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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.

Volumetric capnography in the diagnosis and the therapeutic monitoring of pulmonary embolism in the emergency department

Verschuren, Franck 07 December 2005 (has links)
CO2 and its influence on environmental and ecological processes focuses the attention of all current media. In the medical area, expired CO2 measurement with Capnography has gained acceptance for all patients needing clinical monitoring and supervision. But recent research works are showing the promises of CO2 as a diagnostic tool or therapeutic monitoring. In this case, measurement of expired CO2 in function of the expired volume, called Volumetric Capnography, has a theoretical better performance than the traditional time-based Capnography. When expired CO2 data are combined to arterial CO2 sampling, the clinician faces breath-by-breath curves, which give a bedside knowledge of the pulmonary ventilation and perfusion status of his patient. Pulmonary embolism is a particular application of Volumetric Capnography. This frequent and challenging disease is characterized by impaired relationships between the pulmonary ventilation and perfusion, going from deadspace to shunt. Volumetric Capnography deserves a careful attention in this area, since its combination with other clinical or biological signs could become part of a diagnostic procedure, either for the detection of the disease when capnographic parameters are clearly impaired, or for ruling out this diagnosis when Volumetric Capnography analysis is normal. In the same way, monitoring the efficacy of thrombolytic therapy when pulmonary embolism is massive is another particular interest for expired CO2 measurement. Physicians working in the Emergency Department demand performing devices for improving patient care. Such devices can be particularly adapted to daily practice if they can be used by the bedside, if they are non-invasive, safe, efficient, feasible, and applicable to non-intubated patients. Volumetric Capnography, which seems to answer those requirements, will certainly deserve growing attention and interest in the future as a direct application of pulmonary pathophysiology. Even if Volumetric Capnography is still at the frontier between clinical research and clinical practice, let us hope that the studies presented in this thesis will improve the clinical acceptance of this attractive technology.

Capnografia volumétrica na avaliação de doenças crônicas pulmonares / Volumetric capnography for the evaluation of chronic airways diseases

