Blood pressure monitor

• US 10,028,668 B2
• Filed: 05/06/2015
• Issued: 07/24/2018
• Est. Priority Date: 05/06/2014
• Status: Active Grant

• Current Assignee: AliveCor Inc.
• Original Assignee: AliveCor Inc.
• Inventors: Albert, David E.
• Primary Examiner(s): Fernandez, Katherine
• Assistant Examiner(s): Yang, Yi-Shan
• Application Number:
  US14/705,755
• Publication Number:
  US 20150320328A1
• Time in Patent Office: 1,175 Days
• CPC Class Codes: A61B 2505/07 Home care
• CPC Class Codes: A61B 5/02125 of pulse wave propagation time
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/33 specially adapted for cooperation with other devices
• CPC Class Codes: A61B 5/332 Portable devices specially adapted therefor
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/6898 Portable consumer electronic devices, e.g. music players, telephones, tablet computers
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence

Abstract

Described herein are methods, systems, and software for monitoring blood pressure. In some embodiments, a using a mobile device is used. The blood pressure monitoring system utilizes heart rate measurements at two separate locations on the body to calculate a differential pulse arrival time which is used to estimate blood pressure. The heart rate measurements can be taken simultaneously, or they can be taken sequentially while simultaneously taking ECG measurement. If taken sequentially, the heart rate measurements are aligned with the ECG to determine the differential. Accurate, inexpensive, and discreet blood pressure monitoring is thus provided.

Claims

1. A method comprising:

sensing, with a first electrode and a second electrode configured to operate with a mobile computing device, a first electrocardiogram (ECG) of a subject;

sensing, with an optical sensor configured to operate with said mobile computing device, a first photoplethysmogram (PPG) of said subject simultaneously to sensing said first ECG of said subject;

sensing with said first electrode and said second electrode, a second ECG of said subject;

sensing with said optical sensor, a second PPG of said subject simultaneously to sensing said second ECG;

averaging said first ECG and said second ECG thereby generating an average QRS waveform;

determining a first Pulse Arrival Time (PAT) using the average QRS waveform and the first PPG aligned with the average QRS waveform;

determining a second PAT using the average QRS waveform and the second PPG aligned with the average QRS waveform; and

determining a blood pressure of said subject based on a differential PAT comprising a difference between the first PAT and the second PAT.

2. The method of claim 1, wherein said optical sensor comprises a camera that operates at a minimum speed of 30 frames per second.

3. The method of claim 1, wherein said first and second electrodes are removable from said mobile computing device.

4. The method of claim 1, wherein said mobile computing device is configured to display said blood pressure of said subject on said mobile computing device.

5. The method of claim 1, wherein said mobile computing device comprises a smartphone.

6. The method of claim 1, wherein said mobile computing device comprises a tablet.

7. The method of claim 1, wherein said mobile computing device comprises a smartwatch.

8. A system comprising:

a mobile computing device comprising a processor, an optical sensor, and a display, wherein the optical sensor is configured to sense a first PPG and a second PPG of a subject;

a first electrode and a second electrode connected to said mobile computing device, and configured to sense a first ECG and a second ECG of said subject; and

a non-transitory computer readable storage medium encoded with a computer program including instructions executable by said processor to cause said processor to;

generate an average QRS waveform by averaging the first ECG and the second ECG;

determine a first PAT using the average QRS waveform and the first PPG aligned with the average QRS waveform;

determine a second PAT using the average QRS waveform and the second PPG aligned with the average QRS waveform; and

determine a blood pressure of said subject based on a differential PAT comprising a difference between the first PAT and the second PAT.

9. The system of claim 8, wherein said computer program including instructions executable by said processor further causes said processor to display said blood pressure of said subject on said mobile computing device.

10. The system of claim 8, wherein the mobile computing device comprises a smartphone.

11. The system of claim 8, wherein the mobile computing device comprises a tablet.

12. The system of claim 8, wherein the mobile computing device comprises a smartwatch.

13. The system of claim 8, wherein said optical sensor is a camera that operates at a minimum speed of 30 frames per second.

14. The system of claim 8, wherein said optical sensor is a camera that operates at a minimum speed of 60 frames per second.

15. The system of claim 8, wherein said first and second electrodes are removable from said mobile computing device.