology and to communicate with each other via a direct data path. This thesis is concerned with the design, coordination and testing of a hybrid D2D and cellular network. Design requirements and choices in physical and MAC layer functions to support D2D discovery and communication underlaying LTE networks are analyzed. In addition, a centralized scheduling strategy in base station is proposed to coordinate D2D data communication operating in LTE spectrum. The scheduling strategy combines multiple techniques, including mode selection, resource and power allocation, to jointly achieve an overall user performance improvement in a cell. Finally the performances of D2D data communication underlaying LTE system are calibrated in a multi-link scenario via system-level simulation

Device-to-Device communications have the great potential to bring significant performance boost to the conventional heterogeneous network by reusing cellular resources. In cellular networks, Device-to-Device communication is defined as two user equipments in a close range communicating directly with each other without going through the base station, thus offloading cellular traffic from cellular networks. In addition to improve network spectral efficiency, D2D communication can also improve energy efficiency and user experience. However, the co-existence of D2D communication on the same spectrum with cellular users can cause severe interference to the primary cellular users. Thus the performance of cellular users must be assured when supporting underlay D2D users. In this work, we have investigated cross-layer optimization, resource allocation and interference management schemes to improve user experience, system spectral efficiency and energy efficiency for D2D communication underlaying heterogeneous networks. By exploiting frequency reuse and multi-user diversity, this research work aims to design wireless system level algorithms to utilize the spectrum and energy resources efficiently in the next generation wireless heterogeneous network.

Billions of devices are connected to networks, which share data between them or with the processing device. With the advent of technology, cost-effective hardware can be interface with sensors and can act as an IoT device; This provides them with digital intelligence and communicates by connecting to Network. Like in other network devices, security is of utmost importance in IoT as well. Security in IoT is challenging than in traditional devices because of lower computing power, lower computing resources, small battery, and many IoT devices deployed. Research in cryptography, a lightweight communication protocol is focused. However, there is no substantial research effort for the identity of IoT devices which is the fundamental factor in Security. Traditional devices use MAC address, IP Address, and IMEI for physical identity but these parameters for physical device identification are prone to sniffing and spoofing; Thus, is not that reliable. Relying on these parameters for the security of IoT devices compromises the critical information and IoT device itself.The thesis utilizes the information from the packets used for communication in networks for device identification. We use IAT (Inter Arrival Time) and RTT (Round Trip Time) of packets at the router side to uniquely identify the IoT device. IAT is the time difference between two packets received at Router and RTT is the time from request to response packets at Router. IAT and RTT are different for a device as it depends on the hardware and software of a device. We plot the graph of IAT and RTT separately and use deep learning as a tool to identify a device. We use different deep learning algorithms for identification. We use CNN and LSTM for IAT graphs and RTT graphs. Both deep Learning algorithms achieve good accuracy in the classification of a device using both parameters (IAT and RTT) but to verify using the publicly available dataset, we achieved 97% accuracy in classifying using IAT using CNN in the testing dataset. Using CNN+LSTM we achieve an accuracy of 91.45% in the classification of a device using IAT as a parameter in the testing dataset.

This degree project tries to give a design solution, a machine for the company “VECTO Materialhantering AB” specialised in total system solutions within internal transport systems and material handling technology. VECTO supply material handling equipment both as stand-alone modules, turn-key plants and complete system solutions with KUKA and ABB robots. The turning device can working with several different weights.

As mobile phones get increasingly complicated the demands for an effective firmware update service increase. A proposed solution is Firmware Over The Air (FOTA) and the Open Mobile Alliance’s Device Management where mobile phones can be updated and managed via the mobile phone network. However, before these operations can be carried out, all FOTA capable mobile phones that should be served must be discovered and registered with a distributor of updates. The information provided must be sufficient to uniquely identify devices, initiate a Device Management session, and determine if a firmware update is needed. This thesis addresses the problems that a solution in automatically collecting this information. Several solutions are presented and their suitability evaluated on the basis of defined and analyzed requirements. The solutions most thoroughly examined are various manual solutions, retrieval of information from core network nodes, and utilizing the Short Message Service (SMS) or Unstructured Supplementary Service Data (USSD). A phone application has been implemented according to the requirements from the Chinese network operator China Mobile Communications Corporation (CMCC). It is a part of a solution in which the information is delivered via a SMS session. The design and development phase of the application is described, accompanied by a brief description of the Symbian OS and the working environment (tools, devices, etc.) needed to implement this solution. This work took place at the Sony Ericsson office in Beijing, China. The application implemented is robust and it is impossible to avoid registration, furthermore the user can not be exposed to acknowledgement messages. It has been made possible on the cost of decreased phone performance (a few kB of memory) since the application runs all the time. Malfunctioning phone or network may hinder registration.
Mobiltelefoner blir ständigt mer komplicerade vilket medför att efterfrågan av en effektiv lösning för uppdateringar av mjukvaran i mobiltelefonerna ökar. Lösningen är Firmware Over The Air (FOTA) och Device Management; mobiltelefonerna uppdateras och sköts via mobiltelefonnätverket. Men innan förfaranden kan exekveras måste alla mobiltelefoner med FOTA som ska omfattas av tjänsten upptäckas och registreras hos den som distribuerar uppdateringarna. Den information som måste levereras måste vara tillräcklig för att kunna identifiera mobiltelefonen, genomföra en Device Management session och avgöra om en uppdatering av mjukvaran är nödvändig. Detta examensarbete behandlar de problem som en lösning i vilken information tillhandahålls möter. Ett flertal lösningar presenteras och deras lämplighet utvärderas på basis av definierade och analyserade krav. De mest ingående undersökta lösningarna är olika manuella lösningar, insamling av information från noderna av kärnnätverket samt utnyttjande av SMS eller USSD. En telefonapplikation har implementeras enligt krav från den kinesiska operatören CMCC. Applikationen är en del av en lösning i vilken informationen levereras via en SMS-session. Applikationens design och utvecklingsfasen är beskriven, samt en översiktlig beskrivning av Symbian operativsystem och utvecklingsmiljön (verktyg, mobiltelefoner, etc.) som behövdes för att implementera lösningen. Detta arbete genomfördes på Sony Ericssons kontor i Beijing, Kina.