Veronez, Liliani de Fátima, 1980- 12 March 2014 (has links)
Orientadores: Ilma Aparecida Paschoal, Mônica Corso Pereira / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T20:34:20Z (GMT). No. of bitstreams: 1 Veronez_LilianideFatima_D.pdf: 6581224 bytes, checksum: 21912792a141bd85146488626d2e9e24 (MD5) Previous issue date: 2014 / Resumo: As doenças pulmonares obstrutivas de diferentes etiologias se apresentam com envolvimento progressivo das vias aéreas periféricas. As vias aéreas periféricas, conhecidas como zona silenciosa do pulmão, não são adequadamente avaliadas com testes convencionais de função pulmonar. O princípio do gás "washout" eliminação de gases tem sido utilizado para detectar heterogeneidade da ventilação pulmonar e para estimar a localização do processo da doença subjacente. A capnografia volumétrica (CV) analisa o padrão de eliminação de CO2 como uma função do volume expirado. Objetivo: medir os "slopes" da fase 3 normalizados pelo volume corrente expiratório em pacientes com bronquiectasia não-fibrose cística (BQNF ) e em pacientes com bronquite crônica tabágica obstrutiva (BCTO), a fim de comparar os slopes obtidos para os grupos. Métodos: Pacientes com BQNF e com BCTO foram incluídos sequencialmente a partir dos ambulatórios de Insuficiência Respiratória Crônica do HC-Unicamp. Um grupo controle foi estabelecido para grupo BQNF, pareados por sexo e idade. Todos os indivíduos realizaram espirometria, CV e teste da caminhada dos seis minutos (TC6). Duas comparações foram feitas: grupo BQNF vs o grupo controle, e BQNF vs o grupo BCTO. O projeto foi aprovado pelo comitê de ética da nossa instituição. Os testes estatísticos utilizados foram Wilcoxon ou teste t de Student diferenças estatisticamente significativas foram consideradas com p < 0,05. Resultados: na comparação do grupo BQNF (N = 20) vs grupo controle (N = 20), foram encontradas diferenças significativas no IMC e em diversas variáveis funcionais (espirometria, CV, TC6) com os piores resultados observados no grupo BQNF. Na comparação entre o grupo BCTO (N = 20) vs grupo BQNF, embora os pacientes com BCTO tivessem piores valores na espirometria e TC6, as variáveis capnograficas Slp2, Slp3/Ve e Slp3/EtCO2 foram semelhantes. Conclusão: Estes resultados podem indicar que as curvas de eliminação de gás não são suficientemente sensíveis para monitorizar a gravidade das anormalidades estruturais. O papel do slope normalizado da fase 3 pode se explorado como o mais sensível índice de doença das pequenas vias aéreas, embora possa não ser igualmente sensível em discriminar a gravidade das alterações / Abstract: Background: Obstructive lung diseases of different etiologies present with progressive peripheral airway involvement. The peripheral airways, known as silent lung zone, are not adequately evaluated with conventional function tests. The principle of gas washout has been used to detect pulmonary ventilation inhomogeneity and to estimate the location of the underlying disease process. Volumetric capnography (VC) analyses the pattern of CO2 elimination as a function of expired volume. Objective: to measure normalized phase 3 slopes with VC in patients with non-cystic fibrosis bronchiectasis (NCB) and in bronchitic patients with chronic obstructive pulmonary disease (COPD) in order to compare the slopes obtained for the groups. Methods: NCB and severe COPD were enrolled sequentially from an outpatient clinic (Universitary Hospital). A control group was established for NCB group, paired by sex and age. All subjects performed spirometry, VC and Six-Minute Walk Test (6MWT). Two comparisons were made: NCB group vs its control group, and NCB group vs COPD group. The project was approved by the ethical committee of the institution. Statistical tests used were Wilcoxon or Student t-test; statistically significant difference considered with p<0.05. Results: Concerning NCB group (N=20) vs control group (N=20), significant differences were found in BMI and in several functional variables (spirometric, CV, 6MWT) with the worse results observed in NCB group. In the comparison between the COPD group (N=20) vs NCB group, although patients with COPD have had worse spirometric and 6MWT values, the capnographic variables Slp2, Slp3/Ve and Slp3/EtCO2 were similar. Conclusion: These findings may indicate that the gas elimination curves are not sensitive enough to monitor the severity of structural abnormalities. The role of normalized phase 3 slope may be worth explore as a more sensitive index of small airway disease, even though it may not be equally sensitive in discriminating the severity of the alterations / Doutorado / Clinica Medica / Doutora em Clínica Médica

CO2 Flow Estimation using Sidestream Capnography and Patient Flow in Anaesthesia Delivery Systems / CO2-estimering genom Sidestream kapnografi och patientflöde i anestesisystem

Micski, Erik January 2019 (has links)
Volumetric CO2 data from patients in anaesthesia delivery systems are sought after by physicians. The CO2 data obtained with the commonly used sidestream sampling technique are not considered adequate for volumetric CO2 estimation due to distortion and desynchrony with patient flow. The purpose of this thesis was to explore the possibility of using signal enhancing methods to the sidestream data to accurately estimate CO2 flow using a Flow-i anaesthesia delivery system. To evaluate sidestream performance, experimental data was acquired using a mainstream and a sidestream capnograph connected in series to a FRC test lung with known CO2 content, ventilated by a Flow-i anaesthesia machine. The data was then enhanced and analysed using signal processing methods including sigmoid modelling and neural networks. A Feed Forward Neural Network achieved results closest resembling the mainstream capnogram of the evaluated signal processing methods. The mainstream capnogram, considered the benchmark, produced large internal scattering and approximately 25 % offset from actual CO2 flow while using the inherent patient flow data produced by the Flow-i anaesthesia system. When using patient flow data from a Servo-i ventilator, the resulting CO2 flow estimates were drastically improved, producing estimates within 10 % error. This thesis concludes that there are several potential processing methods of the sidestream data to approximate the mainstream signal, however the patient flow of the Flow-i system are a suspected source of error in the CO2 flow estimation.

