Littérature scientifique sur le sujet « Electromagnetic therapy »

As a magnetic therapy apparatus with medical benefits, the Unipolar Pulse Electromagnetic Field (UPEMF) apparatus is presented to produce unipolar pulsed magnetic waveforms with an intensity, shape, and frequency that meet medical requirements. The unipolar pulse is the most significant advantage, as the implemented apparatus is considered to be the first improvement in Pulse Electromagnetic Fields (PEMFs). The magnetic field is generated by a specially designed electromagnetic unit. In this unit, an electromagnet is concentrated by a designed concentrator to strengthen the magnetic field at the north pole and weaken the field on the opposite end. An electromagnetic shield is adopted to eliminate the effects of the south pole but allow the output from the north pole. Excited by a designed pulsed waveform generator, the electromagnetic unit generates a strong alternating-current magnetic field. In my work, the detailed design and development of the electromagnetic unit for UPEMF are introduced, therein being modeled and tested using Finite Element Method simulations. The model is characterized mathematically in three parts: the concentrator, the electromagnetic shield, and the overall unit. The testing and performance measurements of the actual Unipolar Pulse Electromagnetic Field apparatus are achieved using a Gauss meter and oscilloscope.

Unaccustomed exercise consisting of eccentric contractions induces muscle damage that is characterised by muscle weakness, soreness, swelling and increased muscle stiffness. These symptoms affect daily activities and athletic performance; therefore, interventions to attenuate the symptoms and enhance recovery from muscle damage are necessary. Pulsed electromagnetic field therapy (PEMFT) is anecdotally reported to increase muscle blood flow and oxygenation to enhance tissue healing. One previous study showed that PEMFT was effective for alleviating muscle soreness and losses in range of motion after exercise. However, studies investigating the effect of PEMFT on recovery of muscle strength following eccentric exercise are lacking. The purposes of this study were to investigate the effects of PEMFT treatment on muscle temperature, blood flow and oxygenation (Study 1), and on the symptoms associated with eccentric exerciseinduced muscle damage (Study 2). In Study 1, the effects of 30 min PEMFT on muscle temperature, blood flow and oxygenation were examined using nine healthy men (23.6 ± 3.7 years). A device called e-cell™was used for PEMFT in this study, which is the size and shape of a computer mouse weighing approximately 140 g, and sham treatment used a visually identical device without pulsed electromagnetic field production. PEMFT was applied over the bicep brachii of one arm for 30 min, and the other arm received sham treatment, while each subject was lying supine on a massage table. The device was marked A or B; thus, both the investigator and subjects were blinded as to which device was active e-cell™ or sham, and the use of dominant or non-dominant arm for device A or B was randomised and counterbalanced among subjects. Pre-treatment muscle temperature was measured by a thermistor needle (22 gauge, 70 mm) inserted to a depth of 20 mm at 10 mm laterally adjacent to a near infrared spectroscopy (NIRS) probe unit that was attached to the skin at the mid-belly of the biceps brachii, and the post-treatment measurement was taken at 5 mm proximal to the first site. The NIRS was used to measure tissue oxygenation index (TOI), a measure of muscle oxygenation, and total haemoglobin content (tHb), an indirect measure of blood flow, which were recorded throughout the treatment period. Changes in muscle temperature from before to immediately posttreatment were compared between e-cell™ and sham conditions using a paired t-test, and changes in TOI and tHb from baseline to 30 min of treatment (0, 10, 20 and 30 min) were compared between conditions by a two-way repeated measures analysis of variance (ANOVA). Muscle temperature significantly (p In Study 2, eight men and eight women (24.8 ± 6.2 years) performed two bouts of 60 maximal isokinetic (30°⋅s-1) eccentric contractions of the elbow flexors on each arm separated by 4 weeks. In each eccentric contraction, the elbow joint was forcibly extended from a flexed (90°) to a fully extended position (0°). At immediately after, and 1-4 days following the exercise, the exercised arm received 30 min of either e-cell™ or sham treatment described above. The arm dominance and the order of treatment conditions were randomised and counterbalanced among the subjects, and the study was conducted in a double-blinded manner. Dependant variables included maximal voluntary contraction (MVC) strength, range of motion (ROM), upper arm circumference (CIR), muscle soreness by a visual analogue scale, muscle tenderness measured by pressure pain threshold (PPT) and plasma CK activity. Changes in these variables for 7 days following the exercise were compared between e-cell™ and sham treatment conditions, men and women, and the first and second bouts of exercise by a two-way repeated measures ANOVA. The changes in the variables from pre- to post-treatment were also analysed by a two-way repeated measures ANOVA. All variables changed significantly (p

