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.

No description available.

Goal of this thesis is to develop portable monitoring station for radio spectrum monitoring and its controlling application for use by Czech Telecommunication Office. The station is based on Software Defined Radio (SDR) and capable of monitoring in the range of 1 MHz - 6 GHz. Developed application controls not only the SDR but also the external RF unit (including choice of receiving antenna, filter, optional amplification/attenuation and azimuth of antenna rotator). Measurement processed by computer and displayed graphically in form of spectrum diagram and waterfall diagram. Furthermore, the application will perform spectral measurement in compliance with requirements of International Telecommunication Union. The application is also capable of recording into the file and of analyzing historical data from the previous measurement.

A growing number of factors, including costs, technological advancements, ageing populations, and medical errors, are leading industrialized countries to invest in research on alternative solutions to improve their health-care systems and increase patients’ quality of life. Personal health systems (PHS) examplify the use of information and communication technologies that enable a paradigm shift from the traditional hospital-centered healthcare delivery model toward a preventive and person-centered approach. PHS offer the means to monitor a patient’s health using wearable, portable or implantable systems that offer ubiquitous, unobtrusive biodata acquisition, allowing remote monitoring of treatment and access to the patient’s status. Electrical bioimpedance (EBI) technology is non-invasive, quick and relatively affordable technique that can be used for assessing and monitoring different health conditions, e.g., body composition assessments for nutrition. When combined with state-of-the-art advances in sensors and textiles, EBI technologies are fostering the implementation of wearable bioimpedance monitors that use functional garments for personalized healthcare applications. This research work is focused on the development of wearable EBI-based monitoring systems for ubiquitous health monitoring applications. The monitoring systems are built upon portable monitoring instrumentation and custom-made textile electrode garments. Portable EBI-based monitors have been developed using the latest material technology and advances in system-on-chip technology. For instance, a portable EBI spectrometer has been validated against a commercial spectrometer for total body composition assessment using functional textile electrode garments. The development of wearable EBI-based monitoring units using functional garments and dry textile electrodes for body composition assessment and respiratory monitoring has been shown to be a feasible approach. The availability of these measurement systems indicates progress toward the real implementation of personalized healthcare systems. / <p>QC 20170517</p>

Tracheal respiratory sounds analysis has been investigated as a non-invasive method to estimate respiratory flow and upper airway obstruction. However, the flow-sound relationship is highly variable among subjects which makes it challenging to estimate flow in general applications. Therefore, a robust model for acoustical flow estimation in a large group of individuals did not exist before. On the other hand, a major application of acoustical flow estimation is to detect flow limitations in patients with obstructive sleep apnea (OSA) during sleep. However, previously the flow--sound relationship was only investigated during wakefulness among healthy individuals. Therefore, it was necessary to examine the flow-sound relationship during sleep in OSA patients. This thesis takes the above challenges and offers innovative solutions. First, a modified linear flow-sound model was proposed to estimate respiratory flow from tracheal sounds. To remove the individual based calibration process, the statistical correlation between the model parameters and anthropometric features of 93 healthy volunteers was investigated. The results show that gender, height and smoking are the most significant factors that affect the model parameters. Hence, a general acoustical flow estimation model was proposed for people with similar height and gender. Second, flow-sound relationship during sleep and wakefulness was studied among 13 OSA patients. The results show that during sleep and wakefulness, flow-sound relationship follows a power law, but with different parameters. Therefore, for acoustical flow estimation during sleep, the model parameters should be extracted from sleep data to have small errors. The results confirm reliability of the acoustical flow estimation for investigating flow variations during both sleep and wakefulness. Finally, a new method for sleep apnea detection and monitoring was developed, which only requires recording the tracheal sounds and the blood's oxygen saturation level (SaO2) data. It automatically classifies the sound segments into breath, snore and noise. A weighted average of features extracted from sound segments and SaO2 signal was used to detect apnea and hypopnea events. The performance of the proposed approach was evaluated on the data of 66 patients. The results show high correlation (0.96,p < 0.0001) between the outcomes of our system and those of the polysomnography. Also, sensitivity and specificity of the proposed method in differentiating simple snorers from OSA patients were found to be more than 91%. These results are superior or comparable with the existing commercialized sleep apnea portable monitors.

