On measuring the instantaneous blood pressure in an artery via the tissue control method

Abstract

This paper presents a non-invasive approach to measuring the instantaneous arterial blood pressure based upon the tissue control method. According to animal experiments, there exists a pressed location where the mean blood pressure in the artery is equivalent to the mean pressure measured on the skin. At this location, the stiffness measured on the skin is equivalent to the stiffness of the tissue only. By means of the tissue control method, the pulsations of the artery are excluded from tissues. The displacement measured on the skin and the tracking pressure obtained from the controller identify the dynamical impedance of the blood vessel, and then estimate the instantaneous intra-arterial blood pressure. The experimental results show that errors of mean blood pressure, systolic blood pressure and diastolic blood pressure are less than 4%, and indicate that the tissue control method is a feasible way to detect the instantaneous arterial blood pressure.

A Novel Theory: Measuring the Real-Time-Based Arterial Properties via Vascular Loading Decoupling Technique

“…The control diagram for tracking AC part of blood pressure. (13) and (14). 14) and the AC control gain ( ( ) a G n ) is obtained by (15) as well.…”

“…Later, Yamakoshi [9] [10] [11] [12] [13] proposed the volume-compensation method to improve the servo reference, and developed a local pressurization technique to design a pad-type cuff sphygmomanometer [11] [12] for finger and wrist [13] to avoid the occluding cuff encircling the biological segment that makes it uncomfortable in long-term measurements. Based upon the model for transmission of arterial blood pressure [14], none of present non-invasive measuring devices is able to measure the actual instantaneous blood pressure in an artery, mainly because these methods are not capable of determining the transmission characteristics of the tissue and blood vessel. A possible approach to obtain these characteristics is to decouple the pulsation of the blood vessel from the tissues by using control and identification techniques.…”

“…A possible approach to obtain these characteristics is to decouple the pulsation of the blood vessel from the tissues by using control and identification techniques. Therefore, Lin [14] developed an innovative blood pressure measurement technique, named Tissue Control Method (TCM), which is by maintaining the DC part of blood pressure and tracking the AC part of blood pressure to cause the vascular truly unloading; the blood vessel is pulsated without the influence of surrounding tissues. Accordingly, the variation of blood vessel diameter is obtained, but meanwhile, the AC part of blood pressure is lost, that is, the reference pressure for controller is absent as well.…”