Dissertationen zum Thema „NON-INVASIVELY“

By using near infrared spectroscopy (NIRS) and by modifying the current Somanetics® optodes being used with the INVOS oximeter, the modified optodes are made to be fairly functional not only across the forehead, but across the hairy regions of the scalp as well. A major problem arises in the positioning of these optodes on the patients scalp and holding them in place while recording data. Another problem arises in the inconsistent repeatability of the trends displayed in the recorded data. A method was developed to facilitate the easy placement of these optodes on the patients scalp keeping in mind thepatient's comfort. The sensitivity of the optodes, too, was improved by incorporating better refined techniques for manufacturing the fiber optic brushes and fixing the same to the optode transmitting and receiving windows. The modified and improved optodes, in the single as well as in the multiplexed modes, were subjected to various tests on different areas of the brain to determine their efficiency and functionality.

There is a broad range of technologies available for wireless communications for moving vehicles, such as Worldwide Interoperability for Microwave Access (WiMax), 3G, Dedicated Short Range Communication (DSRC)/ Wireless Access for Vehicular Environment (WAVE) and Mobile Broadband Wireless Access (MBWA). These technologies are needed to support delay-sensitive safety related applications such as collision avoidance and emergency breaking. Among them, the IEEE802.11p standard (aka DSRC/WAVE), a Wi-Fi based medium RF range technology, is considered to be one of the best suited draft architectures for time-sensitive safety applications. In addition to safety applications, however, services of non-safety nature like electronic toll tax collection, infotainment and traffic control are also becoming important these days. To support delay-insensitive infotainment applications, the DSRC protocol suite also provides facilities to use Internet Protocols. The DSRC architecture actually consists of WAVE Short Messaging Protocol (WSMP) specifically formulated for realtime safety applications as well as the conventional transport layer protocols TCP/UDP for non-safety purposes. But the layer four protocol TCP was originally designed for reliable data delivery only over wired networks, and so the performance quality was not guaranteed for the wireless medium, especially in the highly unstable network topology engendered by fast moving vehicles. The vehicular wireless medium is inherently unreliable because of intermittent disconnections caused by moving vehicles, and in addition, it suffers from multi-path and fading phenomena (and a host of others) that greatly degrade the network performance. One of the TCP problems in the context of vehicular wireless network is that it interprets transmission errors as symptomatic of an incipient congestion situation and as a result, reduces the throughput deliberately by frequently invoking slow-start congestion control algorithms. Despite the availability of many congestion control mechanisms to address this problem, the conventional TCP continues to suffer from poor performance when deployed in the Vehicular Ad-hoc Network (VANET) environment. Moreover, the way non-safety applications, when pressed into service, will treat the existing delay-sensitive safety messaging applications and the way these two types of applications interact between them are not (well) understood, and therefore, in order for them to coexist, the implication and repercussion need to be examined closely. This is especially important as IEEE 802.11p standards are not designed keeping in view the issues TCP raises in relation to safety messages. This dissertation addresses the issues arising out of this situation and in particular confronts the congestion challenges thrown up in the context of heterogenous communication in VANET environment by proposing an innovative solution with two optimized congestion control algorithms. Extensive simulation studies conducted by the author shows that both these algorithms have improved TCP performance in terms of metrics like Packet Delivery Fraction (PDF), Packet Loss and End-to-End Delay (E2ED), and at the same time they encourage the non-safety TCP application to behave unobtrusively and cooperatively to a large extent with DSRC’s safety applications. The first algorithm, called vScalable-TCP – a modification of the existing TCPScalable variant – introduces a reliable transport protocol suitable for DSRC. In the proposed approach, whenever packets are discarded excessively due to congestion, the slow-start mechanism is purposely suppressed temporarily to avoid further congestion and packet loss. The crucial idea here is how to adjust and regulate the behaviour of vScalable-TCP in a way that the existing safety message flows are least disturbed. The simulation results confirm that the new vScalable-TCP provides better performance for real-time safety applications than TCP-Reno and other TCP variants considered in this thesis in terms of standard performance metrics. The second algorithm, named vLP-TCP – a modification of the existing TCP-LP variant – is designed to test and demonstrate that the strategy developed for vScalable-TCP is also compatible with another congestion control mechanism and achieves the same purpose. This expectation is borne out well by the simulation results. The same slow-start congestion management strategy has been employed but with only a few amendments. This modified algorithm also improves substantially the performance of basic safety management applications. The present work thus clearly confirms that both vScalable-TCP and vLP-TCP algorithms – the prefix ‘v’ to the names standing for ‘vehicular’ – outperform the existing unadorned TCP-Scalable and TCP-LP algorithms, in terms of standard performance metrics, while at the same time behaving in a friendly manner, by way of sharing bandwidth non-intrusively with DSRC safety applications. This paves the way for the smooth and harmonious coexistence of these two broad, clearly incompatible or complementary categories of applications – viz. time-sensitive safety applications and delay-tolerant infotainment applications – by narrowing down their apparent impedance or behavioural mismatch, when they are coerced to go hand in hand in a DSRC environment.