In the last decades, electromagnetic therapy generated an intense interest due to its use for the treatment of some pathological states related to musculoskeletal system. In particular, electromagnetic fields (EMFs) provide a therapeutic tool used to improve tissue regeneration in bone non-union fractures, to facilitate skin wound healing and to reduce pain symptomatology. This therapy represents a valid and non-invasive approach widely used to treat the area of interest avoiding side effects and the FDA approved its use to treat bone disorders. This therapy uses the electromagnetic radiations in the frequency range between 3 Hz and 300 Hz. These are non-ionizing and low energy radiations capable to induce heterogeneous effects on a very large number of biological processes such as cell cycle distribution and proliferation, apoptosis and cell migration. All of these effects vary in relation to frequency, amplitude, length of exposure and are also related to the intrinsic susceptibility of different cell lines. This aspect makes molecular investigations complicated because the cellular response is strictly related to the electromagnetic treatment used to irradiate samples. Since the mechanism of action by which this physical stimulus acts on cells is still lacking, our efforts have been addressed to define a coherent biochemical and molecular picture, considering the activities of the key enzymes of the most important metabolic pathways. Decreasing level in PKasic activity was found in cells exposed to ELF EMFs and this effect was associated with the inhibition of the isoform M2 of PK which is expressed in our cellular model. In literature, it has been described that this isoform is inhibited by a redox mechanism which cause the oxidation of the Cys358 residue, promoting a metabolic shift toward an anabolic state. Our biochemical results indicate that ELF EMFs treatments seem to elicit a similar response in NIH3T3 cells. Moreover cell migration and proliferation, the two biological processes involved in wound healing process, has been studied using in vitro scratch assay in order to modeling the dynamic of the wound closure.

Tissue healing is in general a complex process, which involves both local and systemic responses, and bone regeneration in particular is much slower than repair in any other human tissue. Thus, it exhibits a great challenge in clinical practice and in the field of research. Bone regeneration is comprised of a series of biological events, involving a number of cell types and intracellular and extracellular molecular- signaling pathways, with a definable temporal and spatial sequence, in an effort to optimize the skeletal repair and restore its functionality. Photobiomodulation (PBM) therapy has been shown to be effective in modulating both local and systemic responses, by enhancing cellular activities resulting in an increase in function, especially in injured tissues, leading to optimization of tissue repair and regeneration. In bone tissue, application of the photonic energy leads to bone healing by the activation of osteoblasts, leading to proliferation and differentiation, as well as osteoclast inhibition and, consequently, neoformation of bone matrix. The process of the in vitro pre-osteoblasts maturation, mimicking their in vivo behavior, passes through three distinct stages of development: proliferation, early differentiation (maturation) and late differentiation (mineralization). Despite the extensive research on the effects of photobiomodulation (PBM) light on bone regeneration, the current outcomes ranging from positive to negative effect remain controversial. These contradictory data are thought to be due to; incomplete knowledge and understanding of the mechanistic effects of laser light on cells, lack of standardized laser dosimetry, inefficient laser beam profile, improper study design and varied methods of investigation. The literature is hindered by a considerable heterogeneity of the irradiation parameters of PBM, as well as, the methods utilized to evaluate the results and the type of osteoblast-like cells irradiated. This has led to a need of standardization. Moreover, heterogeneity of the current studies and their limitations could be due to study designs and inefficient beam profile, resulting in undesirable effects and accounting for negative and inconclusive outcomes. Ultimately, lack of intimate knowledge and understanding of the PBM light behavior impinging on the target tissue, as well as the optical tissue properties, can compromise optimization of the therapeutic outcomes. Thus, an evidence-based decision for definite therapeutic application of PBM in bone regeneration is required. In this thesis, we addressed the above issues and challenges via two elements, the electromagnetic (EM) modeling experiments and the molecular and cellular impact of PBM on bone regeneration (In vitro studies). The Electromagnetic models In my PhD proposal, I intended to both create an EM model, for the first time, and examine the mechanism of interaction