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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Ação da polaridade na estimulação elétrica transcutânea para o tratamento de áreas doadoras de enxertos autógenos em pacientes queimados: estudo clínico randomizado cego / Effect of polarity on transcutaneous electrical stimulation for the treatment of autogenous graft donor sites in burn patients: randomized blinded clinical study

Camila Silva de Carvalho 30 August 2017 (has links)
O cuidado com as áreas doadoras de enxertos de pele merece constante atenção, visto que desencadeia desconforto por dor e restrição de movimentos. Existem evidências de que a estimulação elétrica pode acelerar a cicatrização de feridas e produzir analgesia, e que diferentes parâmetros físicos podem interferir nas respostas apresentadas. O objetivo do estudo foi avaliar o efeito da polaridade da corrente na cicatrização e na dor. Para tanto foram comparados os efeitos da estimulação elétrica de alta voltagem (EAV), polarizada, e a estimulação elétrica nervosa transcutânea (ENT), despolarizada, no tratamento das áreas doadoras de pacientes queimados. Para tanto, foram avaliados 48 voluntários do sexo masculino randomizados em três grupos: submetidos à estimulação elétrica de alta voltagem (GEAV), média idade de 34,2(±9,8) anos, n=17; submetidos à estimulação elétrica nervosa transcutânea (GENT), com 34(±9,5) anos, n= 16; e não submetido à estimulação elétrica ou grupo controle (GC) média de idade 35(±9,5 anos), n= 15. Os procedimentos terapêuticos foram aplicados nas extremidades da área doadora, no primeiro pós-operatório, até a epitelização completa. As variáveis avaliadas foram avaliação clínica, o tempo (dias) de epitelização, estimado pelo desprendimento do curativo primário sobre a lesão, avaliação da dor pela escala numérica de dor, a temperatura cutânea pela termografia infravermelha, qualidade da cicatriz (book de fotos, escala ® Vancouver, software Image J ). Após a análise dos dados, foi aplicado o teste de Shapiro-Wilk, em seguida o comportamento pré e pós-intervenção intragrupo foi aplicado o teste Wilcoxon. Para comparação entre os grupos foi efetuado teste de Kruskal-Wallis seguido de post-hoc de Dunn, em todos os casos foi utilizado o nível de significância de 5% (p<0,05). Os achados apontam que o tempo de desprendimento do curativo Rayon das áreas doadoras foi significativamente menor para GEAV apresentando (p<0,033). Houve redução significativa da dor (p<0,05) para o GEAV e para o GENT, quando comparado ao GC. A quantidade relacionada a solicitação de analgésicos foi reduzida para os grupos estimulados, com diferença significativa do GEAV versus GC (p<0,002) e GENT versus GC (p<0,001). Não houve diferença significativa na temperatura cutânea entre os grupos. Não houve diferença significativa no escore final da escala Vancouver e nem quantidade de crostas entre os grupos. A polaridade da corrente pode ter influenciado no tempo de epitelização, porém não interferiu na dor e na qualidade da área doadora. / The cares with donor areas of skin grafts deserve constant attention, since it triggers discomfort due to pain and movement restriction. There are evidences that electric stimulation may accelerate wound healing and produce pain relief. The objective of this study was to evaluate the effect of electric current polarity on the healing and pain. Therefore, the effects of stimulation on high voltage pulsed current (HVPC) and nervous transcutaneous stimulation (TENS) were compared in the treatment of donor areas of burns victims. Therefore, 48 volunteers of the male sex were randomized between three groups: submitted to high voltage pulsed current stimulation (GHVPC), with 34.2 (± 9.8) years, n=17; submitted to nervous transcutaneous stimulation (GTENS), with 34 (±9.5) years, n=16; and nonsubmitted to stimulation group, or control group (GC), average age of 35 (± 9,5) years, n=15. The therapeutic procedures were applied on the edges of the donor area, at the first postoperative, until complete healing. The evaluated variables were ephitelization time (days), estimated by the unfastening of the primary curative on the wound, evaluation of pain by numerical scale of pain, skin temperature by infrared thermography, scar quality (photo book, Vancouver scale and Image J® software). After data analysis, the Shapiro-Wilk test was applied, and the Wilcoxon test was applied to the before and after intervention. Kruskal-Wallis test followed by Dunn post-hoc was used to compare the groups. In all cases, the significance level of 5% (p<0.05) was used. The findings indicate that the time of release of the Rayon dressing from the donor sites was significantly reduced for GEAV (p <0.033). A reduction of pain relief was significant (p<0.05) for the GEAV and for the GENT, when compared to the GC. Amount the number of solitation for analgesic drugs was decreased for the groups stimulated with significant difference of the GEAV verse GC (p<0.002) and GENT verse GC (p <0.001). Change in cutaneous temperature was not significant between groups. There was no difference significant in score of Vancouver scale and in the number of crusts in the groups. The polarity of the current might have influenced the healing time, however not the pain nor the quality of the donor site.
42

