Risk determination of coronary artery disease

A method performed by an electronic stethoscope or a system for indicating a risk for coronary artery disease (CAD) for a person, the method comprising:

• obtaining a sound recording covering a plurality of heartbeats from a microphone placed on the person's chest;
• identifying a plurality of heart sounds in the sound recording;
• obtaining a plurality of segments from the sound recording based on the plurality of heart sounds, wherein each segment covers at least a portion of a heart cycle including a diastole;
• determining a frequency power measure (FPM) based on a signal strength of a first frequency window of a period in the diastole of a first number of segments of the plurality of segments;
• determining an amplitude of a fourth heart sound (S4Amp) based on the plurality of heart sounds and the plurality of segments;
• determining an indication of a heart rate variability (HRV) based on the plurality of heart sounds;
• and
• determining the indication of the risk for coronary artery disease (CAD) based on the frequency power measure (FPM), the amplitude of the fourth heart sound (S4Amp), and the indication of the heart rate variability (HRV).

A system for indicating a risk for coronary artery disease (CAD) for a person, wherein the system comprises:

• a microphone configured for obtaining a recording of heart sounds from the person's heart when placed on the person's chest;
• and
• a processor operatively connected to the microphone and configured, when programmed by executable instructions, to:
• (a) identify a plurality of heart sounds in the sound recording;
• (b) obtain a plurality of segments from the sound recording based on the plurality of heart sounds, wherein each segment covers at least a portion of a heart cycle including a diastole;
• (c) determine a frequency power measure (FPM) based on a signal strength of a first frequency window of a period in the diastole of a first number of segments of the plurality of segments;
• (d) determine an amplitude of a fourth heart sound (S4Amp) based on the plurality of heart sounds and the plurality of segments;
• (e) determine an indication of a heart rate variability (HRV) based on the plurality of heart sounds;
• and
• (f) determine an indication of the risk for coronary artery disease (CAD) based on the frequency power measure (FPM), the amplitude of the fourth heart sound (S4Amp), and the indication of the heart rate variability (HRV).

A computer program product for use in a system comprising a microphone configured to be placed on a person's chest for obtaining a recording of heart sounds from the patient's heart, and a processor operatively connected to the microphone, wherein the computer program product comprises program code instructions configured, when executed by the processor of the system, to cause the processor to perform a method comprising the steps of:

• (a) identifying a plurality of heart sounds in the sound recording;
• (b) obtaining a plurality of segments from the sound recording based on the plurality of heart sounds, wherein each segment covers at least a portion of a heart cycle including a diastole;
• (c) determining a frequency power measure (FPM) based on a signal strength of a first frequency window of a period in the diastole of a first number of segments of the plurality of segments;
• (d) determining an amplitude of a fourth heart sound (S4Amp) based on the plurality of heart sounds and the plurality of segments;
• (e) determining an indication of a heart rate variability (HRV) based on the plurality of heart sounds;
• and
• (f) determining an indication of a risk for coronary artery disease (CAD) based on the frequency power measure (FPM), the amplitude of the fourth heart sound (S4Amp), and the indication of the heart rate variability (HRV).