Cancellous bone constitutes much of the volume of bone which makes up axial skeletal sites such as the vertebrae of the spine and the femoral neck. However the increased vascularity of cancellous bone compared with cortical bone means that it is more prone to drug, endocrine and metabolic related effects and therefore these skeletal sites are more prone to the bone condition osteoporosis. With the bone condition osteoporosis increasing in prevalence it is becoming far more important not only for those at risk of having the condition to be diagnosed earlier, but also for the effects of the condition to be better understood. There is a need for the better clinical management of fractures and for therapies and medical practices that will best avoid the low trauma fractures that are seen as a consequence of the condition. This study is in two separate sections, the first constitutes an investigation into the diagnostic abilities of the CUBA Clinical and Sunlight Omnisense quantitative ultrasound systems; and on the other hand an examination of the osteoporotic risk factor questionnaires, Osteoporosis Risk Assessment Instrument (ORAI), Osteoporosis Index of Risk (OSIRIS), Osteoporosis Self-assessment Tool (OST), Patient Body Weight (pBW), Simple Calculated Osteoporosis Risk Estimation (SCORE) and the Study of Osteoporotic Fractures (SOFSURF). The skeletal status was assessed by DXA at the axial skeleton. The aim was to differentiate between the systems that could rationally be used to screen populations to identify those who needed DXA densitometry investigations, on the basis of ability. The second section of the study focused on the biomechanics of cancellous bone, with the initial studies examining the compressive properties of both osteoporotic and osteoarthritic cancellous bone and the effects that the conditions have on the compressive mechanics of the bone. The later section is the first ever study into the K, G and J-integral fracture mechanics of cancellous bone. It used osteoporotic and osteoarthritic cancellous bone from the femoral head of a cohort of ultrasound scanned patients and of some equine vertebral cancellous bone. The study focused on the identification of the dominant independent material variables which affected the compressive and fracture mechanics of cancellous bone, and the differences that were seen between the two different skeletal conditions. In addition to the independent variables, quantitative ultrasound (QUS) scans were performed on the donors of the femoral heads which enabled investigation into QUS’s ability to predict either the compressive or fracture mechanics of bone in-vivo. The study demonstrated that the investigation of the calcaneus using the CUBA clinical system provided the highest level of diagnostic accuracy (AUC: 0.755 - 0.95), followed by the questionnaires, of which the OSIRIS questionnaire was the best performer (AUC: 0.74 – 0.866), and lastly the Sunlight Omnisense results. The best option for the prediction of the lowest feasible DXA T-score was a combination of the CUBA Clinical results, the individual’s weight and the OSIRIS questionnaire (r2 = 45.5%), with potential minor, but significant, support also added by the OST and SOFSURF questionnaires (r2 = 46.8%). The compressive testing demonstrated that osteoporotic and osteoarthritic bone both performed differently with respect to the apparent density, with the osteoporotic bone adhering to the previously published power function relationships, but with the osteoarthritic bone having lower power functions. The stress intensity factor for plane strain testing (KQ or KC) and the critical strain energy release rate results were both influenced primarily by the apparent density with the K values obeying a power relationship to the power of 1.5 and G a relationship to the power 2. However, both the composition and integrity of the collagen network, (demonstrated by collagen cross-link analysis), played roles in the explanation of the fracture mechanics results. The J-integral results were distinctly different to those of the K and G results with regard to their dependence on composition and it is hypothesised that this is due to the structure of the bone having more dominant effects than the apparent density. In conclusion, the fracture mechanics of cancellous bone are contributed to by a complex combination of a number of variables, but with apparent density dominating the K and G fracture mechanics to a power function of between 1 and 2. Currently available QUS systems demonstrated an ability to relate to the Young’s modulus and strength but also, in this study, to the fracture mechanics variables of the cancellous bone from the hip. This relationship is a profound outcome which may help the clinical management of the condition and the fractures when they occur. The dependence on fracture mechanic variables points to a clear causal relationship between the bone fracture parameters and bone condition as underlying factors of osteoporotic fractures.

