The development of vibrational distribution measurement system with high spatial resolution and the research on the generation mechanism of audible clicks of mechanical prosthetic heart valve

点击翻译按钮获取中文摘要

To clarify the mechanism of audible closing clicks generation of mechanical heart valves, research and development of vibrational distribution sensor system with high spatial resolution was made. The small optical fiber displacement sensor was developed, and by arraying this, the simultaneous measurement of vibrational distribution was realized. The displacement sensor unit, developed, consisted of optical fiber bundle for light emission and reception and focusing lens, and its diameter was less than 3 mm. The sensor unit had the displacement resolution of less than 1 micron and the spatial resolution of 5 mm in the simultaneous measurement (focused spot diameter itself was 0.5 〜 1 mm). Calibration was made by recording data of the reflected light quantity for the displacement magnitude by driving the sensor array by linear actuator, while the vibration of measuring object had stopped. By this calibrating function, the accurate vibration measurement which did not depend on reflection characteristic of the measuring object's surface was realized. Using developed sensor system, the vibrational distribution of peripheral part (made of the silicone rubber) of mechanical heart valve was measured. It became clear that the level of the vibrational component of high frequency range increased as approaching to the housing of the valve. This spatial heterogeneity of this vibrational distribution seemed to be a cause of the peculiarity of the audible clicks.