Other

Apple Inc.

International Business Machines Corporation

Neurosky, Inc.

University of California

Thomas J Sullivan

Richard C Kimoto

Ravi Narasimhan

Zijing Zeng

Derek Park-Shing Young

Erno H Klaassen

Todd K Whitehurst

Stephen J Waydo

Wren Nancy Dougherty

Santiago Quijano

Paras Samsukha

Chad A Bossetti

Xiaoyu Guo

Anirban Chatterjee

Dario D'Angelo

Robert K Montgomery, Ii

Rui Qiao

Vasco D Polyzoev

Mohsen Mollazadeh

Alan Ray Smith

Richard H Koch

Tobias J Harrison-Noonan

Gert Cauwenberghs

Habib Sami Karaki

An Luo

Arnaud Delorme

Mary Anne Morgan

Trung Q Nguyen

Stephen R Deiss

R Keith Montgomery

Ravi Narashimhan

Detecting user contact with one or more electrodes of a physiological signal sensor can be used to ensure physiological signals measured by the physiological signal sensor meet waveform characteristics (e.g., of a clinically accurate physiological signal). In some examples, a mobile and/or wearable device can comprise sensing circuitry, stimulation circuitry, and processing circuitry. The stimulation circuit can drive one or more stimulation signals on one or more electrodes, the resulting signal(s) can be measured (e.g., by the sensing circuitry), and the processing circuitry can determine whether a user is in contact with the electrode(s). Additionally or alternatively, in some examples, mobile and/or wearable device can comprise saturation detection circuitry, and the processing circuitry can determine whether the sensing circuitry is saturated.

Contact detection for physiological sensor

Methods and devices for obtaining a blood pressure measurement of a subject measure a transit time of a blood pulse of the subject. A method includes sensing, with a pulse ejection sensor of a wrist-worn device, ejection of blood from the left ventricle. Arrival of a resulting blood pressure pulse at the wrist is sensed via a pulse arrival sensor of the wrist-worn device. A transit time of the blood pressure pulse from the left ventricle to the wrist is determined. A relative blood pressure value of the subject is determined based on the transit time. A reference absolute blood pressure value associated with the relative blood pressure value is received. An absolute blood pressure value for the relative blood pressure value is determined based on the reference absolute blood pressure value and the relative blood pressure value.

Blood pressure monitoring using a multi-function wrist-worn device

A pulse transit time is measured non-invasively and used to calculate a blood pressure value. A method of determining one or more blood pressure values includes propagating an alternating drive current through a thorax of a subject via electrodes located on a wrist-worn device. Resulting voltage levels of the subject are sensed by the wrist-worn device. The voltage levels are processed to detect when a volume of blood is ejected from the left ventricle. Output from a pulse arrival sensor coupled to the wrist-worn device is processed to detect when a blood pressure pulse generated by ejection of the volume of blood from the left ventricle arrives at the wrist. A pulse transit time (PTT) for transit of the blood pressure pulse from the left ventricle to the wrist is calculated. One or more blood pressure values for the subject are determined based on the PTT.

Electrical coupling of pulse transit time (PTT) measurement system to heart for blood pressure measurement

A low-profile blood pressure measurement system and methods of use are disclosed. The system includes an expandable member or structure that has a multi-compartment structure and/or is mounted on a rigid surface or structure. The system is incorporated into a portable multi-function device, or is configured to communicate with a portable multi-function device.

Cuff designs and methods

The present disclosure generally relate s to blood pressure monitoring. In some embodiments, methods and devices for measuring a mean arterial pressure and/or for monitoring blood pressure changes of a user are provided. Blood pressure measured by one or more pressure sensors may be adjusted using one or more correction factors. The use of the one or more correction factors disclosed herein may allow for more compact, convenient, and/or accurate wearable blood pressure measurement devices and methods. In particular, wrist-worn devices may be provided which are less bulky than current devices and may facilitate more frequent and accurate blood pressure monitoring.

Devices and systems for correcting errors in blood pressure measurements

Wrist-worn devices and related methods measure a pulse transit time non-invasively and calculate a blood pressure value using the pulse transit time. A wrist-worn device include a wrist-worn elongate band, at least four EKG or ICG electrodes coupled to the wrist-worn device for detecting a ventricular ejection of a heart, a photo-plethysmogram (PPG) sensor coupled to the wrist-worn device for detecting arrival of a blood pressure pulse at the user's wrist, and a controller configured to calculate a pulse transit time (PTT) for the blood pressure pulse. The controller calculates one or more blood pressure values for the user based on the PTT.