of the electromagnetic fields (EMFs) with cells/tissues and establish the link that can be utilized in my cellular experiments. As the project evolved, it became clear this work was breaking new grounds and was significantly more complex than initially envisaged. As it is a small part of a much larger exciting project undertaken by University of Genoa, it has meant that I need to coordinate my work with the overall timetable of this larger project. As a result, I decided to defer, the interaction of the EMF with cells of interest part, to my Post doctorate study. We developed, for the first time, a set of simple models to examine the behavior of the local electromagnetic field (EMF), determining the PBM effects on mitochondria. This set of models was tested and crosschecked for its validity by evaluating various variables in terms of, polarization, absorption and scattering coefficient, dissipated energy density and irradiance, as well as the refractive index. Ultimately, our model and preliminary data are the first stepping-stone for further experiments, in order to understand the mechanism of interaction between electromagnetic fields and cells or tissues. Our conclusions showed that when these set of models are utilized, for the phenomenon of interest, the incident field polarization had small effects on the electromagnetic field and negligible consequences on the average energy, as well as, on the dissipated power densities. The same was shown to hold true for different orientations that the mitochondria can assume. The analogous conclusions were obtained by taking into account the possible changes in the dimensions or of the real part of the refractive index of the considered organelles. The variations of the absorption coefficient were shown to have significant effects on the average dissipated power density in the mitochondria but these effects can be predicted in a surprisingly simple way. It was proved that the numerical analysis, of the problems of interest, could be computed by using three-dimensional models, involving only a few mitochondria in the plane, which was transverse to the direction of propagation of the illuminating light that generated a uniform distribution of the energy over 1cm2 area. The one- dimensional models provided significant information on the EMF, utilized to stimulate the mitochondria. Mitochondria behaved like weak scatterers. Therefore, it was not necessary to analyze large extension of such organelles to understand what happen inside one of them. The molecular and cellular impact of 980nm PBM on osteoblast maturation: in vitro studies Our pilot study data, on the bone marrow stromal cells (BMSCs), strongly suggested that the high fluence concept (over 60J/cm2 in continuous emission mode (CW)) delivered by flattop beam profile device (FT) can promote BMSCs differentiation towards osteogenesis. Moreover, the results showed an increase in cytokines synthesis with potent anti-inflammatory properties and a decrease in the release of proinflammatory mediators. This provided me with a platform, demonstrating the validity of high fluence in facilitating osteoblasts differentiation through BMSCs. Based on this; I formulated three PBM protocols for 980nm to be tested on pre- osteoblast cell line in my definitive in vitro studies. The first phase of in vitro studies aimed to evaluate the 980nm bio-stimulatory effects on osteoblasts maturation, optimise the PBM effects on bone healing with various beam profiles delivery devices, and establish protocol/protocols of 980nm PBM in bone regeneration. The primary objective was to determine the optimal 980nm dosimetry, which exerts bio- stimulatory effects to accelerate and enhance the bone regenerative process. The secondary objective was to evaluate the intra-cellular pathways of the photon-cell interaction across the metabolic proliferative and differentiation changes, which ultimately lead to bone healing and repair. The results of this study validated the contribution of PBM in bone regeneration and elucidated the biochemical effects at a cellular level. Moreover, the role of different dosages of 980nm PBM irradiation delivered by FT; in comparison to the Gaussian beam profiles (Standard (ST)) on bone regeneration were highlighted. The setup of the power outputs on the laser device was 1.1Watt (W) for the ST and 1W for the FT. However, the real (the threshold) power output reaching the target, measured by power meter, was as ∼0.9 W, (Irradiance ∼ 0.9W/cm2, Exposure time 60 seconds, energy ∼55 J (Joule), fluence ∼55 J/cm2) delivered with the FT beam profile in CW in comparison to the ST, on MC3T3-E1 pre-osteoblast maturation. The protocol was based on 60 seconds exposure time for two consecutive weeks, which employed for all the groups. The laser grouping and their associated irriadtied energies were as follows: Group 1- Irradiation once per week (Total enrgy 110J). Group 2- Irradiation three times per week (Alternate day) (Total energy 330J). Group 3 - irradiation five- times per week (Total energy 550 J). The control cultures were processed in identical conditions except that the laser device was kept off all the time. The total energy was 0J.
