Apparatus and method for non-invasively measuring blood pressure of mammal subject

Patent metadata

Field	Value
Publication number	US-12478268-B2
Application number	US-201916670161-A
Country	US
Kind code	B2
Filing date	Oct 31, 2019
Priority date	Oct 31, 2018
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

Provided are apparatuses and methods for non-invasively measuring a blood pressure of a mammal subject. The apparatus includes a first sensor system and a second sensor system time-synchronized to each other and spatially separated by a pulse arrival distance L, and a microcontroller unit (MCU). The first and second sensor systems are respectively attached to first and second positions of the mammal subject for detecting first and second signals. The second position is more distal or proximal to a heart of the mammal subject than the first position. The MCU processes the output signals to determine a pulse arrival time (PAT) as a time delay Δt between detections of the first and second signals, and determines a pulse wave velocity (PWV) based on the PAT and L, where
PWV = L Δ ⁢ ⁢ t .
Then the MCU determines the blood pressure P from the PWV, where P is a parabolic function of the PWV.

First claim

What is claimed is:

1. An apparatus for non-invasively measuring a blood pressure of a mammal subject, comprising:
a first sensor system and a second sensor system that are time-synchronized to each other and spatially separated by a pulse arrival distance L, wherein the first sensor system is attached to a first position of the mammal subject for detecting a first signal, the second sensor system attached to a second position of the mammal subject for detecting a second signal, the second position is more distal or proximal to a heart of the mammal subject than the first position, and the pulse arrival distance L is defined by the first and second positions, wherein each of the first sensor system and the second sensor system comprises:
a plurality of electronic components, and a plurality of flexible and stretchable interconnects electrically connected to different electronic components, wherein the plurality of electronic components comprise a sensor member for measuring the first signal or the second signal of the mammal subject;
an elastomeric encapsulation layer at least partially surrounding the plurality of electronic components and the plurality of flexible and stretchable interconnects to form a tissue-facing surface operably attached to the mammal subject and an environment-facing surface; and
a microfluidic chamber formed between the tissue-facing surface and the plurality of electronic components in the elastomeric encapsulation layer;

wherein the sensor member of the first sensor system includes at least one electrode, and the microfluidic chamber of the first sensor system has at least one through openings defined therethrough such that during use the at least one electrode is directly in epidermal contact with a skin surface of the mammal subject through the at least one opening for detecting the first signal; and
a microcontroller unit (MCU) adapted in wireless communication with the first sensor system and the second sensor system, and configured to:
receive output signals of the first sensor system and the second sensor system;
process the output signals to determine a pulse arrival time (PAT) as a time delay Δt between detection of the first signal and detection of the second signal;
determine a pulse wave velocity (PWV) based on the PAT and the pulse arrival distance L, wherein

PWV
=

L

Δ
⁢

⁢
t

;

and
determine the blood pressure P of the mammal subject from the PWV, wherein P is a parabolic function of the PWV.

2. The apparatus of claim 1 , wherein P=αPWV 2 +β, and a and B are empirically determined constants depending on artery geometry and artery material properties of the mammal subject.

3. The apparatus of claim 2 , wherein at a blood pressure range between 5 kPA and 20 kPa,
0.13 kPa×s 2 /m 2 ≤α≤0.23 kPa×s 2 /m 2 ; and

2.2 kPa≤β≤3.2 kPa.

4. The apparatus of claim 1 , wherein the MCU is further configured to transmit the determined blood pressure to at least one of a patient database, a cloud server, and a mobile device.

5. The apparatus of claim 1 , wherein the MCU is further configured to generate an alarm when the determined blood pressure is out of a pre-defined range, and notify a practitioner or caregiver of the alarm.

6. The apparatus of claim 1 , wherein the plurality of flexible and stretchable interconnects comprise at least one of serpentine interconnects and zigzag interconnects.

7. The apparatus of claim 1 , wherein the first sensor system is an electrocardiography (ECG) system, and the second sensor system is a photoplethysmography (PPG) sensor system.

8. The apparatus of claim 7 , wherein the sensor member of the first sensor system comprises at least two ECG electrodes spatially separated from each other by an electrode distance.

9. The apparatus of claim 7 , wherein the sensor member of the second sensor system comprises a photoplethysmogram (PPG) sensor comprising an optical source and an optical detector located within a sensor footprint.

10. The apparatus of claim 1 , wherein the first sensor system is an inertial motion sensor system or an accelerometer system.

11. The apparatus of claim 1 , wherein the first position is at a torso region of the mammal subject, and the second position is at an extremity region of the mammal subject.

12. The apparatus of claim 1 , being used for continuously measuring the blood pressure of the mammal subject for a time period.

13. The apparatus of claim 1 , wherein each system is in wireless communication with the MCU via a near field communication (NFC) protocol, or Bluetooth protocol.

14. The apparatus of claim 1 , wherein the mammal subject is a human subject or a non-human subject.

15. The apparatus of claim 1 , wherein the microfluidic chamber is at least partially filled with at least one of an ionic liquid and a gel.

16. The apparatus of claim 15 , wherein the ionic liquid in the microfluidic chamber contains a dye for visualization.

17. The apparatus of claim 1 , wherein the at least one electrode includes a pair of electrodes spatially separated from each other by an electrode distance for ECG generation.

18. The apparatus of claim 17 , wherein each of the pair of electrodes is either a mesh electrode or a solid electrode.

19. An apparatus for non-invasively measuring blood pressure of a mammal subject, comprising:
a sensing apparatus attached to the mammal subject, comprising:
a first sensor system operably attached to a first position of the mammal subject for detecting a first signal; and
a second sensor system operably attached to a second position of the mammal subject for detecting a second signal,
wherein the second position is more distal or proximal to a heart of the mammal subject than the first position, and the first sensor system and the second sensor system are time-synchronized, and spatially separated by a pulse arrival distance L defined by the first and second positions; and
wherein each of the first sensor system and the second sensor system comprises a plurality of electronic components, and a plurality of flexible and stretchable interconnects electrically connected to different electronic components, wherein the plurality of electronic components comprise a sensor member for measuring the first signal or the second signal of the mammal subject; an elastomeric encapsulation layer at least partially surrounding the plurality of electronic components and the plurality of flexible and stretchable interconnects to form a tissue-facing surface operably attached to the mammal subject and an environment-facing surface; and a microfluidic chamber formed between the tissue-facing surface and the plurality of electronic components in the elastomeric encapsulation layer;
wherein the sensor member of the first sensor system includes at least one electrode, and the microfluidic chamber of the first sensor system has at least one through openings defined therethrough such that during use the at least one electrode is directly in epidermal contact with a skin surface of the mammal subject through the at least one opening for detecting the first signal; and

a microcontroller unit (MCU) in wireless comm

Assignees

• Univ Northwestern

Inventors

• Rogers John A
• Xu Shuai
• Ma Yinji
• Choi Jungil
• Hourlier-Fargette Aurelie
• Huang Yonggang

Classifications

• A61B2562/164

  the sensor is mounted in or on a conformable substrate or carrier · CPC title

• A61B5/742

  using visual displays (displays for heart-related electrical signals, e.g. ECG, A61B5/339) · CPC title

• A61B5/7405

  using sound · CPC title

• A61B5/7225

  Details of analogue processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation (input circuits for detecting, measuring, or recording bioelectric or biomagnetic signals A61B5/30; specific diagnostic methods using bioelectric or biomagnetic signals A61B5/316) · CPC title

• A61B5/6833

  Adhesive patches · CPC title