Permanent heart assist system

• US 20030163020A1
• Filed: 02/21/2003
• Published: 08/28/2003
• Est. Priority Date: 02/26/2002
• Status: Active Grant

• Current Assignee: Frazier O. Howard
• Original Assignee: Frazier O. Howard
• Inventors: Frazier, O. Howard
• Granted Patent: US 7,238,151 B2
• Time in Patent Office: Days
• US Class Current: 600/16
• CPC Class Codes: A61M 2205/8243 by induction
• CPC Class Codes: A61M 2230/30 Blood pressure A61M2230/04 takes precedence
• CPC Class Codes: A61M 60/139 inside the aorta, e.g. intra-aortic balloon pumps
• CPC Class Codes: A61M 60/148 in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices
• CPC Class Codes: A61M 60/178 drawing blood from a ventricle and returning the blood to the arterial system via a cannula external to the ventricle, e.g. left or right ventricular assist devices
• CPC Class Codes: A61M 60/237 the blood flow through the rotating member having mainly axial components, e.g. axial flow pumps
• CPC Class Codes: A61M 60/419 the force acting on the blood contacting member being permanent magnetic, e.g. from a rotating magnetic coupling between driving and driven magnets
• CPC Class Codes: A61M 60/422 the force acting on the blood contacting member being electromagnetic, e.g. using canned motor pumps
• CPC Class Codes: A61M 60/554 of blood pressure
• CPC Class Codes: A61M 60/873 specially adapted for wireless or transcutaneous energy transfer [TET], e.g. inductive charging
• CPC Class Codes: A61M 60/88 Percutaneous cables
• CPC Class Codes: A61M 60/894 Passive valves, i.e. valves actuated by the blood
• CPC Class Codes: A61M 60/896 having flexible or resilient parts, e.g. flap valves

Abstract

A heart assist system includes an axial-flow blood pump capable of being implanted in the descending thoracic aorta; a pressure-feedback controller connected to the pump, for controlling the pump, the controller capable of being implanted in the body; and a rechargeable battery pack connected to the pump and to the controller, for providing power to the pump, the battery pack capable of being implanted in the body.

A method for assisting a failing heart comprises the steps of a) in response to when a measured dP/dT signal increases during systole, signaling an implanted aortic blood pump to go into a systolic mode and pump blood at a first flow rate; and b) in response to when the dP/dT signal peaks in the negative region, signaling the pump to go into a diastolic mode and pump blood at a second flow rate.

Claims

1. A heart assist system for obtaining a desired end-systolic aortic pressure, the system comprising:

a. an axial-flow blood pump for unloading the left ventricle of the heart, the pump capable of being implanted in the descending thoracic aorta;

b. a pressure-feedback controller connected to the pump, for controlling the pump, the controller capable of being implanted in the body; and

c. a rechargeable battery pack connected to the pump and to the controller, for providing power to the pump, the battery pack capable of being implanted in the body.

2. The system of claim 1, wherein an impeller of the pump is capable of residing inside the descending thoracic aorta, and drive magnets for the impeller are capable of being placed circumferentially around the outside of the aorta.

3. The system of claim 2, wherein the pump is capable of being sown into the aorta with the use of a graft.

4. The system of claim 3, wherein the pump impeller is magnetically suspended, without the need for bearings.

5. The system of claim 4, wherein the pump is capable of operating in a pressure sensitive mode, with forward flow only during cardiac systole.

6. The system of claim 5, further comprising a distal valve at the pump outlet to eliminate diastolic back flow.

7. The system of claim 6, wherein the pump is capable of electric operation via transcutaneous power transmission.

8. The system of claim 6, wherein the pump is capable of electric operation via percutaneous power transmission.

9. A method for assisting a failing heart, by unloading the left ventricle of the heart, comprises the steps of:

a. implanting an axial-flow blood pump in the descending thoracic aorta of a human;

b. sensing the intraventricular pressure of the heart, indicated by dP/dT signals;

c. sensing when the dP/dT signal increases during systole;

d. in response to when the dP/dT signal increases during systole, signaling the pump to go into a systolic mode and pump blood at a first flow rate;

e. sensing when the dP/dT signal peaks in the negative region; and

f. in response to when the dP/dT signal peaks in the negative region, signaling the pump to go into a diastolic mode and pump blood at a second flow rate appropriate for the diastolic phase of the cardiac cycle.

10. The method of claim 9, wherein the second flow rate is reduced from the first flow rate.

11. The method of claim 9, wherein the second flow rate is held substantially the same as the first flow rate.

12. The method of claim 9, wherein the second flow rate is increased from the first flow rate.