DEVELOPMENT OF BLOOD PRESSURE DATA ACQUISITION SYSTEM MAKING USE OF THE TECHNOLOGY TO REALIZE THE ENVIRONMENT OF INNER HUMAN BODY AT OUTSIDE HUMAN BODY

本文对血压测量的机理和测量结果的准确性进行了讨论。首先，我们设计并加工了一种设备，以精确模拟血压测量过程中人体上臂血管的压力脉动和振动特性的行为。实验参数主要包括平均压力水平、压力脉动幅度和血管振动范围，即振动的起始点和消失点以及相应的平均血压水平，并根据可折叠管的物理模型，考虑了管的刚度效应，开发了计算机程序，对血管的行为进行了精确模拟。将计算结果与实验结果进行了比较，取得了较好的一致性。此外，我们进行了基础研究，发展了薄柔性结构与流动流体之间的流固耦合的计算方法，其中首次处理了流体力的非线性，并首次通过计算导出了极限环振荡。该方法有望在不久的将来成为分析血管和叶片动态特性的工具。

This study is concerned with the mechanism of blood pressure measurement and the argument on the accuracy of the measured results. First, we designed and machined an equipment to simulate precisely the behavior of the pressure pulsation and the vibration characteristics of blood vessel of an upper arm of a human body during blood pressure measurement. Experimental parameters we mainly focused on are average pressure level, amplitude of pressure pulsations and the range of observed blood vessel vibrations i.e. the initiation and vanishing point of vibration and corresponding average blood pressure level.We also developed computer code to simulate the behavior of the blood vessel precisely based on the physical model of the collapsible tube taking account of the effect of rigidity of the tube. Comparisons between calculated and experimental results are made and the reasonable agreement is obtained. In addition, we conducted a basic research to develop the method of calculation concerned with fluid structure interaction between thin flexible structure and the flowing fluid where non-linearity of the fluid force is first treated and the limit cycle oscillation is first derived by calculation. This method is anticipated to become a tool to analyze the dynamic characteristics of blood vessels and vane in near future.