Digital artery blood pressure monitor

Patent metadata

Field	Value
Publication number	US-12268484-B2
Application number	US-202016923906-A
Country	US
Kind code	B2
Filing date	Jul 8, 2020
Priority date	Jan 24, 2017
Publication date	Apr 8, 2025
Grant date	Apr 8, 2025

Abstract

An example of a digital artery blood pressure monitor may include a tactile sensor array disposed on an inner surface of a cuff, the tactile sensor array including a plurality of capacitive sensors to detect pressure changes within a digital artery of a finger due to blood flow, where the pressure changes cause changes to capacitance values of one or more capacitive sensors of the tactile sensor array, and control circuitry coupled to the tactile sensor array to receive the capacitance values from the tactile sensor array, and determine a blood pressure based on the capacitance values.

First claim

What is claimed is:

1. A finger-wearable blood pressure monitoring device, comprising:
a cuff;
a bladder disposed proximate to the cuff;
a pressure sensor coupled to the bladder to detect pressure changes within a digital artery of a finger due to blood flow when the finger wears the finger-wearable blood pressure monitoring device, wherein the bladder extends partially along a circumference of an inner surface of the cuff and is disposed between the pressure sensor and the finger when the finger wears the finger-wearable blood pressure monitoring device, and wherein the pressure sensor is disposed on the inner surface of the cuff; and
control circuitry coupled to the pressure sensor to receive pressure data representative of the pressure changes and determine a blood pressure based on the pressure data.

2. The finger-wearable blood pressure monitoring device of claim 1 , wherein the bladder is inflatable to cause the finger to be pressed onto the cuff when the bladder is inflated.

3. The finger-wearable blood pressure monitoring device of claim 2 , wherein the bladder is coupled to a pump configured to pump air into the bladder to inflate the bladder.

4. The finger-wearable blood pressure monitoring device of claim 2 , further including a heating element and a refrigerant disposed inside the bladder, wherein the heating element is activated to cause the refrigerant to change from a liquid state to a gas state to inflate the bladder.

5. The finger-wearable blood pressure monitoring device of claim 2 , further including a heating element included in a reservoir coupled to the bladder.

6. The finger-wearable blood pressure monitoring device of claim 1 , wherein a mean arterial pressure is determined based on the pressure data.

7. The finger-wearable blood pressure monitoring device of claim 1 , further comprising a tactile sensor array positioned to additionally detect the pressure changes based on changes to capacitance values, the tactile sensor array including a plurality of capacitive sensors formed from a plurality of layers, the plurality of layers including:
a first conductive layer disposed on a substrate;
a second conductive layer; and
deformable dielectric pillars disposed between the first and second conductive layers, wherein each deformable dielectric pillar in combination with the first and second conductive layers form an instance of a capacitive sensor of the tactile sensor array, and wherein a deformation of the deformable dielectric pillars causes the capacitance values of the capacitive sensor to change.

8. The finger-wearable blood pressure monitoring device of claim 7 , wherein the plurality of layers further include:
a protective layer disposed on the second conductive layer, and wherein slits are formed in at least the protective layer to reduce mechanical coupling between instances of the plurality of capacitive sensors.

9. The finger-wearable blood pressure monitoring device of claim 7 , wherein the plurality of layers further include a dielectric layer disposed on the second conductive layer.

10. The finger-wearable blood pressure monitoring device of claim 7 , wherein the second conductive layer is a continuous layer of conductive cloth.

11. The finger-wearable blood pressure monitoring device of claim 1 , wherein the cuff has a shape to fit at least partially around the finger, and wherein the cuff is adjustable to fit around fingers of different sizes.

12. The finger-wearable blood pressure monitoring device of claim 1 , further comprising a temperature sensor disposed proximate to the cuff to determine a temperature of the finger when the cuff is worn by a user, and wherein the temperature sensor is further coupled to the control circuitry to provide the temperature to the control circuitry.

13. The finger-wearable blood pressure monitoring device of claim 1 , further comprising a microphone disposed proximate to the cuff to record blood pulses in the digital artery, and wherein the microphone is further coupled to the control circuitry to provide the recorded blood pulses to the control circuitry.

14. The finger-wearable blood pressure monitoring device of claim 1 , further comprising a photoplethysmography sensor disposed proximate to the cuff to emit light into the finger and measure an amount of light exiting the finger when the finger wears the finger-wearable blood pressure monitoring device, and wherein the photoplethysmography sensor is further coupled to the control circuitry to provide the measurement of the amount of light exiting the finger to the control circuitry.

15. The finger-wearable blood pressure monitoring device of claim 1 , wherein the cuff and the control circuitry are disposed inside a glove finger or mounted to a stationary surface or a handheld device.

16. A finger cuff blood pressure measuring apparatus, comprising:
a cuff;
a bladder disposed proximate to the cuff;
a pressure sensor coupled to the bladder to detect pressure changes within a digital artery of the finger due to blood flow when the finger is inserted in the cuff, wherein the bladder extends partially along a circumference of an inner surface of the cuff and is disposed between the pressure sensor and the finger when the finger is inserted in the cuff, and wherein the pressure sensor is disposed on the inner surface of the cuff; and
control logic coupled to the pressure sensor, the control logic including at least one non-transitory machine-accessible storage medium that provides instructions for obtaining a blood pressure estimation that, when executed by the control logic, cause the apparatus to:
determine, based on pressure data received from the pressure sensor, pressure changes due to blood flow in the digital artery; and
based on the pressure changes, determine a blood pressure.

17. The finger cuff blood pressure measuring apparatus of claim 16 , wherein the at least one non-transitory machine-accessible storage medium further provides instructions that, when executed by the control logic, cause the apparatus to;
perform frequency domain analysis on the pressure data to determine a mean arterial pressure, a systolic blood pressure, and a diastolic blood pressure at the digital artery.

18. The finger cuff blood pressure measuring apparatus of claim 16 , wherein, the bladder is inflatable and positioned on the cuff to be pressed against the finger when the bladder is inflated, and
wherein the at least one non-transitory machine-accessible storage medium further provides instructions that, when executed by the control logic, further cause the apparatus to:
inflate the bladder to a first pressure, the first pressure at least greater than a systolic blood pressure of the user;
upon reaching the first pressure, deflate the bladder at a controlled rate; and
while the bladder is deflating, record pressure data from the pressure sensor to determine a maximum pulsatile due to blood flow in the digital artery.

19. The finger cuff blood pressure measuring apparatus of claim 16 , wherein the at least one non-transitory machine-accessible storage medium further provides instructions that, when executed by the control logic, further cause the apparatus to:
determine a mean arterial pressure at the digital artery based on the pressure data;
compare the mean arterial pressure to a threshold mean arterial pressure value; and
provide an alert if the mean arterial pressure is above the threshold mean arterial pressure value, wherein the alert is provided via an external reader.

20. The fin

Assignees

• Verily Life Sciences Llc

Inventors

• Narasimhan Ravi
• Parlikar Tushar
• Whitehurst Todd

Classifications

• A61B5/024

  Measuring pulse rate or heart rate · CPC title

• A61B5/7278

  Artificial waveform generation or derivation, e.g. synthesizing signals from measured signals · CPC title

• A61B5/029

  Measuring blood output from the heart, e.g. minute volume · CPC title

• A61B5/02125

  of pulse wave propagation time · CPC title

• A61B2562/0247

  Pressure sensors · CPC title