Cannula pumps for temporary cardiac support and methods of their application and use

• US 5,888,241 A
• Filed: 11/19/1997
• Issued: 03/30/1999
• Est. Priority Date: 10/30/1992
• Status: Expired due to Term

• Current Assignee: M.D. Robert Jarvik
• Original Assignee: M.D. Robert Jarvik
• Inventors: Jarvik, Robert
• Primary Examiner(s): Yu, Mickey
• Assistant Examiner(s): SNOW, BRUCE EDWARD
• Application Number:
  US08/974,019
• Time in Patent Office: 496 Days
• Field of Search: 623/2, 623/3, 604/43, 604/175, 600/16, 600/17, 417/254, 417/255, 417/256
• US Class Current: 600/16
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• 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 60/165 implantable in, on, or around the heart
• CPC Class Codes: A61M 60/174 discharging the blood to the ventricle or arterial system via a cannula internal to the ventricle or arterial system
• 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 60/183 drawing blood from both ventricles, e.g. bi-ventricular assist devices [BiVAD]
• CPC Class Codes: A61M 60/221 the blood flow through the rotating member having both radial and axial components, e.g. mixed flow pumps
• 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 60/38 Blood oxygenation
• CPC Class Codes: A61M 60/414 transmitted by a rotating cable, e.g. for blood pumps mounted on a catheter
• 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 60/515 Regulation using real-time patient data
• 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
• CPC Class Codes: A61M 60/538 Regulation using real-time blood pump operational parameter data, e.g. motor current
• CPC Class Codes: A61M 60/585 User interfaces
• CPC Class Codes: A61M 60/824 Hydrodynamic or fluid film bearings
• CPC Class Codes: A61M 60/825 Contact bearings, e.g. ball-and-cup or pivot bearings
• CPC Class Codes: A61M 60/827 Sealings between moving parts
• CPC Class Codes: A61M 60/829 having a purge fluid supply
• CPC Class Codes: A61M 60/861 : Connections or anchorings for connecting or anchoring pumps or pumping devices to parts of the patient's body
• CPC Class Codes: A61M 60/878 : Electrical connections within the patient's body

Abstract

A cannula pump is provided which incorporates a miniature rotary pump into a cardiac cannula of essentially the same size as currently utilized with routine cardiopulmonary bypass. The pump may be inserted via a single small incision in the heart to obtain both inflow and outflow cannulation simultaneously, and provide sufficient flow to completely unload the ventricle during its use. Because application of the device is extraordinarily simplified, it is suitable for rapid emergency insertion in any setting where the chest can be safely opened, including emergency room and battlefield applications. A small electric motor, implanted within the heart, provides power to the impeller via a small shaft supported on blood immersed bearings. A disposable cannula pump utilized with a reusable motor provides an inexpensive device for routine surgical use.

Claims

1. An apparatus for pumping blood, which comprises:

a) a cannula housing including a pump section and a motor section, the pump section and the motor section having substantially equal outer diameters, the cannula housing further including at least one inlet opening defined in a sidewall of the cannula housing to permit blood to enter into the cannula housing and at least one outlet opening to permit blood to exit the cannula housing, the cannula housing at least partially positionable within a patient'"'"'s heart and dimensioned for insertion and removal through a small incision in the patient'"'"'s heart;

b) a blood pumping mechanism disposed within the pump section and having a rotating member mounted for rotational movement therein by at least one mechanical bearing, wherein the rotating member directly imparts pump energy to blood entering the cannula housing through the at least one inlet opening to direct the blood through the at least one outlet opening of the cannula housing; and

c) an electric motor disposed within the motor section and operatively connected to the rotating member to drive the rotating member to thereby pump blood.

2. The apparatus of claim 1 wherein the electric motor has a magnetically actuated rotor, the rotor operatively connected to a drive shaft associated with the rotating member, the rotor imparting rotational movement to the drive shaft to cause corresponding rotation of the rotating member.