The metabolic activity and the osteoblasts maturation were analyzed by alkaline phosphatase assay, alizarin red S histological staining, immunoblot and/or double immunolabeling analysis for Bcl2, Bax, Runx-2, Osx, Dlx5, osteocalcin, and collagen Type 1. Our data, for the first time, prove that laser irradiation of 980 nm wavelength with flattop beam profile delivery system, compared to standard-Gaussian profile, has improved photobiomodulatory efficacy on pre-osteoblastic cells differentiation. Mechanistically, the irradiation enhances the pre-osteoblast differentiation through activation of Wnt signaling as well as the Smads 2/3-βcatenin pathway. Our results indicated and valued the intra-cellular pathways of the photon-cell interaction across the metabolic, proliferative and differentiation changes in the cells. Additionally, our data showed that the cells irradiated THREE times a week (Total energy of 330 J) and ONCE a week (Total energy of 110 J) for two consecutive weeks protocols have increased the proliferation and differentiation of the osteoblasts in both ST & FT hand-pieces but the data showed increasingly statistical significant in the FT group. The only Runx2 was detected when the cells were irradiated with the ST hand-piece. Therefore, total energy of 110 J when either of the hand-pieces utilized, has influenced early differentiation markers. Interestingly, when the process was carried out, until the mineralization and maturation (Late osteogenesis), the ST hand-piece irradiation failed to induce an effective process, and did not lead to matrix deposition, while the FT profile showed a significant effect. In conclusion, our data, for the first time, prove that laser irradiation of 980 nm wavelength with the FT beam profile delivery system in comparison to the ST profile has a great photobiomodulatory efficacy on pre-osteoblastic cells differentiation, which would assist in accelerating bone regeneration, due to its homogeneous energy distribution at each point of its cross-section. Moreover, the irradiation protocols of three times a week and once a week for two consecutive weeks were able to increase the pre-osteoblasts and osteoblasts transcription factors, which were strongly and statistically significantly increased when the FT hand-piece was utilized. Therefore, the 980 nm laser irradiation protocol was able to promote the MC3T3-E1 cell differentiation. Researchers have demonstrated that the major barrier for an effective biological healing is insufficient laser photonic energy delivered to the injured site. PBM can modify the cell metabolism by increasing the mitochondria's ATP production. Currently, the challenge is to understand the target tissues optical properties and its cellular pathway when irradiated with laser phonic energy. In this way, modification of various energy exposure values can influence clinical outcomes predictability. Therefore, in the second phase of my in vitro study, we evaluated the effect of 980nm irradiation delivered with ST and FT beam profile hand-pieces on monolayer cell, at various power outputs; 0.8W, 0.5W and 0.25W. However, the exact power output values reaching the target, measured by power meter, were as follows: 0.75W, 0.45W, and 0.20W respectively. The MC3T3-E1 cells irradiated for two consecutive weeks, according to the following protocols: once a week (Total energy 90, 54, 24 J), respectively); three times a week (total energy 270, 162, 72J, respectively); five times a week (total energy 450, 270, 120 J, respectively). Metabolic activity of viable cells evaluated as follows: Hoechst staining; Western blotting for Runx-2, Bcl2, Bax, Osx, Dlx5, β-catenin, Smads 2/3, TGFβ, p.PI3K, PI3K, p.AKt, AKt, and p.ERK. Our data, for the first time, prove that the 980 nm irradiation at power output setting at 0.75W (0.75W/cm2) for 60 seconds in CW stimulated the MC3T3-E1 pre- osteoblasts viability, by affecting the critical pre-survival markers such as p.PI3K, p.Akt, Bcl2 and Bclxl. Moreover, we concluded