In this thesis, we present first principles simulations to investigate the device-todevice variation induced by random discrete dopant (RDD) in Si nanoFET channels. Our simulations are from atomic first principles and parameter-free, by combining nonequilibrium Green's functions (NEGF) with the density functional theory (DFT). To deal with the problem of disorder scattering and configuration averaging, the coherent potential approximation (CPA) and nonequilibrium vertex correction (NVC) theory are employed. To calculate the variance of the conductance due to RDD, a local concentration approximation (LCA) on top and beyond the CPA-NVC theory is applied. Our first principles simulations provide not only the average conductance but also the variance of it. A systematic review of the quantum transport and electronic structure theory is made, including the physics, mathematics and simulation algorithms behind the NEGF-DFT, the CPA-NVC and finally the LCA methods. Our ab initio results show that for uniform doping of the Si nanoFET channel, the variation of the OFFstate leakage current decreases dramatically with increasing doping concentration or channel length; in localized doping, doping close to the channel center can have much smaller current variation than the corresponding uniform doping. Our ab inito results provide a vivid physical picture as why large device-to-device variation is expected in very small structures having small number of impurity atoms. The results also indicate that device-to-device variation induced by RDD in Si nanoFET channels can be suppressed by choosing an appropriate doping strategy. Our numerical data is organized by fitting to the WKB tunneling formula.
Dans ce mémoire, nous présentons des simulations à partir des premiers principes pour l'étude des variations dispositif-à-dispositif induites par dopant ponctuel aléatoire (RDD) dans des canaux nanoFET en Si. Nos simulations sont à partir des premiers principes atomiques et libres de paramètre, en combinant les fonctions de Green hors équilibre (NEFG) avec la théorie de la fonctionnelle de densité (DFT). Afin d'adresser le problème de la dispersion dûe au désordre et aux moyennes de configuration, l'approximation du potentiel cohérent (CPA) et la correction vertex hors équilibre (NVC) sont employées. Afin de calculer la variance de la conductance dûe au RDD, une approximation de la concentration locale (LCA) est appliquée par-dessus et au-delà de la théorie CPA-NVC. Nos simulations à partir des premiers principes fournissent non seulement la conductance moyenne mais aussi sa variance. Une revue systématique de la théorie du transport quantique et de la structure électronique est faite, incluant la physique, les mathématiques et les algorithmes de simulation derrière les méthodes NEFG-DFT, CPA-NVC et finallement LCA. Nos résultats ab initio montrent que pour un dopage uniforme du canal nanoFET en Si, la variation du courant de fuite à l'état OFF diminue de manière dramatique avec l'augmentation de la concentration de dopage ou de la longueur du canal ; dans le cas de dopage localisé, un dopage proche du centre du canal peut avoir une variation du courant plus petite qu'un dopage uniforme. Nos résultats ab inito fournissent une image physique claire de la raison pour laquelle une large variation dispositif-àdispositif peut être attendue dans des structures très petites comportant un petit nombre d'impuretés. Les résultats indiquent aussi que la variation dispositif-à-dispositif induite par RDD dans les canaux nanOFET en Si peut être supprimée en choisissant une stratégie de dopage approprié. Nos données numériques sont organisées par ajustement à la formule d'effet tunnel WKB.

Device-to-Device (D2D) communication is one of the technologies for next generation communication system. Unlike traditional cellular network, D2D allows proximity users to communicate directly with each other without routing the data through a base station. The main aim of this study is to improve the overall energy efficiency (EE) of D2D communications overlaying cellular system. To reduce the complexity of joint EE optimization, we decompose the main EE problem into two subproblems; resource efficiency (RE) optimization in the first stage and EE optimization for D2D pairs in the second stage. Firstly, we propose an alternative two-stage RE-EE scheme for a single cellular user equipment (CUE) and a D2D pair utilizing uplink spectrum. Later, we extend this work for multiple CUEs and D2D pairs by considering the downlink orthogonal frequency division multiple access (OFDMA). By exploiting a range of optimization tools including the Bisection method, interior point algorithm, fractional programming, Dinkelbach approach, Lagrange dual decomposition, difference of convex functions, and concave-convex procedure, the original non-convex problems are solved and we present iterative two-stage RE-EE solutions. Simulation results demonstrate that the proposed two-stage scheme for uplink scenario outperforms the cellular mode and dedicated mode of communications and the performance is close to the global optimal solution. The results also show that the proposed schemes for downlink resource sharing provide improved system EE performance with significant gain on EE for D2D users compared to a two-stage EE-EE solution, which is obtained numerically. Furthermore, the RE and EE optimization for non-orthogonal multiple access (NOMA) are considered to study the effect of users' access to the whole spectrum. The results indicate that the proposed RE scheme for NOMA with D2D communications achieves higher system EE compared to the OFDMA based schemes.