Desenvolvimento de um novo modelo de hiperalgesia muscular induzida por contração isométrica sustentada em ratos / Development of a new model for study of muscle hyperalgesia in rats

Santos, Diogo Francisco da Silva dos, 1988- 25 August 2018 (has links)
Orientador: Maria Claudia Gonçalves de Oliveira Fusaro / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Aplicadas / Made available in DSpace on 2018-08-25T13:04:54Z (GMT). No. of bitstreams: 1 Santos_DiogoFranciscodaSilvados_M.pdf: 1159978 bytes, checksum: d14c7c199ca0e75686645ae3ca6a131c (MD5) Previous issue date: 2014 / Resumo: De todas as dores que acometem o ser humano ao longo da sua existência, a dor muscular, especialmente a induzida por contração isométrica sustentada, é uma das mais prevalentes e possui um importante impacto sócio-econômico. Entretanto, apesar da sua relevância clínica, os mecanismos moleculares envolvidos no desenvolvimento da dor muscular induzida pela contração isométrica sustentada são pouco conhecidos. Isto se deve, principalmente, à ausência de um modelo experimental mais realístico e com bom grau de predição do controle farmacológico desta dor. Portanto, o objetivo deste trabalho foi desenvolver um novo modelo de hiperalgesia muscular induzido por contração isométrica sustentada em ratos. A contração isométrica sustentada foi realizada por estimulações elétricas aplicadas diretamente no ventre do músculo gastrocnêmio de ratos wistar e os parâmetros foram de 19 milissegundos de duração de pulso, frequência em 50 Hertz, intensidade de 1,6 Volts (V) por um período de 1 hora. A hiperalgesia muscular mecânica foi avaliada com o método Randall Selitto nos tempos de meia hora até 48 horas após o término da contração isométrica sustentada. A contração isométrica sustentada, obedecendo o parâmetros supracitados, induziu hiperalgesia muscular mecânica por 1 hora, regredindo com valores próximos ao basal 2 horas após o término da contração. As respostas com 1,6V por 1 hora, foram significativamente maiores do que as induzidas por estimulações de 1,6V por 15 e 30 minutos; 0,5 e 1,0V por 1h ou sham. Demonstramos ainda que a hiperalgesia muscular mecânica induzida pela contração isométrica sustentada foi bloqueada pela dexametasona, evidenciando o caráter inflamatório desse novo modelo, respaldado pela presença de células inflamatórias no tecido muscular, confirmadas pela análise histológica. Juntos, estes dados sugerem que esse novo modelo de hiperalgesia muscular se aproxima de uma condição mais próxima da real encontrada nas dores musculares decorrentes das atividades diárias, além de possuir um grande potencial científico para os estudos dos mecanismos fisiopatológicos envolvidos na dor muscular relacionada à contração isométrica sustentada / Abstract: Among the types of pain that affect people throughout their lives, muscle pain, specially the one induced by sustained isometric contraction, is one of the most prevalent and has an important socio-economic impact. However, despite their clinical relevance, the molecular mechanisms involved in the development of muscle pain induced by sustained isometric contraction are unknown. This is mainly due to the absence of a more realistic experimental model that has a good degree of prediction of pharmacological control of pain. Therefore, the aim of this study was to develop a new model of muscle hyperalgesia induced by sustained isometric contraction in Wistar rats. The sustained isometric contraction was performed by the electrical stimulation directly to the belly of the gastrocnemius muscle of rats and the parameters were 19 millisecond of pulse duration, frequency of 50Hz, and intensity of 1.6 volts (V) for a period of 1 hour. Randall Selitto method was used to measure muscular hyperalgesia 30 minutes until 48 hours after the finish of sustained isometric contraction. This protocol induced mechanical muscle hyperalgesia for one hour and, after two hours, the responses were similar to the baseline. These responses were significantly higher than those induced by stimulation 1.6V for 15 and 30 minutes, 0.5 and 1.0 V for 1h or sham. We also demonstrated that the mechanical muscle hyperalgesia induced by sustained isometric contraction was blocked by dexamethasone, indicating the inflammatory nature of this new model, supported by the presence of inflammatory cells in muscle tissue, confirmed by histological analysis. Together, these data suggest that this new model of muscle hyperalgesia approaching a condition closest to the actual found in muscle pain resulting from daily activities, besides having a great scientific potential for the study of pathophysiological mechanisms involved in muscle pain related to contraction sustained isometric / Mestrado / Metabolismo e Biologia Molecular / Mestre em Ciências da Nutrição e do Esporte e Metabolismo
43