Thesis (M.S.) -- University of Maryland, College Park, 2004.
Thesis research directed by: Dept. of Animal and Avian Sciences. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

Androgens are correlated with reproductive behaviours including courtship and aggression. In the weakly electric fish, Apteronotus leptorhynchus, 11-ketotestosterone (11-KT) has been previously implicated in the regulation of electrocommunication behaviours that are believed to have roles in both aggression and courtship. In this thesis a method for performing repeated, non-invasive measurements of androgens released into the water was validated and applied for the first time in A. leptorhynchus. Changes in 11-KT levels and electrocommunication behaviour were observed in males following environmental cues that simulated the onset of the breeding season. Males showed an increase in mean electric organ discharge frequency (EODf), which is consistent with earlier results showing a female preference for high EODf. A subset of males with high EODfs showed increases in both 11-KT and EODf which provides support for an EODf-based dominance hierarchy in this species. No direct correlation was seen between 11-KT and EODf, however, which suggests that other factors are involved in regulating male EODf. Electrocommunication signals produced during inter-male aggression were confirmed to serve in deterring attacks, and their pattern of production further suggested the formation of a dominance hierarchy. Evidence is presented that another type of electrocommunication signal previously implicated in courtship may be an inter-male signal of submission. The method for non-invasive hormone sampling first applied here will form the basis for future investigations of the hormonal control of communication behaviour.
Les androgènes sont corrélés avec les comportements reproductifs et agressifs. Chez les poissons faiblement électriques Apteronotus leptorhynchus, la 11-ketotestosterone (11-KT) a déjà été impliquée dans la régulation des comportements de communication électriques avec des rôles prévu dans l'agression et la cour. Dans cette mémoire une méthode pour faire des mesures répétées qui ne sont pas envahissantes des androgènes libérés dans l'eau a été validée et appliquée pour la première fois dans A. leptorhynchus. Des changements dans les niveaux de 11-KT et la production des comportements de communication électrique ont été observés chez les mâles pendant une période de reproduction conditionnée. Entre les mâles, il y avait une augmentation de la fréquence de la décharge de l'organe électrique (EODf), ce qui est avec des résultats précédents montrant que les femelles matures ont une préférence pour les mâles avec des EODf élévées. Un sous-ensemble de mâles ayant des EODfs élevée a montré des augmentations dans le niveau de 11-KT et la EODf, ce qui soutient une hiérarchie de dominance fondée sur la EODf. Globalement, aucune corrélation n'a été observée entre 11-KT et EODf, ce qui suggère que d'autres facteurs sont impliqués dans la régulation du EODf dans les mâles. Les comportements de communication électrique produits pendant l'agression entre mâles servent à dissuader les attaques et leur mode de production aussi suggère la formation d'une hiérarchie de dominance. Une preuve est aussi présentée qu'un autre comportement de communication électrique impliqué dans la reproduction peut être un signal masculin de la soumission. À l'avenir, la méthode appliquée ici pour la première fois chez les poissons faiblement électriques sera en mesure de répondre à ces questions en profondeur.

