Abstract: One embodiment is a method of performing thoracic tomography on a human subject including performing multiple 4-wire impedance measurements on a region of interest to obtain measured impedance data; comparing the measured impedance data to simulated impedance data obtained from a plurality of models of the region of interest; for each of the models, determining a fit of the model based on a comparison between the simulated impedance data obtained from the model and the measured impedance data; and integrating individual resistivity estimates obtained from the models based on a fit of the model such that the individual resistivity estimate from a better fitting model is weighted more heavily in a final resistivity estimate than an individual resistivity estimate from a worse fitting model.

Abstract: One embodiment is a method of extracting respiratory parameters from a short duration thoracic impedance (“TI”) signal, the method comprising preprocessing the TI measurement signal to obtain a respiratory signal therefrom; assessing the respiratory signal for at least one of signal quality and signal integrity; executing at least one of an autocorrelation algorithm and a time-domain zero-crossing algorithm on the respiratory signal to extract at least one respiratory parameter therefrom, the at least one respiratory parameter comprising at least one of respiration rate (“RR”) and tidal volume (“TV”).

Abstract: There is disclosed herein examples of systems and methods of processing captured heart sounds with frequency-dependent normalization. Based on an amount of attenuation of a first heart sound, a second heart sound can be normalized by modifying portions of the second heart sound by amounts determined based on frequencies of the portions. Accordingly, the systems and methods disclosed herein can result in different amounts of modification of different portions of the second heart sound based on the different frequencies of the portions.

Abstract: The present disclosure describes a system for detecting abnormal blood pressure or blood volume in a user, the system comprising a processing system; a pulse transit time (PTT) detection system for providing a PTT signal indicative of a PTT of the user to the processing system, wherein PTT of the user is used as a surrogate for a blood pressure (BP) of the user; and an electrodermal activity (EDA) detection system for providing an EDA signal indicative of an EDA of the user to the processing system; wherein the processing system processes the PTT signal and the EDA signal to determine an index indicative of an abnormal blood pressure or blood volume of the user.

Abstract: There is disclosed herein examples of systems and methods for compressing a signal. Samples of the signal can be segmented and the samples within each of the segments can be averaged to produce a value that can represent the samples within the segment. The number of samples to average in each segment may be determined based on an error threshold, such that the number of samples being averaged can be maximized to produce less data to be transmitted while maintaining the representation of the samples within the error threshold. In some embodiments, a signal can be separated into a timing reference, a representative periodic function, and a highly compressible error signal. The error signal can be utilized for reproducing a representation of the signal.

Abstract: There is disclosed herein examples of systems and methods for compressing a signal. Samples of the signal can be segmented and the samples within each of the segments can be averaged to produce a value that can represent the samples within the segment. The number of samples to average in each segment may be determined based on an error threshold, such that the number of samples being averaged can be maximized to produce less data to be transmitted while maintaining the representation of the samples within the error threshold. In some embodiments, a signal can be separated into a timing reference, a representative periodic function, and a highly compressible error signal. The error signal can be utilized for reproducing a representation of the signal.

Abstract: Devices, systems, and methods for non-invasively detecting and monitoring medical conditions using multiple modalities of sensing include at least two electrodes configured to be positioned on a subject, an acoustic sensor configured to be positioned on a subject, a thoracic impedance measurement module connected to the electrodes, for measuring a first impedance between the electrodes, and a heart acoustic measurement module connected to the acoustic sensor, for detecting and measuring a heart sound from the acoustic sensor.

Abstract: Determining bio-impedance of a body, or portion thereof, of a subject has been utilized for determining health characteristics (such as heart conditions) of the subject. The systems and procedures described herein may provide for correction and/or compensation for electrode contact impedance and for accurately determining bio-impedance. The system may take into account impedance sensitivity and/or frequency sensitivity when performing the bio-impedance determination to improve the bio-impedance determination.

