The paper presents evaluation of the proposed phonocardiography (PCG) measurement system designed primarily for heartbeat detection to estimate heart rate (HR). Typically, HR estimation is performed using electrocardiography (ECG) or pulse wave as one of the fundamental diagnostic methodologies for assessing cardiac function. The system includes novel both sensory part and data processing procedure, which is based on signal preprocessing using Wavelet Transform (WT) and Shannon energy computation and heart sounds classification using K-means. Due to the lack of standardization in the placement of PCG sensors, the study focuses on evaluating the signal quality obtained from 7 different sensor locations on the subject's chest and investigates which locations are most suitable for recording heart sounds. The suitability of sensor localization was examined in 27 subjects by detecting the first two heart sounds (S1, S2). The HR detection sensitivity related to reference ECG from all sensor positions reached values over 88.9 and 77.4% in detection of S1 and S2, respectively. The placement in the middle of sternum showed the higher signal quality with median of the proper S1 and S2 detection sensitivity of 98.5 and 97.5%, respectively.
- MeSH
- elektrokardiografie MeSH
- fonokardiografie MeSH
- lidé MeSH
- srdeční frekvence MeSH
- srdeční ozvy * MeSH
- sternum MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Fetal phonocardiography is a non-invasive, completely passive and low-cost method based on sensing acoustic signals from the maternal abdomen. However, different types of interference are sensed along with the desired fetal phonocardiography. This study focuses on the comparison of fetal phonocardiography filtering using eight algorithms: Savitzky-Golay filter, finite impulse response filter, adaptive wavelet transform, maximal overlap discrete wavelet transform, variational mode decomposition, empirical mode decomposition, ensemble empirical mode decomposition, and complete ensemble empirical mode decomposition with adaptive noise. The effectiveness of those methods was tested on four types of interference (maternal sounds, movement artifacts, Gaussian noise, and ambient noise) and eleven combinations of these disturbances. The dataset was created using two synthetic records r01 and r02, where the record r02 was loaded with higher levels of interference than the record r01. The evaluation was performed using the objective parameters such as accuracy of the detection of S1 and S2 sounds, signal-to-noise ratio improvement, and mean error of heart interval measurement. According to all parameters, the best results were achieved using the complete ensemble empirical mode decomposition with adaptive noise method with average values of accuracy = 91.53% in the detection of S1 and accuracy = 68.89% in the detection of S2. The average value of signal-to-noise ratio improvement achieved by complete ensemble empirical mode decomposition with adaptive noise method was 9.75 dB and the average value of the mean error of heart interval measurement was 3.27 ms.
The publication presents a comparative study of two fibre-optic sensors in the application of heart rate (HR) and respiratory rate (RR) monitoring of the human body. After consultation with clinical practitioners, two types of non-invasive measuring and analysis systems based on fibre Bragg grating (FBG) and fibre-optic interferometer (FOI) have been designed and assembled. These systems use probes (both patent pending) that have been encapsulated in the bio-compatible polydimethylsiloxane (PMDS). The main advantage of PDMS is that it is electrically non-conductive and, as well as optical fibres, has low permeability. The initial verification measurement of the system designed was performed on four subjects in a harsh magnetic resonance (MR) environment under the supervision of a senior radiology assistant. A follow-up comparative study was conducted, upon a consent of twenty volunteers, in a laboratory environment with a minimum motion load and discussed with a head doctor of the Radiodiagnostic Institute. The goal of the laboratory study was to perform measurements that would simulate as closely as possible the environment of harsh MR or the environment of long-term health care facilities, hospitals and clinics. Conventional HR and RR measurement systems based on ECG measurements and changes in the thoracic circumference were used as references. The data acquired was compared by the objective Bland⁻Altman (B⁻A) method and discussed with practitioners. The results obtained confirmed the functionality of the designed probes, both in the case of RR and HR measurements (for both types of B⁻A, more than 95% of the values lie within the ±1.96 SD range), while demonstrating higher accuracy of the interferometric probe (in case of the RR determination, 95.66% for the FOI probe and 95.53% for the FBG probe, in case of the HR determination, 96.22% for the FOI probe and 95.23% for the FBG probe).