The evolution of wireless networks towards 5G dictates the integration of a mul-titude of heterogeneous radio access technologies to the traditional macro-cell systems. Equipping the network with numerous small cell nodes, such as fem-tocell and picocell base stations (BSs), implies a spectrum efficient and network performance improving solution to support the rapidly increasing user demands. However, this can be proven to be a cost-inefficient method that increases the capital and operational expenditures of the network operators as well as the power consumption, especially in low-traffic network conditions where a number of BSs should be switched-off. To this end, device-centric solutions that leverage the potentials stemming from the proximity, mobility and increased dynamics of user devices should be considered. To this end, direct, proximity-based Device-to-Device (D2D) communication, where two close-ranged user equipments (UEs) are able to exchange data by bypassing the BS, is expected to play predominant role in improving the overall network welfare and ease part of the traffic developed on the BSs side. This thesis focuses on the soft integration of inband D2D communications in emerging cellular networks where D2D-enabled devices utilize the licensed spec-trum. In the introductory part of the thesis we highlight the merits that this communication paradigm can offer in terms of spectrum utilization, energy sav-ing, delay reduction and data rate improvement. We also provide an overview of the D2D use cases that enable opportunities for new services, its potential in improving the overall network performance as well as its offloading capability that can ease the traffic employed along the network. In the sequel, we proceed with our proposed methodology that aims at easing the coexistence of cellular and D2D users in emerging cellular networks. One of the main contributions of the thesis is the optimization of cell association for D2D UEs (DUEs). Cell association for D2D communications is an unexplored area and a rather fertile ground for research. Following the conventional motif, a user device would preferably couple with a high power macro cell BS that provides the user with the highest signal power. However, with the advent of D2D com-munications, this could be proven to be highly inefficient for users that want to communicate directly and are associated with different BSs because BS intercom-munication complexity and access delay is introduced. To this end, we propose a number of optimization formulations for D2D-based cell association that takes into consideration not only the nature of the inband D2D communications (un-derlay or overlay), but also performance-hindering factors such as user density, interference and so on. Other than the throughput enhancing and power saving attributes of the proposed framework, notable resource efficiency improvement is achieved. Indicatively, for both underlay and overlay D2D communications, more than 12% and 45% radio resource utilization mitigation is ensured compared to baseline methods. On top of optimizing cell association for D2D communications, we further investigate the problem of resource allocation in different D2D underlaying cellu-lar network scenarios where DUEs are permitted to reuse the cellular resources and, therefore, high levels of interference need to be prevented. By consider-ing different deployment scenarios, we propose a set of low-complexity heuristic algorithms with the aim to achieve high data rate performance for D2D com-munications with respect to meeting the cellular users’ quality of service (QoS) requirements. The proposed algorithms are evaluated in high-traffic networking scenarios where D2D communications underlay relay-enabled cellular networks. In aggregate, more than 10% of sum throughput performance is achieved against various resource allocation techniques. In the sequel, we explore the dynamics of virtualizing the radio resources for efficient sharing as, nowadays, we are witnessing higher network heterogeneity and the emergence of multiple stakeholders with the overarching need to significantly reduce deployment costs and achieve a sustainable network operation. Network virtualization has emerged as a promising technique to overcome the complexity of current network operation as well as facilitate inter-operators’ sharing. There-fore, disruptive approaches to manage radio and network-virtualized resources are expected to be a catalyst element of future mobile network architectures. Despite the fact that a number of solutions for radio access network (RAN) virtualization emerged over the last few years, it is worth pointing out that little attention has been placed on issues related to D2D virtualization. Therefore, based on the integration of an inter-tenant controller that enables the radio resource sharing between multiple operators, we devise a set of efficient algorithms to optimize the throughput performance of D2D communications in virtualized environments as well as reduce the utilization levels of the allocated radio resources. More than 12% of sum-rate performance improvement compared to legacy, intra-tenant ap-proaches where the radio resources are assigned based on which device initiates the communication per case. Finally, a summary of the research outcomes along with some future directions for D2D communications concludes this thesis.

To address the problem of radio spectrum congestion due to increasing demand for wireless communications services, cellular communication systems are going towards small cells with small transmit powers. At the same time, in-band fullduplex (FD) radio design has gained considerable attention due to achievements in signal processing that can make design of full-duplex radios possible for systems with small transmit power. In theory full-duplex radios can double the spectral efficiency of the system. However existing radios still do not provide enough self-interference (SI) cancelation to be used in large transmit power systems. Meanwhile device-to-device communication (D2D) is seen as a promising idea to increase the performance of wireless networks. In D2D, users in vicinity communicate directly without going through base station. So far, very limited work has been carried out to study the applicability of available full-duplex radios in D2D. In this thesis, we investigate full-duplex D2D and amount of self-interference cancelation required in D2D in cellular systems. While D2D users share the same radio resources with cellular users, both cellular and D2D pair will receive interference. Resource allocation and interference management become crucial in D2D communication. Both uplink and downlink resource sharing are considered. In uplink resource sharing, to handle the interference on the base station power control is used in D2D transmitter. To deal with the interference at D2D receivers from cellular user’s uplink transmission, interference-limited-area (ILA) method is used to select users with negligible interference on them. When D2D pair is using downlink resources of cellular users, users receive interference from D2D transmissions. Limiting this interference is also done using ILA method. On the other hand, for the purpose of resource sharing, the user with smallest downlink transmit power is selected to minimize the interference on D2D receivers. Half-duplex (HD) and full-duplex D2D scenarios are considered in both uplink and downlink resource sharing. Simulations show that how much of self-interference cancelation is required in different scenarios. Effects of the numbers of the selected users for resource sharing, distance between D2D users and also inter-cell interference is studied. It can be concluded that using available full-duplex radios in D2D communication can almost reach the theoretical doubling of throughput in full-duplex mode compared to half-duplex mode.