Abstract: There is disclosed herein examples of systems and methods of processing captured heart sounds with frequency-dependent normalization. Based on an amount of attenuation of a first heart sound, a second heart sound can be normalized by modifying portions of the second heart sound by amounts determined based on frequencies of the portions. Accordingly, the systems and methods disclosed herein can result in different amounts of modification of different portions of the second heart sound based on the different frequencies of the portions.

Abstract: There is disclosed herein examples of systems and methods for compressing a signal. Samples of the signal can be segmented and the samples within each of the segments can be averaged to produce a value that can represent the samples within the segment. The number of samples to average in each segment may be determined based on an error threshold, such that the number of samples being averaged can be maximized to produce less data to be transmitted while maintaining the representation of the samples within the error threshold. In some embodiments, a signal can be separated into a timing reference, a representative periodic function, and a highly compressible error signal. The error signal can be utilized for reproducing a representation of the signal.

Abstract: Devices, systems, and methods for non-invasively detecting and monitoring medical conditions using multiple modalities of sensing include at least two electrodes configured to be positioned on a subject, an acoustic sensor configured to be positioned on a subject, a thoracic impedance measurement module connected to the electrodes, for measuring a first impedance between the electrodes, and a heart acoustic measurement module connected to the acoustic sensor, for detecting and measuring a heart sound from the acoustic sensor.

Abstract: According to one configuration, a system includes sensor hardware and signal processor resource to monitor and analyze bio-media (such as blood and/or other matter) of a person under test. During operation, the sensor hardware monitors the bio-media of the person under test and produces an output. The monitored output (such as one or more signals) varies in magnitude based at least in part on person-induced movement. The signal processor resource analyzes the output produced by the sensor hardware. Based on the analysis, and detected variation in the output of the sensor hardware as caused by the person's movement, the signal processor resource produces a setting for a biometric parameter of interest associated with monitoring the bio-media. Note that the system as described herein can be used to measure different biometric parameters of interest such as venous blood oxygen content, vein stiffness, etc.

Abstract: According to one configuration, a system includes sensor hardware and signal processor resource to monitor and analyze bio-media (such as blood and/or other matter) of a person under test. During operation, the sensor hardware monitors the bio-media of the person under test and produces an output. The monitored output (such as one or more signals) varies in magnitude based at least in part on person-induced movement. The signal processor resource analyzes the output produced by the sensor hardware. Based on the analysis, and detected variation in the output of the sensor hardware as caused by the person's movement, the signal processor resource produces a setting for a biometric parameter of interest associated with monitoring the bio-media. Note that the system as described herein can be used to measure different biometric parameters of interest such as venous blood oxygen content, vein stiffness, etc.

Abstract: Methods and apparatuses for an oxygen consumption monitoring system are disclosed herein. In one embodiment, an oxygen consumption monitoring system is disclosed. The oxygen consumption monitoring system may comprise a probe, wherein the probe comprises a light source and a photodetector; and a main unit, wherein the main unit comprises a microcontroller and wireless transmitter. The probe may be hermetically sealed and may be capable of being implanted onto tissue. The photodetector may be capable of collecting reflectance data from the light emitted by the light source. The reflectance data may be capable of being sorted into arterial and venous blood oxygen consumption data for the tissue onto which the probe was placed or implanted. The data from the probe may be further sorted and processed to produce perfusion, heart rate, energy expenditure, caloric burn, blood pressure, hemoglobin concentration changes, and tissue oxidative stress.

Abstract: Methods and apparatuses for a tissue mechanical property monitoring system are disclosed herein. In one embodiment, a tissue mechanical property monitoring system is disclosed. The tissue mechanical property monitoring system may comprise a probe, wherein the probe comprises a light source and a photodetector; and a main unit, wherein the main unit comprises a microcontroller and wireless transmitter. The probe may be hermetically sealed and may be capable of being implanted onto tissue. The photodetector may be capable of collecting reflectance data from the light emitted by the light source. The reflectance data may be capable of being sorted and processed into tissue mechanical property data such as tissue compliance, vascular resistance, and the like for the tissue illuminated with the probe.