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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

Are Respiratory Behaviors Affected in Individuals With Adductor Spasmodic Dysphonia?

Biedess, Katie 01 June 2006 (has links)
Adductor spasmodic dysphonia (ADSD) is a focal dystonia that is characterized by voice breaks due to involuntary contractions of the adductor muscles of the vocal folds. These spasms can interfere with the coordination and balance of the respiratory and phonatory systems interfering with normal voice production. Disruptions in normal respiratory behaviors are well documented in inviduals with laryngeal disorders, including ADSD. Previous research regarding respiratory processes in ADSD has focused on airflow and pressure; however, there are many other parameters that have not been considered and may shed new light on the respiratory behaviors of individuals with ADSD. Therefore, the current pilot study attempted to determine if individuals with ADSD differed from controls in various breathing parameters while engaged in conversational and reading tasks.Thirty individuals were tested; fifteen in the ADSD group and fifteen in the age- and gender-matched control group. Respitrace, an inductive plethysmography device, calculated 14 different respiratory measures related to volume, timing, thoracic displacement and respiratory efficiency. The results of the study indicated that various significant differences existed between groups. Those with ADSD were found to have statistically higher ventilation rates, a greater frequency of breaths per minute, a higher degree of muscular inefficiency/breathlessness and labored breathing. These results indicated that individuals with ADSD suffered from disordered breathing due to the neurologically related obstruction at the level of the larynx. Differences according to task were also found. Specifically, the rib cage contributed to a lesser extent in voice production and the participants utilized longer inspiratory times, exhaled a larger volume of air and took longer to reach peak expiratory flow during conversational tasks when compared to reading tasks. These differences were attributed to a higher cognitive-linguistic demand required during conversational speech. Overall, the results of this study have many clinical implications. Most importantly, these findings support the idea that individuals with ADSD may experience difficulties with respiration as the effects of their Botox injection begin to wear off. Further research is needed with regards to the effects laryngeal spasms have on other respiratory behaviors.
42

