Patent ID: 6425872
Filing Date: 2002-07-30
Classification: A61B

Abstract:
A physical parameter measuring system comprising:an exciter applying oscillations to a subject; a sensor monitoring the oscillations propagated through the subject to provide a signal indicative thereof in sequence; a phase detector detecting a phase of the signal outputted from said sensor to map, in sequence, the signal on a two-dimensional plane as a sample point and providing a sample point signal indicative thereof; an A/D converter converting the sample point signal into a digital sample point signal in sequence; an arc center determining circuit determining a center of an arc defined by a distribution of the sample points mapped for a given period of time, the arc center determining circuit including a sample group selecting circuit selecting the sample points which are located at an interval greater than a given reference sample-to-sample distance to form a sample group consisting of at least three of the selected sample points, and a circle center determining circuit determining a center of a circle passing through the sample group as the center of the arc; and a phase angle determining circuit determining a phase angle of the sample point as viewed from the arc center determined by said arc center determining circuit and providing it as a parameter used to determine a physical parameter of the subject.