- Klíčová slova
- Bragg grating, ballistocardiography (BCG), biomedical engineering, electrocardiography (ECG), heart rate (HR), interferometer, magnetic resonance imaging (MRI), non-invasive measurements, patient monitoring, phonocardiography (PCG), polydimethylsiloxane (PDMS), respiratory rate (RR), vital signs,
- MeSH
- artefakty MeSH
- dechová frekvence fyziologie MeSH
- dospělí MeSH
- elektrokardiografie MeSH
- fonokardiografie MeSH
- interferometrie přístrojové vybavení MeSH
- lidé středního věku MeSH
- lidé MeSH
- lidské tělo MeSH
- magnetická rezonanční tomografie * MeSH
- mladý dospělý MeSH
- optická vlákna MeSH
- optické jevy * MeSH
- počítačové zpracování signálu MeSH
- pohyb těles MeSH
- srdeční frekvence fyziologie MeSH
- technologie optických vláken přístrojové vybavení MeSH
- vlnková analýza MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
- MeSH
- dějiny 19. století MeSH
- lidé MeSH
- poslech srdce dějiny MeSH
- Check Tag
- dějiny 19. století MeSH
- lidé MeSH
- Publikační typ
- biografie MeSH
- časopisecké články MeSH
- historické články MeSH
- portréty MeSH
- Geografické názvy
- Česká republika MeSH
- O autorovi
- Skoda, Josef
- MeSH
- dějiny 19. století MeSH
- kardiologie dějiny MeSH
- perkuse dějiny MeSH
- poslech srdce dějiny MeSH
- Check Tag
- dějiny 19. století MeSH
- Publikační typ
- biografie MeSH
- časopisecké články MeSH
- historické články MeSH
- portréty MeSH
- Geografické názvy
- Československo MeSH
- Rakousko MeSH
- O autorovi
- Skoda, J
The use of anthracycline antitumour agents (e.g., adriamycin and daunorubicin) is limited by their dose-related cardiotoxicity. The effects of the repeated i.v. administration of daunorubicin (50 mg/m2, once weekly, max. 11 weeks)) were investigated in rabbits in vivo from the point of view of the occurrence of cardiotoxicity and compared with a control group of animals. Noninvasive polygraphic records (in ketamine anaesthesia, 50 mg/kg i.m.) were used for the measurement of systolic time intervals (especially the PEP:LVET ratio) to evaluate the function of the heart. The administration of daunorubicin induced a significant, progressive increase in the PEP:LVET ratio (0.3775-0.9473) and in the PEP:LVETcorr. ratio, as well as a lengthening of the preejection period PEP and a shortening of the left ventricular ejection time LVET without significant changes in the electromechanical systole Q-2. The values in the daunorubicin group were mostly significantly different from the control group of animals. The results of polygraphic records reflect thus a presence of cardiac dysfunction on the basis of daunorubicin-induced cardiomyopathy. It is thus possible to conclude that the results obtained in the study confirm the adequacy of the rabbit model of daunorubicin-induced cardiomyopathy and the methods used in the study.