Avec la croissance rapide de la demande de trafic de données des clients, l'amélioration de la capacité du système et l'augmentation du débit des utilisateurs sont devenues des préoccupations essentielles pour le futur réseau de communication sans fil de cinquième génération. Dans ce contexte, la communication terminal-à-terminal (Device-to-Device D2D) et le Full Duplex (FD) sont proposés comme solutions potentielles pour augmenter l’efficacité spectrale et le débit des utilisateurs dans un réseau cellulaire. Le D2D permet à deux périphériques proches de communiquer sans participation de la station de base ou avec une participation limitée. D'autre part, la communication en FD permet une transmission et une réception simultanées dans la même bande de fréquence. En raison de la propriété de distance courte des liaisons D2D, exploiter la technologie FD dans la communication D2D est un excellent choix pour améliorer encore plus l’efficacité spectrale cellulaire et le débit des utilisateurs. Cependant, les émetteurs-récepteurs FD constituent de nouveau défis pour la communication D2D. Par exemple, en FD les émetteurs-récepteurs ne peuvent pas supprimer d’une manière parfaite l’auto-interférence (SI) générée au niveau des récepteurs lors de la transmission des données (par le propre émetteur du dispositif cellulaire). Ainsi, l’auto-interférence résiduelle qui est étroitement liée à la valeur de la puissance de l’émetteur affecte fortement les performances de la transmission FD. De plus, la technique en FD crée des interférences supplémentaires dans le réseau, ce qui peut dégrader ses performances par rapport à la transmission en semi-duplex (Half-duplex HD). Ainsi, une bonne gestion des ressources radio est nécessaire pour exploiter les avantages de la FD et garantir la qualité de service (QoS) des utilisateurs. Les travaux de cette thèse portent sur l'allocation de puissance et l'attribution de canaux d'un réseau FD-D2D. En particulier, cette thèse aborde d’abord le problème de l’allocation de puissance et propose une méthode d'allocation de puissance (PA) optimale centralisée simple mais efficace, puis développe le schéma optimal conjoint d’AP et d’AC pour un réseau FD-D2D. Un algorithme de complexité réduite CATPA, basé sur une allocation CA suivie d'une allocation PA, est aussi développée et proposé. La thèse présente à la fin une stratégie efficace d'AP décentralisée en utilisant les outils de la théorie des jeux
With the rapidly growing of the customers' data traffic demand, improving the system capacity and increasing the user throughput have become essential concerns for the future 5G wireless communication network. In this context, D2D communication and FD are proposed as potential solutions to increase the spatial spectrum utilization and the user rate in a cellular network. D2D allows two nearby devices to communicate without BS participation or with limited participation. On the other hand, FD communication enables simultaneous transmission and reception in the same frequency band. Due to the short distance property of D2D links, exploiting the FD technology in D2D communication is an excellent choice to further improve the cellular spectrum efficiency and the users’ throughput. However, practical FD transceivers add new challenges for D2D communication. For instance, the existing FD devices cannot perfectly eliminate the SI imposed on the receiver by the node’s own transmitter. Thus, the RSI which is tightly related to the transmitter power value highly affects the performance of FD transmission. Moreover, the FD technique creates additional interference in the network which may degrade its performance when compared with the half-duplex transmission. Thus, proper radio resource management is needed to exploit the benefits of FD and guarantee the QoS of the users. The works in this dissertation focus on the PA and CA of a FD-D2D network. In particular, this thesis first addresses the PA problem and proposes a simple yet efficient centralized optimal PA framework, and next, it derives the optimal joint PA and CA scheme for an FD-D2D network. A simple sub-optimal algorithm for resource allocation named CATPA, based on CA followed by PA, is also derived and proposed. This dissertation also develops, in the end, an efficient decentralized PA using game theory tools that will be an essential part of future works in the context of distributed radio resource management