Embolia pulmonar experimental = um modelo quase fatal / Experimental pulmonary embolism : a near-fatal model

Pereira, Daniel José 19 August 2018 (has links)
Orientador: Heitor Moreno Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-19T02:49:22Z (GMT). No. of bitstreams: 1 Pereira_DanielJose_M.pdf: 8289618 bytes, checksum: f81b30485257dfeb1919e76b99cecc7d (MD5) Previous issue date: 2011 / Resumo: Introdução: estudos experimentais de embolia pulmonar (EP) são habitualmente realizados sob ventilação mecânica. Como a maioria dos pacientes com suspeita de EP adentra os Serviços de Emergência em respiração espontânea e em ar ambiente, estudos que medissem as variáveis hemodinâmicas, gasométricas e capnográficas, nestas condições, em muito contribuiriam para compreensão mais específica das alterações cardiopulmonares e gasométricas na fase aguda da doença. Observa-se que faltam na literatura estudos experimentais que avaliem animais em tais condições. Objetivo: o objetivo do presente estudo foi submeter à EP animais sob ventilação espontânea e sem oxigênio suplementar. A EP por coágulos autólogos foi induzida em seis porcos e os registros cardiorrespiratórios e gasométricos foram realizados no pré e pós-EP. O valor da pressão média de artéria pulmonar (PMAP) "quase fatal" foi previamente determinada. Resultados: a presença de choque obstrutivo agudo pôde ser evidenciada pelo aumento da PMAP (de 17,8±3,5 para 41,7±3,3mmHg) (P<0,0001) e pela queda do débito cardíaco (de 4,9±1,0 para 2,7±1,0L/min) (P<0,003). Consequentemente, a presença de acidose metabólica pode ser constatada (de 2,4±0,6 para 5,7±1,8mmol/L) (P<0,0001). Observou-se ainda a presença de hipoxemia (de 73,5±12,7 para 40,3±4,6mmHg) (P<0,0001), porém, a PaCO2 não variou (de 44,9±4,4 para 48,2±6,0mmHg) (NS). Houve expressivos aumentos, tanto para P(a-et)CO2 (de 4,8±2,8 para 37,2±5,8mmHg) quanto para a P(A-a)O2 (de 8,2±8,9 para 37,2±10,3mmHg) (P<0,0001). Como tentativa de compensação à acidose metabólica, evidenciou-se significativo aumento do volume minuto alveolar total (de 4,0±0,9 para 10,6±2,9L/min) (P<0,0001). Conclusão: neste modelo, a PMAP quase fatal foi de 2 a 2,5 vezes a PMAP basal e as variáveis capnográficas, associadas a gasometria arterial e venosa, mostraram-se eficazes em discriminar um quadro obstrutivo agudo / Abstract: Introduction: Experimental studies on pulmonary embolism (PE) are usually performed under mechanical ventilation. Most patients with suspicion of PE enter the Emergency Services in spontaneous breathing and environmental air. Thus, under these conditions, measurements of hemodynamic, gasometric and capnographic variables contribute largely to a more specific comprehension of cardiopulmonary and gasometric alterations in the acute phase of the disease. Studies which evaluated animals under conditions are lacking. Objective: This study aimed to submit animals under spontaneous ventilation and without supplemental oxygen to PE. PE was induced in six pigs using autologous blood clots, and cardiorespiratory and gasometric records were performed before and after PE. The values of "near fatal" mean pulmonary arterial pressure (MPAP) were previously determined. Results: The presence of obstructive shock could be evidenced by increased MPAP (from 17.8±3.5 to 41.7±3.3mmHg) (p<0.0001) and decreased cardiac output (from 4.9±1.0 to 2.7±1.0L/min) (p<0.003). Consequently, metabolic acidosis occurred (Lac art)(from 2.4±0.6 to 5.7±1.8mmol/L) (p<0.0001). It was observed hypoxemia (from 73.5±12.7 to 40.3±4.6mmHg) (p<0.0001); however, PaCO2 did not vary (from 44.9±4.4 to 48.2±6.0mmHg) (NS). There were significant increases in both P(a-et)CO2 (from 4.8±2.8 to 37.2±5.8mmHg) and P(A-a)O2 (from 8.2±8.9 to 37.2±10.3mmHg) (p<0.0001). There was also a significant increase in the total alveolar minute volume (from 4.0±0.9 to 10.6±2.9L/min) (p<0.0001). Conclusion: In this model, the near fatal MPAP was from 2 to 2.5 times the basal MPAP; and the capnographic variables, associated with arterial and venous gasometry, showed effective in discriminating an acute obstructive profile / Mestrado / Farmacologia / Mestre em Farmacologia

