Implantable pump system having a coaxial ventricular cannula
An implantable cardiovascular blood pump system is provided, suitable for use as a left ventricular assist device (LVAD) system, having an implantable cardiovascular pump, an extracorporeal battery and a controller coupled to the implantable pump, and a programmer selectively periodically coupled to the controller to configure and adjust operating parameters of the implantable cardiovascular pump. The implantable cardiovascular blood pump includes a coaxial inflow cannula and outflow cannula in fluid communication with one another and with a pumping mechanism. The pumping mechanism may be a vibrating membrane pump which may include a flexible membrane coupled to an electromagnetic actuator assembly that causes wavelike undulations to propagate along the flexible membrane to propel blood through the implantable cardiovascular pump. The implantable cardiovascular pump may be programmed to operate at frequencies and duty cycles that mimic physiologic flow rates and pulsatility while avoiding thrombus formation, hemolysis and/or platelet activation.
1. An implantable cardiovascular pump system comprising,
a housing configured to be implanted in or coupled to a patient's heart;
a pump assembly disposed within the housing, the pump assembly comprising an actuator assembly coupled to a flexible membrane, the flexible membrane unsupported at its outflow end;
an outflow cannula in fluid communication with the pump assembly, the outflow cannula having an inlet and an outlet, the outflow cannula coupled to the housing and having a length such that the outflow cannula extends from the housing into the patient's left ventricle and the outlet of the outflow cannula is disposed through the patient's aortic valve, and the outflow cannula configured to guide blood in a first direction through the patient's aortic valve; and
an inflow cannula in fluid communication with the pump assembly, the inflow cannula having an inlet disposed within the patient's heart and an outlet, and the inflow cannula configured to guide blood in a second direction, different than the first direction,
wherein the actuator assembly is configured to cause the flexible membrane to vibrate to transfer blood from the inlet of the inflow cannula through the housing, across the flexible membrane, and out the outlet of the outflow cannula to pump the blood.
2. The implantable cardiovascular pump system of claim 1 , wherein the housing is configured to be implanted at an apex of the patient's heart such that the outflow cannula extends transapically through a left ventricle of the patient's heart.
3. The implantable cardiovascular pump system of claim 1 , wherein the inflow cannula extends into the housing and is secured to the housing.
4. The implantable cardiovascular pump system of claim 1 , wherein the outflow cannula is configured to extend into the housing and is secured to the pump assembly.
5. The implantable cardiovascular pump system of claim 1 , wherein the outlet of the outflow cannula is configured to extend into an aorta and the outflow cannula is further configured to permit fluid to flow from the pump assembly to the aorta.
6. The implantable cardiovascular pump system of claim 5 , further comprising a stent that is coupled to the outlet of the outflow cannula and is configured to expand to engage a wall of the aorta, thereby centering the outflow cannula within the aortic valve.
7. The implantable cardiovascular pump system of claim 1 , wherein the pump assembly further comprises:
a rigid ring coupled to the flexible membrane;
a stator assembly coupled to the housing;
an electromagnet assembly coupled to the stator assembly, the electromagnet assembly configured to selectively generate a magnetic field;
first and second suspension rings disposed around and coupled to the stator assembly; and
a magnet ring coupled to the rigid ring and first and second suspension rings by a plurality of posts, the magnet ring suspended around the stator assembly and electromagnet assembly and configured to move towards or away from the electromagnet assembly responsive to the magnetic field.
8. The implantable cardiovascular pump of claim 1 , wherein the housing includes a surface having an opening resealably closed by a valve.
9. The implantable cardiovascular pump system of claim 1 , wherein the outflow cannula is configured to extend past the aortic valve and the outflow cannula is sized and configured to permit the aortic valve to open and close around the outflow cannula.
10. The implantable cardiovascular pump system of claim 1 , wherein the outlet of the outflow cannula comprises a stent-mounted valve.
11. The implantable cardiovascular pump system of claim 10 , wherein the stent-mounted valve is a transcatheter aortic valve replacement (TAVR).
12. The implantable cardiovascular pump system of claim 1 , wherein the pump assembly disposed within the housing has a coupling section configured to removably couple the pump assembly to the outflow cannula.
13. The implantable cardiovascular pump system of claim 1 ,
wherein the outlet of the outflow cannula comprises a stent-mounted valve configured to be implanted at the aortic valve and also configured to permit blood flow in only one direction, and
wherein the implantable cardiovascular pump is configured to move blood from the inflow cannula, through the housing, through the outflow cannula and out of the stent-mounted valve.
14. The implantable cardiovascular pump system of claim 13 , wherein the stent-mounted valve is a transcatheter aortic valve replacement (TAVR).
15. The implantable cardiovascular pump system of claim 1 , wherein the inflow cannula and outflow cannula are coaxial.