Method and apparatus for controlling fluid pumps

• US 20020150476A1
• Filed: 02/21/2002
• Published: 10/17/2002
• Est. Priority Date: 09/30/1996
• Status: Active Grant

• Current Assignee: Terumo Cardiovascular Systems Corporation (Terumo Corporation)
• Original Assignee: Terumo Cardiovascular Systems Corporation (Terumo Corporation)
• Inventors: Lucke, Lori E., Willems, Richard M., Griewski, Richard A.
• Granted Patent: US 6,783,328 B2
• Time in Patent Office: Days
• US Class Current: 417/2
• CPC Class Codes: A61M 1/00 Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems catheters A61M25/00; tube connectors, tube couplings, valves or branch units specially adapted for medical use A61M39/00; devices for taking samples of blood A61B5/15; filters implantable into blood vessels A61F2/01
• CPC Class Codes: A61M 1/32 Oxygenators without 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 1/3621 Extra-corporeal blood circuits single-needle circuits A61M1/30
• CPC Class Codes: A61M 1/3666 Cardiac or cardiopulmonary bypass, e.g. heart-lung machines
• CPC Class Codes: A61M 1/367 Circuit parts not covered by the preceding subgroups of group A61M1/3621
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/3365 Rotational speed
• CPC Class Codes: A61M 2205/3368 Temperature
• CPC Class Codes: A61M 2205/3379 Masses, volumes, levels of fluids in reservoirs, flow rates
• CPC Class Codes: A61M 2205/35 Communication
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/505 Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
• CPC Class Codes: A61M 60/113 in other functional devices, e.g. dialysers or heart-lung machines
• 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 60/232 Centrifugal pumps
• CPC Class Codes: A61M 60/279 : Peristaltic pumps, e.g. roller pumps
• CPC Class Codes: A61M 60/408 : the force acting on the blood contacting member being mechanical, e.g. transmitted by a shaft or cable
• 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 60/546 : of blood flow, e.g. by adapting rotor speed
• CPC Class Codes: A61M 60/554 : of blood pressure
• CPC Class Codes: F04B 2205/04 : Pressure in the outlet chamber
• CPC Class Codes: F04B 2207/70 : Warnings
• CPC Class Codes: F04B 43/0081 : systems, control, safety measures
• CPC Class Codes: F04B 43/12 : having peristaltic action
• CPC Class Codes: F04B 49/065 : and making use of computers
• CPC Class Codes: G16H 20/40 : relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture
• CPC Class Codes: G16H 40/63 : for local operation

Abstract

Fluid pump control modes in a medical perfusion system include a Back Off Response Mode, a Flow Servo Mode, a Pressure Servo Mode, and a Master-Slave Servo Mode. In the Back Off Response Mode, pump'"'"'s speed is decremented to a new speed when an excessive flow rate or pressure condition is detected. The new speed is maintained until an additional decrement is required or until the Back Off Response Mode is exited. In the Flow Servo Mode, a pump'"'"'s speed is controlled to maintain a fluid flow rate indicated by a user as a setpoint. In the Pressure Servo Mode, a pump'"'"'s speed is controlled to maintain a pressure indicated by the user as a setpoint. In the Master-Slave Servo Mode, a slave pump receives an indication of a master pump'"'"'s speed, and the slave pump speed is controlled to maintain a specified percentage of the master pump'"'"'s speed.

Claims

1. A method for controlling a fluid pump, comprising:

in response to an alarm condition, reducing a speed of the fluid pump; and

maintaining the new speed.

2. The method of claim 1, comprising:

repeating the steps of reducing and maintaining until the alarm condition goes away.

3. The method of claim 2, wherein the fluid being pumped by the fluid pump is blood.

4. The method of claim 2, wherein in the step of reducing, the speed of the fluid pump is reduced by a predetermined percentage of the fluid pump speed.

5. The method of claim 2, wherein in the step of reducing, the speed of the fluid pump is reduced by a predetermined number of revolutions per minute.

6. The method of claim 2, wherein the alarm condition is based on a fluid pressure which the fluid pump influences, exceeding a critical level.

7. The method of claim 2, wherein the alarm condition is based on a flow rate which the fluid pump influences, exceeding a critical level.

8. The method of claim 1, wherein in the step of reducing, the speed of the fluid pump is reduced to a predetermined speed.

9. The method of claim 1, comprising:

generating an alert to indicate that the fluid pump speed has been automatically reduced in response to an alarm condition.

10. A method for controlling a fluid pump, comprising:

establishing a fluid flow rate setpoint;

receiving fluid flow data;

automatically adjusting a speed of the fluid pump to maintain the measured fluid flow rate at the fluid flow rate setpoint;

detecting an adjustment by the user to the fluid pump speed;

in response to a detected user adjustment of the fluid pump speed, adopting the fluid flow rate at the user adjusted fluid pump speed, as the fluid flow rate setpoint.