The plasma adenosine triphosphate response to dynamic handgrip exercise

Wood, Rachel Elise January 2008 (has links)
Despite over a century of inquiry, the mechanisms that achieve the close matching of oxygen supply to demand during exercise remain elusive. It has been proposed that in addition to its role as the primary oxygen carrier, the red blood cell (RBC) functions as a roving oxygen sensor, linking the oxygen demand at the muscle with oxygen delivery via the circulation (Ellsworth et al. 1995). It is hypothesised that the RBC would release adenosine triphosphate (ATP) in proportion to the number of unoccupied binding sites on the haemoglobin molecule as it traverses regions of high oxygen demand such as the microcirculation of active skeletal muscle. ATP would then stimulate the release of vasodilatory substances from the endothelium which would diffuse to neighbouring vascular smooth muscle resulting in vasodilation and an increase in blood flow in accordance with the oxygen demand set by the muscle. The first step in establishing a role for this mechanism during exercise in humans is to determine whether ATP increases in the venous blood draining an active muscle bed. Based on the handful of published studies, there is an increase in ATP concentration in the femoral vein during knee extensor exercise. However the response has not been studied in other vascular beds in humans. As such, the main aim of this thesis was to measure the ATP response to dynamic handgrip exercise. Secondary aims were to determine whether the response was modified by hypoxia, and to provide information about the timing of the changes in ATP concentration during a bout of handgrip exercise. These questions were addressed in Studies 3 and 4. Because blood flow is central to this hypothesis, a substantial portion of this thesis was also associated with the measurement of forearm blood flow (FBF) using venous occlusion strain gauge plethysmography (VOSGP), and this was conducted in Studies 1 and 2. VOSGP is based on the assumption that with venous outflow prevented, any increase in limb volume is proportional to the rate of arterial inflow. The rate of arterial inflow is determined as the slope of the change in limb volume over time. The slope must be calculated over the initial linear portion of this relationship, when arterial inflow is unaffected by the inevitable rise in venous pressure associated with venous occlusion. VOSGP was initially used to measure blood flow at rest and in response to pharmacological interventions which produced only modest increases in arterial inflow (Joyner et al. 2001). However, measurement of the high rates of arterial inflow that occur with exercise may challenge the limits of this technique. Tschakovsky et al. (1995) reported a marked reduction in arterial inflow over the first four cardiac cycles during venous occlusion following static handgrip exercise that elevated blood flow to 22-24 mL/min/100mL. Only during the first cardiac cycle was arterial inflow unaffected by cuff inflation. As such, the window for measuring high rates of arterial inflow may be very brief. Therefore Study 1 aimed to determine whether blood flow could be measured using VOSGP across the range of arterial inflows that occur with dynamic handgrip exercise. Participants (n = 7) completed four, five-minute bouts of dynamic handgrip exercise at 15, 30, 45, and 60% of maximum voluntary contraction (MVC). FBF was measured using VOSGP at rest, and following five minutes of dynamic handgrip exercise. The slope of the change in limb volume was measured over the first one, two, three, and four consecutive cardiac cycles following the onset of occlusion. FBF was 2.5 ± 0.5 at rest, and 16.5 ± 4.9, 24.9 ± 9.4, 44.1 ± 22.0, and 57.8 ± 14.9 mL/min/100mL following five minutes of exercise at 15, 30, 45, and 60% MVC, respectively. At rest, arterial inflow decreased across the four cardiac cycles (P = 0.017 for the main effect), however post-hoc pairwise comparisons revealed no significant differences between any of the cardiac cycles. In contrast, the inclusion of two, three, or four cardiac cycles at 30 and 60% MVC, and three or four cardiac cycles at 15 and 45% MVC resulted in reductions in calculated arterial inflow compared with using the first cardiac cycle alone (P > 0.05). The inclusion of just two cardiac cycles resulted in a 9-26% reduction in calculated arterial inflow depending on the workload. This reduction was even more pronounced when three (19-40%) or four (26-50%) cardiac cycles were included. In conclusion, resting FBF can be calculated over at least four cardiac cycles during venous occlusion at rest. However, exercising FBF should be calculated from the first cardiac cycle only following dynamic handgrip exercise across the range of intensities used in this study. This extends the findings of Tschakovsky et al. (1995) who demonstrated this effect following handgrip exercise at a single intensity. Study 2 was designed to establish the FBF response to dynamic handgrip exercise, whether the workloads produced different blood flow responses, and to establish the within- and between-day reproducibility of FBF measured using VOSGP. In Part A (within-day reproducibility), participants (n = 7) completed three trials of dynamic handgrip exercise at four intensities (15, 30, 45, and 60% MVC), with each exercise trial separated by 10 minutes of rest. In Part B (between-day reproducibility) participants (n = 7) completed three trials of dynamic handgrip exercise at 15, 30, and 45% MVC on three separate days within a two week period. FBF was measured at rest, and each minute of exercise during brief (5-7 second) pauses in contractions. FBF response. FBF increased from rest at all workloads (P > 0.05), and then plateaued between Minutes 1 to 5 at the 15 and 30% MVC workloads and between Minutes 2 and 5 at the 45% workload (P > 0.05 for each minute compared to Minute 5). Too few participants completed the 60% workload to permit any statistical analysis. FBF reached values of 13.0 ± 2.0, 26.8 ± 8.4, 44.8 ± 14.9, and 52.9 ± 5.1 mL/min/100mL in the final minute of exercise at the 15, 30, 45, and 60% MVC workloads. FBF was different between the 15, 30, and 45% workloads by Minute 3 (P > 0.05). Reproducibility. The within-day test-retest reliability of exercising FBF was poor to moderate (ICC = 0.375-0.624) with individual coefficients of variation (CVs) ranging from 6-25%, 9-23%, and 9-31% for the 15, 30, and 45% MVC workloads, respectively. The between-day test-retest reliability for resting FBF was moderate (ICC = 0.644, P > 0.05; individual CVs between 1 and 31%). Between-day test-retest reliability for exercising FBF was poor to moderate (ICC = 0.381-0.614), with individual CVs ranging from 14-24%, 8-23%, and 6-18% for the 15, 30, and 45% workloads, respectively. It was concluded from