Method and apparatus for determining blood pressure on measured heart sounds

A non-transitory computer-readable medium tangibly embodying computer-executable instructions of a program being executable by a hardware processor of a computing device with a user interface to provide operations comprising:

• measuring heart sounds through non-invasive transducers;
• separating the measured heart sounds into a first heart sound (S1) and a second heart sound (S2);
• mathematically characterizing S1 and S2;
• determining a blood pressure based on the characterization;
• denoising the heart sounds;
• determining a heart rate;
• and
• segmenting the heart sounds to identify S1 and S2;
• wherein the denoising instructions for denoising S1 and S2 further comprise:
• determining a propagation speed of signal propagation within a patient by iteratively varying an assumed distance between a sensor and a heart valve;
• and
• identifying S1 and S2 based on the determination of the propagation speed of signal propagation.

A system for measuring blood pressure, comprising:

• a sensor configured non-invasively and positioned on a chest area to acquire heart sounds;
• and
• a computer coupled to the sensor, the computer configured to:
• measure heart sounds;
• separate the measured heart sounds into a first heart sound (S1) and a second heart sound (S2);
• mathematically characterize S1 and S2;
• determine a blood pressure based on the characterization;
• denoise the heart sounds;
• determine a heart rate;
• and
• segment the heart sounds to identify S1 and S2;
• wherein the denoising further comprises the computer configured to:
• determine a propagation speed of signal propagation within a patient by iteratively varying an assumed distance between a sensor and a heart valve;
• and
• identify S1 and S2 based on the determination of the propagation speed of signal propagation;
• and
• wherein the instructions to determine the propagation speed include the computer configured to establish an influence matrix that identifies an optimal influence matrix to separate source signals.

A method of determining blood pressure, comprising:

• measuring heart sounds through transducers on an outer surface of a chest;
• separating the measured heart sounds into a first heart sound (S1) and a second heart sound (S2);
• mathematically characterizing S1 and S2;
• determining a blood pressure based on the characterization;
• denoising the heart sounds;
• determining a heart rate;
• and
• segmenting the heart sounds to identify S1 and S2;
• wherein segmenting the heart sounds to identify S1 and S2 comprises:
• selecting a resampling window based on the determined heart rate;
• resampling the measured heart sounds to identify local maxima and a maximum peak in a cardiac cycle;
• determining a duration between the local maxima;
• and
• determining which of the local maxima represents S1 and which represents S2 based on a duration between the local maxima, based on an interval S1 to S2 that is known to be smaller than an interval of S2 to S1.

A non-transitory computer-readable medium tangibly embodying computer-executable instructions of a program being executable by a hardware processor of a computing device with a user interface to provide operations comprising:

• measuring heart sounds through non-invasive transducers;
• separating the measured heart sounds into a first heart sound (S1) and a second heart sound (S2);
• mathematically characterizing S1 and S2;
• determining a blood pressure based on the characterization;
• denoising the heart sounds;
• determining a heart rate;
• and
• segmenting the heart sounds to identify S1 and S2;
• and
• wherein the instructions segmenting the heart sounds to identify S1 and S2 further comprise instructions to:
• select a resampling window based on the determined heart rate;
• resample the measured heart sounds to identify local maxima and a maximum peak in a cardiac cycle;
• determine a duration between the local maxima;
• and
• determine which of the local maxima represents S1 and which represents S2 based on a duration between the local maxima, based on an interval S1 to S2 that is known to be smaller than an interval of S2 to S1.

A system for measuring blood pressure, comprising:

• a sensor configured non-invasively and positioned on a chest area to acquire heart sounds;
• and
• a computer coupled to the sensor, the computer configured to:
• measure heart sounds;
• separate the measured heart sounds into a first heart sound (S1) and a second heart sound (S2);
• mathematically characterize S1 and S2;
• determine a blood pressure based on the characterization;
• denoise the heart sounds;
• determine a heart rate;
• and
• segment the heart sounds to identify S1 and S2;
• wherein segmenting the heart sounds to identify S1 and S2 further comprises the computer configured to:
• select a resampling window based on the determined heart rate;
• resample the measured heart sounds to identify local maxima and a maximum peak in a cardiac cycle;
• determine a duration between the local maxima;
• and
• determine which of the local maxima represents S1 and which represents S2 based on a duration between the local maxima, based on an interval S1 to S2 that is known to be smaller than an interval of S2 to S1.