Abstract: A method for optimizing a pulse wave velocity measurement system, comprising: (i) transmitting a pulse from a pulse generator of a first sensor component of the pulse wave velocity measurement system, wherein the first sensor component further comprises a first clock, and wherein the pulse is transmitted from the pulse generator at a known transmission time based on the first clock; (ii) receiving the transmitted pulse by a pulse receiver of a second sensor component of the pulse wave velocity measurement system, wherein the second sensor component further comprises a second clock, and wherein the pulse is received at a known receipt time based on the second clock; (iii) comparing the known transmission time to the known receipt time; and (iv) optimizing, based on the comparison, the pulse wave velocity measurement system.

Abstract: A pressure distribution profile of a subject lying on a mat is used to derive a measure of pulse wave velocity. Beat locations are identified where beat pressure signals are identified, and pulse timing information is obtained from the beat locations. By determining a subject posture, the beat locations are mapped to anatomical body locations and arterial path length information is obtained for the anatomical body locations. A pulse wave velocity is then estimated from the pulse timing information and arterial path lengths. This method enables measuring the pulse wave velocity during sleep in a comfortable, easy and unconstrained manner. This is accomplished by analyzing signals from a pressure sensitive surface for example on top of a bed mattress or by embedding a pressure sensitive layer in the mattress.

Abstract: The present disclosure pertains to a system configured to detect slow wave sleep and/or non-slow wave sleep in a subject during a sleep session based on a predicted onset time of slow wave sleep and/or a predicted end time of slow wave sleep that is determined based on changes in cardiorespiratory parameters of the subject. Cardiorespiratory parameters in a subject typically begin to change before transitions between non-slow wave sleep and slow wave sleep. Predicting this time delay between the changes in the cardiorespiratory parameters and the onset and/or end of slow wave sleep facilitates better (e.g., more sensitive and/or more accurate) determination of slow wave sleep and/or non-slow wave sleep.

Abstract: The present disclosure pertains to a system (10) configured to determine spectral boundaries (216, 218) for sleep stage classification in a subject (12). The spectral boundaries may be customized and used for sleep stage classification in an individual subject. Spectral boundaries determined by the system that are customized for the subject may facilitate sleep stage classification with higher accuracy relative to classifications made based on static, fixed spectral boundaries that are not unique to the subject. In some implementations, the system comprises one or more of a sensor (16), a processor (20), electronic storage (22), a user interface (24), and/or other components.

Abstract: A sensor system comprises first and second PPG sensors. A monitoring system monitors detection by at least one of the first and second detectors an optical calibration signals, for performing time calibration between the first and second PPG sensors. This system makes use of two PPG sensors. To enable these sensors to be independent units, rather than being fully integrated into a combined system, a calibration system is provided. Based on detected optical signals, the behavior over time of each PPG sensor can be monitored and thus calibration can take place.

Abstract: A sensor system comprises first and second PPG sensors. A monitoring system monitors detection by at least one of the first and second detectors an optical calibration signals, for performing time calibration between the first and second PPG sensors. This system makes use of two PPG sensors. To enable these sensors to be independent units, rather than being fully integrated into a combined system, a calibration system is provided. Based on detected optical signals, the behavior over time of each PPG sensor can be monitored and thus calibration can take place.

Abstract: An apparatus comprises a sensor for measuring a physiological parameter of a subject, wherein the physiological parameter sensor is adapted to be worn by the subject; an actuator comprising an electro-active polymer material, EAP, portion for adjusting the position of the physiological parameter sensor relative to the subject; a feedback sensor for measuring movement of the physiological parameter sensor and/or the subject; a controller configured to process the measurements of the feedback sensor and to adjust the position of the actuator based on information from the feedback sensor.

Abstract: The present disclosure pertains to a system configured to determine one or more parameters based on cardiorespiratory information from a subject and determine sleep stage classifications based on a discriminative undirected probabilistic graphical model such as Conditional Random Fields using the determined parameters. The system is advantageous because sleep is a structured process in which parameters determined for individual epochs are not independent over time and the system determines the sleep stage classifications based on parameters determined for a current epoch, determined relationships between parameters, sleep stage classifications determined for previous epochs, and/or other information. The system does not assume that determined parameters are discriminative during an entire sleep stage, but maybe indicative of a sleep stage transition alone. In some embodiments, the system comprises one or more sensors, one or more physical computer processors, electronic storage, and a user interface.

Abstract: A pressure distribution profile of a subject lying on a mat is used to derive a measure of pulse wave velocity. Beat locations are identified where beat pressure signals are identified, and pulse timing information is obtained from the beat locations. By determining a subject posture, the beat locations are mapped to anatomical body locations and arterial path length information is obtained for the anatomical body locations. A pulse wave velocity is then estimated from the pulse timing information and arterial path lengths. This method enables measuring the pulse wave velocity during sleep in a comfortable, easy and unconstrained manner. This is accomplished by analyzing signals from a pressure sensitive surface for example on top of a bed mattress or by embedding a pressure sensitive layer in the mattress.

Abstract: An optical vital signs sensor (100) is provided, which comprises a PPG sensor (102), a force transducer (130) configured to measure a force applied via the PPG sensor (102) to a skin (1000) of the user and a processing unit (140) configured to extract information regarding a blood volume pulse from the output of the PPG sensor (102) and to map the extracted information to the blood pressure value at a specific force applied to the PPG sensor (102).