this study that VOSGP provides adequately reproducible measurements to detect changes in FBF of the magnitude seen between workloads in this study. However, the variability in the measurement precludes its use when smaller differences are of interest. Based on the previous findings reporting an increase in ATP concentration during dynamic knee extensor exercise in the leg (Gonzalez-Alonso et al. 2002; Yegutkin et al. 2007), Study 3 was designed to determine whether ATP concentration increased in the venous effluent during dynamic handgrip exercise in the forearm. Since the deoxygenation of haemoglobin is a primary stimulus for ATP release from red blood cells, a further aim was to determine whether this response was augmented by systemic hypoxia. Participants (n = 6) completed four, five-minute bouts of dynamic handgrip exercise at 30, 45, 65, and 85% MVC under normoxia (inspired oxygen fraction = 0.21) and hypoxia (inspired oxygen fraction = 0.12). Blood samples for the determination of ATP concentration were drawn at rest and 180 seconds after the onset of exercise at each workload from a catheter inserted into a forearm vein. Venous plasma ATP concentration at rest was 0.28 ± 0.11 μM/L and remained unchanged during exercise at workloads up to 85% MVC (P > 0.05). Systemic hypoxia, sufficient to reduce arterial oxygen saturation to 83 ± 2%, also failed to alter the plasma ATP concentration (P = 0.148). The lack of a change in ATP concentration was unexpected but there are several possible explanations. It is possible, although unlikely, that ATP was not released in the forearm microcirculation. The previous demonstration that ATP increased in response to static handgrip exercise (Forrester and Lind 1969) would suggest that this was probably not the case. When considered in the context of the findings from Study 4, the most plausible explanation is that a less than optimal blood sampling site may have hindered the measurement of a change in ATP. The blood flow response at the onset of dynamic exercise in the forearm is at least biphasic; Phase 1 describes the immediate, large increase in blood flow within 2 seconds of the onset of exercise and is believed to be governed by mechanical factors whereas Phase 2 has a latency of ~20 seconds and describes a further, slower increase until blood flow reaches steady state (Saunders et al. 2005b). The temporal characteristics of Phase 2, along with the fact that blood flow during this phase is closely related to the metabolic rate of the muscle, suggest regulation by metabolic factors. Currently there is scant evidence detailing the time course of vasodilator release, although it is important to demonstrate that the release of a vasodilatory substance precedes the blood flow response it is proposed to influence (Delp 1999). ATP is released from red blood cells in proportion to the offloading of oxygen and a reduction in the oxygen content of venous blood draining a muscle bed occurs within 10 seconds of the onset of exercise. Thus the release of ATP should follow soon thereafter. As such, Study 4 was designed to determine whether ATP increased in the venous effluent of the forearm following 30 and 180 seconds of dynamic handgrip exercise at 45% MVC; and whether this increase corresponded with a decrease in venous oxygen content. Participants (n = 10) completed two bouts of dynamic handgrip exercise at 45% MVC; the first was one minute in duration, and the second was four minutes in duration. Venous blood samples for the determination of ATP and venous oxygen content were drawn at rest and during exercise from a catheter inserted in a retrograde manner into the median cubital vein. Arterialised samples for the estimation of arterial blood gases and ATP concentration were obtained from the non-exercising hand. ATP concentration in arterialised blood from the non-exercising arm was 0.79 ± 0.30 μM/L at rest and remained unchanged at both time points during exercise (P > 0.05). ATP concentration in the venous blood of the exercising arm increased from 0.60 ± 0.17 μM/L at rest to 1.04 ± 0.33 μM/L 30 seconds after the onset of exercise (P > 0.05), and remained at this higher level after 180 seconds (0.92 ± 0.26 μM/L, P > 0.05 versus rest). This corresponded with a decrease in venous oxygen content from 103 ± 23 mL/L at rest to 68 ± 16 mL/L 30 seconds after the onset of exercise (P > 0.05) and 76 ± 15 mL/L (P > 0.05 versus rest) 180 seconds into exercise. Furthermore, at 180 seconds of exercise, ATP concentration was moderately and inversely related to venous oxygen content (r = -0.651, p > 0.05). In conclusion, this study provides the first evidence that ATP concentration is increased in the blood draining the exercising forearm muscles in response to dynamic handgrip exercise. The finding that ATP concentration was increased just 30 seconds after the onset of exercise is also novel, and particularly interesting in the context of the recently reported dynamic response characteristics of the forearm blood flow response. In conclusion, the work contained within this thesis provides several important findings. The first study has provided evidence that measuring high rates of arterial inflow using VOSGP is possible, but that the window for making these measurements is small, probably as brief as a single cardiac cycle. The second study demonstrated that while the reproducibility of forearm blood flow measurements using VOSGP is poor, it is adequate to detect the large changes that occurred between workloads. However, VOSGP cannot be used to detect more modest differences. Common to both Study 3 and 4 was the measurement of ATP at rest, and 180 seconds after the onset of dynamic handgrip exercise at 45% MVC. The primary difference was the position of the catheter which was inserted in an antegrade manner in Study 3, and in a retrograde manner in Study 4. Since ATP was unchanged in Study 3 but increased under similar conditions in Study 4, it is likely that ATP was also released during exercise in Study 3, but that a less than optimal blood sampling site precluded its measurement. This illustrates the necessity to sample blood from as close as possible to the probable site of ATP release, the muscle microcirculation. The most important and novel findings from this body of work come from Study 4. This is the first study to demonstrate an increase in ATP concentration in the forearm in response to dynamic handgrip exercise. However, the most novel finding was that ATP concentration was elevated just 30 seconds after the onset of exercise. Such an early increase has not previously been reported during dynamic exercise in any vascular bed. This is an important finding since establishing the time course for the release of vasodilatory substances is critical to our understanding of the mechanisms that regulate blood flow during exercise.
43

