Methods and apparatus for controlling heart assist devices

• US 7,169,109 B2
• Filed: 10/01/2001
• Issued: 01/30/2007
• Est. Priority Date: 10/03/2000
• Status: Expired due to Term

• Current Assignee: Arrow International, LLC (Teleflex Incorporated)
• Original Assignee: Arrow International Incorporated (Teleflex Incorporated)
• Inventors: Schreuder, Johannes Jacobus, Jansen, Jozef Reinier Cornelis
• Primary Examiner(s): Pezzuto; Robert E.
• Assistant Examiner(s): Patel; Natasha
• Application Number:
  US10/297,118
• Publication Number:
  US 20040059183A1
• Time in Patent Office: 1,947 Days
• Field of Search: 600 16- 18, 600/481, 623/3.28, 623/3.1
• 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: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61M 1/3663 Flow rate transducers; Flow integrators
• CPC Class Codes: A61M 2205/33 Controlling, regulating or measuring
• CPC Class Codes: A61M 2205/3303 Using a biosensor
• 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 60/196 replacing the entire heart, e.g. total artificial hearts [TAH]
• CPC Class Codes: A61M 60/295 Balloon pumps for circulatory assistance
• CPC Class Codes: A61M 60/515 Regulation using real-time patient data
• CPC Class Codes: A61M 60/546 of blood flow, e.g. by adapting rotor speed

Abstract

An apparatus for a heart assist device, comprising a processing unit for computing the blood flow rate from the arterial pressure curve and for predicting at every heartbeat the closing time of the heart valve from the curve of the blood flow rate. The processing unit is adapted to deliver a signal for controlling a heart assist device at a point in time, a period ahead in time of the closing time of the heart valve, wherein the mechanical properties of the said heart assist device are taken into account in determining the period. The apparatus adapts itself to changes in a patient'"'"'s heart frequency and aortic pressure.

Claims

1. An apparatus for controlling a heart assist device, comprising a processing unit for computing the blood flow rate (q(t)) from the arterial pressure curve and for predicting at every heartbeat the closing time of the heart valve from the curve of the blood flow rate, wherein the processing unit is adapted to deliver a signal for controlling a heart assist device at a point in time, a period ahead in time of the closing time of the heart valve, wherein the mechanical properties of said heart assist device are taken into account in determining said period, wherein the processing unit is adapted to determine said period by determining the maximum of the blood flow rate curve, taking a percentage of said maximum as a threshold value, and comparing the computed blood flow rate with said threshold value to determine said point in time, and wherein said threshold value is greater than q(t)=0.

2. The apparatus according to claim 1, wherein said heart assist device is an intra-aortic balloon pump having a balloon, wherein said signal initiates the inflation of the balloon.

3. The apparatus according to claim 1, characterized in that the processing unit is arranged for automatically controlling an intra-aortic balloon pump, wherein the deflation of the balloon is initiated on the basis of a derivative from the electrocardiogram with every heartbeat.

4. The apparatus according to claim 1, wherein computation of the curve of the blood flow rate from the arterial blood pressure is based on a Windkessel model that comprises a characteristic input resistance, an arterial compliance, and a peripheral resistance.

5. A method for controlling a heart assist device, comprising computing the blood flow rate (q(t)) from the arterial pressure curve and predicting at every heartbeat the closing time of the heart valve from the curve of the blood flow rate, wherein a signal for controlling a heart assist device is delivered at a point in time, a period ahead in time of the closing time of the heart valve, wherein the mechanical properties of said heart assist device are taken into account in determining said period, wherein said period is determined by determining the maximum of the blood flow rate curve, taking a percentage of said maximum as a threshold value, and comparing the computed blood flow rate with said threshold value to determine said point in time, and wherein said threshold value is greater than q(t)=0.

6. The method according to claim 5, wherein an intra-aortic balloon pump is controlled automatically, wherein the deflation of the balloon is initiated on the basis of a derivative from the electrocardiogram with every heartbeat.

7. The method according to claim 5, wherein computation of the curve of the blood flow rate from the arterial blood pressure is based on a Windkessel model that comprises a characteristic input resistance, an arterial compliance, and a peripheral resistance.

8. The method according to claim 5, wherein said heart assist device is an intra-aortic balloon pump having a balloon, wherein said signal initiates the inflation of the balloon.

9. An apparatus for controlling a heart assist device, comprising a processing unit for computing the blood flow rate from the arterial pressure curve and for predicting at every heartbeat the closing time of the heart valve from the curve of the blood flow rate, wherein the processing unit is adapted to deliver a signal for controlling a heart assist device at a point in time, a period ahead in time of the closing time of the heart valve, wherein the mechanical properties of said heart assist device are taken into account in determining said period, wherein the processing unit is adapted to determine said period by determining the maximum of the blood flow rate curve, taking a percentage of said maximum as a threshold value, and comparing the computed blood flow rate with said threshold value to determine said point in time, wherein said heart assist device is an intra-aortic balloon pump having a balloon, wherein said signal initiates the inflation of the balloon, and wherein said signal to inflate said intra-aortic balloon pump is delivered about 40 msec ahead of the closing time of the heart valve.

10. The apparatus according to claim 9, characterized in that the processing unit is arranged for automatically controlling the intra-aortic balloon pump, wherein the deflation of the balloon is initiated on the basis of a derivative from the electrocardiogram with every heartbeat.

11. The apparatus according to claim 9, wherein computation of the curve of the blood flow rate from the arterial blood pressure is based on a Windkessel model that comprises a characteristic input resistance, an arterial compliance, and a peripheral resistance.

12. A method for controlling a heart assist device, comprising computing the blood flow rate from the arterial pressure curve and predicting at every heartbeat the closing time of the heart valve from the curve of the blood flow rate, wherein a signal for controlling a heart assist device is delivered at a point in time, a period ahead in time of the closing time of the heart valve, wherein the mechanical properties of said heart assist device are taken into account in determining said period, wherein said period is determined by determining the maximum of the blood flow rate curve, taking a percentage of said maximum as a threshold value, and comparing the computed blood flow rate with said threshold value to determine said point in time, wherein said heart assist device is an intra-aortic balloon pump having a balloon, wherein said signal initiates the inflation of the balloon, and wherein said signal to inflate said intra-aortic balloon pump is delivered about 40 msec ahead of the closing time of the heart valve.

13. The method according to claim 12, wherein the intra-aortic balloon pump is controlled automatically, wherein the deflation of the balloon is initiated on the basis of a derivative from the electrocardiogram with every heartbeat.

14. The method according to claim 12, wherein computation of the curve of the blood flow rate from the arterial blood pressure is based on a Windkessel model that comprises a characteristic input resistance, an arterial compliance, and a peripheral resistance.