Abstract Multimodal measurements are increasingly being employed in the study of human physiology. Brain studies in particular can draw advantage of simultaneous measurements using different modalities to analyse correlations, mechanisms and relationships of physiological signals and their dynamics in relation to brain functions. Moreover, multimodal measurements help to identify components of physiological dynamics generated specifically by the brain. This thesis summarizes the study, design and development of non-invasive medical instruments that can be utilized in conjunction with magnetic resonance imaging (MRI). A key challenge in the development of measurement methods is posed by the extraordinary requirements that the MRI environment poses - all materials need to be MR-compatible and the selected instruments and devices must not be affected by the strong magnetic field generated by the MRI scanner nor the MRI by the instruments placed within its scanning volume. The presented methods allow simultaneous continuous measurement of heart rate (HR) and metabolism from the brain cortex as well as pulse wave velocity (PWV) and blood pressure measurements in synchrony with electroencephalography (EEG) and MRI. Furthermore, the thesis explored the reliability and accuracy of the responses gathered by the developed instruments and, using new experimental methods, estimated the propagation of near-infrared light in the human brain. The goal of the novel multimodal measurement environment is to provide more extensive tools for medical researchers, neurologists in particular, to acquire accurate information on the function of the brain and the human body. Measurements have been performed on more than 70 persons using the presented multimodal setup to study such factors as the correlation between blood oxygen level-dependent (BOLD) data and low-frequency oscillations (LFOs) during the resting state. / Tiivistelmä Multimodaalisia kuvantamismenetelmiä käytetään enenevässä määrin ihmisen fysiologian ja elintoimintojen tutkimisessa. Erityisesti aivotutkimuksessa samanaikaisesti useammalla modaliteetilla mittaaminen mahdollistaa erilaisten fysiologisten mekanismien ja niiden korrelaatioiden tutkimisen kehon ja aivotoimintojen välillä. Lisäksi multimodaaliset mittaukset auttavat yksilöimään fysiologiset komponentit toisistaan ja identifioimaan aivojen tuottamia fysiologisia signaaleja. Tämä väitöskirja kokoaa tutkimustyön sekä laite- ja instrumentointisuunnittelun ja sen kehittämistyön ei-invasiivisesti toteutettujen lääketieteen mittausmenetelmien käyttämiseksi magneettikuvauksen aikana. Erityishaasteena työssä on ollut magneettikuvausympäristö, joka asettaa erityisvaatimuksia mm. mittalaitteissa käytettäville materiaaleille sekä laitteiden häiriönsiedolle magneettikuvauslaitteen aiheuttaman voimakkaan magneettikentän takia. Kehitettävät mittausmenetelmät eivät myöskään saa aiheuttaa häiriöitä magneettikuvauslaitteen tuottamalle kuvainformaatiolle. Väitöskirjassa esitettävät mittausmenetelmät tekevät mahdolliseksi mitata magneettikuvausympäristössä ihmisen sydämen sykettä, veren virtauksen kulkunopeutta ja verenpaineen vaihteluja sekä aivokuoren metaboliaa - kaikki synkronissa aivosähkökäyrän mittaamisen ja magneettikuvantamisen kanssa. Lisäksi väitöskirjassa tutkitaan kehitettyjen mittausmenetelmien antamaa mittaustarkkuutta sekä arvioidaan lähi-infrapunavalon etenemistä ihmisen aivoissa uudenlaisella menetelmällä. Kehitetyllä multimodaalisella mittausympäristöllä on tavoitteena antaa lääketieteen alan tutkijoille, erityisesti neurologeille, käyttöön mittausmenetelmiä, joiden avulla voidaan tutkia ihmisen aivojen ja kehon välisiä toimintoja aiempaa kattavammin. Laitekokonaisuudella on tutkittu jo yli 70:tä henkilöä. Näissä mittauksissa on tutkittu mm. veren happitasojen hitaita vaihteluja ihmisen aivojen ollessa lepotilassa, ns. resting state -tilassa.

