Continuous non-invasive wearable blood pressure monitoring system

• US 10,117,586 B1
• Filed: 03/31/2015
• Issued: 11/06/2018
• Est. Priority Date: 03/31/2014
• Status: Active Grant

• Current Assignee: Kehaai Incorporated
• Original Assignee: Sensogram Technologies, Inc.
• Inventors: Mouradian, Vahram, Poghosyan, Armen
• Primary Examiner(s): Cattungal, Sanjay
• Application Number:
  US14/675,639
• Time in Patent Office: 1,316 Days
• Field of Search: 600473-480
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2560/0475 Special features of memory means, e.g. removable memory cards
• CPC Class Codes: A61B 2562/0238 Optical sensor arrangements for performing transmission measurements on body tissue
• CPC Class Codes: A61B 2576/00 Medical imaging apparatus involving image processing or analysis A61B1/00009, A61B6/52 and A61B8/52 take precedence; image processing per se G06T; details of algorithms for analysing medical images G06T7/0012
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/0082 adapted for particular medical purposes
• CPC Class Codes: A61B 5/02108 from analysis of pulse wave characteristics
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: G16H 30/40 for processing medical images, e.g. editing

Abstract

Presented are embodiments of an apparatus and methodology integrated in the system for non-invasive, continuous, wearable, remote and mobile monitoring of human blood pressure by photoplethysmography (PPG) based sensor and an electronic processing unit with the embedded radio allowing the reading and transmittal of the read blood pressure data to the remote location.

Claims

1. A method of continuously monitoring blood pressure, the method comprising:

(a) performing a calibration sub-process to determine and store inductance (L) and compliance of the cardiovascular system (C) for each individual user;

(b) retrieving the stored values for L and C;

(c) receiving a photoplethysmographic (PPG) signal for each pulse or for a given time period;

(d) filtering the received PPG signal to produce a clean PPG signal;

(e) determining the heart rate;

(f) determining the peripheral resistance using the heart rate;

(g) calculating the blood pressure using the clean PPG signal, the peripheral resistance, L and C; and

(h) determining the systolic and diastolic blood pressure.

2. The method of claim 1, further comprising repeating steps (b) through (h) for each predetermined time period.

3. The method of claim 1, further comprising repeating steps (b) through (h) for each pulse of a user.

4. The method of claim 1, further comprising storing the systolic and diastolic blood pressure in a memory.

5. A system for continuously monitoring blood pressure, the system comprising:

a light source;

an optical sensor positioned to receive reflected light from the light source;

a signal processing unit adapted to receive an electrical signal from the optical sensor and configured to output a clean digital signal;

a microprocessor in communication with the light source, the signal processing unit, a memory and a computer/wireless interface, the microprocessor having instructions for;

(a) performing a calibration sub-process to determine and store inductance (L) and compliance of the cardiovascular system (C) for each individual user;

(b) retrieving the stored values for L and C;

(c) receiving a photoplethysmographic (PPG) signal for each pulse or for a given time period;

(d) filtering the received PPG signal to produce a clean PPG signal;

(e) determining the heart rate;

(f) determining the peripheral resistance using the heart rate;

(g) calculating the blood pressure using the clean PPG signal, the peripheral resistance, L and C; and

(h) determining the systolic and diastolic blood pressure.

6. The method of claim 5, further comprising repeating instructions (b) through (h) for each predetermined time period.

7. The method of claim 5, further comprising repeating instructions (b) through (h) for each pulse of a user.