Device for determining a characteristic point in the cardiac cycle

• US 20050197584A1
• Filed: 03/01/2005
• Published: 09/08/2005
• Est. Priority Date: 12/22/1995
• Status: Active Grant

• Current Assignee: Arrow International, LLC (Teleflex Incorporated)
• Original Assignee: Arrow International Investment Corporation (Teleflex Incorporated)
• Inventors: Schreuder, Johannes Jacobus, Hoeksel, Sebastiaan Adrianus Alphonsus Petrus, Jansen, Josef Reinier Cornelus
• Granted Patent: US 7,090,644 B2
• Time in Patent Office: Days
• US Class Current: 600/481
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 60/139 inside the aorta, e.g. intra-aortic balloon pumps
• CPC Class Codes: A61M 60/295 Balloon pumps for circulatory assistance
• CPC Class Codes: Y10S 128/90 Blood pressure recorder

Abstract

The present invention relates to a device for determining a characteristic point in the cardiac cycle that comprises means for calculating the curve of the blood flow rate D(t) in the aorta from the curve of the arterial blood pressure signal P(t) and determining from the curve of the blood flow rate D(t) in each cardiac cycle the time at which an incisura point lies. The device can be used for activating an intra-aortal balloon pump (IABP).

Claims

1-9. -9. (canceled)

10. A method for activating an intra-aortal balloon pump (IABP) comprising:

(a) calculating the curve of the blood flow rate D(t) in the aorta from the curve of the arterial blood pressure signal P(t) and determining from the curve of the blood flow rate D(t) in each cardiac cycle the time at which an incisura point lies, wherein the incisura point is determined from a first local minimum in the curve of the blood flow rate D(t) after the beginning of an ejection phase;

(b) delivering a first signal when the incisura point is reached, wherein said first signal activates an intra-aortal balloon pump (IABP) to inflate; and

(c) delivering a second signal at the beginning of the ejection phase, wherein said second signal activates an intra-aortal balloon pump (IABP) to deflate.

11. The method according to claim 10, wherein the blood flow rate D(t) lies below a threshold value Dd.

12. The method according to claim 11, wherein Dd is equal to 10% of the blood flow rate when the blood flow rate from the left ventricle has reached its maximum value.

13. The method according to claim 11, wherein Dd=0.

14. The method according to claim 10, wherein the incisura point is determined when D(t)=0 after the beginning of an ejection phase.

15. The method according to claim 10, which further comprises filtering out a high-frequency noise on the arterial blood pressure signal P(t).

16. The method according to claim 10, wherein calculation of the curve of the blood flow rate D(t) in the aorta from the curve of the arterial blood pressure signal P(t) is based on the Windkessel model.