Random noise typically described as undesirable disturbance has always been suppressed by spending large amount of energy whether it is the eld of electronics, computer tech- nology based arti cial intelligence or robotics. In contrast the e ect of noise on non- linear system like biological system has been found to be positive. Naturally existing noise in the environment is utilized by the biological system for their improved performance in infor- mation processing. Yuragi (in Japanese) is referred to as biological uctuation. Inspired from this biological activity of exploiting noise for seeking the potential bene ts of low power consumption, adaptive to the environment and stable, there has been signi cant progress in development of applications of Yuragi to robotic systems as a complementing work between robotics and biology. In order to develop the mathematical function of such bene cial noise that is biologically inspired its necessary to understand the struc- ture of physiological noise. This thesis tries to demonstrate a newly adopted paradigm to retrieve the structure of noise from neural recording of human brain. EEG dataset has been recorded from a single channel, dry electrode device. The brains electrical activity recorded non- invasively from the device is contaminated by various types of noise, both of biological and non- biological nature. This work tries to characterize both type of noise and intends to nd the emerging pattern from biological noise and reject non biological uctuation which can potentially be from electrical interference present in environment and acquired while travelling through electrode.

碩士
義守大學
生物醫學工程學系
104
Degenerative osteoarthritis is a common disease in medical institutions. Therefore, it is very important and urgentto early diagnose the degeneration of knee joints.The purpose of the thesis was toimprove the wireless and wearable measurement system developed by our laboratory for non-invasive detection of osteoarthritis (OA) of knee joints. To validate its feasibility of the measurement system, the study recruited 125 subjects including 29 control participants (Group 1) and 96 OA patients (Group 2: OA-I, Group 3: OA-II and Group 4: OA-III&IV) in the Department of Orthopedics, E-Da Hospital. In human trials, those subjectswere asked to perform the active, passive swings,the step-forward and –backward motions, walking movement, and squatting movement. During these experiments, the vibration signals from the knee joints were recorded with the measurement system.The vibration signals generated by the normal and osteoarthritis joints wereanalyzed by using the frequency-domain techniques, Fast Fourier Transform (FFT). After filtering the requency components less than 5 Hz, the energy ratio of 5~200 Hz in the vibration signals recorded from the knee surface during the active swinging was significantly smaller in Group 1 than OA Group (lateral condyle: 32.22±7.69vs36.09±7.48%, p=0.012; mid-patella: 29.35±7.81 vs 33.77±9.25%, p=0.016; medial condyle: 35.09±11.03 vs 39.81±10.79 %, p=0.033). Recorded at the lateral condyle and mid-patella, the energy ratio of 400~1KHz in the the vibration signals was significantly greater in Group 1 than OA Group (mid-patella: 29.27±5.00 vs 27.05±4.63 %, p=0.021; mid-patella: 30.20±5.63 vs 27.60±5.57 %, p=0.022).Using the Median Frequencyuency (MDF), it was found that MDFwas significantly greater in Group 1 than OA Group (lateral condyle: 308.47±45.05 vs 287.39±48.98 Hz, p=0.032; mid-patella: 312.76±48.55 vs 288.50±56.40 Hz, p=0.030; medial condyle: 280.64±70.13 vs 252.34±68.69 Hz, p=0.045). Furthermore, at the mid-patella, Group 1 showed significant difference in MDF as compared with Group 2 (312.76±48.55 vs 281.09±63.14Hz, p=0.045). In addition, at the medial condyle, there was significant difference in MDF between Group 1 and Group 4 (280.64±70.13vs 215.89±74.48Hz, p=0.002). In summary, a wireless and wearable measurement system is improved in the thesis. Energy ratio of a specific frequency band of vibration signals can be used to distinguish the control from the OA knee joints. Moreover, the MDF parameter can be applied to differentiae the severity of OA knees.