The gains of direct communication between user equipment in a network may not be fully realised due to the separation between the user equipment and due to the fading that the channel between these user equipment experiences. In order to fully realise the gains that direct (device-to-device) communication promises, idle user equipment can be exploited to serve as relays to enforce device-to-device communication. The availability of potential relay user equipment creates a problem: a way to select the relay user equipment. Moreover, unlike infrastructure relays, user equipment are carried around by people and these users are self-interested. Thus the problem of relay selection goes beyond choosing which device to assist in relayed communication but catering for user self-interest. Another problem in wireless communication is the unavailability of perfect channel state information. This reality creates uncertainty in the channel and so in designing selection algorithms, channel uncertainty awareness needs to be a consideration. Therefore the work in this thesis considers the design of relay user equipment selection algorithms that are not only device centric but that are relay user equipment centric. Furthermore, the designed algorithms are channel uncertainty aware. Firstly, a stable matching based relay user equipment selection algorithm is put forward for underlay device-to-device communication. A channel uncertainty aware approach is proposed to cater to imperfect channel state information at the devices. The algorithm is combined with a rate based mode selection algorithm. Next, to cater to the queue state at the relay user equipment, a cross-layer selection algorithm is proposed for a twoway decode and forward relay set up. The algorithm proposed employs deterministic uncertainty constraint in the interference channel, solving the selection algorithm in a heuristic fashion. Then a cluster head selection algorithm is proposed for device-to-device group communication constrained by channel uncertainty in the interference channel. The formulated rate maximization problem is solved for deterministic and probabilistic constraint scenarios, and the problem extended to a multiple-input single-out scenario for which robust beamforming was designed. Finally, relay utility and social distance based selection algorithms are proposed for full duplex decode and forward device-to-device communication set up. A worst-case approach is proposed for a full channel uncertainty scenario. The results from computer simulations indicate that the proposed algorithms offer spectral efficiency, fairness and energy efficiency gains. The results also showed clearly the deterioration in the performance of networks when perfect channel state information is assumed.

Crowdsourcing is emerging as a new data-collection, solution-finding, and opinion-seeking model that obtains needed services, ideas, or content by soliciting contributions from a large crowd of public participants. D2D based crowdsensing is particularly desired when the initiator cannot directly reach out to the participants or the conventional approaches for data transportation are costly. This dissertation studies the ultra-large scale crowdsensing applications in such mobile D2D networks. First, I proposed and addressed MCC(Minimum-Cost Crowdsourcing) problem by exploring a multi-dimensional design space to seek an optimal solution that minimizes the total crowdsensing cost while satisfying the coverage probability over the FoI. In particular, three strategies (or options) are in consideration: task allocation strategy, data processing strategy and computation offloading strategy. The difficulty is to determine the three options for each node in order to minimize the overall system cost. Second, there are a class of applications, where the originator is only allowed to recruit a given number of participants. Therefore, from the perspective of limited participants, we proposed a competition based participant recruitment mechanism to wisely choose the set of nodes while achieving the best benefit. I have proposed a dynamic programming algorithm as a first attack to this problem, followed by two distributed alternatives, which prove to be more practical and adaptive. During the above two topics, we find the existing routing protocols cannot efficiently support the ultra-large scale crowdsensing, thus we built a resource constrained routing protocol in D2D, aiming to approach the large-scale, bandwidth-hungry crowdsensing task in a more efficient way. With the requirement of restricted node storage and link bandwidth as well as end-to-end delay, I formulated a non-linear traffic allocation optimization problem with an approximation algorithm and distributed heuristic solution. Finally, I have carried out extensive complexity analysis, simulation, prototyping and implementation, experimentation and performance evaluation. Through the step-by-step exploration and verification, I have demonstrated the efficiency of the proposed heuristics and revealed empirical insights into the design tradeoffs and practical considerations in D2D-based crowdsourcing.

In current cellular networks the demand of traffic is rapidly increasing and new techniques need to be developed to accommodate future service requirements. Device-to-Device (D2D) communications is one technique that has been proposed to improve the performance of the system by allowing devices to communicate directly without routing traffic through the base station. This technique has the means to improved performance and support new proximity based services.   Nowadays new applications based on geographical proximity are becoming more and more popular suggesting that D2D communications will have a high de- mand in the near future. Thus the study of the scalability of D2D communications is of paramount importance.   We define the scalability of D2D communications underlay cellular networks as the maximum number of D2D links that can share the cellular resources while assuring QoS to both D2D links and cellular users. In this thesis we study the scalability of D2D communication underlay cellu- lar networks in a multi-cell environment. We propose interference coordination schemes to maximize the number of D2D links while assuring QoS to D2D links and cellular users.   Three interference coordination schemes have been proposed considering dif- ferent levels of available channel state information (CSI). The first scheme is called no CSI centralized (N-CSIC) scheme and it is based on a centralized solution where no CSI is needed. The second is partial CSI distributed (P-CSID) scheme and it is based on a distributed solution where partial CSI is available. The last scheme is named full CSI optimal (F-CSIOp) scheme and it is achieved by formulating an optimization problem considering full CSI to be available.   Extensive mathematical and numerical analysis is conducted to develop and evaluate the proposed schemes. The results show that F-CSIOp scheme offers the best performance followed by the P-CSID and finally N-CSIC, thus a clear relationship is found between complexity and performance.   The P-CSID offers a practical solution for a low complexity interference co- ordination scheme that achieves good scalability and capacity for a wide range of strict QoS requirements. Moreover the results show that further improvement can be achieved if proper selection of the involved parameters is done along with the implementations of closed loop power control (CLPC) schemes.   The N-CSIC scheme provides a good solution for low SINR values of D2D links when the QoS of cellular users is low. Thus it is a good candidate for applications like sensor networks or M2M communications where the SINR requirements are rather low and there are no primary users to impose more interference constraints.   Finally we conclude that good scalability and capacity can be achieved with the proposed low complexity interference coordination schemes for D2D communications and provide interesting topics for future research.

