인공 심장에서 작동하는 기계식 심장 판막의 음향 신호 특성 연구 = A Study of the Acoustical Properties of the Mechanical Heart Valve Employed in an Artificial heart

다국어 초록 (Multilingual Abstract)

We studied the acoustical characteristics of the mechanical valve employed In the Korean type Artificial Heart. Bj□erk- Shiley tilting disc valve was chosen for the study and acoustic measurements were performed for the artificial heart operated in a mock circulation system as well as implanted to an animal as a Bi Venticular Assist Device (BVAD). In the mock system, three different conditions of the valve were examined which were normal, damaged (torn off), pseudo-thrombus attached.
Microphone measurements for the BVAD were carried out at a regular time interval for 5 days after the implantation operation. Of the recorded acoustic emissions from the artificial heart, click sounds mainly originated from the valves were further analyzed using Multiple Signal Classification (MUSIC) for estimating their spectral properties. It was observed that the spectral peaks below 4 kHz and the optimal order number for MUSIC, equivalent to the number of the spectral component, might be the key parameters which were highly correlated to the physiological states of the valve such as the mechanical damage of the valve or the formation of thrombus on the valves.

목차 (Table of Contents)

• 1. 서론
• 2. 음향 신호 측정
• 2.1. 측정 장치
• 2.2. in vitro 및 in vivo 측정
• 3. 신호 처리 방법
• 4. 결과
• 4.1. in vitro test
• 4.2. in vivo test
• 5. 토론