Alterações ventilatórias em pacientes com fibrose cística submetidos a teste submáximo de seis minutos / Ventilatory changes in patients with cystic fibrosis in test submaximal to six minutes

Parazzi, Paloma Lopes Francisco, 1982- 25 August 2018 (has links)
Orientadores: José Dirceu Ribeiro, Camila Isabel Santos Schivinski / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-25T16:15:32Z (GMT). No. of bitstreams: 1 Parazzi_PalomaLopesFrancisco_M.pdf: 3954861 bytes, checksum: 8928c4e51b5e3873d43ddcec22c35069 (MD5) Previous issue date: 2014 / Resumo: Introdução: Na fibrose cística (FC) os testes que avaliam a aptidão física tem sido estudado como marcador de prognóstico ou como ferramenta de avaliação da condição cardiorrespiratória. Objetivo: avaliar e comparar variáveis da ventilação pulmonar utilizando a capnografia volumétrica (capV): VE, VCO2, VE/VCO2, VD/VT, PetCO2; variáveis de espirometria: VEF1%, CVF% e VEF1/CVF; e parâmetros cardiorrespiratórios: FCar, FR, SpO2 no repouso e durante teste de esforço em crianças, adolescentes e adultos jovens entre 6 a 25 anos de idade, com (GFC) e sem fibrose cística (GC). Método: estudo clínico, prospectivo, controlado, com 128 indivíduos, 64 com FC, de ambos os gêneros, de Hospital Universitário. Todos realizaram exercício em esteira e os exames propostos após aprovação do Comitê de Ética da Instituição e assinatura do termo de Consentimento Livre e Esclarecido. Resultados: os pacientes com FC apresentaram valores estatisticamente diferentes para as variáveis de CapV e espirometria ao longo do teste de exercício. Antes do exercício as variáveis também foram diferentes, porém com significância estatística para: espirometria, SpO2, FR, VCO2, VE/VCO2, PetCO2 e escala de Borg. A comparação entre os grupos de pacientes com FC e GC foi realizada pelos testes Kruskal-Wallis e Mann-Whitney. Conclusão: a CapV é um instrumento que pode ser utilizado para análise de parâmetros ventilatórios durante o exercício físico. Todas as variáveis cardiorrespiratórias, da espirometria e da capnografia foram diferentes nos pacientes com FC quando comparados aos indivíduos saudáveis antes, durante e após exercício físico / Abstract: Introduction: In cystic fibrosis (CF) tests that assess physical fitness has been studied as a prognostic marker or as a tool for assessing the cardiorespiratory fitness Objective: To evaluate and compare variables of pulmonary ventilation using volumetric capnography (CAPV): VE, VCO2, VE/VCO2, VD/VT, PetCO2; spirometric variables: % FEV1 , FVC and FEV1/FVC % ; and cardiorespiratory parameters: FCar , RR, SpO2 at rest and during exercise testing in children, adolescents and young adults aged 6-25 years of age with (GFC) and without cystic fibrosis (GC). Method: Clinical, prospective, controlled study with 128 subjects, 64 with CF, of both genders, of University Hospital. All patients underwent treadmill exercise tests and proposed after approval by the Institutional Review Board and signing the consent form. Results: CF patients had statistically different values for the variables CAPV and spirometry throughout the exercise test. Before exercise variables were also different, but with statistical significance for spirometry, SpO2, RR, VCO2, VE/VCO2, PetCO2 Borg scale. The comparison between groups of patients with CF and control groups was performed by Kruskal - Wallis and Mann - Whitney tests. Conclusion: CAPV is a tool that can be used for analysis of ventilatory parameters during exercise. All cardiorespiratory variables, spirometry and capnography were different in CF patients compared to healthy subjects before and after exercise / Mestrado / Saude da Criança e do Adolescente / Mestra em Ciências

Avaliação funcional e estrutural da doença pulmonar em crianças e adolescentes com fibrose cística / Functional and structural evaluation of lung disease in children and adolescents with cystic fibrosis