Book Summary: Nurses play a key role in high-quality health care for people with intellectual and developmental disabilities (IDD)--and now this up-to-date textbook fully prepares them to provide patients with the best possible services across the lifespan. The most comprehensive text available for nurses who specialize in IDD, this essential book clarifies evidence-based practices and gives readers an integrated, interdisciplinary approach to care that meets each person's individual needs. Cecily Betz and Wendy Nehring--authors of the respected text Promoting Health Care Transitions for Adolescents with Special Health Care Needs and Disabilities--gather the latest research and wisdom of 18 diverse authorities in the medical field. Together, they give pre- and in-service nurses the foundation of knowledge they need to help ensure equal access to health care for people with IDD choose from today's models and philosophies of carepromote their patients' psychosocial developmentprovide effective physical careconduct health assessments and develop individualized plans of caremaintain successful interdisciplinary collaboration with other professionals address the issues associated with specific disabilities, including autism, Down syndrome, cerebral palsy, fragile X, sensory impairment, and medical and behavioral health problems support developmental transitions across the lifespan expand their knowledge of genetics and apply it to nursing practice skillfully manage ethical and legal issuesunderstand the service agencies used by individuals with IDD Enhanced with clinical practice guidelines to support effective work with individuals who have IDD, this textbook lights every nurse's path to person-centered, evidence-based care that improves their patients' lives.

Written by nurse practitioners for nurse practitioners, this one-of-a-kind resource provides the expert guidance you need to provide comprehensive primary care to children with special needs and their families. It addresses specific conditions that require alterations in standard primary care and offers practical advice on managing the major issues common to children with chronic conditions. A consistent format makes it easy to locate essential information on each condition. Plus, valuable resources help you manage the issues and gaps in health care coverage that may hinder quality care.

Mask layout design is an important part in silicon photonic device design flow; the space used and the quality of the mask directly affect the cost of fabrication and quality of the outcome. To effectively minimize time spent on drawing masks, fixing design violations, and reducing unused spacings between each structure, we use effective approaches in the mask design process to ensure the listed criteria are met. Using the PCell and the hierarchy drawing methods, GDS files that contain different device parameters can be generated efficiently. As a result, direct GDS modeling efficiency is improved. An experimental setup that is capable of obtaining high quality measurement data is critical to device measurement. The concept of an automated measurement station can effectively reduce work needed from the experimenter while providing quality results. With the implemented fiber-to-fiber and fiber array automated measurement station, multi-device measurement can be set up to run automatically in minutes whereas traditional manual measurement stations require one's presence and constant attention. In this thesis, we have illustrated several mask drawing approaches and showed the drawing steps of two masks in detail. We have described two automated experimental setups, fiber-to-fiber and fiber array, in detail and included various measurement results to show the capabilities of these two stations.