Estudamos 62 pacientes, que com teste ergométrico positivo, manifestaram angina estável e estavam sob controle farmacológico. Todos apresentavam cinecoronariografia mostrando obstrução >70% em pelo menos uma das principais artérias coronárias. Objetivamos avaliar parâmetros eletrocardiográficos e de pressão arterial, durante procedimento odontológico restaurador sob anestesia local com e sem vasoconstritor em presença de doença arterial coronária. As idades variaram de 39 a 80, média de 58,7±8,8 anos, sendo 51 (82,3%) homens. Trinta pacientes foram randomizados para receber anestesia local com solução de lidocaína a 2% com adrenalina 1:100.000 e os demais para lidocaína a 2% sem vasoconstritor. Todos os pacientes foram submetidos à monitorização ambulatorial da pressão arterial (MAPA) e eletrocardiografia dinâmica por 24 horas, iniciados 2 horas antes do procedimento odontológico. Consideramos 3 períodos de registro: (1) basal - os 60 minutos que antecederam ao procedimento odontológico; (2) procedimento - desde o início da anestesia até o final do procedimento odontológico restaurador; (3) subseqüente completar das 24 horas. A análise de variância com medidas repetidas mostrou que houve elevação significativa da pressão arterial sistólica e diastólica do período basal para o procedimento nos dois grupos estudados (aproximadamente 14mmHg e 5 a 7mmHg) respectivamente, quando analisados separadamente e quando confrontados não apresentaram diferença de comportamento entre si. A freqüência cardíaca não se alterou nos dois grupos estudados. Depressão do segmento ST >1mm ocorreu em 10 (17,9%) pacientes; todos os eventos ocorreram no mínimo 2 horas após o término do procedimento odontológico. Extra - sístoles supra-ventriculares e/ou extra-sístoles ventriculares em número maior do que 10/hora estiveram presentes em 17 (30,4%) pacientes durante as 24 horas e durante o período do procedimento em 7 (12,5%), sendo 4 (13,8%) do grupo que recebeu anestesia sem adrenalina e 3 (11,1%) do grupo que recebeu anestesia com adrenalina e o teste Exato de Fisher não mostrou diferença entre os grupos. Concluímos que não houve diferença em relação ao comportamento de pressão arterial, freqüência cardíaca, evidência de isquemia e arritmias entre os grupos. O uso associado de vasoconstritor mostrou-se, portanto, seguro dentro dos limites do estudo. / We enrolled 62 patients with positive exercise stress test who presented with stable angina and were receiving drug therapy. All had a coronary angiography screening showing >70% obstruction in at least one of the main coronary arteries. The study aimed to compare electrocardiographic and blood pressure parameters during restorative dentistry procedure under local anesthesia, both with and without vasoconstrictor, in the presence of coronary artery disease. Ages ranged from 39 to 80, (mean ± SD) 58.7±8.8 years, 51 (82.3%) of them were male. Thirty patients were randomly assigned to receive 2% lidocaine local anesthesia with 1:100,000 epinephrine, the others receiving 2% lidocaine without vasoconstrictor. All the patients underwent ambulatory blood pressure and 24-hour Holter monitoring, beginning two hours ahead of the dental procedure. Recording were made during (1) baseline - 60-minute period before dental procedure began; (2) procedure - from beginning of anesthesia until the end of the procedure; and (3) subsequent 24-hour period. Analysis of variance with repeat measures showed significant diastolic and systolic blood pressure increases from baseline to the period of the procedure, in the two study groups (approximately 14 mm Hg, and 5 to 7 mm Hg, respectively); both in a separate analysis and in a comparative analysis no significant difference between them could be confirmed. Heart rate did not change in neither of the two groups. ST-segment >1 mm depression was detected in 10 (17.9%) patients; all these events occurred at least two hours after the end of the dentistry procedure. Premature supraventricular systoles and/or premature ventricular systoles in a greater number than 10/hour were seen in 17 (30.4%) patients in the 24-hours period after the procedure; during the procedure they occurred in 7 (12.5%) patients, of whom 4 (13.8%) were in the group without, and 3 (11.1%) in the group with vasoconstrictor. The Fisher\'s exact test revealed no difference between the groups. We concluded that there was no difference of blood pressure, heart rate, evidence of ischemia or arrhythmia episodes between the groups. Thus, the associated use of vasoconstrictor proved to be safe within the limits of this study