Oliveira, Pricila Mara Novais de, 1983- 26 August 2018 (has links)
Orientador: José Dirceu Ribeiro / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T23:03:29Z (GMT). No. of bitstreams: 1 Oliveira_PricilaMaraNovaisde_D.pdf: 1258403 bytes, checksum: 7846e1b92c8fe1c6ba25524109c50608 (MD5) Previous issue date: 2015 / Resumo: Introdução: Estudos recentes indicam que a espirometria não é uma ferramenta sensível para avaliar a função pulmonar em pacientes com fibrose cística (FC). A tomografia computadorizada de alta resolução (TCAR) de tórax é considerada o padrão ouro para avaliação do dano estrutural pulmonar nesses pacientes. Já a capnografia volumétrica (VCap) tem demonstrado ser uma ferramenta promissora na avaliação da homogeneidade da ventilação pulmonar. No nosso conhecimento não existem estudos comparando esses exames. Por isso o objetivo desse estudo foi avaliar e comparar os testes de VCap, espirometria e TCAR pontuada pelo escore de Bhalla modificado na avaliação da doença pulmonar em crianças e adolescentes com FC. Método: Realizou-se avaliação transversal e longitudinal de pacientes com FC de ambos os sexos fora de exacerbação pulmonar aguda. A VCap e espirometria foram realizadas no mesmo dia. A TCAR foi obtida na avaliação de rotina realizada por esses pacientes e as imagens foram pontuadas por 2 avaliadores através do escore de Bhalla modificado. Os resultados da VCap e espirometria foram correlacionados com o escore de TCAR. Os resultados obtidos pelo grupo de pacientes com espirometria normal e alterada foram comparados. Além disso, a progressão da doença pulmonar foi avaliada e comparada através dos três exames realizados. Resultados: A tese é apresentada no formato de três artigos. No capitulo 1, realizou-se uma revisão da literatura sobre VCap. No capítulo 2, realizou-se um estudo transversal com 41 pacientes com FC com idade média de 13,8 anos. O escore de TCAR médio foi 20,64 (6,5-33,5) e 14 pacientes (34,1%) tiveram espirometria normal. O índice capnográfico (KPIv) apresentou correlação com o escore de TCAR (r=0,52; p=0,001), VEF1% (r=-0,70; p<0,001) e FEF25-75% (r=-0,65; p<0,001). Porém o FEF25-75% demonstrou maior correlação com o escore de TCAR (r= -0,65; p<0,001).O KPIv e o slope III (SIII) da VCap foram maiores nos pacientes com espirometria alterada (p=0,01 e p=0,04, respectivamente). No capítulo 3, realizou-se um estudo longitudinal com 23 pacientes avaliados pelas ferramentas propostas. Tanto a espirometria, quanto o escore da TCAR e a VCap demonstraram piora da doença pulmonar no período estudado. A variação anual do escore de TCAR (+7,38%) foi maior do que a variação do KPIv (+0,32%), do FEF25-75% (-5,71%) e do VEF1% (4,39%). Pacientes com comprometimento leve da função pulmonar apresentaram maior declínio do VEF1 e menor aumento da pontuação do escore de TCAR quando comparados aos moderados e graves (p=0,02). Conclusão: A VCap é uma ferramenta útil na monitorização das doenças pulmonares em crianças e adolescentes com FC. O KPIv derivado da Vcap correlaciona-se com o escore de TCAR e espirometria. Porém, o escore de TCAR se correlaciona melhor com a espirometria do que com a VCap. Mais estudos são necessários para avaliar a habilidade do SIII e KPIv para discriminar pacientes com espirometria normal e alterada. A espirometria, VCap e TCAR detectaram piora da doença pulmonar nos pacientes avaliados. Porém, a variação anual do escore de TCAR foi maior do que a piora da função pulmonar medida pela espirometria e da homogeinidade da ventilação