Disclosed are medical devices with an acceleration sensor configured to generate acceleration data, a processor, and a memory. The memory, which may be a non-transitory computer readable medium, contains computer-executable instructions that, when executed by the processor, causes the processor to perform the following: obtain the acceleration data from a first range of time and a second range of time different from the first range, generate heart sound data based on the acceleration data, and determine that the medical device has flipped in orientation during the second range of time by comparing the heart sound data obtained during the first range of time with the heart sound data obtained during the second range of time.

An illustrative system includes two wearable devices configured to be worn near a jaw on opposite sides of a user's head, each device comprising: at least one microphone, at least two accelerometers, at least one loudspeaker, wherein the system is configured to process data acquired by the accelerometers and by the microphones to: detect chewing, and output an audible notification via the loudspeakers to notify the user to brush the user's teeth after chewing is no longer detected.

An illustrative system includes two wearable devices configured to be worn near a jaw on opposite sides of a user's head, each device comprising: at least one microphone, at least two accelerometers, at least one loudspeaker, wherein the system is configured to process data acquired by the accelerometers and by the microphones to: detect chewing, and output an audible notification via the loudspeakers to notify the user to brush the user's teeth after chewing is no longer detected.

An apnea analysis system may include a photoplethysmographic (PPG) sub-system, a breath detection sub-system, and an apnea analysis module. An apnea analysis system includes a photoplethysmographic (PPG) sub-system, a breath detection sub-system, and an apnea analysis module. The PPG sub-system is configured to be operatively connected to an individual and output a PPG signal from the individual. The breath detection sub-system is configured to be operatively connected to the individual and output a breath signal from the individual. The apnea analysis module is in communication with the PPG sub-system and the breath detection sub-system. The apnea analysis module analyzes the breath signal and a respiratory component of the PPG signal and, based on the analysis, identifies a presence of apnea, differentiates between obstructive apnea and central apnea, and provides an indication of the identified apnea.

An electronic stethoscope includes an acoustic sensor assembly having a first microphone to detect biological sounds within a body, a detection system in communication with the first microphone to receive an auscultation signal from the first microphone, the auscultation signal including information of the biological sounds detected by the first microphone. The stethoscope also includes a second microphone in communication with the detection system to detect noise from an environment of the body. The detection system receives a noise signal from the second microphone, and provides a resultant signal based on the auscultation signal and the noise signal. The detection system subtracts information from the auscultation signal to produce the resultant signal, where the subtracted information is based on the noise signal such that the subtracted information is based more on higher frequency ranges of the noise signal compared to a lower frequency range corresponding to the biological sounds.

The invention determines an efficiency value (E) denoting preferably the relative period of muscle fibre activity during a recorded period of exercise, and a strength value (S) representing the number of muscle fibres recruited during a movement as part of the exercise or of a muscle contraction, and a temporal value (T) representing the frequency with which muscle fibres are activated repeatedly during exercise, and finally combines the efficiency value (E), the strength value (S) and the temporal value (T) by a linear combination to obtain an index value (ESTi) indicative of the fitness level of the individual. The obtained ESTi Score is useful for assessing the training level of an animal or human individual and the individual's potential for different types of sports and other activity. Also the effect of past training or diet can be assessed, and the possible need for changes in training or diet can be assessed.

A system for monitoring medical conditions including pressure ulcers, pressure-induced ischemia and related medical conditions comprises at least one sensor adapted to detect one or more patient characteristic including at least position, orientation, temperature, acceleration, moisture, resistance, stress, heart rate, respiration rate, and blood oxygenation, a host for processing the data received from the sensors together with historical patient data to develop an assessment of patient condition and suggested course of treatment, including either suspending or adjusting turn schedule based on various types of patient movement. Compliance with Head-of-Bed protocols can also be performed based on actual patient position instead of being inferred from bed elevation angle. The sensor can include bi-axial or tri-axial accelerometers, as well as resistive, inductive, capacitive, magnetic and other sensing devices, depending on whether the sensor is located on the patient or the support surface, and for what purpose.

An embodiment of the invention provides a method of diagnosing obstructive sleep apnea, the method comprising: acquiring a sleep sound signal comprising sounds made by a person during sleep; detecting a plurality of snore sounds in the sleep sound signal; determining a set of mel-frequency cepstral coefficients for each of the snore sounds; determining a characterizing feature for the sleep sound signal responsive to a sum of the variances of the cepstral coefficients; and using the characterizing feature to diagnose obstructive sleep apnea in the person.

Provided herein are systems, devices, and methods to measure auditory signals from a subject to determine a state of a subject. The auditory signals measured may provide a tool to monitor the development of disease state(s) or abnormal physiologic conditions (e.g., wheezing, fluid accumulation, abnormal heart murmur or rhythm, etc).

A method for measuring sound from vortices in the carotid artery comprising: first and second quality control provisions, wherein the quality control compares detected sounds to predetermined sounds, and upon confirmation of the quality control procedures, detecting sounds generated by the heart and sounds from vortices in the carotid artery for at least 30 seconds.