that 980nm PBM delivered with FT at 0.75W power output was comparable to results with the ST. However, 0.45W and 0.20W did not modulate the cell metabolic features. Additionally, none of the laser protocols delivered with FT or ST had any influence on the cell differentiation process. In summary, our in vitro studies data, for the first time, have demonstrated the potential of utilizing the FT beam profile with our established protocols in bone regeneration, as a therapeutic tool for future pre-clinical and clinical applications. Moreover, these studies have shown the mechanistic effects of the PBM light on intracellular pathway across the metabolic and differentiation of the osteoblasts towards bone regeneration.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A deficiência de hormônio de crescimento (DGH) é tratada convencionalmente com repetidas injeções do hormônio recombinante. Este trabalho teve como objetivo estabelecer uma alternativa de tratamento baseada na transferência dos genes do hormônio de crescimento humano (hGH) ou de camundongo (mGH), em camundongos anões lit/lit ou lit/scid, mediante administração de DNA plasmidial associada à eletrotransferência, com a finalidade de atingir a máxima recuperação de crescimento em comparação ao camundongo normal (catch-up growth). Inicialmente foi realizada a administração do plasmídeo contendo o gene do mGH no músculo quadríceps exposto ou tibial anterior (TA) não exposto. Utilizando diferentes condições de eletrotransferência, baseadas em pulsos alternados de baixa (100 V/cm) e alta (1000 V/cm) voltagem (HV/LV, HV/8LV) ou em pulsos seguidos de baixa voltagem (8 pulsos de 150 V/cm), o músculo TA na condição HV/LV apresentou os maiores níveis de expressão de mGH: 6,7 ± 2,5 ng/mL. O tempo de exposição e a quantidade da enzima hialuronidase (HI) necessária para a eletrotransferência foram também analisados. O tempo de 30 minutos e a dose de 20 U de HI proporcionaram os melhores resultados de expressão. Diferentes quantidades de DNA foram também testadas, mas a administração de 50 μg DNA/animal foi confirmada como a melhor. Na padronização do volume de solução do plasmídeo administrado no TA, foi observado que a injeção de 20 μL de DNA apresentou expressão significativamente maior da proteína em comparação a de 10 μL. Buscando uma maior expressão de GH, foi realizado experimento adicionando poli-L-glutamato ao diluente do DNA, comparando também diferentes condições de eletrotransferência (HV/LV e 375 V/cm). A condição de 375 V/cm, sem a adição do polímero, proporcionou as maiores concentrações, tanto de hGH como de mGH, no soro de camundongos lit/scid e lit/lit, respectivamente. Quando utilizados 3 pulsos de 375 V/cm e a administração do plasmídeo com o gene do mGH em dois locais de cada músculo TA, foram obtidos os mais altos níveis de expressão atingindo 14,7 ± 3,7 ng mGH/mL. Estes foram os parâmetros utilizados em um bioensaio, no qual foi também determinada a medida do comprimento inicial e final do fêmur por radiografia. Neste bioensaio de 36 dias, a curva de crescimento dos camundongos lit/lit tratados foi similar a de camundongos heterozigotos não tratados e os níveis de mGH do grupo DNA foram significativamente maiores (P<0,0002) em relação ao grupo controle. Os camundongos tratados também apresentarem concentração de mIGF-I no soro superior a do grupo controle. Considerando os parâmetros de crescimento avaliados, o grupo tratado com DNA apresentou percentuais de incremento altamente significativos em relação ao grupo controle, com P<0,001 para o peso corpóreo e P<0,002 para o comprimento do corpo, da cauda e para ambos os fêmures, com valores de catch-up da ordem de 79% para o comprimento dos fêmures. Podemos concluir que foi estabelecida uma metodologia eficiente de transferência gênica não viral, que poderá levar a uma completa normalização de crescimento de camundongos anões mediante utilização de animais mais jovens, como mencionado na literatura e em trabalho recente do nosso grupo.
