Functional garments for physiological sensing purposes have been utilized in several disciplinesi.e. sports, firefighting, military and medical. In most of the cases textile electrodes (Textrodes)embedded in the garment are employed to monitor vital signs and other physiologicalmeasurements. Electrical Bioimpedance (EBI) is a non-invasive and effective technology that canbe used for detection and supervision of different health conditions. In some specific applicationssuch as body composition assessment EBIS has shown encouraging results proving good degreeof effectiveness and reliability. In a similar way Impedance Cardiography (ICG) is anothermodality of EBI primarily concerned with the determination of Stroke Volume SV, indices ofcontractility, and other aspects of hemodynamics.EBI technology in the previously mentioned modalities can benefit from a integration with agarment; however, a successful implementation of EBI technology depends on the goodperformance of textile electrodes. The main weakness of Textrodes is a deficient skin-electrodeinterface which produces a high degree of sensitivity to signal disturbances. This sensitivity canbe reduced with a suitable selection of the electrode material and an intelligent and ergonomicgarment design that ensures an effective skin-electrode contact area.This research work studies the performance of textile electrodes and garments for EBIspectroscopy for Total Body Assessment and Transthoracic Electrical Bioimpedance (TEB) forcardio monitoring. Their performance is analyzed based on impedance spectra, estimation ofparameters, influence of electrode polarization impedance Zep and quality of the signals using asreference Ag/AgCl electrodes. The study includes the analysis of some characteristics of thetextile electrodes such as conductive material, skin-electrode contact area size and fabricconstruction.The results obtained in this research work present evidence that textile garments with a dry skinelectrodeinterface like the ones used in research produce reliable EBI measurements in bothmodalities: BIS for Total Body Assessment and TEB for Impedance Cardiography. Textiletechnology, if successfully integrated, may enable the utilization of EBI in both modalities andconsequently implementing wearable applications for home and personal health monitoring. / <p>QC 20121213</p>

Exaggerated cardiovascular reactivity (CVR) to stress has been implicated in the increased risk for cardiovascular disease (CVD) in individuals with posttraumatic stress disorder (PTSD), yet mixed results have been reported. The CVR research may have been confounded by underrepresentation of women, few studies using sophisticated cardiovascular measurement, and a lack of analyses of PTSD symptom clusters. The purpose of the present study was to examine if young civilian women (M ± SD = 29.89±7.33) with PTSD (n=17) demonstrate greater CVR than women with depression (n=12) or no mental illness controls (n=18), and to explore the relationships between CVR and PTSD symptom clusters. Participants were 56% Caucasian, 21% African American, 19% Hispanic, and 4% other. Systolic and diastolic blood pressure (SBP and DBP), heart rate (HR), and impedance cardiography derived cardiac output (CO) and total peripheral resistance (TPR) were utilized to examine CVR during speech preparation/delivery and math tasks. Between-group effects were observed during speech preparation - specifically, lower DBP reactivity for the PTSD group compared to the depression group (p < .05). Between-group effects were also evident during speech delivery, with a trend toward lower DBP reactivity for the PTSD group than the depression group (p <.08), higher CO reactivity for the PTSD group than controls (p <.01), and lower TPR reactivity for the PTSD group than the depression (p <.01) and control groups (p <.01). PTSD severity scores for DSM-IV-TR and DSM-5 were used as independent predictors of CVR in multiple regressions variables. The DSM-IV analysis did not provide significant associations. The DSM-5 yielded significant associations of avoidance and arousal clusters with SBP reactivity during math, a significant association avoidance with DBP reactivity during math, and significant associations of avoidance and arousal with HR reactivity during math. Further exploration of PTSD symptom clusters may provide a clearer picture of the relationship between PTSD/CVR. Higher reactivity and lower reactivity may both be associated with risk for CVD, albeit through separate mechanisms.

Tato diplomová práce se zabývá vytvořením modelu signálu impedančního měření srdce (ICG signál). Impedanční kardiografie podává informaci o změně srdečního objemu během srdečního cyklu. Modelování signálu předchází statistická analýza vzájemné pozice ICG signálu vzhledem k dalším mechanickým srdečním signálům. Konstrukce modelu vychází z reálných nasnímaných signálů. Konečný ICG model je začleněn do již existujícího modelu mechanických interakcí mezi srdcem a plícemi. Výsledkem je funkční model kardio-respiračních interakcí, který bude sloužit v dalších částech výzkumu laboratoře PRETA.

Darbo tikslas: Sukurti kiekybinius signalų morfologijos, atspindinčių širdies veiklos reguliavimą, jos audinių gyvybingumą bei centrinę hemodinamiką, vertinimo metodus. Uždaviniai: 1. Ištirti signalų dekompozicijos baigtiniu bazinių funkcijų rinkiniu (truncated signal representation) metodų tinkamum��, širdies veiklą, jos audinių gyvybingumą bei centrinę hemodinamiką aprašančių signalų, morfologijos analizei; 2. Sukurti signalų, atspindinčių širdies audinių gyvybingumą, optimalaus aprašymo metodą; 3. Sukurti centrinę hemodinamiką atspindinčio krūtinės ląstos impedanso signalo struktūrinės bei morfologinės analizės metodą; 4. Sukurti elektrokardiogramos P-bangos morfologijos dinamikos, atspindinčios širdies veiklos autonominį reguliavimą, kiekybinio įvertinimo metodą. / The aim: To elaborate the quantitative methods for evaluation of morphology of the signals reflecting viability of heart tissue, heart function control and central/peripheral hemodynamics. Objectives: 1. Investigation of usefulness truncated signal representation methods for analysis of morphology of the signals reflecting viability of heart tissue, heart function control and central/peripheral hemodynamics; 2. Elaboration of method for optimal representation of signals reflecting heart tissue viability; 3. Elaboration of method for quantitative evaluation of ECG P-wave morphology dynamics reflecting autonomous heart function control; 4. Elaboration of method for structural and morphological analysis of the chest impedance signals reflecting central hemodynamics.