Recently, novel concepts and medical technologies have developed rapidly with enormous growth and unprecedented expansion in the range of interventions and knowledge offered for health professionals in their clinical decision making. This burgeoning innovation has not necessarily resulted in an incremental availability of knowledge to policymakers and clinicians. In this study critical translation gaps have been addressed strategically in the research-into-action cycle to improve outcomes and services. Given widespread acceptance that waveform morphology and blood pressure (BP) differ considerably between the central aorta and peripheral arterial system, it is clear that BP measurements in the peripheral arteries cannot serve as direct substitutes for their central counterparts. Although non-invasive BP measured in the brachial artery (cuff BP) is the basis for the present management of hypertension, central blood pressure (CBP) has been shown to be the better predictor of cardiovascular outcomes than cuff BP. Consequently, there are substantial research efforts to develop non-invasive estimating methods for CBP, mainly based on the technique of applanation tonometry. However, CBP measured has not been widely adopted in clinical practice. One of the possible gaps is that tonometry-based measurement requires some skills and time to perform and it is a relatively expensive technique. Besides, the accuracy of the current tonometry-based techniques has been questioned. To identify and address the gaps of translating the evidence of the importance of CBP, a series of studies were conducted. To identify existing gaps, I carried out a systematic review and meta-analysis of studies comparing tonometry-based CBP estimates with invasively measured central BP and found that present tonometry-based CBP estimating methods are acceptable in theory, with small errors. However, there is substantial room for improvement in measurement accuracy of CBP. To develop a more accurate, less expensive, and less technically dependent CBP measurement technique, the pulse wave analysis (PWA) technique for brachial pulse volume plethysmography (PVP) waveforms from an oscillometric blood pressure monitor was implemented. Evaluation demonstrated that large random and systematic errors are introduced into the central pulse pressure (PP) estimates when they are calculated as the difference between the estimated central systolic BP (SBP) and central or cuff diastolic BP (DBP), which can be improved substantially with the novel PWA approach. Subsequently, the novel technique was seamlessly incorporated into a standalone automatic BP monitor. In a rigorous validation study, it was demonstrated that CBP can be measured accurately by this stand-alone automatic blood pressure monitor. To apply the CBP concept in clinical practice, the gap between innovation and clinical application should be closed. The diagnostic threshold for confirming a diagnosis of hypertension with CBP has never been proposed; I therefore derived and validated the diagnostic threshold of CBP based on two independent event-based cohorts with long-term follow-up. With the proposed cut-off limits for the diagnosis of hypertension, the diagnostic accuracy of the stand-alone CBP monitor reference to invasively measured CBP was estimated. It was then suggested that traditional cuff BP may be reliable in confirming the diagnosis of hypertension and in justifying subsequent treatment with its high specificity. However, because of low sensitivity, the cuff BP could render possible management inaccessible to a considerable proportion of hypertensive subjects, who may be identifiable through the noninvasive CBP monitor. Finally, in responding to the gap between clinical application and policy, a health economic evaluation was required to support the cost-effectiveness of the new emerging technique. A comprehensive Markov modelling was performed and this confirmed the cost-effectiveness of CBP monitoring, which resulted from a greater quality gain that outweighed its supplementary cost. Given more data supporting the diagnostic and prognostic role of CBP, it should be considered to be an effective strategy for the management of hypertension.
Thesis (Ph.D.) -- University of Adelaide, School of Translational Health Science, 2013

The diets of marine organisms provide valuable insights into their behaviour, ecology, population vulnerabilities and the role they play in marine foodwebs. Many seabird populations are threatened by interactions with commercial fisheries resulting in incidental mortality or competition for resources, and global environmental changes are affecting the abundance and availability of prey. Understanding their prey requirements and dietary flexibility in this context is valuable for effective conservation and management. Conventional studies using stomach contents analysis can be invasive and suffer considerable drawbacks such as overestimation of prey represented by hard parts and underestimation of soft-bodied prey. DNA metabarcoding of scats provides a non-invasive dietary analysis method that identifies prey DNA and overcomes some of the drawbacks of conventional methods. However, this method has rarely been used on seabirds. It is unknown whether DNA is viable in scats that have been exposed to the harsh weather typical of seabird colonies, if dietary information can be collected during all breeding stages, or whether DNA metabarcoding offers improvements over other dietary assessment methods for evaluating marine ecosystem changes and interactions with fisheries. Albatrosses provide an ideal model to develop and apply DNA metabarcoding to seabirds. They are one of the most threatened seabird groups due primarily to human activities impacting upon breeding populations, and are used as keystone monitoring species for identifying changes in marine ecosystems. In