Tracheal respiratory sounds analysis has been investigated as a non-invasive method to estimate respiratory flow and upper airway obstruction. However, the flow-sound relationship is highly variable among subjects which makes it challenging to estimate flow in general applications. Therefore, a robust model for acoustical flow estimation in a large group of individuals did not exist before. On the other hand, a major application of acoustical flow estimation is to detect flow limitations in patients with obstructive sleep apnea (OSA) during sleep. However, previously the flow--sound relationship was only investigated during wakefulness among healthy individuals. Therefore, it was necessary to examine the flow-sound relationship during sleep in OSA patients. This thesis takes the above challenges and offers innovative solutions. First, a modified linear flow-sound model was proposed to estimate respiratory flow from tracheal sounds. To remove the individual based calibration process, the statistical correlation between the model parameters and anthropometric features of 93 healthy volunteers was investigated. The results show that gender, height and smoking are the most significant factors that affect the model parameters. Hence, a general acoustical flow estimation model was proposed for people with similar height and gender. Second, flow-sound relationship during sleep and wakefulness was studied among 13 OSA patients. The results show that during sleep and wakefulness, flow-sound relationship follows a power law, but with different parameters. Therefore, for acoustical flow estimation during sleep, the model parameters should be extracted from sleep data to have small errors. The results confirm reliability of the acoustical flow estimation for investigating flow variations during both sleep and wakefulness. Finally, a new method for sleep apnea detection and monitoring was developed, which only requires recording the tracheal sounds and the blood's oxygen saturation level (SaO2) data. It automatically classifies the sound segments into breath, snore and noise. A weighted average of features extracted from sound segments and SaO2 signal was used to detect apnea and hypopnea events. The performance of the proposed approach was evaluated on the data of 66 patients. The results show high correlation (0.96,p < 0.0001) between the outcomes of our system and those of the polysomnography. Also, sensitivity and specificity of the proposed method in differentiating simple snorers from OSA patients were found to be more than 91%. These results are superior or comparable with the existing commercialized sleep apnea portable monitors.

Introdução: A apneia obstrutiva do sono (AOS) é caracterizada por episódios repetidos de colapso parcial ou completo das vias aéreas superiores durante o sono, resultando em eventos respiratórios caracterizados por hipopneias ou apneias, respectivamente. Os eventos respiratórios podem resultar em fragmentação do sono, hipoxemia recorrente e geração de pressão intratorácica negativa. Todos esses mecanismos são potencialmente deletérios ao sistema cardiovascular. A AOS é comum entre pacientes com doença cardiovascular, porém ainda é pouco reconhecida. O padrão ouro para o diagnóstico da AOS é a Polissonografia (PSG) completa. O acesso a PSG completa é limitado, contribuindo para o subdiagnóstico da AOS. A poligrafia noturna de variáveis respiratórias (PGR) é um método simplificado, sendo uma alternativa promissora para o diagnóstico da AOS. No entanto, estudos de validação de PGR incluíram somente populações pré-selecionadas ou referidas para laboratórios de sono e excluíram pacientes com comorbidades significativas. Atualmente a Academia Americana de Medicina do sono reconhece o uso da PGR para o diagnóstico da AOS em pacientes com alta probabilidade pré-teste de AOS moderada a grave e em pacientes sem comorbidades significativas. Objetivo: Validar a PGR para o diagnóstico de AOS entre pacientes consecutivos avaliados para cirurgia de revascularização miocárdica, portanto, com Doença Arterial Coronariana (DAC). Avaliar a prevalência da AOS e a utilidade dos sintomas clínicos para o diagnóstico da AOS entre os pacientes com DAC. Métodos: Pacientes com indicação de revascularização do miocárdio foram avaliados através de exames clínicos e laboratoriais de rotina, escala de sonolência diurna (Epworth) e risco clínico