Noninvasive blood pressure determination method and apparatus

• US 20060217616A1
• Filed: 03/01/2006
• Published: 09/28/2006
• Est. Priority Date: 03/23/2005
• Status: Active Grant

• Current Assignee: Gert Kuchler
• Original Assignee: Somnomedics GmbH & Co. KG
• Inventors: Kuchler, Gert
• Granted Patent: US 7,374,542 B2
• Time in Patent Office: Days
• US Class Current: 600/485
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• 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 5/6826 Finger
• CPC Class Codes: A61B 5/6838 Clamps or clips

Abstract

The method and the apparatus serve for non-invasively determining the blood pressure of a patient. An electrical cardiac potential measurement signal and a pulse-pressure-wave measurement signal are detected which, starting from the heart, propagate within the blood vessels as far as to a pulse-feeling location. A pulse-pressure-wave propagating time between the heart and the pulse-feeling location is determined, based on the electrical measurement signal and the pulse measurement signal. The blood pressure is determined by the aid of a function interrelationship on the basis of the propagating time, with the function interrelationship comprising a first portion that specifies the active elasticity behaviour of the blood vessels, and a second portion that specifies the passive electricity behaviour of the blood vessels. In this way, especially accurate blood pressure determination is rendered possible.

Claims

1. A method of noninvasively determining a blood pressure (P) of a patient (2), in which

a) an electrical cardiac potential measurement signal (EM) is detected;

b) a pulse measurement signal (PM) of a pulse pressure wave which, starting from a patient'"'"'s heart, propagates within blood vessels is detected at a pulse-feeling location (15);

c) a propagating time (T) of the pulse pressure wave between the heart and the pulse-feeling location (15) is determined, based on the electrical measurement signal (EM) and the pulse measurement signal (PM);

d) wherein the blood pressure (P) is determined from the propagating time (T) by means of a function interrelationship that comprises a first portion specifying an active elasticity behaviour of the blood vessels and a second portion specifying a passive elasticity behaviour of the blood vessels.

2. A method according to claim 1, wherein, in determining the blood pressure, an additional calibration portion is considered in the function interrelationship.

3. A method according to claim 1, wherein a body height of the patient (2) is considered in determining the blood pressure.

4. A method according to claim 1, wherein the electrical measurement signal (EM) and the pulse measurement signal (PM) are detected virtually at the same location.

5. A method according to claim 1, wherein in the function interrelationship the blood pressure determination is based on, use is made of an equation

6. An apparatus for noninvasively determining of a blood pressure (P) of a patient (2), comprising

a) an ECG sensor (3;

18) for detecting an electrical cardiac potential measurement signal (EM);

b) a pulse sensor (4;

19) for detecting a pulse measurement signal (PM) of a pulse pressure wave which, starting from the heart, propagates within the blood vessels as far as to a pulse-feeling location (15) where the pulse sensor (4;

19) is disposed;

c) an evaluation unit (6) for determining a propagation time (T) of the pulse pressure wave between the heart and the pulse-feeling location (15) on the basis of the electrical measurement signal (EM) and the pulse measurement signal (PM);

d) wherein the evaluation unit (6) is designed for determining the blood pressure (P) from the propagating time (T) by means of a function interrelationship which comprises a first portion that specifies the active elasticity behaviour of the blood vessels, and a second portion that specifies the passive elasticity behaviour of the blood vessels.

7. An apparatus according to claim 6, wherein the evaluation unit (6) is designed for consideration of an additional calibration portion, obtained from a calibration measurement, in the blood pressure determination by the function interrelationship.

8. An apparatus according to claim 6, wherein means (11) are provided for input or detection of the body height (H) of the patient (2).

9. An apparatus according to claim 6, wherein the ECG sensor (18) and the pulse sensor (19) are accommodated in ajoint detection module (16).

10. An apparatus according to claim 6, wherein an equation for the blood pressure determination function interrelationship is deposited in the evaluation unit (6), according to which