3. The apparatus of claim 2, wherein the rotating member is mounted about a blood immersible rotatable bearing.

4. The apparatus of claim 1, wherein the cannula housing includes a constricted portion, the constricted portion defining the outflow opening.

5. The apparatus of claim 4, wherein the constricted portion is generally frusto-conically shaped.

6. The apparatus of claim 1, wherein the cannula housing is generally cylindrical in configuration.

7. An apparatus for pumping blood, which comprises:

a) a cannula housing including a pump section and a motor section, the pump section and the motor section having substantially equal outer diameters, the cannula housing further including a plurality of inlet openings formed in the sidewall thereof to permit blood to enter into the cannula housing and at least one outlet opening to permit blood to exit the cannula housing, the cannula housing at least partially positionable within a patient'"'"'s heart and dimensioned for insertion through a small incision in the patient'"'"'s heart;

b) a blood pumping mechanism disposed within the pump section and having a rotating member mounted for rotational movement therein, wherein the rotating member imparts pump energy to blood entering the cannula housing through the at least one inlet opening to direct the blood through the at least one outlet opening of the cannula housing; and

c) an electric motor disposed within the motor section and operatively connected to the rotating member to drive the rotating member to thereby pump blood.

8. An apparatus for pumping blood, which comprises:

a) a cannula housing including a pump section and a motor section, the pump section and the motor section having substantially equal outer diameters, the cannula housing further including at least one inlet opening to permit blood to enter into the cannula housing and at least one outlet opening to permit blood to exit the cannula housing, the cannula housing at least partially positionable within a patient'"'"'s heart and dimensioned for insertion and removal through a small incision in the patient'"'"'s heart;

b) a blood pumping mechanism disposed within the pump section and having a rotating member mounted for rotational movement therein by at least one bearing, wherein the rotating member directly imparts pump energy to blood entering the cannula housing through the at least one inlet opening to direct the blood through the at least one outlet opening of the cannula housing; and

c) an electric motor disposed within the motor section and operatively connected to the rotating member to drive the rotating member to thereby pump blood, the electric motor having a magnetically actuated rotor, the rotor operatively connected to a drive shaft associated with the rotating member, the rotor imparting rotational movement to the drive shaft to cause corresponding rotation of the rotating member, the electric motor being detachably mounted to the drive shaft such that the electric motor is replaceable.

9. An apparatus for pumping blood, which comprises:

a) an elongated cannula housing defining a longitudinal bore and having at least one inlet opening for permitting blood to flow into the cannula housing and an outlet opening for permitting blood to exit the cannula housing and a path for blood flow defined between the inlet and outlet openings;

b) a pumping member disposed within the cannula housing in the path of the blood flow and mounted for rotational movement therewithin to impart pump energy to the blood;

c) a rotatable drive shaft for imparting rotational movement to the pump member, the rotatable drive shaft mounted within the cannula housing by a mechanical sleeve bearing; and

d) a self contained miniaturized electric motor disposed within the cannula housing and dimensioned to be positioned within the heart of the patient, the electric motor imparting rotational movement to the rotatable drive shaft, the electric motor being longitudinally displaced from the path of the blood flow.

10. The apparatus of claim 9, wherein the motor housing is formed integral with the cannula.

19. The apparatus of claim 9 wherein the rotatable drive shaft is mounted within the cannula housing by first and second mechanical sleeve bearings.

20. The apparatus of claim 9 wherein the pumping member is mounted about a blood immersible rotatable bearing, the rotatable bearing affixed to the drive shaft such that rotational movement of the drive shaft causes corresponding rotational movement of the rotatable bearing and the pumping member.

21. The apparatus of claim 9 wherein the cannula housing includes at least one side opening in a side wall portion thereof, the one side opening being the one inlet opening for permitting blood to flow into the cannula housing.

