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A comparison of helium dilution and plethysmography in measuring static lung volumesGuldbrand, Anna January 2008 (has links)
<p>In order to examine the usefulness of the multi breath helium dilution method (MB) it was compared to the single breath helium dilution method (SB) and body plethysmography (BP). Residual volume (RV), total lung capacity (TLC) and vital capacity (VC) were measured in seventeen subjects with obstructive (11) or restrictive (6) lung disease and four normal subjects.</p><p>With information from professional literature and current periodicals, advantages and disadvantages with all three methods were compared. ANOVA and Student's t-test were performed on the measurement results.</p><p>The results of the statistical tests tell us there are differences among the methods in the group of obstructive patients. They also reveal a notable difference between the MB and SB methods when measuring the same parameter. In addition, it was noted that none of the existing sets of prediction equations fulfill the requirements established on high quality lung function testing.</p><p>Although a thorough evaluation of the reproducibility of the method is still required, it appears to be a viable alternative to body plethysmography. We claim that measuring the above mentioned static lung volumes with only the single breath helium dilution method cannot be considered a satisfactory practice.</p>
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Motion Artifact Reduction in Impedance Plethysmography SignalAnsari, Sardar 28 June 2013 (has links)
The research related to designing portable monitoring devices for physiological signals has been at its peak in the last decade or two. One of the main obstacles in building such devices is the effect of the subject's movements on the quality of the signal. There have been numerous studies addressing the problem of removing motion artifact from the electrocardiogram (ECG) and photoplethysmography (PPG) signals in the past few years. However, no such study exists for the Impedance Plethysmography (IP) signal. The IP signal can be used to monitor respiration in mobile devices. However, it is very susceptible to motion artifact. The main aim of this dissertation is to develop adaptive and non-adaptive filtering algorithms to address the problem of motion artifact reduction from the IP signal.
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Hemodinâmica venosa de membros inferiores em mulheres durante a gestação e após o parto / Venous lower limb hemodynamics during Pregnancy and puerperiumGardenghi, Leandro Augusto 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 plethysmographyBarbosa, Renata Cleia Claudino 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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Data acquisition and analysis for reopneumographic study.January 1993 (has links)
by Leung Chung-chu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 101-107). / ABSTRACT --- p.i / ACKNOWLEDGEMENTS --- p.iii / LIST OF ABBREVIATIONS --- p.iv / LIST OF PUBLICATIONS --- p.v / TABLE OF CONTENTS --- p.vi / Chapter CHAPTER 1 --- Introduction / Chapter 1.1 --- Background of the Rheopneumograph --- p.1 / Chapter 1.2 --- The Electrical Bio-impedance (EBI) technique used in Rheopneumography --- p.2 / Chapter 1.3 --- Problems with analysis of Rheopneumograph --- p.6 / Chapter 1.4 --- The EBI measurement unit --- p.8 / Chapter 1.5 --- Data analysis in Rheopneumography and the electrode design --- p.8 / Chapter 1.6 --- Modelling analysis in Rheopneumography --- p.9 / Chapter 1.7 --- Thesis outline --- p.10 / Chapter CHAPTER 2 --- Improvement to the impedance measurement system / Chapter 2.1 --- Introduction --- p.13 / Chapter 2.1.1 --- The Coherent Detection method in EBI signal --- p.13 / Chapter 2.1.2 --- To discuss the problem in Coherent Detection method --- p.16 / Chapter 2.1.3 --- To discuss the problem in Costas Receiver method --- p.16 / Chapter 2.2 --- The concept of the Amplitude Modulation Receiver --- p.17 / Chapter 2.3 --- EBI measurement unit design using AM receiver technique --- p.18 / Chapter 2.3.1 --- The C-Y receiver --- p.18 / Chapter 2.3.2 --- A simple DC offset adjust circuit --- p.23 / Chapter 2.3.3 --- 555KHz local oscillator and constant current source --- p.25 / Chapter 2.3.4 --- Selection of the low pass filter --- p.29 / Chapter 2.4 --- The characteristic of the whole circuit and performance --- p.32 / Chapter 2.5 --- Discussion --- p.36 / Chapter CHAPTER 3 --- Data analysis in Rheopneumogram / Chapter 3.1 --- Introduction --- p.38 / Chapter 3.2 --- The 5-10 electrode array method applied in Thorax Montage --- p.39 / Chapter 3.2.1 --- The definition of the 5-10 electrode array method --- p.39 / Chapter 3.2.2 --- The advantage of the 5-10 electrode array method --- p.41 / Chapter 3.3 --- Signal analysis in subject-to-subject comparison --- p.41 / Chapter 3.3.1 --- The relationship between the ECG and Rheopneumogram --- p.45 / Chapter 3.4 --- Identification of the best electrode location in Rheopneumograph using Pump-jet model --- p.51 / Chapter 3.4.1 --- The fluid mechanical model device (Pump-jet model) --- p.51 / Chapter 3.4.2 --- Result and discussion --- p.57 / Chapter 3.5 --- Electrical conductivity studies in Silicon fluid-Graphite composites applied in EBI electrode array system --- p.62 / Chapter 3.5.1 --- Experimental procedure and results --- p.63 / Chapter 3.6 --- Discussion --- p.73 / Chapter CHAPTER 4 --- Model analysis for the Impedance Rheopneumogram / Chapter 4.1 --- Introduction --- p.76 / Chapter 4.2 --- Blood flow phenomenon study in Rheopneumogram using Pipeline model --- p.78 / Chapter 4.2.1 --- Model derivation --- p.79 / Chapter 4.2.2 --- Result and discussion --- p.86 / Chapter 4.3 --- Blood velocity study in Rheopneumogram using Pump-jet model --- p.94 / Chapter 4.3.1 --- Result and discussion --- p.94 / Chapter 4.4 --- Conclusion --- p.96 / Chapter CHAPTER 5 --- General discussion and Conclusion --- p.97 / Chapter CHAPTER 6 --- Reference --- p.101 / APPENDICES / Chapter I --- Measurement method in the study --- p.107 / Chapter II --- The simplification of an equation in pump-jet model --- p.109 / Chapter III --- The simplification of an equation in pipeline model --- p.111 / Chapter IV --- Impedance relation between body and electrode --- p.112 / Chapter V --- The procedure of the curve fitting --- p.113
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Investigation of Photodetector Optimization in Reducing Power Consumption by a Noninvasive Pulse Oximeter SensorPujary, Chirag Jayakar 16 January 2004 (has links)
Noninvasive pulse oximetry represents an area of potential interest to the army, because it could provide cost-effective, safe, fast and real-time physiological assessment in a combat injured soldier. Consequently, there is a need to develop a reliable, battery-powered, wearable pulse oximeter to acquire and process photoplethysmographic (PPG) signals using an optimized sensor configuration. A key requirement in the optimal design of a wearable wireless pulse oximeter is low power management without compromising signal quality. This research investigated the advantage gained by increasing the area of the photodetector and decreasing the light emitting diode (LED) driving currents to reduce the overall power requirement of a reflectance mode pulse oximeter sensor. In vitro and preliminary in vivo experiments were conducted to evaluate a multiple photodetector reflectance sensor setup to simulate a varying detection area. It was concluded that a reflection pulse oximeter sensor employing a large area photodetector is preferred over a similar transmission type sensor for extending the battery life of a wireless pulse oximeter intended for future telemedicine applications.
