Automatic ambient light cancellation for an optical front end. The present disclosure includes a coarse loop and fine loop in a feedback circuit configured to cancel out currents generated by detection of ambient light. An optical front end comprises a single-ended photo-diode connected to a transimpedance amplifier (TIA) followed by a buffer stage to generate differential output. A feedback loop controls a current digital to analog converter (iDAC) which is used to cancel out undesired current (e.g., from ambient light). This results in the TIA from saturating and maintain good signal quality with greater sensitivity.

An input interface is configured to receive a signal corresponding to a quantity of light that has passed through a living tissue of a subject. A pressurization controller is configured to control a pressurizing operation performed with a pressurization device attached to a body of the subject, thereby changing at least one of a thickness of the living tissue, an amount of blood contained in the living tissue, an amount of cellular interstitial fluid contained in the living tissue, an amount of blood flowing into the living tissue, and an amount of blood flowing out from the living tissue. A processor is configured to acquire, from a temporal change of the signal due to the pressurizing operation, a feature quantity that is used for estimating at least one of a physiological state of the living tissue and a disease state of the subject.

Novel tools and techniques for assessing, predicting and/or estimating effectiveness of hydration of a patient and/or an amount of fluid needed for effective hydration of the patient, in some cases, noninvasively.

An electronic device includes a pressing component and a pressure sensor. The pressing component is disposed on a wearing structure of the electronic device. The pressing component includes an electromagnetic driving member and a pressure bearing member. The pressure sensor is disposed on the pressure bearing member, and the pressure sensor is located on a surface that is of the wearing structure and that faces a measurement body part of a user. The pressure bearing member is configured to be driven by the electromagnetic driving member to press the pressure sensor on the measurement body part, and the pressure sensor is configured to obtain a pulse wave signal of the measurement body part.

A bandage for a medical sensor or system is described, the bandage including plural transparent wings surrounding at least one medical sensor, the plural transparent wings including an adhesive on a first side and including apertures therethrough configured to provide stretchability in at least one direction to the sides and away from the at least one medical sensor.

A system for controlling blood pressure includes a wearable interface having an internal contact surface, the wearable interface configured to at least partially encircle a first portion of a first limb of a subject, a sensing module carried by the wearable interface and configured to determine at least a change in blood pressure of the first limb of the subject, and an energy application module carried by the wearable interface and configured to apply energy of two or more types to the first limb of the subject.

There is disclosed a vital sign measuring device (VSMD) for obtaining an indication of a person’s blood pressure via the person’s finger by means of a finger cuff having an inflatable bladder. Blood pressure may be determined without the use of any electromagnetic radiation, such as miniature dynamic light sensing (mDLS). Apparatuses and methods for obtaining an indication of other vital signs, including hematocrit and total protein, are also disclosed.

Blood pressure detection apparatuses and methods for detecting a blood pressure of a user are described comprising optical sensors/detectors and a force sensor and, in some embodiments, comprising only a force sensor, measuring force applied by a finger. Blood pressure is measured by applying an increasing (or decreasing) force or pressure with a finger of the user on at least the force sensor, which, in some embodiments, may be a plurality of increasing pressure steps, each step being held within a predetermined acceptable pressure/force tolerance range for a predetermined hold time, and measuring the force applied by the finger and, in some embodiments, optically measuring the blood in a vessel in the finger relating to the applied pressure/force. Feedback (visual, haptic, sound) of the applied pressure is provided to the user.

A wearable device and the accompanying method for the determination of continuous pulsatile BP are described. The absolute values can be obtained in the initial phase and how a transfer function can transform the BP-signal obtain at the finger or wrist to correct BP-values corresponding to the brachial artery and at heart level. The wearable device contains an orthostatic level-correcting element, which can measure the vertical distance between heart level and finger/wrist level, where the actual measurement takes places. The wearable device may be in the form of a ring, a watch, or a bracelet. Further, the wearable device has elements for wirelessly transmitting signals to host devices such as a smart phone, tablet or other computers.

The present application provides a personal hand-held monitor for the measurement of a subject's blood pressure and, optionally, one or more other vital signs, comprising a housing located on a personal hand-held computing device or a hand-held component of a computing system; a blood flow occlusion means located in the housing; a pressure sensor adapted to provide an electrical signal indicative of the pressure applied; a means for detecting the flow of blood in the body part of the subject when pressure is applied; and means for receiving electrical signals from the pressure sensor and the blood flow detecting means and for transmitting electrical signals indicative of the pressure and blood flow to the processor of the personal hand-held computing device or the computing system, wherein the processor of the personal hand-held computing device or computing system provide at least a measurement of the blood pressure of a subject. The processor is further adapted to carry out a process to measure a diastolic blood pressure value and a systolic blood pressure value.