avaliada pela VCap. A espirometria apresentou maior declínio nos pacientes classificados como leves, enquanto o escore de TCAR variou mais em pacientes com comprometimento moderado/grave. Nossos resultados reforçam o caráter complementar das ferramentas testadas na avaliação funcional e estrutural da doença pulmonar / Abstract: Introduction: Recent studies have indicated that spirometry is not a sensitive tool to evaluate lung disease in cystic fibrosis (CF) patients. High-resolution computed tomography (HRCT) is considered the gold standard to evaluate structural lung disease. Volumetric capnography (VCap) is a promising clinical tool used to evaluate ventilation homogeneity. In our knowledge, there is no study comparing those tools. Therefore, our study aimed to evaluate and to compare the spirometry test, with VCap, and HRCT punctuated by modified Bhalla score in children and adolescents with CF. Methods: It were conducted a cross-sectional and a longitudinal study of CF patients from both genders out of acute pulmonary exacerbation. They performed VCap and spirometry in a single test occasion. HRCT was obtained in routine evaluation and images were punctuated by 2 observers with modified Bhalla score. VCap and spirometry results were correlated with HRCT scores. Patients¿ groups with normal and abnormal spirometry were compared. Besides, the progression of lung disease was assessed and compared between those three exams. Results: The thesis is presented in three papers format. In chapter 1, we presented a review of VCap. In chapter 2, we presented the cross-sectional study with 41 CF patients with mean age of 13.8 years. HRCT score mean was 20.64 (6.5-33.5) and 14 patients (34.1%) had normal spirometry values. Capnographic index (KPIv) was correlated with the HRCT score (r=0.52; p=0.001), FEV1% (r=-0.70; p<0.001), and FEF25-75% (r=-0.65; p<0.001). Although, FEF25-75% showed stronger correlation with the HRCT score (r= -0.65; p<0.001). KPIv and slope III (SIII) from VCap were higher in patients with abnormal than normal spirometry (p=0.01 and p=0.04 respectively). In chapter 3, we presented the longitudinal study of 23 patients testes with all tests proposed. Spirometry, HRCT score, and VCap demonstrated deterioration of lung disease during the period studied. The annual variation rate of HRCT score (+7.38%) was higher than KPIv (+0.32%), FEF25-75% (-5.71%), and FEV1% (4.39%). Patients with mild lung function had higher decline of FEV1% and less improvement in HRCT score when compared to patients with moderated and severe lung disease (p=0.02). Conclusions: VCap is a useful tool in monitoring lung disease in children and adolescents with CF. KPIv from VCap correlates with HRCT score and spirometry. Still, the HRCT score correlates better with spirometry than with VCap. Further studies are needed to assess the ability of SIII and KPIv to discriminate between patients with normal and abnormal spirometry. Spirometry, VCap and HRCT were able to detect deterioration in lung disease. Although, the annual variation rate of HRCT score were higher than functional decline evaluated by spirometry and ventilation inhomogeneity assessed by VCap. Spirometry had higher annual rate decline in patients with mild lung function, while HRCT score had higher improvement in moderate/severe patients. Our results reinforce the complementary role of those tested tools in functional and structural evaluation of lung disease / Doutorado / Saude da Criança e do Adolescente / Doutora em Ciências

