Elucidation of Cardiovascular System Pathology Using Pulse Wave Phase Space Analysis

Autor: S. A. Ostanin, S. V. Zasorin, V. I. Volkov, V. P. Kulikov, D. Yu. Kozlov
Rok vydání: 2009
Předmět:
Zdroj: Biomedical Engineering. 43:27-30
ISSN: 1573-8256
0006-3398
DOI: 10.1007/s10527-009-9081-0
Popis: Human body pathology and normal states are docu� mented by the World Health Organization. Strict mathe� matical equations and language substitute descriptive and qualitative terms. The goal of this work was to provide express diagno� sis based on twodimensional analysis of cardiovascular system pathology using pulse wave phase space analysis in sphygmography. N. A. Amosov studied contractile myocardium function in phase space with coordinates of amplitude and amplitude change (1). The diagnostic value of this study is due to the fact that damage to the cardiovascular system modifies the signal and its deriva� tive with respect to time. The goal of this work was also to formulate integral numerical coefficient providing identification of cardio� vascular system pathology. One phase space dimension is signal itself (pulse wave pressure P), whereas another phase space dimension is the derivative of this parameter with respect to time dP/dt. The shape of loop of pressure derivative with respect to time dP/dt and its dependence on pressure P revealed specific features of blood flow in the aorta, e.g., specific features of blood flow induced by artery wall myorelaxants (2, 4, 5). It was suggested in (3) that the number of phase variables required to describe homeostasis was several thousands. This requires large computation time and modern computer hardware. Analysis of twodimensional information array requires modern computer hardware and software. The patients in this work were tested sphygmograph� ically for cardiovascular system pathology. A MEDISON 8000EX scanner was used for primary atherosclerosis diagnosis. Carotid artery wall state was assessed in 2�D ultrasonic mode at the site of ultrasonic probe applica� tion. The atherosclerosis diagnosis criteria were: intima� media thickness >1 mm and/or atherosclerosis plaques. The patients with atherosclerosis diagnosis were tested sphygmographically. The results of the tests were processed using pulse wave phase space analysis. An FML�12T�9.2A1�50 piezoelectric element (resonance frequency, 1500 Hz) was used as the sphygmographic sen� sor. The sensor signal was modulated with respect to amplitude and applied to a linear input of the sound card of the computer. The signal frequency was 500 Hz and sampling frequency was 10,000 Hz. The preamplifier input resistance was 100 MΩ. The preamplifier output signal amplitude was proportional to piezoelectric ele� ment current integral. The piezoelectric sensor was installed at the patient's carotid artery. The sensor posi� tioning accuracy was 1 cm. The shape of the sphygmo�
Databáze: OpenAIRE
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