Indirect, oscillometric, digital blood pressure monitoring systems and methods enabling self-calibration to obtain absolute blood pressure values using algorithmic analysis of arterial pressure pulses to establish an oscillometric profile and compensate for intervening effects on digital arterial pressure. Proper algorithmic analysis is dependent upon proper positioning and maintained engagement of a digital cuff on the digit of a user and subsequent hydraulic coupling of the cuff to the arteries within the digit.

Systems and methods are provided to calibrate an analyte concentration sensor within a biological system, generally using only a signal from the analyte concentration sensor. For example, at a steady state, the analyte concentration value within the biological system is known, and the same may provide a source for calibration. Similar techniques may be employed with slow-moving averages. Variations are disclosed.

A calibration method includes receiving magnetic field values, which are generated by a plurality of real magnetic transmitters and are measured at multiple positions on a grid in a region containing a magnetic field perturbing element. Approximate locations of the real magnetic transmitters are received. Using the approximate locations, a respective plurality of imaginary magnetic sources is characterized inside the field perturbing element. Using the measured magnetic field values, the approximate locations, and the characterized imaginary sources, there are iteratively calculated (i) actual locations of the real and imaginary magnetic sources in the region, and (ii) modeled magnetic field values that would result from the real and imaginary magnetic sources at the actual locations. Using the calculated locations, and the modeled magnetic field values at the multiple positions on the grid, a magnetic field calibration function is derived for the region.

An implantable medical device comprises an electronic functional device for performing a function of said implantable medical device, said electronic functional device having an operational state for performing said function and a switched-off state. A wake-up device serves for transferring said functional device from said switched-off state to said operational state. The wake-up device comprises a first timer circuit for repeatedly transferring the functional device to the operational state according to a predetermined first timing scheme, a detection device for detecting a signal from a signal source external to the implantable medical device, and a second timer circuit for repeatedly switching the detection device to a reception state according to a second timing scheme.

Disclosed is a method for determining an unworn state of a sensor system comprising a pair of sensors configured for mounting on first and second body parts either side of a joint. The method comprises: obtaining one or more measurements from each sensor; calculating a relative angle between the two sensors using one or more of the obtained one or more measurements; calculating, using one or more of the obtained one or more measurements, a joint angle between the first and second body parts, where the joint angle is defined in a plane of normal bending of the joint; and determining, based on the calculated angles, whether either of the sensors is not mounted and if so, determining that the system is in an unworn state. Also disclosed is a system for providing information about a joint.

An electronic face-identification device, which performs face scanning with ultrasonic waves, includes a housing and an ultrasound device disposed within the housing. The ultrasound device may be configured to transmit ultrasonic waves through air to a face and scan the face with the ultrasonic waves, to receive reflected waves through the air corresponding to reflections of the ultrasonic waves from the face, and to perform a recognition process for the face based on reflections of the ultrasonic waves from the face. The ultrasound device may include a plurality of ultrasound transducers, and electronic circuitry configured to transmit signals to the ultrasound transducers and receive signals from the ultrasound transducers. The face-identification device may be incorporated into various electronic equipment, such as hand-held equipment in the form of smartphones and tablet computers, as well as in larger scale installations at airports, workplace entryways, and the like.

Methods, systems, and apparatuses for dynamic modification of calibration frequency. Dynamic modification of calibration frequency may include one or more of: receiving sensor data conveyed by an analyte sensor comprising an analyte indicator, using the sensor data to calculate one or more analyte levels, and receiving one or more reference analyte level measurements. Dynamic modification of calibration frequency may include using the sensor data, the one or more calculated analyte levels, and/or the one or more reference analyte level measurements to calculate a degradation rate of the analyte indicator of the analyte sensor. Dynamic modification of calibration frequency may include setting a dynamic calibration frequency based on the calculated degradation rate.

Methods, systems, and devices for temperature calibration are described. A device may support temperature calibration for a set of temperature sensors. For example, a wearable device may activate a set of temperature sensors associated with the wearable device. The set of temperature sensors may include a primary temperature sensor and one or more secondary temperature sensors. The wearable device may determine a trigger to calibrate the one or more secondary temperature sensors based on one or more conditions, and calibrate the one or more secondary temperature sensors using the primary temperature sensor based on the trigger. Based on the calibrating, the wearable device may process temperature data associated with a user that is received from one or more of the primary temperature sensor or the one or more secondary temperature sensors.

This invention generally relates to methods useful for measuring heart rate, respiration conditions, and oxygen saturation and a wearable device that incorporate those methods with a computerized system supporting data collection, analysis, readout and sharing. Particularly this present invention relates to a wearable device, such as a wristwatch or ring, for real time measuring heart rate, respiration conditions, and oxygen saturation.

Techniques are described for non-invasive, cuff-less measurement of blood pressure of a user using a portable electronic device. Illumination is projected through a body part and received by photodetectors on the other side of the body part. The body part includes elastic pathways of the circulatory system through which blood flows. Cycles of contraction and relaxation by the heart cause pulse waves to travel through the blood, which cause volumetric changes in the elastic pathways. The transient changes in blood volume result in corresponding transient changes in the amount of illumination that is absorbed by the body part versus the amount that passes through to the photodetectors, as manifest by a detection output signal. Calibration data can be used to convert the detection output signal to blood pressure measurements, such as including diastolic and systolic blood pressure readings.