Abstract: Systems and methods for providing sensory stimuli induce and/or enhance sleep and/or slow wave neural activity of a subject during sleep. Operation of the systems and methods is based on measured information related to cardiac attributes and/or respiratory attributes of the subject, and corresponding cardiac parameters and/or respiratory parameters based thereon. Attributes may be measured and/or monitored via one or more sensors, e.g. worn on an extremity of the subject and/or placed at a distance from the subject. Sensory stimulation delivered to the subject during specific targeted periods of sleep may enhance slow wave neural activity.

Abstract: A sensor system comprises first and second PPG sensors. A monitoring system monitors detection by at least one of the first and second detectors an optical calibration signals, for performing time calibration between the first and second PPG sensors. This system makes use of two PPG sensors. To enable these sensors to be independent units, rather than being fully integrated into a combined system, a calibration system is provided. Based on detected optical signals, the behavior over time of each PPG sensor can be monitored and thus calibration can take place.

Abstract: A sensor system comprises first and second PPG sensors. A monitoring system monitors detection by at least one of the first and second detectors an optical calibration signals, for performing time calibration between the first and second PPG sensors. This system makes use of two PPG sensors. To enable these sensors to be independent units, rather than being fully integrated into a combined system, a calibration system is provided. Based on detected optical signals, the behavior over time of each PPG sensor can be monitored and thus calibration can take place.

Abstract: The present invention relates to a device (16) and method for monitoring a physiological state of a subject (32). To reduce the energy consumption but still provide a high accuracy, the proposed device comprises a sensor interface (18) for obtaining from a sensor (20) a sensor signal indicative of a vital sign of a subject; a power storage interface (22) for obtaining a charge value indicative of a charge state of a power storage (24) powering the sensor; a duty cycle module (28) for controlling the duty cycle of the sensor based on the charge value; and a processing unit (26) for extracting at least one feature indicative of a physiological state of the subject from the sensor signal.

Abstract: The present disclosure pertains to a system (10) configured to determine spectral boundaries (216, 218) for sleep stage classification in a subject (12). The spectral boundaries may be customized and used for sleep stage classification in an individual subject. Spectral boundaries determined by the system that are customized for the subject may facilitate sleep stage classification with higher accuracy relative to classifications made based on static, fixed spectral boundaries that are not unique to the subject. In some implementations, the system comprises one or more of a sensor (16), a processor (20), electronic storage (22), a user interface (24), and/or other components.

Abstract: The present disclosure pertains to a system configured to detect slow wave sleep and/or non-slow wave sleep in a subject during a sleep session based on a predicted onset time of slow wave sleep and/or a predicted end time of slow wave sleep that is determined based on changes in cardiorespiratory parameters of the subject. Cardiorespiratory parameters in a subject typically begin to change before transitions between non-slow wave sleep and slow wave sleep. Predicting this time delay between the changes in the cardiorespiratory parameters and the onset and/or end of slow wave sleep facilitates better (e.g., more sensitive and/or more accurate) determination of slow wave sleep and/or non-slow wave sleep.

Abstract: The present disclosure pertains to a system configured to determine one or more parameters based on cardiorespiratory information from a subject and determine sleep stage classifications based on a discriminative undirected probabilistic graphical model such as Conditional Random Fields using the determined parameters. The system is advantageous because sleep is a structured process in which parameters determined for individual epochs are not independent over time and the system determines the sleep stage classifications based on parameters determined for a current epoch, determined relationships between parameters, sleep stage classifications determined for previous epochs, and/or other information. The system does not assume that determined parameters are discriminative during an entire sleep stage, but maybe indicative of a sleep stage transition alone. In some embodiments, the system comprises one or more sensors, one or more physical computer processors, electronic storage, and a user interface.

Abstract: An apparatus comprises a sensor for measuring a physiological parameter of a subject, wherein the physiological parameter sensor is adapted to be worn by the subject; an actuator comprising an electro-active polymer material, EAP, portion for adjusting the position of the physiological parameter sensor relative to the subject; a feedback sensor for measuring movement of the physiological parameter sensor and/or the subject; a controller configured to process the measurements of the feedback sensor and to adjust the position of the actuator based on information from the feedback sensor.

Abstract: An actigraphy method includes receiving a physiological parameter signal as a function of time for a physiological parameter other than body motion (such as electrocardiography or a respiration monitor), computing a body motion artifact (BMA) signal as a function of time from the physiological parameter signal (for example, using a local signal power signal, a local variance signal, a short-time Fourier transform, or a wavelet transform over epochs of duration on order a few minutes or less), and computing an actigraphy signal as a function of time from the BMA signal, for example by applying a linear transform to the BMA signal and optionally applying filtering such as median removal and/or high-pass filtering.

Abstract: An electronic switch for controlling a device 170 by switching a function of the device at least in dependence on a sleep stage of a human. The switch includes an EEG data interface configured to receive brain activity data from an EEG sensor 120 configured to monitor electrical activity of the brain of the human during a training phase, an EEG sleep classifier 125 configured to classify sleep stages of the human from the received brain activity data, and a body data interface configured to receive body activity data from an alternative sensor 130 configured to monitor a bodily function of the human both during the training phase and during a subsequent usage phase.