11. The method of claim 10, wherein the fluid flow rate setpoint is established by adjusting the speed of the fluid pump until a desired fluid flow rate is achieved, and then adopting the fluid flow rate corresponding to the present fluid pump speed as the new fluid flow rate setpoint.

12. The method of claim 10, comprising:

in response to an alarm condition, reducing a speed of the fluid pump to a new speed, and adopting the fluid flow rate corresponding to the new speed, as the fluid flow rate setpoint.

13. The method of claim 12, wherein the fluid pump is a second fluid pump, and a first fluid pump is controlled based on performance of the second fluid pump, comprising:

receiving an indication of a speed of a second fluid pump; and

controlling a speed of the first fluid pump based on the received indication, to maintain a speed of the first fluid pump at a specified percentage of the speed of the second fluid pump.

15. The method of claim 14, wherein the fluid pressure setpoint is established by adjusting the speed of the fluid pump until a desired fluid pressure is achieved, and then adopting the fluid pressure corresponding to the present fluid pump speed as the new fluid pressure setpoint.

16. The method of claim 14, comprising:

in response to an alarm condition, reducing a speed of the fluid pump to a new speed, and adopting the fluid pressure corresponding to the new speed, as the fluid pressure setpoint.

17. The method of claim 16, wherein the fluid pump is a second fluid pump, and a first fluid pump is controlled based on performance of the second fluid pump, comprising:

receiving an indication of a speed of a second fluid pump; and

controlling a speed of the first fluid pump based on the received indication, to maintain a speed of the first fluid pump at a specified percentage of the speed of the second fluid pump.

20. The system of claim 19, comprising:

means for reducing the speed of the means for pumping fluid until the alarm condition ceases.

21. The system of claim 20, wherein the means for reducing reduces the speed by a predetermined percentage.

22. The system of claim 20, wherein the means for reducing reduces the speed by a predetermined number of revolutions per minute.

23. The system of claim 20 wherein the means for reducing reduces the speed to a predetermined speed.

24. The system of claim 19, comprising:

means for generating an alert to indicate that the speed has been automatically reduced in response to an alarm condition.

26. The system of claim 25, comprising:

means for reducing a speed of the means for pumping fluid to a new speed in response to an alarm condition; and

means for adopting the fluid flow rate corresponding to the new speed, as the fluid flow rate setpoint.

28. The system of claim 27, comprising:

means for reducing a speed of the means for pumping fluid to a new speed, in response to an alarm condition; and

means for adopting the fluid pressure corresponding to the new speed, as the fluid pressure setpoint.

14. A method for controlling a fluid pump, comprising:

establishing a fluid pressure setpoint;

receiving fluid pressure data;

automatically adjusting a speed of the fluid pump to maintain the measured fluid pressure at the fluid pressure setpoint;

detecting an adjustment by the user to the fluid pump speed;

in response to a detected user adjustment of the fluid pump speed, adopting the pressure at the user adjusted fluid pump speed, as the fluid pressure setpoint.

18. A method for controlling a first fluid pump, comprising:

receiving an indication of a speed of a second fluid pump; and

controlling a speed of the first fluid pump based on the received indication, to maintain a speed of the first fluid pump at a specified percentage of the speed of the second fluid pump.

19. A perfusion system, comprising:

means for pumping fluid; and

means for reducing a speed of the means for pumping fluid to a new speed in response to an alarm condition, and maintaining the new speed.

25. A perfusion system, comprising:

means for pumping fluid;

means for establishing a fluid flow rate setpoint;

means for receiving fluid flow data;

means for automatically adjusting a speed of the means for pumping fluid to maintain the measured fluid flow rate at the fluid flow rate setpoint;

means for detecting an adjustment by the user to the speed; and

means for adopting the fluid flow rate at the user adjusted speed, as the fluid flow rate setpoint.

27. A perfusion system, comprising:

means for pumping fluid;

means for establishing a fluid pressure setpoint;

means for receiving fluid pressure data;

means for automatically adjusting a speed of the means for pumping fluid to maintain the measured fluid pressure at the fluid pressure setpoint;

means for detecting an adjustment by the user to the speed; and

means for adopting the pressure at the user adjusted speed as the fluid pressure setpoint.

29. A perfusion system, comprising:

first means for pumping fluid;

second means for pumping fluid;

means for receiving an indication of a speed of the first means for pumping fluid; and

means for controlling a speed of the second means for pumping fluid based on the received indication, to maintain a speed of the second means for pumping fluid at a specified percentage of the speed of the first means for pumping fluid.