The MouthPad - a Tongue Interface for Hands-Free Computer Control

Draghici, Ovidiu January 2014 (has links)
Tongue-computer interfaces allow people with upper limb disability to control a computer with their tongue. A number of assistive devices, that make use of this technology, have been developed in the last two decades: some employ contact impedance, membrane switches, or miniature joysticks, while others use magnetic or piezoelectric sensors. This thesis proposes a new tongue-computer interface, which was designed to enable users to manipulate a computer pointer by moving the tip of their tongue over an intraoral electrode array. The system maps the contact between the tongue and the electrodes, detects the movements of the tongue, and translates it into pointer movements. Compared to similar devices, the MouthPad does not require any head gear or sensors, and does not employ heavy signal processing. The hardware is simplified by using a small number of electrodes and only one output channel, multiplexed over the electrode array. A low power footprint allows the potential miniaturization of the system, so that it could fit on palatal retainer, and allow for permanent unobtrusive usage. The performance of the device was evaluated by measuring the throughput and the accuracy as defined in ISO 9241-9 standard. Two extra measures proposed in the literature, target re-entry and movement offset, were used for the evaluation of the accuracy. The measured throughput values were situated between 78% and 88% of the throughput rates of regular computer joysticks.
44

A multimodal intervention for progressive multiple sclerosis

Bisht, Babita 01 August 2014 (has links)
Multiple sclerosis (MS) is a complex, progressive disease of the central nervous system with potential multifactorial etiology. Subjects with MS experience varying symptoms such as fatigue, muscle weakness, gait and balance impairments, etc. With time, intensity of the symptoms progresses, especially if subjects are in the progressive phase of the disease. So far, there is no effective treatment available which can reverse or even stop progression of the symptoms and disability associated with MS. Given the multifactorial nature of MS, use of multiple interventions is recommended for its treatment. As use of multiple pharmacological agents is usually limited due to adverse side effects, non-pharmacological treatments such as diet, exercises and stress management may provide a safer and potentially effective treatment option. The main aim of this study was to investigate the effects of a combination of non-pharmacological treatments on subjects with progressive MS. In this open-label, single arm cohort study, we investigated the effects of a multimodal intervention consisting of modified Paleolithic diet, nutritional supplements, stretching exercises, strengthening exercises with electrical stimulation of trunk and lower limb muscles, meditation and massage on multiple symptoms associated with progressive MS. We investigated the effects on fatigue, quality of life, clinical disability, walking performance and balance of the subjects over a period of 12 months. Twenty subjects (15 female) with progressive MS (18 secondary progressive and 2 primary progressive) and mean Expanded Disability Status scale (EDSS) score of 6.2 (range, 3.5 to 8) participated in the 12-month main phase of the study. In a subset of subjects (8 SPMS, 2 PPMS; EDSS 6.2 + 1.4), effects of the intervention on microstructure of whole brain, corpus callosum and corticospinal tracts using diffusion tensor imaging (DTI), and measures of clinical disability including ambulation, hand function and cognitive functions were also investigated. Adherence and dosage of individual components of the intervention were calculated from subjects' daily logs. All clinical assessments were completed at baseline, 3, 6, 9 and 12 months. MRI data were collected at 1 and 12 months post-intervention on a subset of 10 subjects. Safety analyses were completed based on monthly side effects questionnaires and blood analyses at 1, 3, 6, 9 and 12 months. Overall subjects showed good adherence with this intervention and did not report any serious side effects. Subjects reported significant improvement in perceived fatigue, energy and general health within 3 months from baseline and sustained the improvement until 12 months. Fifty percent of the subjects showed significant and consistent increases in both comfortable (during timed up and go test) and fast (during timed 25 foot walk) walking speeds. Small but significant improvements in the measures of balance such as Berg Balance test and time to stand up from seated position were also observed. Interestingly, subjects with comparatively lower physical impairment at baseline showed higher improvements in fatigue, walking and balance tests compared to the subjects with severe physical impairments at baseline. We observed consistent improvements in the cognitive functions of the subjects and in the white matter integrity of left corticospinal tracts. Clinical disability assessed with EDSS, and DTI metrics of most white matter tracts did not change significantly during the study period. These results show that a multimodal intervention can be safely implemented and sustained by subjects with progressive MS. This intervention decreases perception of fatigue and improves quality of life of these subjects. Furthermore, this intervention has beneficial effects on subject's walking ability, balance and cognitive functions and white matter integrity. Initiating this intervention during early stage of the disease when subjects have only mild to moderate disability seems to be more beneficial. Larger, randomized, controlled trials are needed to establish efficacy of this multimodal intervention on MS and elucidate mechanisms underlying its effects on MS.
45

Human entorhinal cortex electrical stimulation evoked short-latency potentials in the broad neocortical regions: Evidence from cortico-cortical evoked potential recordings / ヒト嗅内野電気刺激は短潜時の電位を広範な大脳皮質領域に誘発する:皮質皮質間誘発電位 (CCEP) 記録からのエビデンス

Takeyama, Hirofumi 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22312号 / 医博第4553号 / 新制||医||1040(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 伊佐 正, 教授 林 康紀, 教授 高橋 淳 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
46

