Model-based synthetic fuzzy logic controller for indirect bloodpressure measurement

摘要

In this paper, a new measurement system for the noninvasivenmonitoring of the continuous blood pressure waveform in the radialnartery is presented. The proposed system comprises a model-based fuzzynlogic controller, an arterial tonometer and a micro syringe device. Thenflexible diaphragm tonometer registers the continuous blood pressurenwaveform. To obtain accurate measurement without distortion, thentonometer's mean chamber pressure must be kept equal to the meannarterial pressure (MAP), the so-called optimal coupling condition, suchnthat the arterial vessel has the maximum compliance. Since the MAPncannot be measured directly, to keep the optimal coupling conditionnbecomes a tracking control problem with unknown desired trajectory. Tonsolve this dilemma, a model-based fuzzy logic controller is designed toncompensate the change of MAP by applying a counter pressure on thentonometer chamber through the micro syringe device. The proposedncontroller consists of a model-based predictor and a synthetic fuzzynlogic controller (SFLC). The model-based predictor estimates the MAPsnchanging tendency based on the identified arterial pressure-volume model