Blood processing systems and methods employing fluid pressure actuated pumps and valves

• US 6,759,007 B1
• Filed: 09/03/1999
• Issued: 07/06/2004
• Est. Priority Date: 09/03/1999
• Status: Expired due to Term

• Current Assignee: Fenwal Incorporated (Fresenius SE & Co. KGaA)
• Original Assignee: Baxter International Inc.
• Inventors: Jacobson, James D, Westberg, Tom
• Primary Examiner(s): Bianco, Patricia
• Application Number:
  US09/389,934
• Time in Patent Office: 1,768 Days
• Field of Search: 604/4.01, 604/5.01, 604/60--, 604/6.1, 604/6.11, 604/6-5-, 604/19, 604/27, 604/28, 604/30, 604/33, 604/35, 604/38, 604/65, 604/67, 604/118-21, 604/131, 604/140, 604/141, 604/143, 604/146, 604/147, 604/149, 604/150-52, 604/181, 604/186, 604/207, 604/246-47, 604/249, 210/739, 210/741, 210/744-45, 210/767, 210/781-82, 210/787, 210/790, 210/85, 210/87-8, 210/90, 210/98, 210/103, 210/143, 210/257.1, 210/252-6, 210/282, 210/258-62, 422/44-48, 494/35, 494/43, 494/45, 494/60-63, 417/15, 417/17, 417/26, 417/27, 417/29, 417/148, 417/216, 417/279, 417/321, 417/477.2, 417/481, 417/485-87, 417/490-96, 128/920, 128/DIG.12
• US Class Current: 422/44
• CPC Class Codes: A61M 1/30 Single needle dialysis ; Reciprocating systems, alternately withdrawing blood from and returning it to the patient, e.g. single-lumen-needle dialysis or single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 1/302 having a reservoir for withdrawn untreated blood
• CPC Class Codes: A61M 1/303 having a reservoir for treated blood to be returned
• CPC Class Codes: A61M 1/308 Volume control, e.g. with open or flexible containers, by counting the number of pump revolutions, weighing
• CPC Class Codes: A61M 1/362227 the interface providing means for actuating on functional elements of the cassette, e.g. plungers
• CPC Class Codes: A61M 1/36225 with blood pumping means or components thereof
• CPC Class Codes: A61M 1/362261 at least one cassette surface or portion thereof being flexible, e.g. the cassette having a rigid base portion with preformed channels and being covered with a foil
• CPC Class Codes: A61M 1/362262 Details of incorporated reservoirs
• CPC Class Codes: A61M 1/362264 the filter being a blood filter
• CPC Class Codes: A61M 1/362265 Details of valves
• CPC Class Codes: A61M 1/362266 Means for adding solutions or substances to the blood
• CPC Class Codes: A61M 1/3696 with means for adding or withdrawing liquid substances during the centrifugation, e.g. continuous centrifugation
• CPC Class Codes: A61M 2205/128 with incorporated valves
• CPC Class Codes: A61M 2205/331 used as turbidity change detectors, e.g. for priming-blood or plasma-hemoglubine-interface detection
• CPC Class Codes: A61M 2205/3393 by weighing the reservoir
• CPC Class Codes: A61M 60/113 in other functional devices, e.g. dialysers or heart-lung machines
• CPC Class Codes: A61M 60/30 Medical purposes thereof other than the enhancement of the cardiac output
• CPC Class Codes: A61M 60/427 the force acting on the blood contacting member being hydraulic or pneumatic
• CPC Class Codes: A61M 60/43 using vacuum at the blood pump, e.g. to accelerate filling
• 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 2205/09 : Flow through the pump
• CPC Class Codes: F04B 49/06 : Control using electricity regulating by means of floats actuating electric switches F04B49/04
• CPC Class Codes: Y10S 128/12 : Pressure infusion

Abstract

Systems and methods for processing blood use at least one fluid activated pump and at least one fluid activated valve. The systems and methods apply positive and negative fluid pressures to operate the pump and valve. Different pressure conditions are applied to the pump and the valve, to insure that a valve used in conjunction with a pump is not overcome by the pressure applied to operate the pump, and that both the valve and pump are not overcome by normal system processing pressures.