Improving meat tenderness with vitamin D3 and electrical stimulation

Molema, Matlho Segopotso 22 September 2008 (has links)
Meat tenderness is regarded as the single most important characteristic of meat quality. Fifty Bonsmara feedlot steers were fed a commercial feedlot ration (10,5 MJ MElKg DM, 12% CP), supplemented with 0,15mg Zilmaxlkg live weight in the feed and with different levels of vitamin D3 (1 to 5 X 106 IU Vit D3 /day) for five days prior to slaughter. The steers were randomly allocated to the vitamin D3 treatments and a control group that received no vitamin D3 supplementation. The steers were fed from ca. 248 ± 3 kg live weight, while Zilmax was fed for the last 35 days to a target weight of ca 400kg. All steers were slaughtered at a commercial abattoir after a Zilmax withdrawal period of 7 days. Samples from m. longissimuss lumborum were collected 24h post-mortem for sheer force testing on an Instron apparatus equipped with a Wamer Bratzler shear blade. Cooking loss was determined by measuring the amount of fluid loss after cooking. Feedlot performance, carcass characteristics and drip loss of meat samples did not differ significantly between the different vitamin D3 treatments. The inclusion of 5 X 106 IU of vitamin. D3 resulted in significantly lower shear force (SF) values compared to the steers in the control group. The results suggest that dietary supplementation of 5 X 106 IU of vitamin. D3 may significantly improve the tenderness of meet from steers fed 0, IS mg Zilmax ®/kg live weight for the last 35 days in the feedlot. The aim of the second study was to explore the effectiveness of the use of electrical stimulation on tenderness of mutton. In this experiment 22 wethers of class AB weighing between 45 and 50kg were used. The carcasses were assigned to two treatment groups, of which group one was electrically stimulated (ES) and the other group was not electrically stimulated (NES). The results revealed that electrical stimulation did not significantly affect of the fatty acid content of meat and crude fat content. Treatment however, significantly (P< 0,038) influenced the moisture content of the samples. There was a variation in SF values between the two treatment groups; SF of samples from the ES group were lower compared to that of the NES group. This suggests that ES can be successfully applied to reduce the variation in tenderness within the class- AB mutton. / Dissertation (MSc(Agric) : Meat Science)--University of Pretoria, 2007. / Animal and Wildlife Sciences / unrestricted
47

A NOVEL APPROACH TO PERIPHERAL NERVE ACTIVATION USING LOW FREQUENCY ALTERNATING CURRENTS

Awadh Mubarak M Al Hawwash (9179432) 05 August 2020 (has links)
The standard electrical stimulation waveform used for electrical activation of nerve is a rectangular pulse or a charge balanced rectangular pulse, where the pulse width is typically in the range of ∼100 µsec through ∼1000 µsec. In this work, we explore the effects of a continuous sinusoidal waveform with a frequency ranging from 5 through 20 Hz, which was named the Low Frequency Alternating Current (LFAC) waveform. The LFAC waveform was explored in the Bioelectronics Laboratory as a novel means to evoke nerve block. However, in an attempt to evoke complete nerve block on a somatic motor nerve, increasing the amplitude of the LFAC waveform unexpectedly produced nerve activation, and elicited a strong non-fatiguing muscle contraction in the anesthetized rabbit model (unpublished observation). The present thesis aimed to further explore the phenomenon to measure the effect of LFAC waveform frequency and amplitude on nerve activation.<div><br></div><div>In freshly excised canine cervical vagus nerve (n=3), it was found that the LFAC waveform at 5, 10, and 20 Hz produced burst modulated activity. Compound action potentials (CAP) synchronous to the stimuli was absent from the electroneurogram (ENG) recordings. When applied <i>in-vivo</i>, LFAC was capable of activating the cervical vagus nerve fibers in anaesthetized swine (n=5) and induced the Hering-Breuer reflex. Additionally, when applied <i>in-vivo</i> to anesthetized Sprague Dawley rats (n=4), the LFAC waveform was able to activate the left sciatic nerve fibers and induced muscle contractions.</div><div><br></div><div>The results demonstrate that LFAC activation was stochastic, and asynchronous to the stimuli unlike conventional pulse stimulation where nerve and muscle response simultaneously and synchronously to stimulus. The activation thresholds were found to be frequency dependent. As the waveform frequency increases the required current amplitude decreases. These experiments also implied that the LFAC phenomenon was most likely to be fiber type-size dependent but that more sophisticated exploration should be addressed before reaching clinical applications. In all settings, the LFAC amplitude was within the water window preventing irreversible electrochemical reactions and damages to the cuff electrodes or nerve tissues. This thesis also reconfirms the preliminary LFAC activation discovery and explores multiple methods to evaluate the experimental observations, which suggest the feasibility of the LFAC waveform at 5, 10, and 20 Hz to activate autonomic and somatic nerve fibers. LFAC appears to be a promising new technique to activate peripheral nerve fibers.</div>
48

A Novel Approach to Peripheral Nerve Activation Using Low Frequency Alternating Currents

