Cardiac assist device fully implantable within a patient and method of assisting the beating of the patient's heart. The cardiac assist device can include a cardiac jacket that wraps around at least a portion of the heart and a fluid reservoir coupled to the cardiac jacket. The cardiac assist device can include a pump that provides fluid to the cardiac jacket from the fluid reservoir and a motor coupled to the pump. A speed of the motor can control a fluid volume in the cardiac jacket. The cardiac assist device can include a pacemaker coupled to the motor. The pacemaker can control the speed of the motor based on cardiac parameters.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a cardiac assist device according to one embodiment of the invention.
FIG. 2 is a schematic view of a cardiac assist device according to another embodiment of the invention.
Claims
1. A cardiac assist device fully implantable within a patient to assist a heart, the cardiac assist device comprising:
a cardiac jacket that wraps around at least a portion of the heart;a fluid reservoir coupled to the cardiac jacket via an inflow canal and an outflow canal;a pump that provides fluid to the cardiac jacket from the fluid reservoir;a motor coupled to the pump, a speed of the motor controlling a fluid volume in the cardiac jacket; anda pacemaker coupled to the motor, the pacemaker controlling the speed of the motor based on at least one cardiac parameter.
2. The cardiac assist device of claim 1 wherein the cardiac jacket, the fluid reservoir, the pump, the motor, and the pacemaker are implantable and do not require any external ports.
3. The cardiac assist device of claim 1 wherein none of the cardiac jacket, the fluid reservoir, the pump, the motor, and the pacemaker interface with a patient's blood.
4. The cardiac assist device of claim 1 wherein the cardiac jacket includes a non-distensible layer and a compressible layer.
5. The cardiac assist device of claim 4 wherein the non-distensible layer is an external layer and the compressible layer is an internal layer.
6. The cardiac assist device of claim 5 wherein the internal layer includes shape memory wires positioned at least one of vertically and horizontally.
7. The cardiac assist device of claim 5 wherein the internal layer includes carbon nanotubes.
8. The cardiac assist device of claim 7 wherein the carbon nanotubes transmit at least one cardiac parameter via telemetry.
9. The cardiac assist device of claim 1 wherein the cardiac jacket includes at least two compartments.
10. The cardiac assist device of claim 9 wherein the at least two compartments include at least two of a left ventricular compartment, a right ventricular compartment, an atrial compartment, and a ventricular compartment.
11. The cardiac assist device of claim 10 wherein the left ventricular compartment and the right ventricular compartment are controlled independently with a delay.
12. The cardiac assist device of claim 1 I wherein the delay is about 30 milliseconds to about 34 milliseconds.
13. The cardiac assist device of claim 1 wherein at least one of the inflow canal and the outflow canal includes a check valve.
14. The cardiac assist device of claim 1 wherein a fluid space in the cardiac jacket is primed with fluid at about zero pressure.
15. The cardiac assist device of claim 1 wherein at least one of the cardiac jacket and the fluid reservoir is constructed of at least one layer of material that is leak-proof, impermeable, and self-sealing.
16. The cardiac assist device of claim 1 wherein a prime volume of the fluid reservoir is predetermined based on a size of the patient and a degree of left ventricular dysfunction.
17. The cardiac assist device of claim 16 wherein the fluid reservoir includes an additional fluid volume to adjust hemodynamics, the additional fluid volume being about 10 percent to about 20 percent of the prime volume.
18. The cardiac assist device of claim 16 wherein a compression fluid volume is added to the prime volume, the compression fluid volume depending on a desired systolic pressure.
19. The cardiac assist device of claim 1 wherein the pump includes a length of about three centimeters to about four centimeters and a diameter of about five centimeters.
20. The cardiac assist device of claim 1 wherein the pump is constructed of material including high purity thermoplastic.
21. The cardiac assist device of claim 1 wherein the pump includes at least one impellar and a shaft constructed of a material including ceramic.
22. The cardiac assist device of claim 1 and further comprising a connector to change rotation of the motor to linear movement of the pump, the connector including a wheel, the wheel having a diameter approximately equal to a displacement of a shaft of the pump.