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A model-based motion-resistant method for noninvasive and continuous measurement of arterial blood pressure. / CUHK electronic theses & dissertations collectionJanuary 2005 (has links)
Finally, the effects of external physical factors, such as temperature and contact force, on BP estimation based on m-NHA, were discussed and verified by experiments. Especially, a computational efficient algorithm was developed based on an optical model for motion resistant BP estimation, as well as the estimation of blood oxygen saturation (SaO2). We first developed an optical model with motion effect based on the photon-diffusion analysis, instead of the Beer-Lambert's law, which generally describes the light absorption but fails to account for light scattering in tissue. Based on the optical model, a novel motion resistant algorithm, minimum correlation discreet saturation transform (MCDST), was proposed for the estimation of arterial BP and SaO 2 as well. The novel algorithm is based on the time and time-delayed independence of the "true" signal and motion noise by use of dual PPGs (pulse oximeter). Experimental results indicate that MCDST has a comparable performance in SaO2 estimation and m-NHA calculation, as compared to another clinically verified motion-resistant algorithm---discreet saturation transform (DST). Most importantly, MCDST is much more computationally efficient than DST, because the former only uses simple linear algebra, while the latter uses the adaptive filter. It indicates that MCDST can reduce the required power consumption and circuit complexity of the implementation. It is vitally important for wearable devices, where the small physical size and long battery life are crucial. / First of all, a modified left-ventricle (LV) arterial coupling model was developed by incorporating a nonlinear pressure dependent compliance and two resistances for valve stenosis. A modified LV-arterial coupling model with pressure dependent compliance and taking into account the hypertensives with valve stenosis is quite necessary for proper description of the BP regulation for hypertensives with mitral and/or aortic stenosis, as well as normal people. / Hypertension is the most common cardiovascular disease and is a major public health problem in both developed and developing countries. As hypertension is often asymptomatic, continuous monitoring of blood pressure (BP) for the initiate treatment before the onset of organ damage is of vital importance for home healthcare. However, most of current BP meters, such as sphygmomanometer, are not suitable for the targeted applications because they provide only intermittent blood pressure readings and may cause circulatory interference with the usage of cuff. Moreover, they are not applicable in mobile environment due to the bulky design and the lack of efficient motion resistant algorithms. The objective of this research is to propose a motion resistant method for noninvasive and continuous BP measurement using dual photoplethysmograms (PPG), which could be potentially embedded in the portable or wearable devices for long term BP monitoring. / In summary, the research in this thesis not only covers the fundamental work, such as the modification of heart-arterial system coupling model and the proposal of a novel signal processing method MCDST, but also includes the practical techniques for the estimation of arterial BP as well as oxygen saturation. Expectations for further studies are suggested at the end of this thesis. / Secondly, based on the modified model, a novel parameter, normalized harmonic area (NHA), was proposed for BP estimation by quantifying the frequency distribution in the simulated aortic pressure waveforms. The excellent relationship between NHA and BP was verified by the simulation results. To establish a measurable parameter corresponding to NHA, PPG is investigated because it is widely used for the peripheral circulation monitoring and can be easily obtained at any location on the skin surface. Based on the assumption of quadratic transfer function from aortic pressure to PPG at fingertip, the discreet period transform (DPT) was applied on PPG signal to produce a modified NHA (m-NHA) for BP estimation. For the clinical tests on 85 subjects, the difference between the estimated and the measured blood pressure by m-NHA is 0.97+/-7.9mmHg for systolic blood pressure (SBP) and 0.40+/-4.5mmHg for diastolic blood pressure (DBP), respectively. This result is as good as that (0.73+/-7.6mmHg for SBP, and 0.40+/-4.5mmHg for DBP) from the widely reported pulse transit time (PTT) approach. / Yan Yongsheng. / "November 2005." / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6561. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
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Avaliação da resposta broncodilatadora imediata ao formoterol em doença pulmonar obstrutiva crônica (dpoc) com pouca reversibilidadeSouza, 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.
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Arterial Perfusion Detection Method By Synchronous DetectionPrevot, Yohan 04 November 2005 (has links)
The pressure ulcer is a well-known clinical problem that has plagued many patients in acute-care hospitals and chronic-care facilities. The pressure ulcer has the potential to diminish the quality of a patient's life by hindering the person's physical and emotional well-being. In addition, pressure ulcers are a high-cost problem. Past studies have shown that costs related to the treatment of pressure ulcers have reached 1.335 billion dollars a year in the United States alone.
A pressure ulcer is defined as a lesion created by unrelieved pressure, which causes tissue ischemia and subsequently damages the underlying tissue. This sequence of events is mainly centered on ischemia. Ischemia is a condition created by an insufficient flow of blood to an organ or part of an organ such as the skin. The outcome of ischemia is cell death at the tissue level, which is commonly termed necrosis.
In the past, researchers employed several different non-invasive techniques in order to detect changes in the condition of human skin when blood flow was restricted. The two most commonly used practices were Laser Doppler Velocimetry and Continuous Wave Ultrasound. Laser Doppler Velocimeter is used to measure cutaneous blood flow in a study region. The moving red blood cells in blood vessels cause a Doppler shift of incident laser light, which correlates with the velocity of blood flow. Continuous Wave Ultrasound involves an ultrasound signal, which is transmitted into the skin. The change in frequency of the reflected signal with respect to the transmitted signal provides an indication of blow flow.