Spatially proximal devices wanting to exchange information are expected to become more prevalent in wireless networks, rendering the option for direct device-to-device (D2D) communication increasingly important. On the one hand, within networks where communication via infrastructure has been the convention, enabling such an option for short-range and single-hop communication between co-located devices might potentially bring about performance benefits on several accounts. On the other hand, in the realm of networks where direct interaction between devices has been an obvious option, there is a growing demand for supporting extreme-data-rate applications and much denser deployments of simultaneous transmissions. This dissertation explores these aspects by addressing two main problems: (i) analyzing the performance benefits of D2D communication integrated into cellular mobile networks, and (ii) investigating the feasibility of mmWave (millimeter wave) frequencies for personal networks of wearable (body-born) devices in enclosed settings. Under sufficient spatial locality in wireless traffic within cellular networks, the D2D mode of communication can be leveraged to employ a denser spectral reuse, thereby achieving very high area spectral efficiencies (bits/s/Hz per unit area). Enabling D2D entails a reshaping of the network topology comprising the sources of useful signal and harmful interference from the vantage of each receiver, which is a factor that delimits network performance fundamentally. Therefore, to gauge the performance gains of D2D and to identify the challenges thereof, it is essential to model D2D communication in a large multicellular setting, without missing key features of the ensuing interference environment. In this regard, we develop a robust analytical framework, utilizing tools from stochastic geometry. The dissertation propounds a novel approach to the application of stochastic geometry that is shown to improve the simplicity, accuracy, and generality of wireless network analysis. The performance evaluation conducted using the framework, while demonstrating the potential of D2D, also indicates the need for managing the interference surge. Prompted by this, and to illustrate the flexibility of the framework, we further extended it to incorporate interference protection schemes based on exclusion regions and the benefits thereof are assessed. The presence of multiple wearable networks—each comprising several on-body device-pairs worn by people—in proximity might result in an extreme density of simultaneous wireless transmissions. Such a scenario is expected to become commonplace in enclosed settings, e.g., commuter trains, subways, airplanes, airports or offices, and be further challenging due to an increasing demand for data-rate-intensive wireless applications in wearable technology. This combination of very-short-range communication, high-data-rate applications, and dense spectral reuse seems to render operation at mmWave frequencies a suitable candidate; add to that the possibility of accommodating antenna arrays within devices for directional beamforming. Hence, we investigate the feasibility of enclosed mmWave wearable networks, with a particular focus on appropriately modeling the impact of propagation mechanisms at these frequencies. In the propagation modeling, specular reflections off surfaces are explicitly accounted for, as they are expected to contribute useful signal power while, at the same time, intensify the interference. Recognizing the increased prominence of blocking by obstacles, body-blockages in the direct and reflected propagation paths are also modeled. The impact of these mechanisms on the spectral efficiency of the network is evaluated, aided by the application of stochastic geometry and random shape theory. Under relevant indoor settings, and in the plausible absence of strong direct signal, the reliability of surface reflections in providing useful signal power for efficient communication is investigated and the need for directional antennas is established.
Se espera que los dispositivos espacialmente proximales que desean intercambiar información se vuelvan más frecuentes en redes inalámbricas, lo que hace cada vez más importante la opción para la comunicación directa de dispositivo-a-dispositivo (D2D). Por un lado, dentro de las redes en las que la comunicación a través de la infraestructura ha sido la convención, permitir tal opción para la comunicación de corto alcance y single-hop entre dispositivos ubicados conjuntamente podría potencialmente generar beneficios de rendimiento en varios aspectos. Por otro lado, en el ámbito de las redes en las que la interacción directa entre dispositivos ha sido una opción obvia, existe una demanda creciente de soportar aplicaciones de velocidad extrema de datos e implementaciones mucho más densas de transmisiones simultáneas. Esta disertación explora dichos aspectos abordando dos problemas principales: (i) analizando los beneficios de rendimiento de la comunicación D2D integrada en las redes móviles celulares y (ii) investigando la viabilidad de las frecuencias mmWave (onda milimétrica) para redes personales de dispositivos wearables (usado en el cuerpo) en entornos cerrados. Bajo suficiente localidad espacial en el tráfico inalámbrico en redes celulares, el modo de comunicación D2D puede ser apalancado para emplear una reutilización espectral más densa, logrando así eficiencias espectrales de área muy alta (bits/s/Hz por unidad de área). La habilitación de D2D implica una remodelación de la topología de red que comprende las fuentes de señal útil e interferencia perjudicial desde la ventaja de cada receptor, lo cual es un factor que delimita el funcionamiento de la red de manera fundamental. Por tanto, para medir las ganancias de rendimiento de D2D y para identificar los retos de la misma, es esencial para modelar la comunicación D2D en un gran ajuste multicelular, sin faltar las características clave del entorno de interferencia resultante. En este sentido, se desarrolla un sólido marco analítico, utilizando herramientas de geometría estocástica. La disertación propone un nuevo enfoque para la aplicación de la geometría estocástica para mejorar la simplicidad, precisión y generalidad del análisis de redes inalámbricas. La evaluación realizada utilizando dicho enfoque, al mismo tiempo que demuestra el potencial de D2D, también indica la necesidad de manejar la oleada de interferencia. Impulsado por estos resultados, y para ilustrar la flexibilidad del marco, también se amplía para incorporar esquemas de protección contra interferencias basados en regiones de exclusión y se evalúan sus los beneficios. La presencia de redes wearables múltiples—cada una de las cuales comprende varios pares de dispositivos en el cuerpo desgastados por personas—en proximidad puede dar como resultado una densidad extrema de transmisiones inalámbricas simultáneas. Se espera que este escenario se convierta habitual en entornos cerrados, por ejemplo, trenes de cercanías, subterráneos, aviones, aeropuertos u oficinas, y será un reto adicional debido a la creciente demanda de aplicaciones inalámbricas intensivas en datos en tecnología wearable. Esta combinación de comunicaciones de muy corto alcance, en aplicaciones de alta velocidad de datos y de reutilización espectral densa parece hacer que la operación en las frecuencias mmWave sea un candidato adecuado; se añade la posibilidad de alojar conjuntos de antenas dentro de dispositivos para el beamforming direccionales. Por tanto, también se investiga la viabilidad de las redes wearables mmWave cerradas, con especial énfasis en modelar apropiadamente el impacto de los mecanismos de propagación en estas frecuencias. En el modelado de propagación, las reflexiones especulares de las superficies se explican explícitamente, ya que se espera que contribuyan a la potencia de la señal útil, mientras que, al mismo tiempo, intensificar la interferencia. Reconociendo la mayor prominencia del bloqueo por obstáculos, también se modelan los bloqueos corporales en los caminos de propagación directa y reflejada. El impacto de estos mecanismos en la eficiencia espectral de la red se evalúa, ayudado por la aplicación de la geometría estocástica y la teoría de la forma aleatoria. Bajo configuraciones internas relevantes, y en la ausencia plausible de señal directa fuerte, se investiga la fiabilidad de las reflexiones superficiales proporcionando potencia de señal útil para una comunicación eficiente y se establece la necesidad de antenas direccionales.

In this thesis, performance of relay-assisted Device-to-device (D2D) communication is investigated where D2D traffic is carried through relay nodes. I develop resource management schemes to maximize end-to-end rate as well as conversing rate requirements for cellular and D2D UEs under total power constraint. I also develop a low-complexity distributed solution using the concept of message passing. Considering the uncertainties in wireless links (e.g., when interference from other relay nodes and the link gains are not exactly known), I extend the formulation using robust resource allocation techniques. In addition, a distributed solution approach using stable matching is developed to allocate radio resources in an efficient and computationally inexpensive way under the bounded channel uncertainties. Numerical results show that, there is a distance threshold beyond which relay-assisted D2D communication significantly improves network performance at the cost of small increase in end-to-end delay when compared to conventional approach.