INTRODUÇÃO: A incidência de doença arterial coronária em candidatos a transplante renal é alta, sendo a principal causa de mortes neste grupo de pacientes. Os resultados obtidos com exames não invasivos usados na detecção de doença arterial coronariana destes pacientes têm-se mostrado variados e, de modo geral, insatisfatórios para uma condição clínica considerada grave. A ressonância magnética cardiovascular é utilizada cada vez mais no estudo de doença arterial coronária na população geral, apresentando bons resultados na identificação de isquemia e de fibrose miocárdica. Entretanto, este método, até o momento, não foi avaliado neste grupo de pacientes. O objetivo deste trabalho é avaliar a capacidade da ressonância magnética cardíaca em detectar doença arterial coronária em candidatos a transplante renal sob dois diferentes aspectos: diagnóstico de lesão coronariana significativa (redução do diâmetro luminal maior ou igual a 70%), avaliada pela alteração da perfusão miocárdica, comparando os resultados com a cintilografia e tendo a angiografia coronária como padrão de referência; e detecção de infarto miocárdico silencioso, comparando com a eletrocardiografia e cintilografia, tendo a ressonância magnética cardiovascular com a técnica de realce tardio como padrão de referência. MÉTODOS: Durante o período de janeiro de 2002 e janeiro de 2004 foram estudados 80 candidatos a transplante renal que apresentavam ao menos um dos seguintes critérios de inclusão: 1. idade igual ou acima de 50 anos; 2. diabete melito; 3. história ou evidência clínica de doença cardiovascular. Todos os pacientes foram encaminhados para serem submetidos a exames de eletrocardiografia, cintilografia, ressonância magnética cardiovascular e angiografia coronária no período máximo de até um ano entre os exames. Na pesquisa de alteração da perfusão miocárdica, comparou-se ressonância magnética cardiovascular com cintilografia em 76 pacientes, tendo a angiografia coronária como padrão de referência na identificação de lesão coronária significativa (estenose igual ou maior que 70% da luz vascular). Na identificação de infarto miocárdico silencioso, comparou-se a ressonância magnética cardiovascular com a eletrocardiografia e cintilografia em 69 pacientes. Os exames foram analisados de modo cego em relação aos resultados dos demais exames. Dados numéricos foram expressos como média, desvio padrão e intervalo de confiança, sendo calculado grau de concordância, testes diagnóstico e de significância entre os métodos. RESULTADOS: Na pesquisa de obstrução coronária significativa, a ressonância magnética cardiovascular apresentou sensibilidade, especificidade e acurácia de 84,1%, 56,3% e 72,4% e a cintilografia miocárdica 65,9%, 68,6% e 67,1%, respectivamente. A ressonância magnética cardiovascular foi significativamente mais sensível que a cintilografia (p=0,039). Na identificação de infarto miocárdico silencioso, o grau de concordância entre a ressonância magnética cardiovascular e o eletrocardiograma foi de 0,28 e entre a ressonância magnética cardiovascular e a cintilografia 0,52. Considerando-se a ressonância magnética cardiovascular como sendo o padrão de referência na identificação de infarto miocárdico silencioso, a sensibilidade, especificidade e acurácia do eletrocardiograma foram de 27,8%, 98% e 79,7% e da cintilografia foram de 66,7%, 87% e 81,2%, respectivamente. CONCLUSÃO: No diagnóstico de lesão coronariana significativa, a ressonância magnética cardiovascular mostrou acurácia similar e maior sensibilidade em relação à cintilografia. Na detecção de infarto miocárdico silencioso, o eletrocardiograma e a cintilografia apresentaram baixa concordância com a ressonância magnética cardiovascular / INTRODUCTION: Coronary artery disease in renal transplant candidates is frequent and is the most common cause of death. Results of standard noninvasive tests for the detection of coronary artery disease in this specific group are incosistent and, overall, considered inadequate for clinical decision making. Cardiovascular magnetic resonance has been used most frequently in the identification of coronary artery disease in the general population with good results in the analysis of myocardial ischemia and fibrosis. However, this method, until now, has not been evaluated for the diagnosis of coronary artery disease in renal transplant candidates. The goal of this study is to assess the capability of cardiovascular magnetic resonance for the detection of coronary artery disease in renal transplant candidates in two different aspects: the diagnosis of significant coronary stenosis (70% or more luminal diameter reduction) assessed by myocardial perfusion abnormalities, comparing the results with scintigraphy and using coronary angiography as the reference method; and the identification of unrecognized myocardial infarction, comparing with electrocardiography and nuclear medicine, using cardiovascular magnetic resonance late enhancement technique as the reference method. METHODS: Between January 2002 and January 2004 we studied 80 renal transplant candidates with at least one of these inclusion criteria: 1. 50 years of age or more, 2. diabetes mellitus, and 3. clinical history or evidence of coronary artery disease. All patients underwent electrocardiogram, nuclear medicine, cardiovascular magnetic resonance and coronary angiography examinations within a maximum period of one year. In the assessment of myocardial perfusion defect, we compared cardiovascular magnetic resonance with scintigraphy in 76 patients with coronary angiography as the reference method in the identification of significant coronary lesion (70% stenosis of the vascular lumen or more). In the identification of unrecognized myocardial infarction, we compared magnetic resonance with electrocardiogram and nuclear medicine in 69 patients. All exams were reviewed by readers blinded to the results of the other exams. Data was presented as mean, standard deviation and confidence interval. Percentual of agreement, diagnostic tests and statistical tests between the exams were calculated. RESULTS: On the assessment of significant coronary stenosis, cardiovascular magnetic resonance showed sensitivity, specificity and accuracy of 84.1%, 56.3%, and 72.4% and nuclear medicine 65.9%, 68.6%, and 67.1%, respectively. Cardiovascular magnetic resonance was significantly more sensitive than scintigraphy medicine (p=0.039). In the identification of unrecognized myocardial infarction, agreement between cardiovascular magnetic resonance and electrocardiogram was 0.28 and between cardiovascular magnetic resonance and scintigraphy was 0.52. Considering cardiovascular magnetic resonance as the reference method in the identification of unrecognized myocardial infarction, the sensitivity, specificity and accuracy of the electrocardiogram were 27.8%, 98% and 79.7%, and for scintigraphy were 66.7%, 87% and 81.2%, respectively. CONCLUSION: In the diagnosis of significant coronary stenosis, cardiovascular magnetic resonance showed similar accuracy and higher sensitivity compared to scintigraphy. In the detection of unrecognized myocardial infarction, the electrocardiogram and scintigraphy presented low agreement with cardiovascular magnetic resonance