23. The cardiac assist device of claim 1 wherein the motor is a servo brushless direct current motor.
24. The cardiac assist device of claim 1 and further comprising a battery connected to the motor, the battery being externally recharged by radio frequency through a coil external to the patient.
25. The cardiac assist device of claim 1 wherein the motor includes a length of about 17 millimeters and a diameter of about 10 millimeters.
26. The cardiac assist device of claim 1 wherein the motor operates according to at least one of a normal voltage of about three Volts to about six Volts, a power output of about two Watts, an efficiency of about 69 percent, a rotor inertia of about 0.6 grams centimeters squared, and a maximum recommended speed of about 1000 revolutions per minute.
27. The cardiac assist device of claim 1 wherein a pressure in the cardiac jacket is about 100 millimeters of mercury when a compression volume is about 70 cubic centimeters.
28. The cardiac assist device of claim 1 wherein the motor and the pump at least one of deliver and remove 100 cubic centimeters of fluid per second to the cardiac jacket.
29. The cardiac assist device of claim 1 wherein the pacemaker regulates compression of the heart by the cardiac jacket, the pacemaker causing compression during a systolic phase in order to increase systolic blood pressure.
30. The cardiac assist device of claim 29 wherein the pacemaker regulates decompression of the heart by the cardiac jacket, the pacemaker causing decompression during a diastolic phase in order to at least partially assist the heart in the diastolic phase.
31. The cardiac assist device of claim 1 wherein synchronization by the pacemaker is based on at least one of dual-mode, dual-pacing, dual-sensing pacing, biventricular pacing, and three-chamber synchronization pacing.
32. The cardiac assist device of claim 1 wherein the pacemaker regulates a pulsation ratio of one of one to one, one to two, one to three, and one to four.
33. The cardiac assist device of claim 1 wherein a lower pulsation ratio extends use of a rechargeable battery powering the motor to between about two hours and about six hours.
34. The cardiac assist device of claim 1 wherein the pacemaker includes a processor that determines left ventricular cardiac parameters and right ventricular cardiac parameters.
35. The cardiac assist device of claim 34 wherein the pacemaker includes a processor that determines at least one of left ventricular end diastolic pressure, left ventricular end systolic pressure, right ventricular end diastolic pressure, right ventricular end systolic pressure, left ventricular volume, right ventricular volume, cardiac tension, cardiac output, systolic blood pressure, diastolic blood pressure, and heart rate.
36. The cardiac assist device of claim 1 wherein the pacemaker responds to changes in the at least one cardiac parameter by changing at least one of an inflation rate, a deflation rate, and fluid volume.
37. The cardiac assist device of claim 1 wherein the pacemaker continuously monitors and regulates cardiac hemodynamics in real time.
38. The cardiac assist device of claim 1 wherein the cardiac jacket, the fluid reservoir, the pump, the motor, and the pacemaker are fully implantable subcutaneously in at least one of the left chest, the right chest, and the upper abdomen.
39. The cardiac assist device of claim 1 wherein the pacemaker is programmed for one of mild heart disease, moderate heart disease, and severe heart disease.
40. A method of assisting a heart of a patient, the method comprising:
fully implanting a cardiac assist device within the patient, the cardiac assist device including a cardiac jacket, a fluid reservoir, a pump, a motor, and a pacemaker;wrapping the cardiac jacket around at least a portion of the heart;pumping fluid to the cardiac jacket from the fluid reservoir; andcontrolling a speed of the motor based on at least one cardiac parameter in order to control a fluid volume in the cardiac jacket.
41. The method of claim 40 and further comprising preventing a patient's blood from interfacing with the cardiac jacket, the fluid reservoir, the pump, the motor, and the pacemaker.
42. The method of claim 40 and further comprising compressing an internal layer of the cardiac jacket and preventing compression of an external layer of the cardiac jacket.
43. The method of claim 42 and further comprising returning the internal layer to an original shape after compressing the internal layer.
44. The method of claim 40 and further comprising transmitting at least one cardiac parameter with carbon nanotubes via telemetry.
45. The method of claim 40 and further comprising wrapping a first compartment of the cardiac jacket around a left ventricle and wrapping a second compartment of the cardiac jacket around a right ventricle.