Characterization of the activity of the involuntary calf muscle pump

Goddard-Marshall, Ayana A. January 2009 (has links)
Thesis (Ph. D.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Bioengineering, Biomedical Engineering, 2009. / Includes bibliographical references.
44

Avaliação da resposta broncodilatadora imediata ao formoterol em doença pulmonar obstrutiva crônica (dpoc) com pouca reversibilidade

Souza, Fábio José Fabrício de Barros January 2008 (has links)
O formoterol é um fármaco beta-agonista de ação prolongada com rápido início de ação e eficácia broncodilatadora que podem determinar melhora significativa e imediata da função pulmonar. Pacientes com DPOC apresentam pouca ou nenhuma resposta ao broncodilatador (BD) no volume expiratório forçado no primeiro segundo (VEF1), podendo apresentar reversibilidade em outras variáveis se avaliados por pletismografia. O objetivo do estudo é avaliar por pletismografia a eficácia broncodilatadora do formoterol após 30 minutos de sua aplicação em portadores de DPOC. Foram estudados 40 pacientes portadores de DPOC com pobre resposta ao BD de curta ação. Encontravam-se no estágio II ou III da DPOC (SBPT/GOLD) e apresentavam VEF1 menor que 70% do valor previsto. Foram randomizados em dois grupos de 20 pacientes, com características clínicas semelhantes, recebendo cada um formoterol ou placebo, através de inalador de pó seco (aerolizer) com repetição das provas funcionais após 30 minutos. Foram observados aumentos significativos do VEF1 (12,4%) grupo formoterol (F) em relação ao grupo placebo (P) que foi de 0,1% (p=0,00065), da capacidade inspiratória (7,4% X 2,7%;p=0,05) e capacidade vital forçada (12,8% X 5,1%; p=0,017), redução importante da resistência das vias aéreas (-14% X 2,6% ; p=0,010). Foram ainda detectadas no grupo F modificações não expressivas do volume residual, da condutância das vias aéreas e da capacidade vital. Concluindo, em portadores de DPOC com pobre reversibilidade ao BD no teste espirométrico simples, o formoterol levou a uma melhora significativa da função pulmonar por pletismografia após 30 minutos de sua administração. / Formoterol is a long-acting ß2 agonist drug with rapid onset of action and the bronchodilator efficacy determine a prompt improvement in lung function. Patients with COPD may show minimal improvement after bronchodilator (BD) on volume in first second (FEV1), but they can show reversibility in other parameters if plethysmography was realized. The objective of this study was to evaluate, by plethysmography, the effectiveness of formoterol as a bronchodilator after 30 minutes of administration to patients with COPD. Forty COPD patients with poorly reversible obstruction confirmed by shortacting bronchodilator use at the spirometric test were prospectively evaluated. All patients were classified as having stage II or III SBPT/GOLD, presenting FEV1 lower than 70% of predict. The patients were randomized in two groups of 20, both with similar clinical characteristics, each group receiving either formoterol or placebo by dry powder device (aerolizer) and the lung function tests were repeated in 30 minutes after the drug administration. Significant increases in FEV1 (12,4%) in formoterol group (F) and 0,1% in placebo group (P) (P=0,00065), in inspiratory capacity (7,4% X 2,7% ; p=0,05) and in forced vital capacity (12,8% X 5,1%; p=0,017) and decrease in airway resistence (p=0,010) were observed in the F= -14% when compared with P= 2,6%. Residual volume decreased while specific airways condutance and vital capacity increased less important. In conclusion COPD patients with poor reversibility, formoterol promoted significant improvement in lung function by plethysmography after 30 minutes of its administration.
45

Estudo das alterações microcirculatórias na população idosa comparadas com adultos jovens / Study of microcirculatory changes in the elderly compared with young adults