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
FAPESP: 14/07380-6

by Lee Wai Chi, Edwin.
Thesis (M.Phil.)--Chinese University of Hong Kong, 1993.
Includes bibliographical references (leaves 115-125).
Acknowledgments --- p.I
List of figures --- p.II
List of tables --- p.III
List of graphs --- p.III
Abstract --- p.VIII
Chapter I.CHAPTER ONE --- Introduction --- p.1
Chapter 1.1 --- Electromagnetic / Magnetic field in biological interventions --- p.1
Chapter 1.2 --- Objective of the study --- p.4
Chapter 1.3 --- Hypothesis of the study --- p.5
Chapter II.CHAPTER TWO --- Literature Review --- p.6
Chapter 2.1 --- Inflammation
Chapter 2.1.1 --- Models of studying tendon injuries --- p.6
Chapter 2.1.2 --- Methods of measuring inflammation --- p.7
Chapter 2.1.3 --- Treatments of soft tissue inflammation --- p.9
Chapter 2.2 --- Aspects of electromagnetic and magnetic fields
Chapter 2.2.1 --- Applications of electromagnetic / magnetic fields in soft tissue inflammation --- p.12
Chapter 2.2.2 --- Physiological effects of electromagnetic/magnetic fields
Chapter 2.2.2.1 --- Experiments on inflammation --- p.16
Chapter 2.2.2.2 --- Experiments on soft tissue / tendon injuries --- p.16
Chapter 2.2.2.3 --- Experiments on blood circulation --- p.18
Chapter 2.2.3 --- Experiments with different parameter settings of PEMF / PMF in soft tissue inflammation --- p.19
Chapter 2.2.4 --- Proposed mechanisms of electromagnetic/magnetic fields --- p.22
Chapter III.CHAPTER THREE --- Methods and Materials --- p.23
Chapter 3.1 --- Animal models --- p.23
Chapter 3.2 --- Apparatus --- p.24
Chapter 3.3 --- Treatment Regimen --- p.27
Chapter 3.4 --- Assessments --- p.29
Chapter IV.CHAPTER FOUR --- Histological Assessment --- p.30
Chapter 4.1 --- Introduction --- p.30
Chapter 4.2 --- Methods --- p.31
Chapter 4.3 --- Results --- p.31
Chapter 4.4 --- Discussions --- p.45
Chapter V.CHAPTER FIVE --- Morphometrical analysis on tissue sections with immunochemical staining --- p.51
Chapter 5.1 --- Introduction
Chapter 5.1.1 --- Different approaches in identification of macrophages --- p.51
Chapter 5.1.2 --- Avidin-biotin enzyme complex assay --- p.52
Chapter 5.2 --- Methods --- p.54
Chapter 5.2.1 --- ABC method --- p.54
Chapter 5.2.2 --- Morphometric analysis of tissue sections --- p.55
Chapter 5.2.3 --- Statistical method --- p.56
Chapter 5.3 --- Results
Chapter 5.3.1 --- Immunochemical results --- p.56
Chapter 5.3.2 --- Morphometric results --- p.60
Chapter 5.4 --- Discussions --- p.64
Chapter VI.CHAPTER SIX --- Biochemical Assessments --- p.67
Chapter 6.1 --- Water content
Chapter 6.1.1 --- Introduction --- p.67
Chapter 6.1.2 --- Methods --- p.68
Chapter 6.1.2.1 --- Water content measurement --- p.68
Chapter 6.1.2.2 --- Statistical method --- p.69
Chapter 6.1.3 --- Results --- p.72
Chapter 6.1.4 --- Discussions --- p.77
Chapter 6.2 --- Total collagen content
Chapter 6.2.1 --- Introduction --- p.81
Chapter 6.2.1.1 --- Hydroxyproline as an indicator for collagen content assay --- p.81
Chapter 6.2.2 --- Methods
Chapter 6.2.2.1 --- Hydrolysis method --- p.82
Chapter 6.2.2.2 --- Standard-curve preparation --- p.83
Chapter 6.2.2.3 --- Statstical method --- p.84
Chapter 6.2.3 --- Results --- p.84
Chapter 6.2.4 --- Discussions --- p.89
Chapter VII.CHAPTER SEVEN --- Discussion --- p.92