Smartphone Capnography : Evaluation of the concept and the associated CO2 indicating sensor / Smartphone Capnography : Utvärdering av konceptet och den tillhörande CO2 indikerande sensorn

Kuutmann, Hanna, Rosén, Emelie January 2014 (has links)
Smartphone capnography is a new concept for respiratory monitoring using a colorimetric sensor in combination with a smartphone and an Android application. Compared to using an infrared spectrophotometric carbon dioxide analyzer (IR-analyzer), the gold standard for respiratory carbon dioxide monitoring, smartphone capnography offers a cheaper and less bulky solution. This master thesis evaluates the performance of smartphone capnography and the colorimetric sensor engineered for this concept. Three different techniques (side stream, shunt stream and main stream) were tested. Additionally, an iPhone application was developed as a proof of concept when using an iPhone for smartphone capnography.   An experimental set-up simulating human breathing was assembled and measurements, at different breathing rates (6-30 breaths/min) and carbon dioxide levels (2-7vol%), were performed with an IR-analyzer as reference. Results showed that capnograms from smartphone capnography was comparable to those from the IR-analyzer and that the approximate accuracy was ±0.25vol% for up to 6 days of use. Results strongly motivate further elaboration of the concept and the three different techniques for measuring. / ”Smartphone capnography” är ett nytt koncept för att monitorera andning. Principen är en kombination av en kolorimetrisk sensor, en smartphone samt en Androidapplikation. Jämfört med den dominerande tekniken, en IR-spektrofotometrisk koldioxidanalysator (IR-analysator), så är “smartphone capnography” både billigare och mindre skrymmande. Detta examensarbete utvärderar konceptet ”smartphone capnography” och en kolorimetrisk sensor speciellt utvecklad för ändamålet. Tre olika tekniker (side stream, shunt stream och main stream) har utvärderats. Slutligen utvecklades en iPhoneapplikation för att visa att konceptet ”smartphone capnography” kan användas även med denna typ av smartphone.   Utvärderingen bestod i att göra mätningar i en experimentell uppställning som simulerar andning. Mätningar gjordes vid varierande andningsfrekvenser (6-30 andetag/min) och koldioxidnivåer (2-7vol%). Mätdata från ”smartphone capnography” jämfördes med mätdata från en IR-analysator. Resultaten visar att kapnogram från ”Smartphone capnography” är jämförbara med kapnogram från IR-analysatorn och att den uppskattade noggrannheten är ±0,25vol% för upp till 6 dagars användning. De goda resultaten motiverar fortsatt utveckling av konceptet smartphone capnography samt de olika mätteknikerna.

Pressure Based Spirometry: Mobile Spirometry Using a Pressure Transducer

January 2013 (has links)
abstract: Spirometry is a type of pulmonary function test that measures the amount of air volume and the speed of air flow from a patient's breath in order to assess lung function. The goal of this project is to develop and validate a mobile spirometer technology based on a differential pressure sensor. The findings in this paper are used in a larger project that combines the features of a capnography device and a spirometer into a single mobile health unit known as the capno-spirometer. The following paper discusses the methods, experiments, and prototypes that were developed and tested in order to create a robust and accurate technology for all of the spirometry functions within the capno-spirometer. The differential pressure sensor is set up with one inlet measuring the pressure inside the spirometer tubing and the other inlet measuring the ambient pressure of the environment. The inlet measuring the inside of the tubing is very sensitive to its orientation and position with respect to the path of the air flow. It is found that taking a measurement from the center of the flow is 50% better than from the side wall. The sensor inlet is optimized at 37 mm from the mouthpiece inlet. The unit is calibrated by relating the maximum pressure sensor voltage signal to the peak expiratory flow rate (PEF) taken during a series of spirometry tests. In conclusion, this relationship is best represented as a quadratic function and a calibration equation is computed to provide a flow rate given a voltage change. The flow rates are used to calculate the four main spirometry parameters: PEF, FVC, FEV1, and FER. These methods are then referenced with the results from a commercial spirometer for validation. After validation, the pressure-based spirometry technology is proven to be both robust and accurate. / Dissertation/Thesis / M.S. Mechanical Engineering 2013

A Portable Colorimetric Sensing Platform for the Evaluation of Carbon Dioxide in Breath

January 2017 (has links)
abstract: This work describes the development of a device for measuring CO2 in breath, which has applications in monitoring a variety of health issues, such as Chronic Obstructive Pulmonary Disease (COPD), asthma, and cardiovascular disease. The device takes advantage of colorimetric sensing technology in order to maintain a low cost and high user-friendliness. The sensor consists of a pH dye, reactive element, and base coated on a highly porous Teflon membrane. The transmittance of the sensor is measured in the device via a simple LED/photodiode system, along with the flow rate, ambient relative humidity, and barometric pressure. The flow is measured by a newly developed flow meter described in this work, the Confined Pitot Tube (CPT) flow meter, which provides a high accuracy with reduced flow-resistance with a standard differential pressure transducer. I demonstrate in this work that the system has a high sensitivity, high specificity, fast time-response, high reproducibility, and good stability. The sensor has a simple calibration method which requires no action by the user, and utilizes a sophisticated, yet lightweight, model in order to predict temperature changes on the sensor during breathing and track changes in water content. It is shown to be effective for measuring CO2 waveform parameters on a breath-by-breath basis, such as End-Tidal CO2, Alveolar Plateau Slope, and Beginning Exhalation Slope. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2017