de apneia do sono (questionário de Berlin), ecocardiograma, PSG e PGR. A PGR utilizada é classificada como tipo 3, com os seguintes canais: fluxo de ar, esforço respiratório, oximetria de pulso, frequência de pulso, ronco e sensor de posição, (Stardust II ®). Resultados: Foram estudados 70 pacientes consecutivos (76% do sexo masculino); idade (média DP) = 58 ± 7 anos, índice de massa corpórea (IMC) [mediana (25-75%)] = 27,6 (25,8-31,1) kg/m2. Vinte pacientes (29%) apresentaram fração de ejeção do ventrículo esquerdo (FEVE) 45%. A PSG da população revelou índice de apneia e hipopneia (IAH)= 2320 eventos/h. A prevalência de AOS com um IAH 5, 15 e 30 eventos/h foi de 87%, 54% e 27%, respectivamente. A sonolência diurna medida pela escala de Epworth e o risco clínico de AOS verificado pelo questionário de Berlin foram pobres preditores de AOS. A sensibilidade / especificidade da PGR para detectar AOS (IAH 5 eventos/h) e AOS grave (IAH 30 eventos/h) foram 0,92/0,67% e 0,42/0,92%, respectivamente. A média da diferença do IAH entre os dois métodos diagnósticos apresentada no Bland-Altman foi de + 5,3, indicando que os valores do IAH da PGR foram em média inferiores aos da PSG. O desvio padrão da diferença foi de 14,6 eventos/hora, apresentando uma considerável concordância entre o IAH da PSG e da PGR. Conclusão: Este estudo valida o uso da PGR para o diagnóstico da AOS em uma população de pacientes consecutivos, avaliados para revascularização do miocárdio, em quem a doença cardíaca é significativa. A prevalência de AOS entre pacientes com DAC é alta atingindo mais de 50% dessa população. No entanto, os sintomas clínicos, nessa população, não são preditores adequados de AOS. Em função da alta prevalência de AOS e baixa especificidade de sintomas clínicos, nossos dados sugerem que a PGR é um instrumento promissor para a avaliação de pacientes com DAC avaliados para cirurgia de revascularização do micárdio / Introduction: Obstructive sleep apnea (OSA) is characterized by repeated episodes of partial or complete collapse of the upper airway during sleep, resulting in respiratory events characterized by hypopnea or apnea, respectively. Respiratory events may result in sleep fragmentation, hypoxemia and recurrent generation of negative intrathoracic pressure. All these mechanisms are potentially harmful to the cardiovascular system. OSA is common among patients with cardiovascular disease, but is still poorly recognized. The gold standard for diagnosis of OSA is polysomnography (PSG). Access to full PSG is limited, contributing to the under diagnosis of OSA. The polygraph nocturnal of respiratory variables (PGR) is a simplified method, being a promising alternative for the diagnosis of OSA. However, validation studies of PGR only included populations pre-selected or referred to sleep laboratories and excluded patients with significant comorbidities. Currently the American Academy of Sleep Medicine recognizes the use of PGR for the diagnosis of OSA in patients with high pretest probability of moderate to severe OSA and in patients without significant comorbidities. Objective: Validate the PGR for the diagnosis of OSA among consecutive patients evaluated for coronary artery bypass grafting (CABG), therefore with Coronary Artery Disease (CAD). To assess the prevalence of OSA and to evaluate the usefulness of clinical symptoms for diagnosis of OSA among patients with CAD. Methods: Patients with indication of CABG were evaluated by clinical examination and routine laboratory, the scale of daytime sleepiness (Epworth) and clinical risk of sleep apnea (Berlin questionnaire), echocardiogram, PSG and PGR. The PGR use is classified as type 3, with the following channels: airflow, respiratory effort, pulse oximetry, pulse rate, snoring and position sensor, (Stardust II ®). Results: We studied 70 consecutive patients (76% male); age (mean SD) = 58 ± 7 years; body mass index (BMI), [median (25-75%)] = 27,6 (25,8 to 31,1) kg/m2. Twenty patients (29%) had left ventricular ejection fraction (LVEF) 45%. The PSG of population showed apnea-hypopnea index (AHI) = 23 20 events / h. The prevalence of OSA with an AHI 5, 15 and 30 events / h was 87%, 54% and 27%, respectively. Daytime sleepiness measured by Epworth Sleepiness Scale and the clinical risk of OSA verified by the Berlin questionnaire were poor predictors of OSA. The sensitivity and specificity to detect