Chapter VIII.CHAPTER EIGHT --- Summary and Conclusions --- p.103
Appendix A : Histological reagents preparations --- p.106
Appendix B : Staining procedures for standard H & E --- p.107
Appendix C : Immunochemical staining reagents preparations --- p.108
Appendix D : Staining procedure for StreptABComplex / HRP --- p.110
AppendixE : Biochemical reagents and preparations --- p.111
Appendix F : Hydrolysis method for the tendon --- p.112
Appendix G : Standard-curve of hydroxyproline --- p.113
Appendix H : Determination of optimal hours for collagen hydrolysis --- p.114
REFERENCES --- p.115

碩士
國立成功大學
電機工程學系專班
101
The idea of minimally invasive electromagnetic thermal ablation therapy is to create an alternating magnetic field in vitro by high-frequency induction heater, and in the magnetic field, the metal needle surrounding the tumor cells can be heated, so as to kill tumor cells and achieve the effect of thermal therapy. The objective of this study was to analyze the temperature data of the metal needle end and point measured in the experiment in order to derive the temperature prediction equation for different currents and depths of therapy. In addition, a man-machine program was designed to allow the doctor to set the time of therapy, choose from the therapy options, monitor the temperature of the metal needle in therapy and preview the heating effect through a graphical interface. Based on the experimental results, we performed nonlinear regression analysis for the experimental data with statistical software and derived the temperature prediction equation for the thyroid needle. Then, the equation was set in the medical Human-Machine interface to allow the medical staff to predict the temperature rise of metal needle before therapy. During the course of the electromagnetic thermal therapy system, temperature feedback control could be performed automatically according to this equation, so as to ensure that the treatment temperature of the metal needle is controlled between 55℃ and 95℃, helping achieve the purpose of therapy more accurately and safely.

Magnetic nanoparticle (MNP) based thermal therapies are currently approved in Europe and poised for clinical translation in the US. The main benefits include the ability to focally and repeatedly treat tissues, including cancers, with a minimally-invasive platform. Nevertheless, a more complete understanding and control of MNP heating is necessary to effectively translate the approach to treat different sizes and geometries of cancer (See Figure 1). The present work discusses contrasts in heating between superparamagnetic and ferromagnetic nanoparticles (sMNP and fMNP), electromagnetic field-dependant MNP response, scaling of MNP volumetric heating, and the ability of theory to predict this behavior.

Computer-assisted interventions (CAI) — which offer advantages such as increased accuracy, reduction of complications, and decreased intervention time — have increased in prevalence in recent years. A type of CAI called image-guided therapy (IGT) can be used to provide navigation for freehand procedures or guidance for localization of medical devices. Electromagnetic (EM) tracking technology can track instruments such as needle tips inside the patient body without the need for a line-of-sight, allowing for minimally invasive imaging-guided procedures [1–3].