Disclosed are one or more proximity sensors. At least one of the proximity sensors includes a first dielectric layer, an electrically conductive layer, and an electrode. The first dielectric layer includes an inner surface and an outer surface. The electrically conductive layer is positioned proximate to one of the inner surface or the outer surface of the first dielectric layer. The electrode includes an outer surface. The outer surface of the electrode is positioned proximate the inner surface of the first dielectric layer. The outer surface of the electrode and the electrically conductive layer define a gap.

A source stochastic signal is deconstructed into its intrinsic components using a decomposition process. The intrinsic components are transformed, and a set of machine learning models are defined and trained to operate with individual ones of the transformed components. The source stochastic signal is thus empirically broken down into underlying components which are then used as learning datasets for the set of machine learning models to predict target components. The target components are then individually predicted and combined to reconstruct a predicted target stochastic signal. The source stochastic signal and the target stochastic signals can be biological signals having a related or common origin, such as photoplethysmogram signals and arterial blood pressure waveforms.

A hemodynamic monitoring system monitors arterial blood pressure of a patient and provides a warning to medical personnel of a predicted future hypotension event of the patient. Waveform analysis is performed on sensed hemodynamic data representative of an arterial pressure waveform of the patient to determine a plurality of hypotension profiling parameters predictive of a future hypotension event for the patient. A set of transformed hypotension profiling parameters is generated based on the hypotension profiling parameters and mean and standard deviation values of the hypotension profiling parameters at a standard mean arterial pressure (MAP) threshold for hypotension and an adjusted MAP threshold for hypotension. A risk score representing a probability of a future hypotension event for the patient is determined based on the set of transformed hypotension profiling parameters. A sensory alarm is invoked to produce a sensory signal in response to the risk score satisfying a predetermined risk criterion.

In an embodiment a wrist-worn electronic device includes a main body, a wrist strap connected to the main body, wherein the wrist strap is configured to place the main body on a wrist of a target user, a wrist size determining part configured to measure, by using the wrist strap of the wrist-worn electronic device, a use circumference of the wrist-worn electronic device that matches a wrist size of the target user, and determine the wrist size of the target user based on the use circumference of the wrist-worn electronic device, and a blood pressure determining part configured to detect a pulse wave signal of the target user, measure a measured blood pressure of the target user based on the pulse wave signal, and correct the measured blood pressure of the target user based on the wrist size of the target user thereby obtaining a first corrected blood pressure of the target user.

Embodiments include systems and methods for determining blood pressure of a user. Embodiments can include a restriction device that is configured to apply an external pressure cycle to a blood vessel of the user and a pressure sensing device that is configured to detect pressures within the blood vessel during the external pressure cycle and output a signal indicative of the detected pressures. Embodiments can also include a processing device that is configured to receive the signal from the pressure sensing device, determine a first set of pressure values corresponding to minimum pressure values for each pulse pressure wave and determine a second set of pressure values corresponding to pressure upstrokes that occur during a descending pressure phase of a respective pulse pressure wave. The system can determine a blood pressure parameter of the user based on the first set of pressure values and the second set of pressure values.

A wearable device may include a sensor. The sensor may include a flexible fabric, a conjugated polymer coating deposited on the fabric via vapor-phase oxidative chemical vapor deposition (oCVD), and a plurality of electrodes in coupled to the conjugated polymer coating. The wearable device may further include a processor communicatively coupled to the electrodes. The processor may measure an electrical property across the electrodes, determine a physiological event based on the measured electrical property, and output measurement information corresponding the physiological event.

The present invention includes an apparatus and method for blood pressure trend determination of a subject comprising: a housing; at least one of a photoplethysmographic (PPG) sensor or a magnetic sensor in or on the housing and adapted to be worn by the subject, wherein the PPG/magnetic sensor uses a pulse oximeter to measure changes in skin light absorption; a processor for receiving a signal from the at least one of the PPG sensor or the magnetic sensor measurements, wherein the processor comprises a non-transitory computer readable medium having instruction stored thereon, wherein the instructions, when executed by the processor, cause the processor to: measure a trend analysis results to determine the blood pressure trend over a time period; and an input/output device that at least one of stores, displays, or transmits blood pressure trend of the subject.

A soft, flexible microtube sensor and associated method of sensing force are described. A liquid metallic alloy is sealed within a microtube as thin as a strand of human hair to form the physical force sensing mechanism. The sensor is hardly distinguishable with the naked eye, and can be used for the continuous biomonitoring of physiological signals, such as unobtrusive pulse monitoring. Also described is a method of fabricating the microtube sensor and wearable devices incorporating one or more microtube sensors.

An apparatus for calibration of a bio-information estimation model includes a sensor configured to obtain a bio-signal from an object in a reference interval; a feature extractor, implemented by at least one processor, configure to extract a reference feature value from the bio-signal; and a calibrator, implemented by the at least one processor, configured to determine whether a condition is satisfied based on at least one of the reference feature value and an offset value, and based on determining that the condition is satisfied, configured to calibrate the bio-information estimation model based on the reference feature value and the offset value.

A vascular baroreflex-related sympathetic activity (VBRSA) detection device, a VBRSA detection program, and a VBRSA detection method capable of detecting in a simple and non-invasive manner VBRSA, which is sympathetic nervous activity of a blood vessel involved in a baroreflex function, are provided. The VBRSA detection device detects the VBRSA based on pulse wave data on a biological artery and a beat interval corresponding to the pulse wave data. The VBRSA detection device includes a VBRSA-series detecting unit that detects, as a VBRSA series indicative of VBRSA, a series where, from among the series in which the beat interval increases or decreases by n (n is a natural number 3 or more) beats consecutively, a correlation coefficient for the beat interval and pulse wave data is greater than any positive threshold up to the (n-1)-th beat and the correlation coefficient at the n-th beat falls to or below the threshold.