- MeSH
- daunomycin toxicita MeSH
- elektrokardiografie MeSH
- fonokardiografie MeSH
- funkce levé komory srdeční MeSH
- kardiomyopatie chemicky indukované patofyziologie MeSH
- kontrakce myokardu MeSH
- králíci MeSH
- tepový objem MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- daunomycin MeSH
The importance of noninvasive methods in cardiology has continuously been increasing; beside electrocardiography, phonocardiology, bicycle ergometry, echocardiography, radioisotopic examination and nuclear magnetic resonance, mechanocardiography preserves its significance, too. There are several reasons for it: modern apparatus technique has brought a pronounced increase in examination accuracy, comparison with invasive methods showed a number of mechanocardiographic data to be of value for left ventricular function evaluation, mechanocardiography is especially useful in repeated and long-term functional observation of the left ventricle, evaluation of treatment effects, revealing the onset of left ventricular dysfunction, the method is relatively economical and applicable even in peripheral workplaces. The literature survey of the study sums up the present knowledge of mechanocardiographic techniques, the genesis of curves and the manner of their evaluation, the physiological and other influences on the mechanocardiographic data and their clinical utilization. An analysis of experience gathered in a number of laboratories all over the world demonstrates the need of further improvement and development of the method. The present dissertation is aimed at this goal. I has set itself a task to contribute to the solution of some methodological problems of mechanocardiography and to evaluate critically its importance for the clinical practice. Polygraphy and apexcardiography (including 1st derivatives of curves) performed both at rest and during isometric handgrip exercise were used. From the obtained curves a wide spectrum of parameters was determined and several indices were calculated, some of them being introduced originally. The mechanocardiographic data were correlated in some studies with the results of echocardiography and bicycle ergometry and with invasive examination (heart catheterization, coronarography). The following results were obtained in the research into mechanocardiographic methodology problems: the suitability of a LPA 100 transducer of Czechoslovak production (Tesla VUST) was demonstrated; some physiological influences on the obtained values were determined (effects of age, respiration, body weight). The author's own method of cardiac cycle intervals correction to comparable values at unified cycle duration was elaborated; the effects of isometric handgrip exercise were studied in detail. The work was focused on verifying the importance of mechanocardiography for clinical cardiology. Therefore the method was used in a number of diseases and pathological conditions to get more complex experience. On the basis of the results obtained the value of mechanocardiography application in coronary artery disease has been demonstrated. The method provides a certain possibility in CAD diagnosis by means of combined evaluation of three sensitive parameters (pulse transmission time and two parameters of alpha wave amplitude). This type of valuation has been proposed by our laboratory.(ABSTRACT TRUNCATED AT 400 WORDS)
- MeSH
- arteriae carotides fyziologie MeSH
- dospělí MeSH
- elektrokardiografie MeSH
- fonokardiografie MeSH
- funkční vyšetření srdce * přístrojové vybavení metody MeSH
- kinetokardiografie MeSH
- koronární nemoc diagnóza MeSH
- lidé středního věku MeSH
- lidé MeSH
- měření krevního tlaku MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
Most currently used mechanical heart valve prostheses generate a distinct metallic sound at closure. Since this sound is often well audible to many patients it can significantly affect their quality of life after heart valve replacement. In this study of surviving patients after heart valve replacement with three types of Björk-Shiley valves (Shiley Inc., Irvine, Ca) one third of the patients claimed that they were in certain situations disturbed by the sound. Several factors were found to be of importance for the perception of mechanical heart valve noise, including age, sex, location of valve, configuration of the thorax, hearing ability and environmental background noise. Preoperative patient information can be of vital importance to avoid postoperative adverse patient reactions.
- MeSH
- kvalita života * MeSH
- lidé středního věku MeSH
- lidé MeSH
- následné studie MeSH
- nemoci srdečních chlopní chirurgie MeSH
- pooperační komplikace psychologie MeSH
- poslech srdce psychologie MeSH
- protézy - design MeSH
- role nemocného * MeSH
- senioři MeSH
- srdeční chlopně umělé psychologie MeSH
- srdeční ozvy psychologie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Using pulsed and continuous wave Doppler echocardiography, the author examined 359 subjects referred to ultrasound examination for a variety of reasons. Thorough examination of persons with morphologically unchanged valves revealed regurgitation in the tricuspid, pulmonary, mitral and aortic valves in 49.4%, 20%, 14.5% and 0.8%, respectively. The degree of regurgitation was invariably haemodynamically insignificant. Some patients had a positive finding in several valves at a time. Overall, regurgitation was found in 247 subjects (69%). While it is evident from the study that the finding of regurgitation in normal valves is relatively frequent, evaluation of its clinical importance remains an open question.
- MeSH
- aortální insuficience diagnóza MeSH
- dítě MeSH
- dopplerovská echokardiografie * MeSH
- dospělí MeSH
- hemodynamika MeSH
- insuficience plicnice diagnóza MeSH
- lidé středního věku MeSH
- lidé MeSH
- mitrální insuficience diagnóza MeSH
- mladiství MeSH
- nemoci srdečních chlopní diagnóza MeSH
- poslech srdce * MeSH
- šelest na srdci * MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- trikuspidální insuficience diagnóza MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- dítě MeSH
- fonokardiografie MeSH
- lidé MeSH
- mitrální chlopeň abnormality MeSH
- mitrální insuficience etiologie patofyziologie MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
