System and method for indicating coronary artery disease risk based on low and high frequency bands

摘要

A system and method for diagnosing coronary artery disease (CAD) comprises an acoustic sensor to be placed on the chest of a patient to generate acoustic signals SA: a control unit adapted to receive said acoustic signals SA, the control unit comprising: an identification unit to identify diastolic or systolic periods in a predetermined time period and to generate a period signal SP; a filtering unit adapted to apply a filter to said identified periods to generate a low frequency band signal SLFB and a high frequency band signal SHFB of said identified periods; and a calculation unit, to calculate a low frequency power measure SLFP and a high frequency feature measure SHFF. A risk-determining unit provides a risk-of-CAD signal based on the low frequency power measure and the high frequency feature measure. The invention also relates to a stethoscope and a method for detection of low frequency power.

主权项

1. A system for detection of frequency power for diagnosing of coronary artery disease (CAD), comprising:
an acoustic sensor adapted to be placed on the chest of a patient, and to generate acoustic signals SA that comprise a range of frequencies including a low frequency band and a higher frequency band; at least one memory adapted to store acoustic signals SA from the acoustic sensor; and a control unit adapted to receive said acoustic signals SA from the memory;
wherein the control unit further comprises:
an identification unit adapted to identify diastolic or systolic periods in a predetermined time period of the stored acoustic signals SA, and to generate a period signal Sp indicating said identified periods;a filtering unit adapted to apply at least one filter to said identified periods and to generate a low frequency band signal SLFB indicating low frequency bands of said identified periods, and to generate a high frequency band signal SHFB indicating high frequency bands of said identified periods; anda calculation unit adapted to estimate the power in said low frequency band of said identified periods, to calculate a low frequency power measure based upon said estimated power and to generate a low frequency power measure signal SLFP indicating said low frequency power measure, and wherein said calculation unit in addition is adapted to calculate a high frequency feature measure based upon an estimated feature in high frequency bands of said periods and to generate a high frequency feature measure signal SHFF indicating said high frequency feature measure, wherein said feature is the power; wherein said system further comprising a risk determining unit adapted to determine a risk of coronary artery disease (CAD) by combining said low frequency power measure and said high frequency power measure and to compare a resulting combined power ratio value with a feature reference value for CAD and to generate a combined risk-of-CAD-signal S′CAD indicating said risk in dependence of said comparison.