11. An apparatus for pumping blood, which comprises:

a) a cannula housing defining a longitudinal bore and having at least one inlet opening formed in a side wall thereof for permitting blood to flow into the cannula housing and an outlet opening for permitting blood to exit the cannula housing and a path for blood flow defined between the inlet and outlet openings;

b) a pumping member disposed within the cannula housing in the path of the blood flow and mounted for rotational movement therewithin to impart pump energy to the blood;

c) a rotatable drive shaft for imparting rotational movement to the pumping member; and

d) a self contained miniaturized electric motor disposed within the cannula housing and dimensioned to be positioned within the heart of the patient, the electric motor imparting rotational movement to the rotatable drive shaft.

12. The apparatus of claim 11, wherein the pumping member is mounted for rotational movement by a blood immersed rotatable mechanical bearing.

13. The apparatus of claim 12, wherein the cannula pump and electric motor are dimensioned for insertion through a small incision in the heart.

14. An apparatus for pumping blood, which comprises:

a) an elongated cannula housing defining a longitudinal bore and having at least one inlet opening for permitting blood to flow into the cannula housing and an outlet opening for permitting blood to exit the cannula housing;

b) a pumping member disposed within the cannula housing and mounted for rotational movement therewithin to impart pump energy to the blood;

c) a flexible rotatable drive shaft for imparting rotational movement to the pumping member; and

d) a self contained miniaturized electric motor disposed within the cannula housing and dimensioned to be positioned within the heart of the patient, the electric motor imparting rotational movement to the rotatable drive shaft.

15. An apparatus for pumping blood, which comprises:

a) an elongated cannula housing defining a longitudinal bore and having at least one inlet opening formed in a sidewall thereof for permitting blood to flow into the cannula and an outlet opening for permitting blood to exit the cannula;

b) a pumping member disposed within the cannula housing and mounted for rotational movement therewithin to impart pump energy to the blood;

c) a rotatable drive shaft for imparting rotational movement to the pumping member; and

d) a self contained miniaturized electric motor disposed within the cannula housing and dimensioned to be positioned within the heart of the patient, the electric motor imparting rotational movement to the rotatable drive shaft, the electric motor being detachably mounted to the drive shaft such that the electric motor is replaceable.

16. An apparatus for pumping blood, which comprises:

a) an elongated cannula housing dimensioned to be at least partially positioned within a heart and defining a longitudinal bore and having at least one inlet opening to allow blood to enter into the cannula housing;

b) a rotary pump mechanism disposed within the cannula housing, the rotary pump mechanism including;

i) an impeller including an impeller hub having impeller blades connected thereto, the impeller hub fixedly mounted about a blood immersed rotatable bearing;

ii) a rotatable drive shaft extending within the cannula housing and being affixed to the rotatable bearing, the rotatable drive shaft supported for rotation by first and second blood immersed stationary bearings, the first stationary bearing disposed adjacent one end of the impeller hub in spaced relation thereto to define a first gap between the first stationary bearing and the impeller hub, the second stationary bearing disposed adjacent the other end of the impeller hub in spaced relation thereto to define a second gap between the second stationary bearing and the impeller hub, the first and second gaps being disposed along a blood path of the cannula housing such that during pumping action of the impeller a stream of blood of sufficient volume and velocity washes the first and second gaps to prevent thrombus accumulation therein; and

c) an electric motor including a magnetically actuated rotor operatively connected to the drive shaft to impart rotational movement to the drive shaft and to the impeller.

17. The blood pump of claim 16, wherein the electric motor is disposed within the housing member.

18. An apparatus for pumping blood, which comprises:

a) a elongated cannula housing including at least one inlet opening to permit blood to enter into the cannula housing and at least one outlet opening to permit blood to exit the cannula housing, the cannula housing having an outside diameter less than or equal to about 12 millimeters to be positionable within a patient'"'"'s heart through a small incision in the patient'"'"'s heart;

b) a blood pumping mechanism including a rotating member mounted for rotational movement, wherein the rotating member imparts pump energy to blood entering the cannula housing through the at least one inlet opening to direct the blood through the at least one outlet opening of the cannula housing; and

c) a motor disposed within the cannula housing and operatively connected to the rotating member to impart rotational movement to the rotating member.