Fluid pump

• US 20040015042A1
• Filed: 02/21/2003
• Published: 01/22/2004
• Est. Priority Date: 02/21/2002
• Status: Active Grant

• Current Assignee: Design Mentor Incorporated
• Original Assignee: Douglas Vincent, Matthew J. Murphy
• Inventors: Vincent, Douglas, Murphy, Matthew J.
• Granted Patent: US 7,238,165 B2
• Time in Patent Office: Days
• US Class Current: 600/17
• CPC Class Codes: A61M 2230/005 Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/04 Heartbeat characteristics, e.g. ECG, blood pressure modulation
• CPC Class Codes: A61M 60/113 in other functional devices, e.g. dialysers or heart-lung machines
• CPC Class Codes: A61M 60/117 for assisting the heart, e.g. transcutaneous or external ventricular assist devices
• 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 60/38 Blood oxygenation
• CPC Class Codes: A61M 60/43 using vacuum at the blood pump, e.g. to accelerate filling
• CPC Class Codes: A61M 60/462 Electromagnetic force
• CPC Class Codes: A61M 60/894 Passive valves, i.e. valves actuated by the blood

Abstract

A pumping system 10 provides a physiological pulsatile flow and includes controller 121, a pump drive head 50 coupled to a motor 12 and a fluid housing 52 having at least one port 60. The port 60 includes a ball valve retainer region 69, a valve seat 73, and an occluder ball 71 disposed in the ball valve retainer region 69. During operation, the motor 12 forces the fluid in and out the fluid housing 52 and causes the occluder ball 71 to move from a first position whereby the fluid cannot pass through the port 60, to a second position whereby the fluid moves annular to and generally around the occluder ball 71. This movement creates a slight flow reversal that “breaks up” any blood clots that may form. The pumping system may be used as part of a cardiopulmonary bypass system, a ventricular assist device (VAD) and/or a heart pump.

Claims

1. A pump for pumping a fluid comprising:

at least one motor;

at least one pump drive head coupled to said motor; and

at least one fluid housing defining a deformable fluid chamber adapted to contain a fluid, said fluid housing including at least one port, said port including a ball valve retainer region, a valve seat, and an occluder ball disposed in said ball valve retainer region, wherein said pump drive head deforms said deformable fluid chamber and causes a pressure differential within said fluid chamber thus changing the volume of said fluid chamber and forcing said fluid in or out said fluid chamber, wherein said pressure differential causes said occluder ball to move from a first position within said ball valve retainer region whereby said fluid cannot pass through said port, to a second position within said ball valve retainer region whereby said occluder ball is forced against said valve retainer and said fluid moves annular to and generally around said occluder ball, and wherein said movement of said occluder ball from said first position to said second position creates a slight reversal in the flow of said fluid.

2. The pump as claimed in claim 1 wherein said motor includes a linear electromagnetic motor coupled to said pump drive head such that said pump drive head is movable in a linear direction.

3. The pump as claimed in claim 2 wherein said linear electromagnetic motor includes:

a core defining an air gap;

at least one coil disposed around at least a portion of said core proximate said air gap; and

a magnet member located in said air gap and movable in said linear direction.

4. The pump as claimed in claim 3 wherein said pump drive head is coupled to said magnet member.

5. The pump as claimed in claim 1 wherein said fluid housing includes a first and at least a second port wherein said first port allows said fluid to flow substantially into said fluid chamber and said second port allows said fluid to flow substantially out of said fluid chamber.

6. The pump as claimed in claim 5 wherein said pump includes:

At least a first and a second motor coupled to and defining a first, second, third and fourth pump;

at least one pump drive head coupled to said at least a first and second motor; and

a first, second, third, and fourth fluid housing, wherein said fluid includes blood, and wherein said first pump pumps said blood from a venous reservoir into a heat exchanger and an oxygenator, said second pump pumps said blood from said oxygenator through an arterial filter disposed proximate said outlet port of said second pump and into a patient'"'"'s arterial system, said third pump pumps a portion of said artial blood from said outlet of said second pump and mixes said portion of said artial blood with a cardioplegia solution, and said fourth pump pumps said mixture of blood and cardioplegia solution through a second heat exchanger disposed proximate said outlet port of said fourth pump and into said arterial system.

