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

• US 5,376,114 A
• Filed: 02/05/1993
• Issued: 12/27/1994
• 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): Green, Randall L.
• Assistant Examiner(s): BURKE, ELIZABETH
• Application Number:
  US08/015,246
• Time in Patent Office: 690 Days
• Field of Search: 623/1, 623/2, 623/3, 623/66, 600/16-18, 128/898, 415/900
• US Class Current: 623/3.3
• 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. A method of inhibiting binding or clogging malfunction caused by blood or thrombus, of a temporary blood pump having blood immersed pump impeller means, blood immersed pump impeller bearing means, motor means, and motor bearing means comprising:

a. enclosing said motor bearing means in a chamber which is sealed except at a single orifice of minimal area through which some blood can pass and through which passes a small diameter shaft to convey power from said motor means to said blood immersed pump impeller means,

b. before blood pumping is begun, filling said chamber with fluid in which said motor bearing means can operate,

c. providing a sufficient distance between said orifice and said motor bearing means, such that only blood mixed with said fluid reaches said motor bearing means during use of the temporary blood pump,

d. and providing a sufficient volume of fluid in said chamber such that blood entering therewithin is diluted by the fluid to inhibit malfunction of the pump.