Disertacijoje iškelta sergančiųjų ūminiu miokardo infarktu ir cukriniu diabetu asmenų nepalankios ligos eigos problema bei apžvelgos galimybės prognozuoti tokių asmenų ligos baigtis.Darbo uždaviniais buvo: 1) įvertinti širdies ritmo variabilumo ir hemodinamikos žymenis sergantiesiems ūminiu miokardo infarktu bei cukriniu diabetu priklausomai nuo ligos eigos ir baigčių, palyginti juos su nesergančiųjų cukrininu diabetu atitinkamais žymenimis; 2) nustatyti sergančiųjų miokardo infarktu prognozinę širdies ritmo variabilumo ir hemodinamikos žymenų vertę mirties, skilvelinės aritmijos, grįžtamosios išemijos išsivystymui ar jungtinei vertinamajai baigčiai stacionare; 3) nustatyti prognozinę širdies ritmo variabilumo ir hemodinamikos žymenų vertę per 1 metus ir per 5 metus po persirgto miokardo infarkto įvykusiems: mirčiai dėl bet kokios ir dėl širdinės priežasties, pakartotino miokardo infarkto išsivystymui, neplanuotos širdies revaskuliarizacijos procedūros atlikimui, nekomplikuotos išeminės širdies ligos eigos buvimui; 4) nustatyti ar prognozinė širdies ritmo variabilumo ir hemodinamikos žymenų vertė analizuojamoms baigtims skiriasi tiriamųjų grupėse: a) cukriniu diabetu sergančiųjų asmenų, b) cukriniu diabetu nesergančiųjų asmenų; 5) gautų prognozinių modelių diskriminuojančias savybes palyginti tarpusavyje ir su pripažintais ūminio miokardo infarkto rizikos vertinimo kriterijais (kairiojo skilvelio išstūmio frakcija, GRACE ir TIMI rizikos vertinimo skalėmis). / Unfavourable outcomes of the diabetic patients with acute myocardial infarction were analysed in the dissertation and possibilities to predict the course of the disease was reviewed. The objectives of the study were: 1) to evaluate the measures of heart rate variability and impedance cardiography for the patients with acute myocardial infarction, and their alterations in reliance on the different outcomes, according to the patients’ status of diabetes mellitus; 2) to determine prognostic value of combined assessment of heart rate variability and impedance cardiographymeasures for in-hospital outcomes of myocardial infarction: in-hospital mortality, ventricular arrhythmia, recurrent ischemia and complicated in-hospital course; 3) to determine prognostic value of combined assessment of heart rate variability and impedance cardiography measures for long-term (1 and 5 years) outcomes after myocardial infarction: mortality (both all-cause death and cardiac death), ischemic complications (recurrent non-fatal myocardial infarction and need for revascularization procedures) and uncomplicated long-term course; 4) to assess whether prognostic value of combined heart rate variability and hemodynamic measures differs in separate patient groups: diabetic or non-diabetic; 5) to compare the discriminative power of the obtained prognostic models and widely recognized risk markers, such as ejection fraction of the left ventricle, GRACE and TIMI scores.

This thesis deals with the methodology of use of whole-body impedance cardiography for evaluation of pulse wave velocity. The first three chapters explain selected hemodynamic properties of the arterial system related to the issue of pulse wave propagation. At the same time the ordinary methods for estimation, its disadvantages and merits has been summarized. Points at issue of whole-body impedance evaluation methodology for pulse wave velocity are researched in second part of this thesis. In order that analysis the procedure for correct methodology has been determined. Particularly determination of reference proximal point for calculation of transit time towards aortic valve, and design and accuracy of transit distance measurement were discussed. Based on the obtained data, a calculation of representative pulse wave velocity to eight limb locations was performed.

This thesis deals with the possibility of using impedance cardiography for calculating cardiac output. Kubicek’s, Sramek‘s and Sramek-Bernstein‘s methods are discussed here. These methods were applied to a data set, obtained by measuring on subjects with implanted cardiostimulators. The subjects’ heart rate was being changed by the programing of cardiostimulators. Thanks to this procedure the measured data were not affected by artifacts, connected with the heart rate change caused by a body stress, or other influences. An influence of heart rate on a cardiac output value based on the statistical processing of the data set was studied.

This Mater's thesis deals with the evaluation of pulse wave velocity using multi-channel whole-body impedance cardiography. Data were taken from the group of healthy volunteers whose impedance changes were measured during rest, respiratory maneuvers, tilt and stress exercise. The result of this measurement are values of peaks of pulse wave time shifts towards R-wave. The velocity values towards the thorax electrodes were recalculated on the basis of knowledge about the pulse wave time shifts and the distances from the heart to the scanned locations, which were measured using the arterial segment's lengths.