7. The pump as claimed in claim 1 wherein said pump includes a first and a second fluid housing and a first and a second pump drive head coupled to a first and a second end of said motor respectively such that said first and said second pump drive heads move 180 degrees out of phase with respect to each other.

8. The pump as claimed in claim 1 wherein said fluid includes blood and said pump includes a heart pump providing a pulsatile and balance flow, wherein said heart pump further includes a controller which applies a current to said motor until said pump drive head reaches a predetermined position with respect to said fluid chamber such that a predetermined volume of blood is displaced within said fluid chamber and a user adjustable, predetermined blood pressure is generated within a patient'"'"'s artierial system.

9. The pump as claimed in claim 1 wherein said pump includes an actuator housing coupled to said deformable fluid housing by way of a tube, said actuator housing defining an actuator chamber having an actuation fluid and a deformable wall proximate said pump drive head, said fluid housing containing said fluid to be pumped and including inlet and outlet ports, wherein said pump drive head deforms said deformable wall of said actuator chamber causing said actuation fluid to flow through said tube and deform said deformable fluid housing, thereby creating a pressure differential within said fluid housing which causes said fluid to be pumped to flow through said inlet and outlet ports.

10. A cardiopulmonary bypass system comprising a first, second, third and fourth pump and including:

at least a first and a second motor;

at least one pump drive head coupled to said at least a first and second motors; and

a first, second, third, and fourth deformable fluid housing each defining a fluid chamber adapted to contain a fluid, said fluid housings including an inlet and an outlet port allowing said blood to pass generally into and generally out of said fluid housing respectively, each port including a ball valve having a first and a second position wherein said fluid can and cannot pass through said port, wherein said pump drive head deforms said deformable fluid chamber causing a pressure differential within said deformable fluid chamber which causes said ball valves to move from said first to said second position and creates a slight reversal in the flow of said fluid, wherein said first pump is adapted to pump said blood from a venous reservoir into a heat exchanger and an oxygenator, said second pump is adapted to pump said blood from said oxygenator through an arterial filter disposed proximate said outlet port of said second pump and into a patient'"'"'s arterial system, said third pump is adapted to pump a portion of said artial blood from outlet of said second pump and mixes said portion of said artial blood with a cardioplegia solution, and said fourth pump is adapted to pump said mixture of blood and cardioplegia solution through a second heat exchanger disposed proximate said outlet port of said fourth pump and into said arterial system.

11. The cardiopulmonary bypass system as claimed in claim 10 wherein said motors include a linear electromagnetic motor coupled to said pump drive heads such that said pump drive heads are movable in a linear direction.

12. The cardiopulmonary bypass system as claimed in claim 11 wherein said linear electromagnetic motors includes:

a core defining an air gap;

at least one coil disposed around at least a portion of said core proximate said air gap; and

a magnet member located in said air gap and movable in said linear direction.

13. The cardiopulmonary bypass system as claimed in claim 12 wherein said pump drive heads are coupled to said magnet member.

14. The cardiopulmonary bypass system as claimed in claim 10 wherein a first and a second pump drive head are coupled to a first and a second end of said first motor and move 180 degrees out of phase with respect to each other, wherein said first and said second pump heads cause alternating pressure differentials within said first and said second deformable fluid housings of said first and said second pumps respectively.

15. The cardiopulmonary bypass system as claimed in claim 10 wherein said pumps further include a controller which applies a current to said motors until said pump drive heads reach a predetermined position with respect to each of said deformable fluid chambers such that a predetermined volume is displaced within said deformable fluid chambers and a user adjustable, predetermined blood pressure is generated within a patient'"'"'s arterial system.