No description available.

The master thesis deals with the issue of gaining the respiratory rate from ECG and PPG signals, which are not only in clinical practice widely used measurable signals. The theoretical part of the work outlines the issue of obtaining a breath curve from these signals. The practical part of the work is focused on the implementation of five selected methods and their final evaluation and comparison.

This work deals with ECG signal measuring and methods of its processing. It compares some of the QRS detection methods and describes some of the testing databases. In this work a detector of QRS complex is realized, it is based on the approach of zero crossings. Next section makes combination of results from separate leads to one, which improves efficiency of detection. One section of this work deals with design and realization delination of ECG signal. In the last part outputs of this delineation are compared with the results of the other authors.

Heart dysfunction is a worldly widespread problem that currently is one of the leading causes of death. Studies indicate that many deaths related to cardiac dysfunction could have been prevented if discovered early. Contemporarily, ultrasound and electrocardiography are indispensable modalities for diagnostic purposes and analysis of cardiac function. The Ventricorder is an Ultra-Wideband radar sensor manufactured by the Norwegian company Novelda. Ventricorder has been shown to be able detect heart movements and breathing but its actual clinical value remains to be investigated. The Cardiac State Diagram (CSD) is a pre-clinical software tool for visualization of the heart's mechanical function. The CSD is confirmed by pilot studies to be able to constitute a basis for diagnosis and cardiac function assessment. Theoretically, the CSD is well suited to be used with the Ventricorder since the Ventricorder detects small changes over time and information about time events is all that is required for the creation of a CSD. Contemporarily, ultrasound tissue velocity imaging (TVI) is usually used for production of CSDs and in this master thesis we examined if the Ventricorder can be used to produce CSDs. This was done by mainly comparing velocity data from the Ventricorder with velocity data from temporally synchronized apical four-chamber images acquired with ultrasound TVI. The results indicate that there is an apparent correlation between these data sets and the Ventricorder should therefore be able to produce data that could constitute the basis for the production of a CSD. What remain now is to confirm these results statistically with a larger test group and to investigate whether all the time instants needed for the production of a CSD can be identified objectively. / Hjärtdysfunktion är ett värdsligt utbrett problem som ligger bakom många dödsfall varje år. Studier har visat att många dödsfall som är relaterade till hjärtdysfunktion hade kunnat förebyggas om de upptäckts i tid. För närvarande är bland annat ultraljud och EKG oumbärliga metoder för diagnostisering och analys av hjärtfunktion. Ventricorder är en typ av radarsensor som utnyttjar ett brett frekvensspektrum, så kallat Ultra Wideband, och är tillverkad av det norska företaget Novelda. Ventricorder har visat sig kunna detektera exempelvis hjärtrörelser och andning men dess kliniska värde har ännu inte undersökts. Cardiac State Diagram (CSD) är ett prekliniskt mjukvaruverktyg för att visualisera hjärtats mekaniska funktion och som har bekräftats genom pilotstudier att kunna användas som underlag för diagnostik och bedömning av hjärtats funktion. Teoretiskt sett är CSD väl lämpat för att användas med Ventricordern eftersom Ventricordern registrerar små rörelser över tid och just ändringar över tid är precis vad som behövs för att skapa ett CSD. I dagsläget används vanligen vävnadsdoppler (TVI) för produktion av CSD och i denna masteruppsats undersöktes huruvida Ventricorder kan användas för att producera CSD. Detta gjordes genom att jämföra mätdata från Ventricorder med temporalt synkroniserade apikala fyrkammar-bilder framställda med vävnadsdoppler. Resultaten indikerar att det finns en påtaglig korrelation mellan dessa data och att mätdatat från en Ventricorder således bör kunna användas för produktion av CSD. Det kvarstår att bekräfta dessa resultat statistiskt med en större testgrupp och att undersöka om samtliga tidsmarkörer som behövs för produktion av ett CSD kan identifieras objektivt.