Claims

1. A blood processing system comprising

a separation device that operates to separate blood subject to a positive processing pressure,

a fluid pressure actuated blood pump comprising a pump chamber responsive to an applied negative pump pressure to draw blood into the pump chamber and an applied positive pump pressure to expel blood from the pump chamber,

a fluid pressure actuated inlet valve governing communicating between the pump chamber and a source of blood responsive to an applied positive valve pressure to close the inlet valve and an applied negative valve pressure to open the inlet valve,

a fluid pressure actuated outlet valve governing communicating between the pump chamber and the separation device comprising a valve chamber responsive to an applied positive valve pressure to close the outlet valve and an applied negative valve pressure to open the outlet valve, and

an actuator operating to selectively apply positive and negative fluid pressure conditions to the blood pump, inlet valve, and outlet valve;

the actuator applying a first negative valve pressure to the inlet valve at a first absolute magnitude;

the actuator applying a second negative pump pressure to the blood pump at a second absolute magnitude;

the actuator applying a first positive valve pressure to the outlet valve at a third absolute magnitude;

said first absolute magnitude greater than said second absolute magnitude;

said third absolute magnitude greater than the absolute magnitude of the positive processing pressure.

2. A system according to claim 1

wherein the fluid pressure comprises positive and negative pneumatic pressure.

3. A blood processing system comprising

a separation device that operates to separate blood subject to a positive processing pressure,

a fluid pressure actuated blood pump comprising a pump chamber responsive to an applied negative pump pressure to draw blood into the pump chamber and an applied positive pump pressure to expel blood from the pump chamber,

a fluid pressure actuated inlet valve governing communicating between the pump chamber and a source of blood and comprising a valve chamber responsive to an applied positive valve pressure to close the inlet valve and an applied negative valve pressure to open the inlet valve,

a fluid pressure actuated outlet valve governing communicating between the pump chamber and the separation device comprising a valve chamber responsive to an applied positive valve pressure to close the outlet valve and an applied negative valve pressure to open the outlet valve, and

an actuator operating to selectively apply positive and negative fluid pressure conditions to the blood pump, inlet valve, and outlet valve, the actuator applying a first positive valve pressure to the inlet valve while applying a second positive pump pressure to the blood pump and while applying first negative valve pressure to the outlet valve, the actuator controlling absolute magnitudes of the pressures such that (i) the absolute magnitude of the second positive pump pressure is not greater than the absolute magnitude of the first positive valve pressure and (ii) the absolute magnitude of the negative valve pressure is greater than the absolute magnitude of the positive processing pressure.

4. A system according to claim 3

wherein the actuator applies a first negative valve pressure to the inlet valve while applying a second negative pump pressure to the blood pump and while applying first positive valve pressure to the outlet valve, the actuator controlling absolute magnitudes of the pressures such that (i) the absolute magnitude of the first negative valve pressure is greater than the absolute magnitude of the second negative pump pressure and (ii) the absolute magnitude of the first positive valve pressure is greater than the absolute magnitude of the positive processing pressure.

5. A system according to claim 3

wherein the fluid pressure comprises positive and negative pneumatic pressure.

7. A method according to claim 4

wherein the fluid pressure comprises positive and negative pneumatic pressure.

6. A method of processing blood using a blood separation device that separates blood subject to a positive processing pressure, the method comprising the steps of

coupling a fluid pressure actuated blood pump to the blood separation device and to a source of blood, the blood pump operating in response to an applied negative pump pressure to draw blood into the pump chamber and an applied positive pump pressure to expel blood from the pump chamber,

governing communication between the source and the blood pump by a fluid pressure actuated inlet valve that operates in response to an applied positive valve pressure to close the inlet valve and an applied negative valve pressure to open the inlet valve,

governing communication between the blood pump and the blood separation device by a fluid pressure actuated outlet valve that operates in response to an applied positive valve pressure to close the outlet valve and an applied negative valve pressure to open the outlet valve, and

applying a first negative valve pressure to the inlet valve while applying a second negative pump pressure to the blood pump and while applying first positive valve pressure to the outlet valve, and

controlling absolute magnitudes of the pressures such that (i) the absolute magnitude of the first negative valve pressure is greater than the absolute magnitude of the second negative pump pressure and (ii) the absolute magnitude of the first positive valve pressure is greater than the absolute magnitude of the positive processing pressure.

