Diaphragm pump

• US 5,458,468 A
• Filed: 03/25/1994
• Issued: 10/17/1995
• Est. Priority Date: 12/29/1988
• Status: Expired due to Fees

• Current Assignee: Ann Louis Chang
• Original Assignee: Victor Peter Chang
• Inventors: Umezu, Mitsuo, Ye, Chun-Xia, Nugent, Allen H.
• Primary Examiner(s): Bertsch, Richard A.
• Assistant Examiner(s): Korytnyk, Peter G.
• Application Number:
  US08/218,153
• Time in Patent Office: 571 Days
• Field of Search: 417/394, 417/395, 604/141, 604/153, 623/3, 415/900, 128/DIG. 12
• US Class Current: 417/395
• CPC Class Codes: A61F 2/2406 without fixed axis
• CPC Class Codes: A61M 60/113 in other functional devices, e.g. dialysers or heart-lung machines
• 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 60/178 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 60/196 replacing the entire heart, e.g. total artificial hearts [TAH]
• CPC Class Codes: A61M 60/33 of kidneys
• CPC Class Codes: A61M 60/43 using vacuum at the blood pump, e.g. to accelerate filling
• 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 60/837 Aspects of flexible displacement members, e.g. shapes or materials
• CPC Class Codes: A61M 60/89 Valves
• CPC Class Codes: A61M 60/892 Active valves, i.e. actuated by an external force
• CPC Class Codes: A61M 60/894 Passive valves, i.e. valves actuated by the blood
• CPC Class Codes: F04B 43/06 Pumps having fluid drive
• CPC Class Codes: F04B 53/104 the closure member being a rigid element oscillating around a fixed point

Abstract

A pump (10) has a housing (11), a base (12) and a flexible diaphragm (13) between the housing and the base. The diaphragm (13) and the base (12) define a driving chamber and the diaphragm (13) and the housing (11) define a pump chamber. The driving chamber is coupled to a pump driver adapted to direct fluid to and from the driving chamber to drive the diaphragm. The pump chamber is of generally conical form with its outlet (21) being located at the apex of the conical pump chamber and the inlet (22) being disposed at an angle inclined to the plane of the base of the conical pump chamber and being generally tangential to the outer portion of the base of pump chamber such that flow through the pump chamber is in the form of a continuous spiral vortex.

Claims

1. A pump comprising a housing, a base, a flexible diaphragm between the housing and the base, with the diaphragm and the base defining a driving chamber and the diaphragm and the housing defining a pump chamber, an inlet to the pump chamber, an outlet from the pump chamber, a port in the driving chamber for coupling the driving chamber to a pump driver adapted to direct fluid to and from the driving chamber to drive the diaphragm, the pump chamber being of generally conical form and having a central axis with the outlet being located on and extending in the direction of the central axis at the apex of the conical pump chamber and the inlet being disposed at an angle inclined to the plane of the base of the conical pump chamber and being generally tangential to the outer portion of the base of the pump chamber such that flow through the pump chamber is in the form of a continuous spiral vortex in which

(i) fluid drawn into the pump chamber by movement of the diaphragm away from the outlet enters the chamber in a downward direction that is tangential to existing flow of fluid in the chamber and flows in a circular path around the periphery of the base of the pump chamber to provide washout at the junction of the diaphragm and pump chamber with the circular cross-section of the pump chamber ensuring circular movement of the fluid, and

(ii) as the diaphragm is moved towards the outlet, the fluid is constrained by fluid continuity, conservation of momentum and the conical shape of the pump chamber to form a converging helix which advances towards the apex of the conical pump chamber to be discharged through the outlet in the direction of the central axis of the pump chamber.

2. A pump according to claim 1 wherein the inlet is inclined at an angle of from 30°

to 60°

the plane of the base of the pump chamber.

3. A pump according to claim 1 wherein the inlet is inclined at an angle of 45°

to the plane of the base of the pump chamber.

4. A pump according to claim 1 wherein the housing and the base each have peripheral flanges which are coupled together with the periphery of the diaphragm clamped and chemically bonded therebetween.

5. A pump according to claim 1 wherein the junction of the diaphragm and housing are coated with a bio-compatible material to eliminate any discontinuity at the junction.

6. A pump according to claim 4 wherein the housing and base are made from transparent epoxy and carbon fibres are embedded around the inlet and outlet, the driving chamber port and the flanges of the housing and the base.

7. A pump according to claim 1 wherein the interior surface of the inlet, outlet and pump chamber are coated with a bio-compatible material.

8. A pump according to claim 5 or claim 7 wherein the bio-compatible material is polysegmented polyurethane.

9. A pump according to claim 1 wherein the diaphragm is formed from polyvinylchloride sheet and there is a layer of bio-compatible material on each Side of the sheet.

10. A pump according to claim 1 wherein the shape of the interior of the base and that of the diaphragm are complementary.

11. A pump according to claim 10 wherein the interior surface of the base is hemi-spherical.

12. A pump according to claim 1 and further including a valve housing connected to the inlet and a valve housing connected to the outlet.

13. A pump according to claim 12 wherein the junction of the valve housing with the inlet and the junction of the valve housing with the outlet are coated with a bio-compatible material to eliminate any discontinuity at those junctions.

14. A method of pumping a fluid comprising introducing the fluid into a conical chamber closed by a diaphragm through an inlet at or adjacent the periphery of the base of the chamber at an angle inclined to the plane of the chamber base so that the fluid enters the chamber tangentially to the existing fluid flow which causes the fluid to flow in a circular path around the periphery of the chamber, operating the diaphragm in a pumping fashion so that when the diaphragm ascends the circulatory fluid is constrained by continuity and conservation of angular momentum to form a converging helix and the conical profile of the chamber results in the angular velocity of fluid increasing axially from the base plane, and, delivering the continuous spiral vortex of fluid so formed through an outlet at the apex of the conical chamber, the conical chamber having a central axis, the outlet being located on and extending in the direction of the central axis such that

(i) fluid drawn into the pump chamber by movement of the diaphragm away from the outlet enters the chamber in a downward direction that is tangential to existing flow of fluid in the chamber and flows in a circular path around the periphery of the base of the pump chamber to provide washout at the junction of the diaphragm and pump chamber with the circular cross-section of the pump chamber ensuring circular movement of the fluid, and

(ii) as the diaphragm is moved towards the outlet, the fluid is constrained by fluid continuity, conservation of momentum and the conical shape of the pump chamber to form a converging helix which advances towards the apex of the conical pump chamber to be discharged through the outlet in the direction of the central axis of the pump chamber.