Flávia Gomes Lopes 29 April 2011 (has links)
O envelhecimento populacional é um fenômeno mundial, assim como o predomínio de mortes por doenças cardiovasculares. Estudos demonstram que o envelhecimento acarreta aumento da rigidez vascular e perturbações na reatividade macrovascular. O presente estudo comparou a microcirculação deste processo com adultos jovens através da pletismografia de oclusão venosa (POV) e da videocapilaroscopia do leito periungueal (VC). Para isto, desenvolveu-se um estudo transversal com dois grupos: idade entre 18 e 30 anos (n=16) e outro grupo com idade igual ou superior a 60 anos (n=21), além da subdivisão deste grupo em três subgrupos: idosas saudáveis (n=8), idosas em tratamento de hipertensão arterial (IDHAS,n=6) e idosas em tratamento de dislipidemia (IDDIS,n=6). Foram realizadas avaliações clínica, antropométrica, bioquímica e microcirculatória. Como resultados, a VC mostrou aumento dos diâmetros capilares aferente, apical e eferente e redução da relação velocidade máxima/ velocidade basal de deslocamento de hemácias para grupo de idosas e todos os subgrupos. A POV revelou diminuição da vasodilatação endotélio-dependente em todos os grupos estudados e a vasodilatação endotélio-independente alterou-se apenas em IDHAS e IDDIS. Como conclusões houve, no envelhecimento, alterações estruturais e funcionais da microcirculação assim como redução da vasodilatação endotélio-dependente. A vasodilatação endotélio-independente manteve-se inalterada, indicando que a célula muscular lisa da parede vascular permanece preservada, porém sofre alterações nos grupos IDHAS e IDDIS. / Population aging is a worldwide phenomenon, as well as the prevalence of deaths from cardiovascular diseases. Studies show that aging brings increased vascular stiffness and altered vascular reactivity. The present study compared the microcirculation of elderly people to young adults by venous occlusion plethysmography (POV) and nailfold videocapillaroscopy (NVC). For this, we developed a cross-sectional study with two groups: those aged between 18 and 30 years (n = 16) and another group aged over 60 years (n = 21), and the subdivision of this group into three subgroups: healthy elderly (n = 8), elderly women being treated for hypertension (IDHAS, n = 6) and older in the treatment of dyslipidemia (IDDIS, n = 6). Clinical, anthropometric, biochemical and microcirculatory parameters were evaluated. As results, NVC showed an increase of afferent, apical and efferent capillary diameters and a lower ratio maximum red blood cell velocity/ baseline red blood cell velocity for the older group and all subgroups. POV showed decreased endothelium-dependent vasodilation in all groups and the endothelium-independent vasodilation was altered only in IDHAS and IDDIS. In conclusion, in the aging, there were structural and functional changes of microcirculation as well as reduced endothelium-dependent vasodilation. The endothelium-independent vasodilation remained unchanged, indicating that smooth muscle cells of the vascular wall remains preserved, but show changes in the groups IDHAS and IDDIS.
46

Avaliação da resposta broncodilatadora imediata ao formoterol em doença pulmonar obstrutiva crônica (dpoc) com pouca reversibilidade

Souza, Fábio José Fabrício de Barros January 2008 (has links)
O formoterol é um fármaco beta-agonista de ação prolongada com rápido início de ação e eficácia broncodilatadora que podem determinar melhora significativa e imediata da função pulmonar. Pacientes com DPOC apresentam pouca ou nenhuma resposta ao broncodilatador (BD) no volume expiratório forçado no primeiro segundo (VEF1), podendo apresentar reversibilidade em outras variáveis se avaliados por pletismografia. O objetivo do estudo é avaliar por pletismografia a eficácia broncodilatadora do formoterol após 30 minutos de sua aplicação em portadores de DPOC. Foram estudados 40 pacientes portadores de DPOC com pobre resposta ao BD de curta ação. Encontravam-se no estágio II ou III da DPOC (SBPT/GOLD) e apresentavam VEF1 menor que 70% do valor previsto. Foram randomizados em dois grupos de 20 pacientes, com características clínicas semelhantes, recebendo cada um formoterol ou placebo, através de inalador de pó seco (aerolizer) com repetição das provas funcionais após 30 minutos. Foram observados aumentos significativos do VEF1 (12,4%) grupo formoterol (F) em relação ao grupo placebo (P) que foi de 0,1% (p=0,00065), da capacidade inspiratória (7,4% X 2,7%;p=0,05) e capacidade vital forçada (12,8% X 5,1%; p=0,017), redução importante da resistência das vias aéreas (-14% X 2,6% ; p=0,010). Foram ainda detectadas no grupo F modificações não expressivas do volume residual, da condutância das vias aéreas e da capacidade vital. Concluindo, em portadores de DPOC com pobre reversibilidade ao BD no teste espirométrico simples, o formoterol levou a uma melhora significativa da função pulmonar por pletismografia após 30 minutos de sua administração. / Formoterol is a long-acting ß2 agonist drug with rapid onset of action and the bronchodilator efficacy determine a prompt improvement in lung function. Patients with COPD may show minimal improvement after bronchodilator (BD) on volume in first second (FEV1), but they can show reversibility in other parameters if plethysmography was realized. The objective of this study was to evaluate, by plethysmography, the effectiveness of formoterol as a bronchodilator after 30 minutes of administration to patients with COPD. Forty COPD patients with poorly reversible obstruction confirmed by shortacting bronchodilator use at the spirometric test were prospectively evaluated. All patients were classified as having stage II or III SBPT/GOLD, presenting FEV1 lower than 70% of predict. The patients were randomized in two groups of 20, both with similar clinical characteristics, each group receiving either formoterol or placebo by dry powder device (aerolizer) and the lung function tests were repeated in 30 minutes after the drug administration. Significant increases in FEV1 (12,4%) in formoterol group (F) and 0,1% in placebo group (P) (P=0,00065), in inspiratory capacity (7,4% X 2,7% ; p=0,05) and in forced vital capacity (12,8% X 5,1%; p=0,017) and decrease in airway resistence (p=0,010) were observed in the F= -14% when compared with P= 2,6%. Residual volume decreased while specific airways condutance and vital capacity increased less important. In conclusion COPD patients with poor reversibility, formoterol promoted significant improvement in lung function by plethysmography after 30 minutes of its administration.
47