OSA (AHI 5 events / h) and severe OSA (AHI 30 / events) of the PGR were 0,92/0,67% and 0,42/0,92%, respectively. The average difference in AHI between the two diagnostic methods presented in Bland-Altman was + 5,3, indicating that the values of the AHI of the PGR were on average lower than the PSG. The standard deviation of the difference was 14,6 events / hour, presenting a considerable agreement between the AHI of PSG and the PGR. Conclusion: This study validates the use of PGR for the diagnosis of OSA in a population of consecutive patients evaluated for CABG, in whom heart disease is significant. The prevalence of OSA among patients with CAD is high reaching over 50% of this population. However, the clinical symptoms are not adequate predictors of OSA in this population. Due to the high prevalence of OSA and low specificity of clinical symptoms, our data suggest that the PGR is a promising tool for the assessment of CAD patients evaluated for surgery for the CABG

Introdução: A apneia obstrutiva do sono (AOS) é caracterizada por episódios repetidos de colapso parcial ou completo das vias aéreas superiores durante o sono, resultando em eventos respiratórios caracterizados por hipopneias ou apneias, respectivamente. Os eventos respiratórios podem resultar em fragmentação do sono, hipoxemia recorrente e geração de pressão intratorácica negativa. Todos esses mecanismos são potencialmente deletérios ao sistema cardiovascular. A AOS é comum entre pacientes com doença cardiovascular, porém ainda é pouco reconhecida. O padrão ouro para o diagnóstico da AOS é a Polissonografia (PSG) completa. O acesso a PSG completa é limitado, contribuindo para o subdiagnóstico da AOS. A poligrafia noturna de variáveis respiratórias (PGR) é um método simplificado, sendo uma alternativa promissora para o diagnóstico da AOS. No entanto, estudos de validação de PGR incluíram somente populações pré-selecionadas ou referidas para laboratórios de sono e excluíram pacientes com comorbidades significativas. Atualmente a Academia Americana de Medicina do sono reconhece o uso da PGR para o diagnóstico da AOS em pacientes com alta probabilidade pré-teste de AOS moderada a grave e em pacientes sem comorbidades significativas. Objetivo: Validar a PGR para o diagnóstico de AOS entre pacientes consecutivos avaliados para cirurgia de revascularização miocárdica, portanto, com Doença Arterial Coronariana (DAC). Avaliar a prevalência da AOS e a utilidade dos sintomas clínicos para o diagnóstico da AOS entre os pacientes com DAC. Métodos: Pacientes com indicação de revascularização do miocárdio foram avaliados através de exames clínicos e laboratoriais de rotina, escala de sonolência diurna (Epworth) e risco clínico de apneia do sono (questionário de Berlin), ecocardiograma, PSG e PGR. A PGR utilizada é classificada como tipo 3, com os seguintes canais: fluxo de ar, esforço respiratório, oximetria de pulso, frequência de pulso, ronco e sensor de posição, (Stardust II ®). Resultados: Foram estudados 70 pacientes consecutivos (76% do sexo masculino); idade (média DP) = 58 ± 7 anos, índice de massa corpórea (IMC) [mediana (25-75%)] = 27,6 (25,8-31,1) kg/m2. Vinte pacientes (29%) apresentaram fração de ejeção do ventrículo esquerdo (FEVE) 45%. A PSG da população revelou índice de apneia e hipopneia (IAH)= 2320 eventos/h. A prevalência de AOS com um IAH 5, 15 e 30 eventos/h foi de 87%, 54% e 27%, respectivamente. A sonolência diurna medida pela escala de Epworth e o risco clínico de AOS verificado pelo questionário de Berlin foram pobres preditores de AOS. A sensibilidade / especificidade da PGR para detectar AOS (IAH 5 eventos/h) e AOS grave (IAH 30 eventos/h) foram 0,92/0,67% e 0,42/0,92%, respectivamente. A média da diferença do IAH entre os dois métodos diagnósticos apresentada no Bland-Altman foi de + 5,3, indicando que os valores do IAH da PGR foram em média inferiores aos da PSG. O desvio padrão da diferença foi de 14,6 eventos/hora, apresentando uma considerável concordância entre o IAH da PSG e da PGR. Conclusão: Este estudo valida o uso da PGR para o diagnóstico da AOS em uma população de pacientes consecutivos, avaliados para revascularização do miocárdio, em quem a doença cardíaca é significativa. A prevalência de AOS entre pacientes com DAC é alta atingindo mais de 50% dessa população. No entanto, os sintomas clínicos, nessa população, não são preditores adequados