There are provided a biological signal measurement device capable of obtaining a variety of biological information and applicable also to medical fields and the like, a biological state inference device, and a biological state inference system using these. The biological signal measurement device 1 of the present invention includes three biological signal detection units, namely, a left upper part biological signal detection unit 11, a right upper part biological signal detection unit 12, and a lower part biological signal detection unit 13. The biological state inference device 1 is capable of obtaining a highly precise inference-use processed waveform from which electrical noise has been removed, by using an appropriate combination of time-series data obtained from the three biological signal detection units 11 to 13. Because the precision of an inference-use processed waveform corresponding to target biological information on breathing, heart sound, or the like increases, the precision of inferring a biological state also increases.

At least one of at least one data-dependent scale factor or at least one data-dependent detection threshold is determined responsive to at least one block of time-series data of an auscultatory-sound signal generated by an auscultatory-sound sensor operatively coupled to a portion of the skin of a test-subject, wherein the at least one data-dependent scale factor or at least one data-dependent detection threshold provides a measure of a range of values of the at least one block of time-series data in relation to a predetermined metric, and is used to determine whether or not the auscultatory-sound sensor is either debonded or detached from the skin of the test-subject.

This document discusses, among other things, systems and methods to determine an indication of contractility of a heart of a patient using received physiologic information, and to determine blood pressure information of the patient using the heart sound information and the determined indication of contractility of the heart. The system can include an assessment circuit configured to determine an indication of contractility of a heart of the patient using first heart sound (S1) information of the patient, and to determine blood pressure information of the patient using second heart sound (S2) information of the patient and the determined indication of contractility of the heart.

An auscultatory sound signal from at least one auscultatory sound-or-vibration sensor is filtered with a high-pass filter and then segmented into a plurality of associated heart cycle segments responsive to associated R-peak locations of an electrographic envelope signal representing an envelope response to an even power of an associated electrographic signal from an ECG sensor. A representation an envelope responsive to an even power of said auscultatory sound signal within said at least one heart cycle is locally modeled about at least a second peak to provide for locating the start of diastole of said at least one heart cycle.

The present invention discloses a dual-microphone adaptive filtering algorithm for collecting body sound signals, characterized in that, using at least two microphones, a primary microphone and a secondary microphone, to collect signals; the primary microphone is used to collect noisy body sound signals, and the secondary microphone is used to collect environmental noise; applying a same high-pass filtering to signals collected by the primary microphone and signals collected by the secondary microphone; using a normalized least mean square algorithm on the primary microphone signals and the secondary microphone signals after the high-pass filtering to calculate a weight of the adaptive filter and to calculate an error signal to filter out environmental noise in the primary microphone signals; processing the error signal for a first time by a low-pass filtering to restore the body sound signals, to obtain the body sound signals output by the adaptive filtering algorithm. This algorithm not only may achieve rapid convergence of filter weights, but also avoid signal distortion, and suppress environmental noise interference quickly and reliably.

An apparatus for locating a source of vibrational cardiac energy within a human, includes a data processing system configured to accept vibrational cardiac data collected by at least three transducers during a plurality of heart cycles. A computer readable medium containing executable computer program instructions which, when executed by the data processing system, cause the data processing system to perform steps that include, performing a time-to-frequency transformation on the vibrational cardiac data acquired within at least a portion of the heart cycles. The time-to-frequency transformation is applied to the vibrational cardiac data acquired synchronously from each transducer to obtain a plurality of complex frequency spectra. The steps include identifying a vernier band (VB) of frequency associated with a feature derived from the plurality of complex frequency spectra. The vibrational cardiac data are processed over the VB of frequency to obtain a first vibrational cardiac energy level for a first location within the human's chest. The first location corresponds to a source of the first vibrational cardiac energy level.

An acoustic sensing apparatus and method are disclosed for acoustically surveying the chest area of a subject, and in particular the rib cage. In use the apparatus is placed on the chest, and it includes an arrangement of one or more sound sensors for sensing acoustic signals received from inside the chest. Based on the signal intensities picked up at a plurality of different locations across the chest, the different locations are each classified by a controller as either rib-aligned or intercostal space-aligned. The controller is further adapted to identify one or more sound intensity hotspots (42) within the signal intensity distribution to locate one or more anatomical objects or regions of interest within the chest, such as the heart mitral valve, the heart tricuspid valve, heart aortic valve, and the pulmonary artery as key areas for an auscultation procedure.

An interface apparatus connects an electronic stethoscope to a computing device and an audio listening device. The apparatus has a housing that includes an audio input port to connect the stethoscope, an audio output port to connect the listening device, and a data transfer port to communicate with the computing device. An electronic circuit within the housing receives an audio signal from the stethoscope through the audio input port, outputs the audio signal to the listening device through the audio output port, and outputs the audio signal to the computing device through the data transfer port. An operating mode switch can toggle the interface apparatus between a first operating mode, where the listening device outputs sound from the stethoscope on one channel and sound from a remote location on a second channel, and a second operating mode, where the listening device outputs sound from the stethoscope on both channels.

A system for monitoring heart activity may provide a power source, digital storage, a processor, a main body with an alignment mechanism facilitating proper placement, and one or more microphones for receiving audio signals and positioned for placement at auscultatory areas. The alignment mechanism may be a dip, depression, notch, or combinations thereof that align the system centrally on the sternum, suprasternal notch, or jugular notch. Further, the audio signals from the microphones may be monitored or recorded as individual tracks corresponding to different auscultatory areas. The auscultatory areas may be selected from an aortic area, pulmonic area, tricuspid area, mitral area, Erb's point, first alternate tricuspid area, and/or second alternate tricuspid area.

A system and method for noninvasively measuring blood pressure is disclosed. In one embodiment, the system includes a monitoring cuff comprising at least one sensor implanted within the monitoring cuff, the at least one sensor being configured to detect blood flow data in a user, an occlusion cuff configured to inflate and deflate to restrict and permit blood flow in the user, the occlusion cuff being in electrical communication with the monitoring cuff, and a computing device configured to control the inflation, deflation, and pressure applied by the occlusion cuff, and the computing device being configured to record and analyze the blood flow data detected by the monitoring cuff.