Cardiovascular Response to Vertebral Osteopathic Manipulative Treatment (OMT), On Asymptomatic Human Subjects

January 2014 (has links)
abstract: Objective: Examine cardiovascular response to OMT via central and peripheral measurements. Methods: Central and peripheral cardiovascular signals of asymptomatic human subjects were monitored during a procedure with alternating rest and active phases. Active phases included systemic perturbations and application of controlled vertebral pressure (OMT) by an experienced osteopathic physician. Pulse plethysmograph and laser Doppler flow sensors measured peripheral flow from index and middle fingers bilaterally. A three-lead EKG monitored cardiac activity. The biosignals were recorded continuously, in real time, and analyzed in time and frequency domains. Results from the control group (n=11), without OMT, and active group (n=16), with OMT, were compared. Peripheral (n=5) and central responders (n=6), subsets of the active group showing stronger peripheral or central response, were examined. In an additional effort, a modified clinical device recorded spectral Doppler ultrasound signals of the radial and dorsalis pedis arteries of clinically asymptomatic human subjects. Controlled physiologic provocations (limb occlusion and elevation), were performed. Time domain and spectral analyses were completed. Results: In the human subject study, the time wave characteristics and spectral analysis resulted in similar trends. Peripheral blood flow attenuated in the control group over time, while it was maintained in the active group, and increased specifically during OMT in the responder groups. Heart rate remained around 65 BPM in the control group, fluctuated between 64-68 BPM in the active group, and dropped 4 and 3 BPM in the peripheral and central responder groups, respectively. The effect in the OMT group was statistically significant compared to no-OMT, however, was not statistically significant within-groups. For the preliminary spectral ultrasound Doppler study, segmental flow was successfully monitored. A prototype "Quick Assessment" tool was developed, providing instant post-processing results for clinical use. Conclusions: OMT along the vertebral column may influence autonomic processes that regulate heart rate and peripheral vascular flow. / Dissertation/Thesis / Masters Thesis Bioengineering 2014
48

Estudo das alterações microcirculatórias na população idosa comparadas com adultos jovens / Study of microcirculatory changes in the elderly compared with young adults

Flávia Gomes Lopes 29 April 2011 (has links)
O envelhecimento populacional é um fenômeno mundial, assim como o predomínio de mortes por doenças cardiovasculares. Estudos demonstram que o envelhecimento acarreta aumento da rigidez vascular e perturbações na reatividade macrovascular. O presente estudo comparou a microcirculação deste processo com adultos jovens através da pletismografia de oclusão venosa (POV) e da videocapilaroscopia do leito periungueal (VC). Para isto, desenvolveu-se um estudo transversal com dois grupos: idade entre 18 e 30 anos (n=16) e outro grupo com idade igual ou superior a 60 anos (n=21), além da subdivisão deste grupo em três subgrupos: idosas saudáveis (n=8), idosas em tratamento de hipertensão arterial (IDHAS,n=6) e idosas em tratamento de dislipidemia (IDDIS,n=6). Foram realizadas avaliações clínica, antropométrica, bioquímica e microcirculatória. Como resultados, a VC mostrou aumento dos diâmetros capilares aferente, apical e eferente e redução da relação velocidade máxima/ velocidade basal de deslocamento de hemácias para grupo de idosas e todos os subgrupos. A POV revelou diminuição da vasodilatação endotélio-dependente em todos os grupos estudados e a vasodilatação endotélio-independente alterou-se apenas em IDHAS e IDDIS. Como conclusões houve, no envelhecimento, alterações estruturais e funcionais da microcirculação assim como redução da vasodilatação endotélio-dependente. A vasodilatação endotélio-independente manteve-se inalterada, indicando que a célula muscular lisa da parede vascular permanece preservada, porém sofre alterações nos grupos IDHAS e IDDIS. / Population aging is a worldwide phenomenon, as well as the prevalence of deaths from cardiovascular diseases. Studies show that aging brings increased vascular stiffness and altered vascular reactivity. The present study compared the microcirculation of elderly people to young adults by venous occlusion plethysmography (POV) and nailfold videocapillaroscopy (NVC). For this, we developed a cross-sectional study with two groups: those aged between 18 and 30 years (n = 16) and another group aged over 60 years (n = 21), and the subdivision of this group into three subgroups: healthy elderly (n = 8), elderly women being treated for hypertension (IDHAS, n = 6) and older in the treatment of dyslipidemia (IDDIS, n = 6). Clinical, anthropometric, biochemical and microcirculatory parameters were evaluated. As results, NVC showed an increase of afferent, apical and efferent capillary diameters and a lower ratio maximum red blood cell velocity/ baseline red blood cell velocity for the older group and all subgroups. POV showed decreased endothelium-dependent vasodilation in all groups and the endothelium-independent vasodilation was altered only in IDHAS and IDDIS. In conclusion, in the aging, there were structural and functional changes of microcirculation as well as reduced endothelium-dependent vasodilation. The endothelium-independent vasodilation remained unchanged, indicating that smooth muscle cells of the vascular wall remains preserved, but show changes in the groups IDHAS and IDDIS.
49

