Problem to be solved: to calculate the stenosis index of the shunt blood vessel in the hemodialysis patient easily and accurately.A blood flow velocity component term (UN UM) calculated from an arbitrary plurality of sections (Section 1, Section 2, interval m, interval n,... (m, n is a natural number) of the shunt blood flow waveform obtained from the shunt sound of a hemodialysis patient, and said person of said shunt sound The ratio (UN UM) \/ (FN FM) of the blood flow frequency frequency component (FN FM) calculated from a plurality of sections of the intention is an arbitrary plural section of the shunt blood flow waveform with reference (Section 1, interval 2, interval M , interval n)(M , n is a natural number), and the ratio of the blood flow frequency component (FSN to FSM ) calculated from an arbitrary plural section of the shunt sound calculated from the above mentioned multiple sections of the shunt sound calculated by (M, n is a natural number) and Then, the stenosis index of the shunt blood vessel is calculated.Diagram【課題】血液透析患者のシャント血管の狭窄指標を簡便に正確に算出する。【解決手段】血液透析患者のシャント音から得られたシャント血流波形の任意の複数区間(区間1、区間2・・・区間m・・・区間n・・・(m、nは自然数))から算出された血流速度成分項(Un-Um)と、前記シャント音の前記任意の複数区間から算出された血流音周波数成分項(Fn-Fm)との比 (Un-Um)/(Fn-Fm)を、基準とするシャント血流波形の任意の複数区間(区間1、区間2・・・区間m’・・・区間n’・・・(m’、n’は自然数))から算出された血流速度成分項(Usn’-Usm’)と、基準とするシャント音の前記任意の複数区間から算出された血流音周波数成分項(Fsn’-Fsm’)との比(Usn’-Usm’)/(Fsn’-Fsm’)で除することによりシャント血管の狭窄指標を算出する。【選択図】図7