The present invention provides non-invasive devices, methods, and systems for determining a pressure of blood within a cardiovascular system of a user, the cardiovascular system including a heart and the user having a wrist covered by skin. More particularly, the present invention discloses a variety of wrist-worn devices having a variety of sensors configured to non-invasively engage the skin on the wrist of the user for sensing a variety of user signals from the cardiovascular system of the user. Generally, approaches disclosed herein may passively track blood pressure values without any interaction required on the part of the user or may allow for on demand or point measurements of blood pressure values by having a user actively interact with the sensors of the wrist-worn device. Approaches disclosed herein further allow for absolute blood pressure values to be determined directly without the requirement for any periodic calibrations or for relative blood pressure values to be tracked so as to provide relative blood pressure indices.

The present invention generally relates to blood pressure monitoring. In some embodiments, methods and devices of measuring a mean arterial pressure are provided and/or monitoring blood pressure changes. A wrist-worn device may include a plurality of sensors backed by a plurality of actuators. Subsets of the plurality of sensors may be selectively actuateable against a wrist of a user using one or more of the plurality of actuators. A preferred sensor and location may be identified based on pressure signals received from each of the sensors. In some embodiments, devices may use a fluid bladder coupled with piezoelectric film sensors. A fluid bladder pressure sensor may be used to calibrate the piezoelectric film signal to provide a static and dynamic pressure reading. In yet another embodiment, a mean arterial pressure may be calculated by processing a swept pressure signal obtained as a sensor is swept through different heights.

Systems, devices, and methods for measuring blood pressure of a user

Methods and devices for removing parasitic effects from body impedance measurements. Such parasitic effects can include parasitic coupling(s)/impedance(s) and/or parasitic coupling between the impedance measurement device and the body tissue being measured. In one approach, a drive current is controlled so as to control the voltage of a sense electrode to reduce a parasitic current. In another approach, different known capacitances are added to enable calculation of unknown electrode impedances. In another approach, a positive feedback loop is used to reduce error associated with a parasitic current of a voltage sensor used to measure resulting subject voltage. In another approach, sequential application of drive voltage to each electrode is used and resulting currents through all electrodes are measured and used to calculate body impedance.

Removing parasitic effects from body impedance measurements with wrist-worn and/or other devices

Wrist-worn devices and related methods measure a pulse transit time non-invasively and calculate a blood pressure value using the pulse transit time. A wrist-worn device includes an accelerometer, a photo-lethysmogram (PPG) or a pulse pressure sensor, and a controller. The PPG or the pulse pressure sensor coupled to the wrist-worn device for detecting an arrival of a blood pressure pulse at the user's wrist. The controller is configured to process output signals from the accelerometer to detect when the blood pressure pulse is propagated from the left ventricle of the user's heart, process a signal from the PPG or the pulse pressure sensor to detect when the blood pressure pulse arrives at the wrist, calculate a pulse transit time (PTT) for propagation of the blood pressure pulse from the left ventricle to the wrist, and generate one or more blood pressure values for the user based on the PTT.

Wrist worn accelerometer for pulse transit time (PTT) measurements of blood pressure

Various techniques for providing a low leakage electrostatic discharge (ESD) structure for non-contact bio-signal sensors are disclosed. In some embodiments, a low leakage ESD structure for a capacitive bio-sensor includes a unity gain buffer, and an ESD protection circuit connected to the unity gain buffer, in which the ESD protection circuit includes a diode connected across an input and an output of the unity gain buffer, and in which a voltage range for the ESD protection circuit is configurable.

Low leakage ESD structure for non-contact bio-signal sensors

A capacitive sensor system including a sensing plate, an amplifier, and a switching circuit is described. The sensing plate is capacitively coupled to a body surface. A change in the electric potential on the body surface generates an electric field that induces change in the electric potential of the sensing plate. The sensing plate includes a sensing node positioned in the electric field for generating an input signal from the electric field. The sensing plate is not in contact with the body surface. The amplifier receives the input signal at the input port, amplifies the input signal and generates an output signal at the output port. The switching circuit is connected to the input port and a reference voltage. The switching circuit non-continuously closes a shunting path from the sensing node to the reference voltage to reset the voltage at the sensing node.

Growing community of inventors

San Jose, CA, United States of America

Thomas J Sullivan