Al Hawwash, Awadh Mubarak M 08 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The standard electrical stimulation waveform used for electrical activation of nerve is a rectangular pulse or a charge balanced rectangular pulse, where the pulse width is typically in the range of ∼100 µsec through ∼1000 µsec. In this work, we explore the effects of a continuous sinusoidal waveform with a frequency ranging from 5 through 20 Hz, which was named the Low Frequency Alternating Current (LFAC) waveform. The LFAC waveform was explored in the Bioelectronics Laboratory as a novel means to evoke nerve block. However, in an attempt to evoke complete nerve block on a somatic motor nerve, increasing the amplitude of the LFAC waveform unexpectedly produced nerve activation, and elicited a strong non-fatiguing muscle contraction in the anesthetized rabbit model (unpublished observation). The present thesis aimed to further explore the phenomenon to measure the effect of LFAC waveform frequency and amplitude on nerve activation. In freshly excised canine cervical vagus nerve (n=3), it was found that the LFAC waveform at 5, 10, and 20 Hz produced burst modulated activity. Compound action potentials (CAP) synchronous to the stimuli was absent from the electroneurogram (ENG) recordings. When applied in-vivo, LFAC was capable of activating the cervical vagus nerve fibers in anaesthetized swine (n=5) and induced the Hering-Breuer reflex. Additionally, when applied in-vivo to anesthetized Sprague Dawley rats (n=4), the LFAC waveform was able to activate the left sciatic nerve fibers and induced muscle contractions. The results demonstrate that LFAC activation was stochastic, and asynchronous to the stimuli unlike conventional pulse stimulation where nerve and muscle response simultaneously and synchronously to stimulus. The activation thresholds were found to be frequency dependent. As the waveform frequency increases the required current amplitude decreases. These experiments also implied that the LFAC phenomenon was most likely to be fiber type-size dependent but that more sophisticated exploration should be addressed before reaching clinical applications. In all settings, the LFAC amplitude was within the water window preventing irreversible electrochemical reactions and damages to the cuff electrodes or nerve tissues. This thesis also reconfirms the preliminary LFAC activation discovery and explores multiple methods to evaluate the experimental observations, which suggest the feasibility of the LFAC waveform at 5, 10, and 20 Hz to activate autonomic and somatic nerve fibers. LFAC appears to be a promising new technique to activate peripheral nerve fibers.
49

mTOR Pathway Activation Following Sciatic Stimulation in Wild-Type and Desmin Knockout Mice

Nelson, Daniel S. 13 December 2012 (has links) (PDF)
The 52 kDa intermediate filament protein desmin plays an important role in force transmission in skeletal muscle by connecting myofibrils at Z-lines and to the sarcolemma. Desmin content in muscle adapts to contractile activity and may be involved in cellular signaling mechanisms responsible for muscle growth. Purpose: To compare signaling responses of the mTOR pathway in wild type (WT) vs desmin knock out (KO) mice. Methods: WT (n=12) and KO (n=12) mice were exposed to high frequency electric stimulation of the left hindlimb to elicit an acute response of the mTOR pathway. Non-stimulated right hindlimbs were used as a within animal control. Right and left TA and EDL muscles were dissected 30 min post-stimulation and examined for changes in mTOR, 4E-BP1 and p70S6K. Results: Relative to WT control samples, total mTOR and total 4E-BP1 content was higher in KO control samples. Electrical stimulation resulted in an increase p70S6K phosphorylation in WT and KO animals however there was no difference between the groups. 4E-BP1 phosphorylation was increased in WT but not KO following electrical stimulation. There was no change in mTOR phosphorylation in response to stimulation in WT or KO. Conclusion: The absence of desmin in skeletal muscle does not impair the phosphorylation of p70S6K demonstrating that a tensile load on the muscle will likely result in an increase in protein synthesis. Elevated levels of total mTOR and 4E-BP1 may imply an adaptation to increase sensitivity to growth stimuli in the muscle.
50

Control of Axonal Conduction by High Frequency Stimulation

Jensen, Alicia Lynn 02 June 2008 (has links)
No description available.

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