Device-to-device (D2D) is a new paradigm in cellular networks that enhances network performance by introducing increased spectral efficiency and reduced communication delay. Efficient data dissemination is indispensable for supporting many D2D applications such as content distribution and location-aware advertisement. In this work, I investigate a new and interesting data dissemination problem where the receivers are not explicitly known and data must be disseminated to the receivers within a probabilistic delay budget. I propose to exploit data depositories, which can temporarily house data and deliver them to interested receivers upon requests. I formally formulate the delay-constrained profit maximization problem for data deposition in D2D networks and show its NP-hardness. Under the unique mobile opportunistic network setting, a practical solution for such problem must be distributed, localized, and online. To this end, I introduce three algorithms for Direct Online Selection of 1-Depository, Direct Online Selection of L-Depositories, and Mixed Online Selection of L-Depositories. To demonstrate and evaluate the system, I implement a prototype using Google Nexus handsets and conduct experiments for five weeks. I further carry out simulations based on real-world mobility traces for evaluation of large-scale networks and various network settings that are impractical to experiment.

Device-to-Device (D2D) communication has become a promising candidate for future wireless communication systems to improve the system spectral efficiency, while reducing the latency and energy consumption of individual communication. With the assistance of cellular network, D2D communications can greatly reduce the transmit distance by utilizing the spatial dispersive nature of ever increasing user devices. Further, substantial spectrum reuse gain can be achieved due to the short transmit distance of D2D communication. It, however, significantly complicates the resource management and performance analysis of D2D communication underlaid cellular networks. Despite an increasing amount of academic attention and industrial interests, how to evaluate the system performance advantages of D2D communications with resource management remains largely unknown. On account of the proximity requirement of D2D communication, the resource management of D2D communication generally consists of admission access control and resource allocation. Resource allocation of cellular assisted D2D communications is very challenging when frequency reuse is considered among multiple D2D pairs within a cell, as intense inter D2D interference is difficult to tackle and generally causes extremely large amount of signaling overheads for channel state information (CSI) acquisition. Hence, the first part of this thesis is devoted to the resource allocation of cellular assisted D2D communication and the performance analysis. A novel resource allocation scheme for cellular assisted D2D communication is developed with low signaling overhead, while maintaining high spectral efficiency. By utilizing the spatial dispersive nature of D2D pairs, a geography-based sub-cell division strategy is proposed to group the D2D pairs into multiple disjoint clusters, and sub-cell resource allocation is performed independently for the D2D pairs within each sub-cell without the need of any prior knowledge of inter D2D interference. Under the proposed resource allocation scheme, tractable approximation for the inter D2D interference modeling is obtained and a computationally efficient expression for the average ergodic sum capacity of the cell is derived. The expression further allows us to obtain the optimal number of sub-cells that maximizes the average ergodic sum capacity of the cell. It is shown that with small CSI feedback, the system capacity/spectral efficiency can be improved significantly by adopting the proposed resource allocation scheme, especially in dense D2D deployment scenario. The investigation of use cases for cellular assisted D2D communication is another important topic which has direct effect on the performance evaluation of D2D communication. Thanks to the spatial dispersive nature of devices, D2D communication can be utilized to harvest the vast amount of the idle computation power and storage space distributed at the devices, which yields sufficient capacities for performing computation-intensive and latency-critical tasks. Therefore, the second part of this thesis focuses on the D2D communication assisted Mobile Edge Computing (MEC) network. The admission access control of D2D communication is determined by both disciplines of mobile computing and wireless communications. Specifically, the energy minimization problem in D2D assisted MEC networks is addressed with the latency constraint of each individual task and the computing resource constraint of each computing entity. The energy minimization problem is formed as a two-stage optimization problem. At the first stage, an initial feasibility problem is formed to maximize the number of executed tasks, and the global energy minimization problem is tackled in the second stage while maintaining the maximum number of executed tasks. Both of the optimization problems in two stages are NP-hard, therefore a low-complexity algorithm is developed for the initial feasibility problem with a supplementary algorithm further proposed for energy minimization. Simulation results demonstrate the near-optimal performance of the proposed algorithms and the fact that the number of executed tasks is greatly increased and the energy consumption per executed task is significantly reduced with the assistance of D2D communication in MEC networks, especially in dense user scenario.

There are high demands of effective and high-performance of collaborations between mobile devices in the places where traditional Internet connections are unavailable, unreliable, or significantly overburdened, such as on a battlefield, disaster zones, isolated rural areas, or crowded public venues. To enable collaboration among the devices in opportunistic networks, code offloading and Remote Method Invocation are the two major mechanisms to ensure code portions of applications are successfully transmitted to and executed on the remote platforms. Although these domains are highly enjoyed in research for a decade, the limitations of multi-device connectivity, system error handling or cross platform compatibility prohibit these technologies from being broadly applied in the mobile industry. To address the above problems, we designed and developed UMSEF - an Universal Mobile Service Execution Framework, which is an innovative and radical approach for mobile computing in opportunistic networks. Our solution is built as a component-based mobile middleware architecture that is flexible and adaptive with multiple network topologies, tolerant for network errors and compatible for multiple platforms. We provided an effective algorithm to estimate the resource availability of a device for higher performance and energy consumption and a novel platform for mobile remote method invocation based on declarative annotations over multi-group device networks. The experiments in reality exposes our approach not only achieve the better performance and energy consumption, but can be extended to large-scaled ubiquitous or IoT systems.