8. A method of processing blood using a blood separation device that separates blood subject to a positive processing pressure, the method comprising the steps of

coupling a fluid pressure actuated blood pump to the blood separation device and to a source of blood, the blood pump operating in response to an applied negative pump pressure to draw blood into the pump chamber and an applied positive pump pressure to expel blood from the pump chamber,

governing communication between the source and the blood pump by a fluid pressure actuated inlet valve that operates in response to an applied positive valve pressure to close the inlet valve and an applied negative valve pressure to open the inlet valve,

governing communication between the blood pump and the blood separation device by a fluid pressure actuated outlet valve that operates in response to an applied positive valve pressure to close the outlet valve and an applied negative valve pressure to open the outlet valve, and

operating the blood pump by applying a first positive valve pressure to the inlet valve while applying a second positive pump pressure to the blood pump and while applying first negative valve pressure to the outlet valve,

controlling absolute magnitudes of the pressures such that (i) the absolute magnitude of the second positive pump pressure is not greater than the absolute magnitude of the first positive valve pressure and (ii) the absolute magnitude of the negative valve pressure is greater than the absolute magnitude of the positive processing pressure.

9. A method according to claim 8 further including the steps of

operating the blood pump by applying a first negative valve pressure to the inlet valve while applying a second negative pump pressure to the blood pump and while applying first positive valve pressure to the outlet valve, and

controlling absolute magnitudes of the pressures such that (i) the absolute magnitude of the first negative valve pressure is greater than the absolute magnitude of the second negative pump pressure and (ii) the absolute magnitude of the first positive valve pressure is greater than the absolute magnitude of the positive processing pressure.

10. A method according to claim 8

wherein the fluid pressure comprises positive and negative pneumatic pressure.

11. A blood processing system comprising

a separation device that operates to separate blood subject to a positive processing pressure,

a fluid pressure actuated blood pump comprising a pump chamber responsive to an applied negative pump pressure to draw blood into the pump chamber and an applied positive pump pressure to expel blood from the pump chamber, said applied positive and negative pressures to the pump chamber applied through a first air line;

a fluid pressure actuated inlet valve governing communicating between the pump chamber and a source of blood responsive to an applied positive valve pressure to close the inlet valve and an applied negative valve pressure to open the inlet valve, said applied positive and negative pressures to the inlet valve applied through a second air line;

a fluid pressure actuated outlet valve governing communicating between the pump chamber and the separation device comprising a valve chamber responsive to an applied positive valve pressure to close the outlet valve and an applied negative valve pressure to open the outlet valve, said applied positive and negative pressures to the outlet valve applied through a third air line;

said applied positive and negative pressures to the pump chamber applied through the first air line having an absolute magnitude less than an absolute magnitude of said applied positive and negative pressures to the inlet valve applied through said second air line; and

said applied positive and negative pressures to the pump chamber applied through the first air line having an absolute magnitude less than an absolute magnitude of said applied positive and negative pressures to the outlet valve applied through said third air line.

12. A blood processing system comprising

a separation device that operates to separate blood subject to a positive processing pressure,

a fluid pressure actuated blood pump, said pump responsive to fluid pressure having a first absolute magnitude;

a fluid pressure actuated inlet valve governing communicating between the pump chamber and a source of blood, said inlet valve responsive to fluid pressure having a second absolute magnitude;

a fluid pressure actuated outlet valve governing communicating between the pump chamber and the separation device, said outlet valve responsive to fluid pressure having a third absolute magnitude;

the first absolute magnitude less than the second and third absolute magnitudes, whereby the inlet and outlet valves are not be actuated by fluid pressure applied to the pump.