Systems and methods for making noninvasive assessments of cardiac tissue and parameters

• US 20070016031A1
• Filed: 03/31/2006
• Published: 01/18/2007
• Est. Priority Date: 11/28/2000
• Status: Active Grant

• Current Assignee: PhysioSonics, Inc., University of Washington
• Original Assignee: Allez Physionix Ltd., University of Washington
• Inventors: Kliot, Michel, Patterson, Rex, Rooke, Alec, Mourad, Pierre
• Granted Patent: US 7,815,574 B2
• Time in Patent Office: Days
• US Class Current: 600/437
• CPC Class Codes: A61B 5/0048 Detecting, measuring or recording by applying mechanical forces or stimuli A61B5/021, A61B5/4884 and A61B9/00 take precedence
• CPC Class Codes: A61B 5/031 Intracranial pressure
• CPC Class Codes: A61B 5/4519 Muscles A61B5/389, A61B5/224 take precedence
• CPC Class Codes: A61B 5/4824 Touch or pain perception evaluation A61B5/4821 takes precedence
• CPC Class Codes: A61B 5/4869 Determining body composition
• CPC Class Codes: A61B 6/503 for diagnosis of the heart
• CPC Class Codes: A61B 6/504 for diagnosis of blood vessels, e.g. by angiography
• CPC Class Codes: A61B 8/00 Diagnosis using ultrasonic, sonic or infrasonic waves imaging of objects using sonar G01S15/00
• CPC Class Codes: A61B 8/04 Measuring blood pressure
• CPC Class Codes: A61B 8/065 to determine blood output from the heart in general A61B5/029
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/0808 for diagnosis of the brain
• CPC Class Codes: A61B 8/0883 for diagnosis of the heart
• CPC Class Codes: A61B 8/0891 for diagnosis of blood vessels
• CPC Class Codes: A61B 8/4236 characterised by adhesive patches
• CPC Class Codes: A61B 8/4444 related to the probe
• CPC Class Codes: A61B 8/4472 Wireless probes
• CPC Class Codes: A61B 8/485 involving measuring strain or elastic properties
• CPC Class Codes: A61B 8/488 involving Doppler signals

Abstract

Systems and methods for noninvasive assessment of cardiac tissue properties and cardiac parameters using ultrasound techniques are disclosed. Determinations of myocardial tissue stiffness, tension, strain, strain rate, and the like, may be used to assess myocardial contractility, myocardial ischemia and infarction, ventricular filling and atrial pressures, and diastolic functions. Non-invasive systems in which acoustic techniques, such as ultrasound, are employed to acquire data relating to intrinsic tissue displacements are disclosed. Non-invasive systems in which ultrasound techniques are used to acoustically stimulate or palpate target cardiac tissue, or induce a response at a cardiac tissue site that relates to cardiac tissue properties and/or cardiac parameters are also disclosed.

Claims

1. A method for determining blood pressure, comprising:

insonating a target tissue site within or on or in proximity to a blood vessel with ultrasound;

acquiring acoustic data from the target tissue site; and

determining a geometrical or material property of the blood vessel based on the acoustic data.

2. A method of claim 1, wherein the target tissue site is a blood vessel or tissue surrounding a blood vessel and additionally comprising inducing tissue displacement at the target tissue site by application of an acoustic radiation force.

3. A method of claim 1, wherein the geometrical property is selected from the group consisting of:

changes in diameter, cross-sectional area, aspect ratio, rate of change of diameter, and velocity.

4. A method of claim i, wherein the acoustic data acquired from the target tissue site is related to tissue stiffness or compliance.

5. A method for determining blood pressure comprising:

determining changes in a geometric property of a blood vessel of interest and the Doppler flow velocity proximal and distal to the blood vessel of interest using ultrasound techniques and calculating blood pressure based on the changes in the geometric property of the blood vessel and the Doppler flow.

6. A method for detecting myocardial ischemia and infarction comprising:

monitoring the cardiac cycle;

acquiring acoustic data relating to tissue displacements at a target myocardial tissue site at multiple time points over the course of at least one cardiac cycle using an ultrasound transducer;

relating the acoustic data with a physiological property of the target myocardial tissue; and

detecting changes in the stiffness, tension, strain or strain rate that are indicative of myocardial ischemia and infarction.

7. A method according to claim 6, comprising acquiring acoustic data relating to intrinsic tissue displacements.

8. A method according to claim 6, additionally comprising non-invasively inducing a tissue displacement at a target myocardial tissue site prior to acquiring acoustic data relating to the tissue displacements.

9. A method according to claim 6, additionally comprising acquiring Doppler ultrasound data at the target myocardial tissue site and relating the acoustic and Doppler ultrasound data with a physiological property of the target myocardial tissue.