The objective of this research was to examine a method for the detection of arterial blood flow, which utilized the 4-electrode sensor for the measurement of Tissue Impedance or the Bio-impedance method. The system developed, for the synchronous detection method, consisted of both analog hardware and software tools. The analog hardware utilized synchronous detection. The software monitored and performed mathematical operations on the retrieved data. The system developed during this research demonstrated the ability to measure the pulsatile impedance of the skin and present the results in a fashion useful to healthcare providers.
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BMI vs kroppsfettprocent : En studie om BMI:s sensitivitet, specificitet och korrelation med kroppsfettprocentKlang, Donnie, Osvald, Carl-Johan January 2012 (has links)
Syfte Syftet med denna studie var att undersöka sensitiviteten och specificiteten hos BMI vid klassificering av övervikt, samt att jämföra gränsvärdena för övervikt mätt med BMI med gränsvärdena för övervikt mätt i fettprocent med BodPod. Metod Urvalet i studien bestod av 359 deltagare mellan 30-50 år (medelvärde – 39,7 år). Av dessa 359 var 192 kvinnor och 167 män. Deltagarna var indelade i fyra aktivitetsnivåer – stillasittande, lågaktiva, aktiva och mycket aktiva. Dessa delades in i två grupper där stillasittande och lågaktiva slogs ihop och aktiva och mycket aktiva slogs ihop. Därefter har gränsvärden för övervikt jämförts, mätt med två olika mätinstrument – BMI (body mass index) och ADP (air displacement plethysmography) samt givit nya förslag på gräns för övervikt med BMI som mätinstrument. Sensitiviteten och specificiteten för BMI för män och kvinnor och olika aktivitetsnivåer har uppmäts. Resultat Resultatet visade att gränsvärdena för övervikt hos kvinnor bör fortfarande ligga runt 25, oavsett aktivitetsnivå, men för män bör gränsvärdena ligga mellan 26-27, beroende på aktivitetsgrad. Sensitiviteten för kvinnor ligger mellan 69-76% beroende på aktivitetsgrad och specificiteten är 83-91%. För män ligger sensitiviteten mellan 76-88% beroende på aktivitetsgrad och specificiteten är 56-68%. Med föreslagna nya BMI-gränser minskar sensitiviteten för män, men specificiteten ökar. Ingen större förändring hos kvinnor. Slutsats Då sensitiviteten och specificiteten är relativt låg för BMI kan det vara bra för en lärare i idrott och hälsa att känna till BMI:s begränsningar. Idrottslärare ska utveckla elevens färdigheter och kunskap inom hälsa och bör lyfta BMI:s styrkor och svagheter i undervisningen eftersom det är ett mått de flesta känner till. BMI är inte ett perfekt mått utan bör kompletteras med andra enkla mätmetoder. Om olika BMI gränsvärden för olika aktivitetsnivåer ska användas bör denna mätning vara mer ingående och inkludera träning på fritiden, vilket inte gjorts i denna studie. / Aim The aim of this study was to examine the sensitivity and specificity of BMI for classification of overweight, as well compared the cutoffs for overweight measured with BMI with the cutoffs for overweight measured in %FM with BodPod. Method The selection of the study consisted of 359 participants between 30-50 years of age (mean age – 39,7 years). Of these 359, 192 were women and 167 were men. The participants were divided into four activity levels – sedentary, low active, active, very active. These were divided into two groups – sedentary and low active into one group and active and very active into another. Then cutoffs for overweight were measured, with two different methods – BMI (body mass index) and ADP (air displacement plethysmography), as well given new suggestions for cutoff levels for overweight measured with BMI. The sensitivity and specificity, for BMI, for men and women and different levels of activity were calculated. Result The result showed that the cutoffs for overweight in women still should be around 25, no matter the level of activity, but for men cutoffs should be between 26-27, considering level of activity. Sensitivity for women is between 69-76% depending on level of activity and specificity 83-91%. For men the sensitivity is between 76-88% depending on level of activity and the specificity 56-68%. With suggested new BMI cutoffs the sensitivity for men decreases, but the specificity increases. No larger change for women. Conclusion As the sensitivity and specificity is relatively low for BMI it could be good for teachers in physical education to know of BMI limitations. PE teachers are supposed to develop the pupils’ skills and knowledge in health and should inform about BMI strengths and weaknesses in education since it is a measure known by most. BMI is not a perfect measurement but should be accompanied by other simple measurements. If BMI cutoffs should take activity into account, this measurement should be more detailed and include physical activity in their leisure time, which was not done in this study.
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