this thesis, I describe the development and assessment of DNA dietary analysis as a non-invasive tool to evaluate and monitor threats to seabird populations posed by changing environmental conditions and interactions with commercial fisheries. To achieve this I have used albatrosses as a model to: 1) Examine the current methods used to assess diets and identify gaps in our knowledge and propose a framework for future diet monitoring studies; 2) Develop optimised scat collection protocols to ensure high quality dietary data is obtained; 3) Determine the importance of gelatinous prey in the diets of a seabird indicator species used for ecosystem monitoring; and 4) Assess the application of DNA metabarcoding to detect fishery discards in the diets of threatened seabirds across broad geographic ranges and determine implications for conservation and management. The first component of this thesis was a systematic review of the literature to identify the methods used to assess albatross diets. I investigated the spatial and temporal application of these methods and species studied to identify knowledge gaps. Most albatross studies have focused on the chick-rearing period, and diet during other breeding phases is comparatively poorly known. There was a pronounced shift over time in the preferred method of characterising diets, from the morphological examination of prey remains to stable isotope analysis of tissue. This shift has reduced the volume of detailed taxonomic information available from morphological studies. Additionally, there are few long-term dietary datasets available. This reduction in recent prey information and paucity of long-term studies impacts our ability to monitor broader changes in marine ecosystems and has implications for management of threatened albatrosses. DNA-based dietary analysis provides a potential method to fill some of these information gaps and provide high taxonomic resolution of prey. Shy albatross (Thalassarche cauta) were used as a case study to investigate how DNA amplification success and the proportion of food DNA detected are influenced by both environmental and physiological parameters. Albatross colonies are often remote and exposed; therefore it is unknown if dietary DNA can easily be obtained from scats in these conditions or during all breeding stages. A broad ranging universal PCR primer set enables identification of all major prey groups; however, this method also amplifies non-food DNA. Both the amount and type of non-target DNA varies with sample freshness, the collection substrate, fasting period and developmental stage of the consumer. I developed optimised scat collection protocols to enable high quality dietary DNA to be collected during all breeding stages. These will also minimise contamination issues from non-target DNA and provide standardised field methods in this rapidly expanding area of research. I was able to apply DNA metabarcoding to assess the diets of black-browed albatross at seven colonies across their species range through collaboration with a global network of researchers. This circumpolar species has suffered population declines due primarily to incidental mortality from commercial fisheries. They are used as an indicator species to identify changes in the overall species composition of an ecosystem by the Commission for the Conservation of Antarctic and Marine Living Resources (CCAMLR) Ecosystem Monitoring Program. As such, they provide an ideal model species to evaluate the use of DNA metabarcoding to monitor marine based threats. Albatross diets were examined at a low level of taxonomic resolution using universal primers to assess the importance of gelatinous prey. Diets are conventionally assessed from stomach content analyses which cannot easily detect soft-bodied prey. Such biases may impact our detection of important ecosystem regime shifts. Fish was the main dietary item at most sites, however scyphozoan jellyfish DNA was present in 37% of samples and up to 80% of samples at some sites. Warmer oceans and overfishing of finfish are predicted to favour jellyfish populations, therefore there is a need to review dietary assessment methods used for ecosystem monitoring. Future seabird monitoring programs should be designed to detect diet changes across the full prey spectrum, including jellyfish, so any potential impact on seabird breeding success and survival can be evaluated. Group-specific primers for bony fish were used to identify the diversity of fish prey consumed by black-browed albatross at five colonies and identify any overlaps with commercial fishery species (either target, bycatch or bait species). Across all sites, 51 fish species from 33 families were identified. There was extensive geographic variation but little inter-annual variability in fish species consumed. The prevalence of commercial fishery species detected in the diets of the albatross during the breeding season highlights that interactions and/or competition with fisheries are still ongoing for this species, particularly at the Falkland and Kerguelen Islands. This study highlights the potential value of DNA metabarcoding as a fishery resource management tool. This body of work has shown that DNA metabarcoding of seabird scats provides a non-invasive dietary method for identifying and monitoring marine based threats, which can be applied during all stages of the breeding season. The ability to detect gelatinous prey and the high taxonomic resolution delivered means it provides a valuable alternate or complementary dietary method for ecosystem monitoring and fishery resource management. The development of DNA dietary analysis techniques described in this thesis will enable researchers and conservation efforts around the world to obtain further information on ecosystem linkages. This will enable ongoing monitoring and evaluation of marine threats to seabird populations.