16. The cardiopulmonary bypass system as claimed in claim 10 wherein each of said pumps includes an actuator housing coupled to said deformable fluid housings through a tube, each of said actuator housings defining an actuator chamber having an actuation fluid and a deformable wall proximate said pump drive heads, wherein said pump drive heads deform said deformable walls of said actuator chambers causing said actuation fluids to flow through said tubes and deform said deformable fluid housings, thereby creating a pressure differential within said deformable fluid housings which causes said fluids to be pumped to flow through said inlet and outlet ports.

17. A minimally invasive extracorporeal ventricular assist device (VAD) that provides a physiological pulsatile flow, said VAD comprising a pump and a fluid chamber having at least one valveless port, wherein said minimally invasive extracorporeal VAD is adapted to be connected to a patient using a percutaneous cannula, wherein the timing of said pump is controlled by reading the EKG of said patient such that during native heart systole, said pump fills said fluid chamber with blood and applies a slight vacuum to said patient'"'"'s arterial system thereby decreasing afterload and increasing cardiac output, and during native heart diastole, said pump empties blood from said fluid chamber increasing said pressure of said patient'"'"'s arterial system.

18. The VAD as claimed in claim 17 wherein said pump includes a linear electromagnetic motor coupled to a pump drive head such that said pump drive head is movable in a linear direction and deforms said fluid chamber.

19. The VAD as claimed in claim 18 wherein said linear electromagnetic motor includes:

a core defining an air gap;

at least one coil disposed around at least a portion of said core proximate said air gap; and

a magnet member located in said air gap and movable in said linear direction.

20. The VAD as claimed in claim 19 wherein said pump drive head is coupled to said magnet member.

21. A method of providing cardiac support comprising:

connecting a ventricular assist device (VAD) having a fluid chamber and a single valveless port to a patient'"'"'s arterial system through said single valveless port;

filling said fluid chamber through said single valveless port with blood during native heart systole; and

emptying said blood from said fluid chamber through said single valveless port during native hearty diastole, wherein said act of filling said fluid chamber applies a slight vacuum to said patient'"'"'s arterial system thereby decreasing afterload and increasing cardiac output, and wherein said act of emptying said fluid chamber increases the pressure of said patient'"'"'s arterial system.

22. The method as claimed in claim 21 wherein said act of connecting said VAD to said patient'"'"'s arterial system includes connecting said VAD to said patient'"'"'s arterial system using a percutaneous cannula.

23. The method as claimed in claim 21 wherein said acts of filling and emptying said fluid chamber is controlled by reading the EKG of said patient.

24. A method of operating a heart pump having a motor displacing blood within a chamber, said method comprising the acts of:

specifying a volume of blood to be displaced by said pump;

specifying a diastolic pressure to be maintain within said chamber during pump diastole;

applying a diastolic current to said motor to maintain said diastolic pressure until said volume of blood has been displaced from said chamber;

specifying a systolic pressure to be maintain within said chamber during pump systole; and

applying a systolic current to said motor to maintain said systolic pressure until said volume of blood has been displaced from said chamber, wherein the length of time said diastolic and said systolic currents are applied to said pump depends upon the pump preload and the pump afterload respectively.

25. The method as claimed in claim 24 wherein said motor is a linear electromagnetic motor coupled to a pump drive head such that said pump drive head is movable in a linear direction to displace said volume of blood.

26. A system for providing electromechanical, physiological blood flow, comprising:

an electromechanical pumping device comprising;

at least one motor, said at least one motor comprising a coil and a moving member; and

at least one blood pump coupled to said moving member of said motor, said blood pump, when coupled to said moving member of said motor, providing physiological blood flow.

27. A pump for pumping a fluid comprising:

at least one motor;

a controller in communication with said motor, said controller having an algorithm for generating a current waveform to said motor to provide pulsatile flow;

at least one pump drive head coupled to said motor; and

at least one fluid housing defining a deformable fluid chamber adapted to contain a fluid, said fluid housing including at least one port allowing said fluid to flow in or out of said fluid housing.

28. The pump as claimed in claim 27 wherein said motor includes a linear electromagnetic motor coupled to said pump drive head such that said pump drive head is movable in a linear direction.

