Impedance pump used in bypass grafts

• US 20070038016A1
• Filed: 01/09/2006
• Published: 02/15/2007
• Est. Priority Date: 01/10/2005
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Gharib, Morteza, Rinderknecht, Derek, Sharp, Brad, Avrahami, Idit
• Granted Patent: US 7,749,152 B2
• Time in Patent Office: Days
• US Class Current: 600/16
• CPC Class Codes: A61M 60/161 mechanically acting upon the outside of the patient's blood vessel structure, e.g. compressive structures placed around a vessel
• CPC Class Codes: A61M 60/289 Devices for mechanical circulatory actuation assisting the residual heart function by means mechanically acting upon the patient's native heart or blood vessel structure, e.g. direct cardiac compression [DCC] devices
• CPC Class Codes: A61M 60/486 generated by electro-active actuators, e.g. using electro-active polymers or piezoelectric elements
• CPC Class Codes: A61M 60/495 Electromagnetic force
• CPC Class Codes: A61M 60/523 using blood flow data, e.g. from blood flow transducers
• CPC Class Codes: A61M 60/531 using blood pressure data, e.g. from blood pressure sensors

Abstract

A pump installed inside a graft in a body such as the human body to force fluid such as blood through that graft. The pump can be one which operates totally from the outside of the graft, forcing fluid through the graft without extending inside the graft. The pump can be an impedance pump, that operates based on the fluidic mismatches between the graft, and other fluid carrying vessels within the human body.

Claims

1. A device comprising:

a pump, located to pump fluid within a first conduit in a body, said pump of a type which does not have any parts that extend within said first conduit within which fluid is being pumped, said pump of a type that has no valves therein, and which pumps based on mismatches in fluidic impedance between said first conduit, within said body, and on which the pump is attached, and other blood carrying vessels that are fluidically coupled to said first conduit;

a power supply for said pump, which causes actuation of the pump to cause pumping, and

a controller for the pump, which controls the pump to operate at a specified rate which causes a specified degree of pumping in said first conduit.

2. A device as in claim 1, wherein said first body conduit is an artificial graft which bypasses a blood carrying vessel inside a human body.

3. A device as in claim 1, wherein said first body conduit is a replacement graft, which replaces a section of a blood carrying vessel inside a human body.

4. A device as in claim 1, wherein said pump includes an actuator, which reduces an area near said actuator, and causes a pressure increase near said area that creates a pumping effect.

5. A device as in claim 1, wherein said controller is wirelessly controllable.

6. A device as in claim 4, wherein said actuator is one of electromagnetic, piezoelectric, ferroelectric, or electrostatic.

7. A graft for a body, comprising:

a section of conduit, having a first and a second end, adapted to be attached to first and second sections of a blood carrying vessel within the body, to be bypassed;

an actuator, attached to said section of conduit, and operating to compress an area of said section of conduit periodically, and in a way that produces fluid flow along said section of conduit at a specified rate, but has no sections extending inside said section of conduit.

8. A graft as in claim 7, wherein said graft bypasses a blood carrying vessel.

9. A graft as in claim 7, wherein said graft replaces a blood carrying vessel.

10. A graft as in claim 7, wherein said actuator is one of piezo electric, ferroelectric, or electrostatic, and causes pinching of an outer wall of said graft.

11. A graft as in claim 7, wherein said graft is in a human body.

13. A method as in claim 11, wherein said pumping comprises pumping based on a fluidic impedance mismatch between the graft and other conduits in the body.

14. A method as in claim 13, wherein said graft is used within a human body.

15. A method as in claim 13, wherein said pumping comprises compressing an area of the graft periodically in a way that periodically increases the pressure in the graft, by a different amount and pressure increase than said other conduits.

16. A method as in claim 15, further comprising using an electronically-controlled controller to monitor the periodic pressure increase.

17. A method as in claim 16, further comprising controlling said controller wirelessly from outside the body.

12. A method, comprising:

installing a graft in a body; and

pumping fluid through the graft without using any parts that extend inside the graft.

18. A method as in claim 12, further comprising using said graft to bypass a blood carrying vessel in a human body.

19. A method as in claim 12, further comprising using said graft to replace a blood carrying vessel in a human body.