Variaveis capnograficas e d-dimeros em pacientes com suspeita de tromboembolismo pulmonar / Capnography variables and d-dimer in patients with suspected pulmonary embolism

Moreira, Marcos Mello 12 August 2018 (has links)
Orientadores: Renato Giuseppe Giovanni Terzi, Ilma Aparecida Paschoal / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-12T22:30:15Z (GMT). No. of bitstreams: 1 Moreira_MarcosMello_D.pdf: 18313915 bytes, checksum: db1efb99a56b2256d14393f2e951147a (MD5) Previous issue date: 2009 / Resumo: Métodos para confirmar o diagnóstico de tromboembolismo pulmonar (TEP) são relativamente invasivos, de alto custo e nem sempre disponíveis. Justifica-se a busca de métodos mais acessíveis, de baixo custo, minimamente invasivos e que possam ser realizados à beira do leito. Foi objetivo deste estudo estabelecer um protocolo de triagem diagnóstica de TEP, minimamente invasivo e de baixo custo, usando para isto a capnografia volumétrica (CV) e o Oímero-O (DO) (ELISA Rápido), para pacientes internados em diferentes unidades de um hospital terciário, atentanto para as possíveis limitações deste protocolo. Foi realizado um estudo prospectivo e observacional com 92 pacientes. Um estudo prévio de CV em 114 voluntários estabeleceu o padrão de normalidade para as variáveis analisadas. No grupo TEP, a CV foi associada à gasometria arterial para cálculo das variáveis do espaço morto e à dosagem do DO. O padrão-ouro para diagnóstico de TEP foi dado pela cintilografia de inalação/perfusão e/ou, tomografia computadorizada helicoidal e/ou, arteriografia pulmonar. Isoladamente, a variável capnográfica que apresentou melhor sensibilidade e especificidade foi a fração tardia do espaço morto alveolar (tO/ate) (91% e 98%, respectivamente). Obteve-se um resultado falso-negativo para o DO e, para a tO/ate, um falso-positivo e três falso-negativos. Quando a tO/ate ,foi associada ao DO, conseguiu-se 100% sensibilidade e 17% de especificidade. Uma outra variável capnográfica importante, por sugerir função pulmonar prévia anormal, e por esta razão, sinalizar uma possível limitação da tO/ate, foi o slope da fase III do capnograma. Por meio dos dados da CV de ambos os grupos (controle e doentes), estabeleceu-se um protocolo que ajuda a direcionar a equipe multiprofissionál quando da suspeita clínica de TEP. / Abstract :Background: Tests used to confirm a diagnosis of pulmonary embolism (PE) are relatively invasive, costly and not always available. Minimally invasive methods that are more accessible, less expensive and easily applied should be sought. Objective: To establish a low-cost, minimally invasive, PE diagnostic protocol in hospitalized patients, using capnographic variables and ELlSA D-dimer (DD) to rule out PE. Methods: A prospective observational study was conducted in 92 patients with suspected PE. The values of reference group for volumetric capnography (VCap) were used in order to compare with patterns of patients with PE. The patients were submitted to arterial blood gas analysis (to calculate the dead space variables) and had the DD values determined. The diagnosis was confirmed through ventilation/perfusion scintigraphy, spiral computed tomography, pulmonary arteriogram, or combinations of the three. Results: The capnographic variable that presented the greatest sensitivity and specificity (91 % and 98%, respectively) was the late dead space fraction (fDlate). Our findings include one false-negative DD result, as well as three false-positive and eight false-negative fDlate results. The combination of the fDlate and DD testing presented 100% sensitivity and 17% specificity. Another important capnographic variable, the phase 111 slope, indicated a possible limitation of VCap, since it interferes with the calculation of fDlate. Conclusion: The protocol established could guide multiprofessional teams in the management of clinical suspicion of PE. We were able to determine that the phase 111 slope might interfere with the calculation of fDlate, especially in patients with a history of abnormal lung function. Throught VCap variables (control group and sickness); was possible establishes a protocol that guide the multiprofissional team in cases of PE. / Doutorado / Pesquisa Experimental / Doutor em Cirurgia

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