Abstract: Systems and methods for suppressing noise in a signal are disclosed herein. In exemplary embodiments of the present invention, noise is suppressed using perceptual adaptive gain control based on signal-to-noise ratios. In other embodiment of the present invention, the gain of a signal is mapped as a function of an active estimate of the envelope of the signal.

Abstract: A heart monitor includes a single chest accelerometer (210), an analog signal conditioning and sampling section (215) responsive to said accelerometer to produce a digital signal substantially representing acceleration, and a digital processor (220) operable to filter the acceleration signal into a signal affected by body motion and to cancel the body motion signal from the acceleration signal, thereby to produce an acceleration-based cardiac-related signal. Other processes and electronic systems are also disclosed.

Abstract: A respiration monitoring device includes an accelerometer (210) for application to the chest, whereby acceleration is possible due to both non-respiratory body motion and respiration, and an electronic circuit (DSP) responsive to an acceleration signal from the accelerometer and operable to separate from the acceleration signal a heart signal, a respiration signal, and a substantially non-respiration body motion signal. Other devices, sensor articles, electronic circuit units, and processes are also disclosed.

Abstract: An electronic monitoring device includes an electronic processor (520) having at least one signal input for body monitoring, and a memory (530) holding instructions for the electronic processor coupled to the electronic processor so that the electronic processor is operable to isolate a cardiac signal including cardiac pulses combined with other cardiac signal variations, and the electronic processor further operable to execute a filter (730) that separates a varying blood flow signal from the cardiac pulses and to output information (790) based on at least the varying blood flow signal. Other devices, sensor assemblies, electronic circuit units, and processes are also disclosed.

Abstract: A method and apparatus for monitoring heart rate. The method includes receiving a digital heart monitoring signal, determining the integrity of said signal with a “hand detect” signal that confirms electrical connection to the subject, dividing the digital heart monitoring signal into at least one frame, generating a folded correlation value for the center sample in the at least one frame, identify the number of peaks folded correlation values based on amplitude and distance parameters of the digital heart monitoring signal in the at least one frame, removing false peaks and collecting peaks corresponding to a length of time, determining the heart rate based on the identified peaks wherein the identified peaks relate to a minimum distance between valid heart beat peaks based on a heart rate estimate, computing the weighted average of heart rate value based on the number of previous heart rate values.

Abstract: A method of processing heart monitoring samples is provided that includes computing a folded correlation value for each heart monitoring sample in a plurality of heart monitoring samples and identifying peaks corresponding to heartbeats based on the folded correlation values of the heart monitoring samples.

Abstract: A method and apparatus of an adaptive gain control (AGC) unit. The method includes receiving a noisy input signal and determining to utilize a stethoscope in at least one of a noise suppression mode or in amplification mode depending if the noise level is at least one of above or below a threshold, wherein the stethoscope is in noise suppression mode when K is less than the threshold and is amplification mode when K is above the threshold.

Abstract: Methods, systems, and computer readable media are provided for identification of heart sound components in an audio signal of heart sounds. Time domain kurtosis and frequency domain kurtosis are used to distinguish peaks corresponding to the primary heart sounds, S1 and S2, from murmur peaks. Timing based error correction may also be used to verify that appropriate peaks corresponding to the primary heart sounds are identified.