Hemodinâmica venosa de membros inferiores em mulheres durante a gestação e após o parto / Venous lower limb hemodynamics during Pregnancy and puerperium

Leandro Augusto Gardenghi 19 February 2016 (has links)
Contexto: Existem controvérsias na literatura médica sobre potenciais alterações da hemodinâmica venosa dos membros inferiores durante a gravidez. Objetivo: Estudar a drenagem venosa em membros inferiores e suas alterações na gestação (1º, 2º e 3º trimestres) e pós-parto mediante Mapeamento Dúplex (MD) das veias profundas e superficiais e a Pletismografia a Ar (PGA). População: Foram recrutadas vinte mulheres primigestas, sem doença venosa prévia, junto aos Núcleos de Saúde da Família ligados ao Centro de Saúde Escola da FMRP-USP. Métodos: O estudo hemodinâmico venoso nos membros inferiores foi realizado empregando-se dois métodos não invasivos: o MD e a PGA. Foram registrados os diâmetros e os refluxos das principais veias (femoral comum, femoral, poplítea, safena magna e parva) dos membros inferiores por meio do MD. Foram avaliados pela PGA: o índice de enchimento venoso (IEV), a fração de ejeção (FE), a fração de volume residual (FVR) e o esvaziamento venoso (OF-outflow). Todos os registros foram obtidos em 3 diferentes períodos da gestação e no pós-parto. Os dados foram estatisticamente analisados e considerou-se p?0,05. Resultados: Houve aumento do diâmetro venoso no território da femoral comum e da safena magna infravalvar bilateralmente, nos 2º e 3º trimestres. Na PGA, registrou-se diminuição da FVR bilateral, elevação do IEV à direita e aumento do OF bilateral no decorrer da gestação. Observou-se edema em 4 (15%) gestantes no segundo trimestre e 11 (55%) no terceiro trimestre. Quanto ao refluxo, documentouse um caso no 2º trimestre no território da safena magna supravalvar esquerda (5%) e mais dois casos no 3º trimestre (15%), sendo uma no território da safena magna infravalvar esquerda e outra gestante com refluxo nos territórios de safena magna infravalvar e safena parva esquerdas. Após o parto, houve regressão de todas essas alterações anatômicas e hemodinâmicas da drenagem venosa dos membros inferiores. Conclusão: Apesar do aumento significativo dos diâmetros das veias femorais comuns e safenas magnas infravalvares bilateralmente, diminuição da FVR bilateral, elevação do IEV à direita, aumento do OF durante a gestação, todas essas alterações retornaram aos parâmetros anatômicos e hemodinâmicos venosos iniciais, após o parto / Background: The relation between pregnancy and venous reflux is still misunderstood and some authors question if pregnancy is the main cause of venous reflux and venous disease. Objective: analyze venous hemodynamics in healthy primigravidae during the first, second and third trimester of pregnancy and in the puerperium. Methods: prospective study with 20 primigravidae evaluated in the first, second and third trimester of pregnancy and postpartum. Duplex scan evaluated venous diameters and reflux; air plethysmography evaluated venous filling index (VFI), ejection fraction (EF), residual volume fraction (RVF), outflow fraction (OF )in both limbs. OF in the right limb while the patient was in left lateral decubitus position was also evaluated. Results: During pregnancy, there was bilateral increase in venous diameters in common femoral and infravalvar great saphenous veins; occurrence of reflux in the left surpravalvar great saphenous vein in one patient (5%) in the second trimester; and occurrence of reflux more other two patents (15%) in the third trimester: one in the left infravalvar great saphenous vein, and other in the left popliteal and small saphenous vein. All these alterations observed during pregnancy disappeared after delivery. VFI decreased after delivery in the left limb, but increased progressively in the right limb, returning to basal level after delivery; EF did not change; RVF decreased during pregnancy, mainly in left limb, and returned to basal level after delivery; OF increased during pregnancy and returned to basal levels after delivery; OF in left lateral decubitus did not change. Conclusion: pregnancy caused a diameter increase in bilateral common femoral and great saphenous veins, unilateral right increase in VFI, bilateral decrease in the RVF and bilateral increase in OF. All these parameters returned to initial status after delivery
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Estudo comparativo entre dois métodos de calibração da pletismografia respiratória por indutância em individuos saudáveis / Comparative study between two methods of calibration of respiratory inductive plethysmography

