Noninvasive systems for blood pressure measurement in arteries

• US 9,622,666 B2
• Filed: 12/14/2012
• Issued: 04/18/2017
• Est. Priority Date: 12/14/2011
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Pahlevan, Niema, Gharib, Morteza
• Primary Examiner(s): Peng, Bo J
• Application Number:
  US13/715,743
• Publication Number:
  US 20130178736A1
• Time in Patent Office: 1,586 Days
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/0507 using microwaves or terahertz waves
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 8/04 Measuring blood pressure
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/4427 Device being portable or laptop-like
• CPC Class Codes: A61B 8/485 involving measuring strain or elastic properties
• CPC Class Codes: A61B 8/5223 for extracting a diagnostic or physiological parameter from medical diagnostic data for algorithms to analyse biomedical images G06T7/0012
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

Hardware and software methodology are described for a non-invasive approach to blood pressure measurement in pulmonary artery and systemic arteries by using wall displacement and blood velocity that are measured using ultrasound, microwave techniques and/or other radiofrequency (RF) techniques.

Claims

1. A method of blood pressure estimation of a human patient, the method comprising:

selecting a blood vessel;

measuring blood vessel distension and blood velocity with at least one sensor;

calculating, in real time, an average blood pressure over a number of cycles based on the measured blood vessel distension and the measured blood velocity using a slope calculated for vessel diameter plotted against the measured blood velocity, wherein the vessel diameter is calculated as the difference between the measured blood vessel distension and an initial diameter (D₀) estimate; and

displaying the calculated average blood pressure on an electronic display.

2. The method of claim 1, wherein the blood vessel is a pulmonary or systemic artery.

3. The method of claim 1, wherein the calculating includes determining the slope at the beginning of a cardiac cycle.

4. The method of claim 1, wherein the blood velocity measured is selected from centerline blood velocity and cross-sectional area average of the velocity.

5. The method of claim 1, wherein the Do is estimated with a selection from:

a search algorithm, age-corrected allometric equations, diastolic diameter, clinically derived values, and an approximate based on patent history.