PROBLEM TO BE SOLVED: To provide a function to discriminate a type of a foreign particle in a foreign particle detecting device for detecting a foreign particle such as a fine obturator and an air bubble in blood flowing in a blood vessel by irradiating an ultrasonic wave.SOLUTION: A foreign particle detecting device includes an ultrasonic irradiation part 2 for irradiating an ultrasonic wave onto a blood vessel, an ultrasonic reception part 2 for detecting an ultrasonic wave reflected by a scatter in blood flowing in a blood vessel, a Doppler signal processing part 4 for processing a signal detected by the ultrasonic reception part, and obtaining and outputting frequency deviation and strength of a reflection wave, and a foreign particle detecting part 5 for detecting a foreign particle in the blood from an output signal form the Doppler signal processing part. The foreign particle detecting part executes a procedure for obtaining the speed of the blood from the output signal from the Doppler signal processing part, a procedure for detecting a foreign particle signal indicating the presence of the foreign particle in the blood from the output signal from the Doppler signal processing part, a procedure for obtaining the speed of the foreign particle from the foreign particle signal, and a procedure for discriminating a type of the foreign particle from a normalized speed as a ratio of the speed of the foreign particle to the speed of the blood.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】超音波を照射して血管を流れる血液中の微小栓子や気泡などの異物粒子を検出するための異物粒子検出装置において、異物粒子の種類を判別する機能を提供する。【解決手段】血管に超音波を照射する超音波照射部2と、血管中を流れる血液中の散乱体によって反射された超音波を検出する超音波受信部2と、超音波受信部によって検出された信号を処理して、反射波の周波数偏移と強度を求めて出力するドプラ信号処理部4と、ドプラ信号処理部の出力信号から血液中の異物粒子を検出する異物粒子検出部5とを有する。異物粒子検出部は、ドプラ信号処理部の出力信号から血液の速度を求める手順と、ドプラ信号処理部の出力信号から血液中の異物粒子の存在を示す異物信号を検出する手順と、異物信号から異物粒子の速度を求める手順と、血液の速度に対する異物粒子の速度の割合としての正規化速度から異物粒子の種類を判別する手順とを実行する。【選択図】図1