de AOS. Em função da alta prevalência de AOS e baixa especificidade de sintomas clínicos, nossos dados sugerem que a PGR é um instrumento promissor para a avaliação de pacientes com DAC avaliados para cirurgia de revascularização do micárdio / Introduction: Obstructive sleep apnea (OSA) is characterized by repeated episodes of partial or complete collapse of the upper airway during sleep, resulting in respiratory events characterized by hypopnea or apnea, respectively. Respiratory events may result in sleep fragmentation, hypoxemia and recurrent generation of negative intrathoracic pressure. All these mechanisms are potentially harmful to the cardiovascular system. OSA is common among patients with cardiovascular disease, but is still poorly recognized. The gold standard for diagnosis of OSA is polysomnography (PSG). Access to full PSG is limited, contributing to the under diagnosis of OSA. The polygraph nocturnal of respiratory variables (PGR) is a simplified method, being a promising alternative for the diagnosis of OSA. However, validation studies of PGR only included populations pre-selected or referred to sleep laboratories and excluded patients with significant comorbidities. Currently the American Academy of Sleep Medicine recognizes the use of PGR for the diagnosis of OSA in patients with high pretest probability of moderate to severe OSA and in patients without significant comorbidities. Objective: Validate the PGR for the diagnosis of OSA among consecutive patients evaluated for coronary artery bypass grafting (CABG), therefore with Coronary Artery Disease (CAD). To assess the prevalence of OSA and to evaluate the usefulness of clinical symptoms for diagnosis of OSA among patients with CAD. Methods: Patients with indication of CABG were evaluated by clinical examination and routine laboratory, the scale of daytime sleepiness (Epworth) and clinical risk of sleep apnea (Berlin questionnaire), echocardiogram, PSG and PGR. The PGR use is classified as type 3, with the following channels: airflow, respiratory effort, pulse oximetry, pulse rate, snoring and position sensor, (Stardust II ®). Results: We studied 70 consecutive patients (76% male); age (mean SD) = 58 ± 7 years; body mass index (BMI), [median (25-75%)] = 27,6 (25,8 to 31,1) kg/m2. Twenty patients (29%) had left ventricular ejection fraction (LVEF) 45%. The PSG of population showed apnea-hypopnea index (AHI) = 23 20 events / h. The prevalence of OSA with an AHI 5, 15 and 30 events / h was 87%, 54% and 27%, respectively. Daytime sleepiness measured by Epworth Sleepiness Scale and the clinical risk of OSA verified by the Berlin questionnaire were poor predictors of OSA. The sensitivity and specificity to detect OSA (AHI 5 events / h) and severe OSA (AHI 30 / events) of the PGR were 0,92/0,67% and 0,42/0,92%, respectively. The average difference in AHI between the two diagnostic methods presented in Bland-Altman was + 5,3, indicating that the values of the AHI of the PGR were on average lower than the PSG. The standard deviation of the difference was 14,6 events / hour, presenting a considerable agreement between the AHI of PSG and the PGR. Conclusion: This study validates the use of PGR for the diagnosis of OSA in a population of consecutive patients evaluated for CABG, in whom heart disease is significant. The prevalence of OSA among patients with CAD is high reaching over 50% of this population. However, the clinical symptoms are not adequate predictors of OSA in this population. Due to the high prevalence of OSA and low specificity of clinical symptoms, our data suggest that the PGR is a promising tool for the assessment of CAD patients evaluated for surgery for the CABG

The thesis describes methods for spectrum monitoring, which are used by the Czech telecommunication office. The thesis describes a design of an RF unit for a portable monitoring station and its potential use. The RF unit consists of several devices, which are connected. Devices like an antenna, a rotator, a rotator control unit, coaxial switches, an amplifier and attenuator were chosen as commercially available devices. It is also described, why were these devices chosen. Other devices such as filters, a control unit for the RF unit and a power supply were designed. The RF unit is controlled by a computer. A software for spectrum monitoring contains a graphical user interface for the RF unit control.