Blood pumping system

• US 4,047,844 A
• Filed: 12/08/1975
• Issued: 09/13/1977
• Est. Priority Date: 12/08/1975
• Status: Expired due to Term

• Current Assignee: Crocker National Bank (Wells Fargo & Company)
• Original Assignee: Searle Cardio-Pulmonary Systems Incorporated (Pfizer Inc.)
• Inventors: Robinson, Thomas C.
• Primary Examiner(s): Freeh, William L.
• Assistant Examiner(s): Look, Edward
• Application Number:
  US05/638,615
• Time in Patent Office: 645 Days
• Field of Search: 417/12, 417/46, 417/138, 417/290, 417/316, 417/317, 417/326, 417/344, 417/346, 417/347, 417/393, 417/3, 417/339, 417/394, 417/395, 251/5, 251/9, 251/10
• US Class Current: 417/3
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 60/104 Extracorporeal pumps, i.e. the blood being pumped outside the patient's body
• CPC Class Codes: A61M 60/38 Blood oxygenation
• CPC Class Codes: A61M 60/427 the force acting on the blood contacting member being hydraulic or pneumatic
• CPC Class Codes: A61M 60/508 Electronic control means, e.g. for feedback regulation
• CPC Class Codes: A61M 60/851 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 43/082 the tubular flexible member being pressed against a wall by a number of elements, each having an alternating movement in a direction perpendicular to the axes of the tubular member and each having its own driving mechanism
• CPC Class Codes: F04B 43/086 with two or more tubular flexible members in parallel F04B43/1136 takes precedence
• CPC Class Codes: F04B 43/1133 with fluid-actuated pump inlet or outlet valves; with two or more pumping chambers in series
• CPC Class Codes: F04B 49/065 and making use of computers

Abstract

A blood pumping system has a pair of integral flexible bodies each provided with an inlet and an outlet and disposed in open top cavities in a housing. The cavities have extensions holding inlet valves and outlet valves for opening and closing the inlets and outlets. A flexible diaphragm overlies the cavities and their extensions and is secured by a cover providing separate chambers over the inlet valves, the outlet valves and the bodies. Solenoid air valves are selectively energized to supply and exhaust the chambers to operate the valves and bodies. Switches responsive to the full and empty positions of the bodies govern the energization of the solenoids through control circuitry including a voltage controlled oscillator, a device for changing the frequency of the oscillator in accordance with the time of operation of at least some of the switches, and a device for ensuring at least a minimum rate of operation of the switches. Alarms are afforded after a predetermined number of switch operations have been missed.

Claims

1. A blood pumping system comprising a pair of pumps each having a pumping chamber defined by a flexible enclosure expandable to a full condition and compressible to an empty condition;

means defining blood inlets to both said chambers;

means defining blood outlets from both said chambers;

inlet valves for controlling flow through said inlets;

outlet valves for controlling flow through said outlets;

first actuators for said inlet valves;

second actuators for said outlet valves;

third actuators movable in one direction for compressing said enclosures to said empty condition and movable in the reverse direction to permit said enclosures to expand to full condition;

electric controllers for said first, second and third actuators;

means responsive to movement of said third actuator to its extreme positions to provide position signals;

means for regulating the rate of operation of said controllers including a variable oscillator supplying a sequence of timed signals to repeatedly and sequentially open said inlet valves, close said outlet valves and permit said pumping chamber to expand to full condition then close said inlet valves, open said outlet valves and move said third actuators in said one direction;

a signal comparator;

means for supplying said oscillator signals to said comparator;

means for supplying said position signal to said comparator; and

means controlled by said comparator in response to differences in the time of receipt of said position signals and said oscillator signals for varying the frequency of said oscillator.

2. A blood pumping system as defined in claim 1 in which said flexible enclosures, said inlet defining means and said outlet forming means are comprised of an integral, flexible, hollow body.

3. A system as defined in claim 1 wherein said means responsive to movement of said third actuator are electric switches.

4. A system as defined in claim 1 wherein said means controlled by said comparator varies the frequency of said oscillator in a direction to decrease the output from said comparator.

5. A system as defined in claim 1 including means providing a count of the signals from said oscillator and means responsive to each position signal for cancelling said count.

6. A system as defined in claim 5 including means for accumulating said counts and means responsive to accumulation of a predetermined number of counts by said accumulating means for actuating an alarm device.