Auxiliary control for a blood pump

• US 3,882,861 A
• Filed: 09/24/1973
• Issued: 05/13/1975
• Est. Priority Date: 09/24/1973
• Status: Expired due to Term

• Current Assignee: Donald E. Kettering, Morris E. Jones
• Original Assignee: Donald E. Kettering, Morris E. Jones
• Inventors: Kettering, Donald E., Jones, Morris E.
• Primary Examiner(s): Truluck, Dalton L.
• Application Number:
  US05/399,904
• Time in Patent Office: 596 Days
• Field of Search: 128/213,214R,214E,214F,214.2,DIG.12,DIG.13 417/44
• US Class Current: 604/66
• CPC Class Codes: A61M 1/14 Dialysis systems; Artificial kidneys; Blood oxygenators semi-permeable membranes characterised by the material, manufacturing processes therefor B01D71/00 ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/34 Filtering material out of the blood by passing it through a membrane, i.e. hemofiltration or diafiltration
• CPC Class Codes: A61M 1/3403 Regulation parameters
• CPC Class Codes: A61M 1/3607 Regulation parameters
• CPC Class Codes: A61M 1/3639 Blood pressure control, pressure transducers specially adapted therefor
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 60/113 in other functional devices, e.g. dialysers or heart-lung machines
• CPC Class Codes: A61M 60/37 Haemodialysis, haemofiltration or diafiltration
• CPC Class Codes: A61M 60/43 using vacuum at the blood pump, e.g. to accelerate filling
• CPC Class Codes: A61M 60/531 using blood pressure data, e.g. from blood pressure sensors
• CPC Class Codes: Y10S 128/12 Pressure infusion

Abstract

An auxiliary control for a blood pump used in hemodialysis which acts upon an existing blood pump controller to continuously vary the pump rate in direct correspondence with changes in flow of a patient'"'"''"'"'s blood reflected as variations in negative pressure in a blood line. The auxiliary control regulates the pump rate by producing an electrical pulse train in which the duration of the pulses corresponds to changes in negative pressure corresponding to changes in the blood flow rate. The control presents means for achieving a rapid response to changes in the flow of the patient'"'"''"'"'s blood.

Claims

1. A blood pump controller responsive to changes in blood flow comprising:

a conventional blood pump for displacing blood through an extracorporeal hemodialysis system including a blood-conducting conduit;

a conventional power source and means for delivering electrical power to the blood pump, the pumping capacity of the pump being proportional to the electrical power delivered to the pump;

means electrically interposed between the power source and the blood pump said means comprising an attachment site means for detachably coupling the blood pump to the power source through the said means;

sensing means in said blood-conducting conduit for monitoring the availability of extracorporeal blood to the pump upstream from the pump; and

means responsive to the sensing means for selectively and continuously varying the amount of electrical power delivered to the blood pump from the power source thereby continuously varying the pumping flow rate of the blood pump, the magnitude of pumping variation being constantly proportional to extracorporeal blood flow upstream from the blood pump during the course of dialysis.

2. A blood pump controller responsive to changes in blood flow comprising:

a conventional blood pump for displacing blood through an extracorporeal hemodialysis system;

a blood conduit for conducting blood from a patient to the blood pump; and

a conventional power source and means for delivering electrical power to the blood pump;

means electrically interposed between the power source and the blood pump, said electrically interposed means comprising;

transducer means connected to the blood conduit producing an electrical signal representing the availability of blood to the pump;

comparing means for comparing the transducer signal with a pre-established reference signal and producing a proportional output signal; and

switching means responsive to the output of the comparing means for producing a periodic pulse train wherein the duration of each pulse is pro-proportional to the output signal of the comparing means, the speed of the blood pump being a direct function of the duration of the pulse.

3. A blood pump controller as defined in claim 2 wherein said transducer means comprises averaging means for averaging the systolic and diastolic blood pressures.

4. A blood pump controller as defined in claim 2 further comprising means for sensing negative blood pressure upstream from the pump and wherein the switching means comprises means for (a) producing a medium duration pulse when the proportional output signal is at an initial reference level representing a predetermined negative blood pressure, (b) decreasing the pulse duration when the proportional output signal indicates reduced patient'"'"''"'"'s blood flow represented by increased negative value of the blood pressure, and (c) increasing the pulse duration when the proportional output signal indicates increased patient'"'"''"'"'s blood flow represented by decreased negative value of the blood pressure.

5. A blood pump controller as defined in claim 4 wherein said pulse responsive switching means further comprises means for closing the circuit between the pump and its corresponding power supply for the duration of each pulse.

6. A blood pump controller as defined in claim 2 wherein said comparing means comprises an operational amplifier.

7. A blood pump contrOller as defined in claim 2, further comprising means responsive to the transducer means for terminating the operation of the blood pump when blood flow is reduced below a predetermined level.