This thesis presents the design, implementation, and validation of a synchronized wireless biomedical measurement system, specifically developed for research in Cardiac-Locomotor Coupling (CLC). By integrating EMG and ECG sensors in combination with inertial measurements, the system enables the simultaneous recording and analysis of physiological and biomechanical data. The adoption of a 433 MHz radio communication protocol ensures reliable synchronization across multiple sensor nodes. Results demonstrate the system’s effectiveness in providing accurate, synchronized data essential for enhancing understanding of CLC and its implications on athletic performance and rehabilitation of patients with heart deficiencies. This project addresses the lack of an integrated, wireless system capable of efficiently synchronizing biomedical measurements, such as heart rate, body movement, and blood pressure, thus facilitating advanced research into CLC. / Denna avhandling presenterar designen, implementationen och valideringen av ett synkroniserat trådlöst biomedicinskt mätsystem, specifikt utvecklat för forskning inom aktiv länkning av rörelseapparaten och hjärtats pumparbete, även känd som Cardiac-Locomotor Coupling (CLC) på engelska. Genom att integrera EMG- och EKG sensorer i kombination med accelerometermätningar möjliggör systemet simultan inspelning och analys av fysiologiska och biomekaniska data. Användningen av en 433 MHz radio-kommunikationsprotokoll säkerställer pålitlig synkronisering över flera sensorsnoder. Resultatet visar systemets effektivitet när det gäller att tillhandahålla noggranna, synkroniserade data som är avgörande för att förbättra förståelsen för CLC och dess implikationer för idrottsprestation och rehabilitering. Detta projekt ämnar att fylla behovet av ett integrerat trådlöst system som är kapabelt att effektivt synkronisera biomedicinska mätningar, såsom hjärtfrekvens, kroppsrörelse och blodtryck, vilket möjliggör avancerad forskning av CLC.

Despite a high proportion of the population experiencing traumatic events within their lifetime, the number of individuals who go on to develop posttraumatic stress disorder (PTSD) is comparatively small; herein highlighting the importance of individual differences in imparting risk and resilience towards the development and maintenance of PTSD. Existing literature illustrates that biological and ecological factors are important in predicting PTSD development, with pathological vulnerabilities excepting their effects at pre- peri- and post trauma stages. Whilst cognitive and emotion based models of PTSD account for the role of a minority of known pre-trauma risk factors, individual differences in peri- and post trauma processes are held as critical to the development of PTSD. The broad range of risk factors implicated in the empirical literature, and necessity of traumatic exposure to PTSD, implicates the utility of a diathesis-stress conceptualisation of PTSD development. The current thesis employed an analogue VR-trauma paradigm to investigate the respective importance of vulnerability factors at each stage, in the prediction of analogue PTSD symptoms (memory problems, startle responses, re-exposure fear habituation), whilst measuring affective and electrophysiological concomitance. Findings supported the importance of peri-traumatic responses in the prediction of PTSD, where present, showing increased predictive capacities over pre- and post-trauma factors. Biological and ecological factors also illustrated important predictive associations, with genetic SNPs implicated in reflex startle and cardiac responses towards intrusive memories. Moreover, peri-traumatic HR decelerations and accelerations mediated the association between pre-trauma factors and cued recall inaccuracy and intrusion severity respectively. Results support existing cognitive and emotional models in their emphasis on peri-traumatic processes but suggest the added utility of a diathesis stress conceptualisation of the development of PTSD, in highlighting the importance of pre-trauma biological and ecological risk and resilience factors.

No description available.