29. The pump as claimed in claim 28 wherein said linear electromagnetic motor includes:

a core defining an air gap;

at least one coil disposed around at least a portion of said core proximate said air gap; and

a magnet member located in said air gap and movable in said linear direction.

30. The pump as claimed in claim 29 wherein said pump drive head is coupled to said magnet member.

31. The pump as claimed in claim 27 wherein said port includes a valve to control the flow of said fluid through said port.

32. The pump as claimed in claim 31 wherein said valve includes a ball valve having a ball valve retainer region, a valve seat, and an occluder ball disposed in said ball valve retainer region, wherein said pump drive head deforms said deformable fluid chamber and causes a pressure differential within said fluid chamber thus changing the volume of said fluid chamber and forcing said fluid in or out said fluid chamber, wherein said pressure differential causes said occluder ball to move from a first position within said ball valve retainer region whereby said fluid cannot pass through said port, to a second position within said ball valve retainer region whereby said occluder ball is forced against said valve retainer and said fluid moves annular to and generally around said occluder ball, and wherein said movement of said occluder ball from said first position to said second position creates a slight reversal in the flow of said fluid.

33. The pump as claimed in claim 27 wherein said controller generates a current waveform for providing a physiological pulsatile flow.

34. The pump as claimed in claim 27 wherein said controller generates a current waveform for providing a user programmable pulsatile flow.

35. The pump as claimed in claim 27 wherein said controller generates a current waveform for providing an arbitrary flow.

36. The pump as claimed in claim 27 wherein said pump includes a first and a second fluid housing and a first and a second pump drive head coupled to a first and a second end of said motor respectively such that said first and said second pump drive heads move 180 degrees out of phase with respect to each other.

37. The pump as claimed in claim 27 wherein said pump includes an actuator housing coupled to said deformable fluid housing by way of a tube, said actuator housing defining an actuator chamber having an actuation fluid and a deformable wall proximate said pump drive head, said fluid housing containing said fluid to be pumped and including inlet and outlet ports, wherein said pump drive head deforms said deformable wall of said actuator chamber causing said actuation fluid to flow through said tube and deform said deformable fluid housing, thereby creating a pressure differential within said fluid housing which causes said fluid to be pumped to flow through said inlet and outlet ports.

38. A cardiopulmonary pump for pumping a fluid comprising:

at least a first and a second motor coupled to and defining a first, second, third and fourth pump;

at least one pump drive head coupled to said at least a first and second motor; and

a first, second, third, and fourth fluid housing each defining a deformable fluid chamber adapted to contain a blood and including a first and a second port to allow said blood to flow substantially into and substantially out of said fluid chambers respectively, and wherein said first pump pumps said blood from a venous reservoir into a heat exchanger and an oxygenator, said second pump pumps said blood from said oxygenator through an arterial filter disposed proximate said outlet port of said second pump and into a patient'"'"'s arterial system, said third pump pumps a portion of said artial blood from said outlet of said second pump and mixes said portion of said artial blood with a cardioplegia solution, and said fourth pump pumps said mixture of blood and cardioplegia solution through a second heat exchanger disposed proximate said outlet port of said fourth pump and into said arterial system.

39. The pump as claimed in claim 38 wherein said inlet and said outlet ports include a valve to control the flow of said blood through said ports.

40. The cardiopulmonary pump as claimed in claim 39 wherein said valve includes a ball valve having a ball valve retainer region, a valve seat, and an occluder ball disposed in said ball valve retainer region, wherein said pump drive head deforms said deformable fluid chamber and causes a pressure differential within said fluid chamber thus changing the volume of said fluid chamber and forcing said blood in or out said fluid chamber, wherein said pressure differential causes said occluder ball to move from a first position within said ball valve retainer region whereby said blood cannot pass through said port, to a second position within said ball valve retainer region whereby said occluder ball is forced against said valve retainer and said blood moves annular to and generally around said occluder ball, and wherein said movement of said occluder ball from said first position to said second position creates a slight reversal in the flow of said blood.