46. The method of claim 40 and further comprising wrapping a first compartment of the cardiac jacket around ventricles and wrapping a second compartment of the cardiac jacket around atrium.
47. The method of claim 45 and further comprising controlling the first compartment and the second compartment independently with a delay.
48. The method of claim 47 and further comprising delaying pulsation between the first compartment and the second compartment by about 30 milliseconds to about 34 milliseconds.
49. The method of claim 40 and further comprising restricting fluid flow between the fluid reservoir and the cardiac jacket to one direction.
50. The method of claim 40 and further comprising priming a fluid space in the cardiac jacket to about zero pressure.
51. The method of claim 40 and further comprising constructing at least one of the cardiac jacket and the fluid reservoir of at least one layer of material that is leak-proof, impermeable, and self-sealing.
52. The method of claim 40 and further comprising determining a prime volume of the fluid reservoir based on a size of the patient and a degree of left ventricular dysfunction.
53. The method of claim 52 and further comprising providing an additional fluid volume to adjust hemodynamics, the additional fluid volume being about 10 percent to about 20 percent of the prime volume.
54. The method of claim 52 and further comprising adding a compression fluid volume to the prime volume, the compression fluid volume depending on a desired systolic pressure.
55. The method of claim 40 and further comprising constructing the pump of material including high purity thermoplastic.
56. The method of claim 40 and further comprising constructing at least one impellar and a shaft of the pump of a material including ceramic.
57. The method of claim 40 and further comprising changing rotation of the motor to linear movement of the pump with a connector, the connector including a wheel, the wheel having a diameter approximately equal to a displacement of a shaft of the pump.
58. The method of claim 40 and further comprising externally recharging a battery connected to the motor by radio frequency through a coil external to the patient.
59. The method of claim 40 and further comprising operating the motor according to at least one of a normal voltage of about three to about six Volts, a power output of about two Watts, an efficiency of about 69 percent, a rotor inertia of about 0.6 grams centimeters squared, and a maximum recommended speed of about 1000 revolutions per minute.
60. The method of claim 40 and further comprising generating a pressure in the cardiac jacket of about 100 millimeters of mercury when a compression volume is about 70 cubic centimeters.
61. The method of claim 40 and further comprising at least one of delivering and removing 100 cubic centimeters of fluid per second to the cardiac jacket.
62. The method of claim 40 and further comprising regulating compression of the heart, and causing compression during a systolic phase in order to increase systolic blood pressure.
63. The method of claim 40 and further comprising regulating decompression of the heart, and causing decompression during a diastolic phase in order to at least partially assist the heart in the diastolic phase.
64. The method of claim 40 and further comprising synchronizing pulsations based on at least one of dual-mode, dual-pacing, dual-sensing pacing, biventricular pacing, and three-chamber synchronization pacing.
64. The method of claim 40 and further comprising regulating a pulsation ratio of one of one to one, one to two, one to three, and one to four.
65. The method of claim 40 and further comprising reducing a pulsation ratio in order to extend use of a rechargeable battery powering the motor to between about two hours and about six hours.
66. The method of claim 40 and further comprising determining left ventricular cardiac parameters and right ventricular cardiac parameters.
67. The method of claim 66 and further comprising determining at least one of left ventricular end diastolic pressure, left ventricular end systolic pressure, right ventricular end diastolic pressure, right ventricular end systolic pressure, left ventricular volume, right ventricular volume, cardiac tension, cardiac output, systolic blood pressure, diastolic blood pressure, and heart rate.
68. The method of claim 40 and further comprising responding to changes in the at least one cardiac parameter by changing at least one of an inflation rate, a deflation rate, and fluid volume.
69. The method of claim 40 and further comprising continuously monitoring and regulating cardiac hemodynamics in real time.
70. The method of claim 40 and further comprising fully implanting the cardiac jacket, the fluid reservoir, the pump, the motor, and the pacemaker subcutaneously in at least one of the left chest, the right chest, and the upper abdomen.
71. The method of claim 40 and further comprising programming the pacemaker for one of mild heart disease, moderate heart disease, and severe heart disease.
Patent Application
20070185369