Renata Cleia Claudino Barbosa 13 June 2011 (has links)
Nas últimas décadas, considerável atenção foi direcionada para os dispositivos de mensuração não invasiva da configuração e coordenação toracoabdominal. Dentre os dispositivos mais empregados, destaca-se aquele que emprega a Pletismografia Respiratória por Indutância (PRI) que, apesar de ser considerado um dispositivo de avaliação reprodutível e acurado, apresenta divergências acerca do método de calibração para estimativa da participação dos compartimentos torácico e abdominal, principalmente quando utilizada em diferentes posturas corporais. O padrão-ouro da calibração da PRI é o método de calibração por isovolume (ISOCAL). Entretanto, a grande maioria dos estudos emprega somente a calibração qualitativa diagnóstica (QDC) devido ao fato desta não necessitar manobras respiratórias específicas. Em vista disso, o objetivo deste estudo foi comparar os dois métodos de calibração da PRI, em 3 diferentes posturas (decúbito dorsal, sedestação e ortostatismo). Foram avaliados 28 indivíduos saudáveis (18 mulheres/10 homens), com idade de 25,4±3,9 anos (média±DP). Todos os indivíduos foram submetidos aos dois métodos de calibração (ISOCAL e QDC) e avaliados nas 03 posturas. Foi verificado que os valores da constante de proporcionalidade dos sinais elétricos dos compartimentos (K) foram distintos em ambos os métodos de calibração nas 3 posturas avaliadas. Os valores de K avaliados com a calibração ISOCAL e QDC foram, respectivamente, 1,6±0,5 vs. 2,0±1,2 em decúbito dorsal, 2,5±0,8 vs. 0,6±0,3 em sedestação, e 2,0±0,8 vs. 0,6±0,3 em ortostatismo (p<0,05 para todas as comparações). Os nossos resultados sugerem que a QDC não deve ser considerada um método acurado para a calibração da PRI. Além disso, os valores da constante K do ISOCAL mostram ainda que a calibração do equipamento deve ocorrer para cada postura avaliada / In recent decades, considerable attention has been directed to devices for noninvasive measurement of thoracoabdominal configuration and coordination. Among the most commonly applied devices, there is one that employs the respiratory inductive plethysmography (PRI), which, despite being considered a device for reproducible and accurate assessment, shows variations on the calibration method to estimate the contribution of the thoracic and abdominal compartments especially when applied in different body postures. The gold standard in the calibration of PRI is the method of isovolume calibration (ISOCAL). However, most studies employ only the qualitative diagnostic calibration (QDC) due to the fact that this does not require specific respiratory maneuvers. This study aims to compare the two methods of calibration of the PRI in three different postures (supine, standing, and seated). A total of 28 healthy subjects (18 men mulheres/10), aged 25.4 ± 3.9 years (mean ± SD). All subjects underwent both methods of calibration (QDC and ISOCAL) and assessed at the 03 postures. It was found that the values of the constant of proportionality of the electrical signals of compartments (K) were different in both calibration methods evaluated in three postures. The values of K evaluated with calibration ISOCAL and QDC were respectively 1.6 ± 0.5 vs. 2.0 ± 1.2 supine position, 2.5 ± 0.8 vs. 0.6 ± 0.3 in seated position, and 2.0 ± 0.8 vs. 0.6 ± 0.3 in standing position (p <0.05 for all comparisons). Our results suggest that the QDC should not be considered an accurate method for calibration of the PRI. Moreover, the values of constant K ISOCAL also show that the calibration of equipment should occur for each position evaluated

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