System for enriching a bodily fluid with a gas

• US 6,582,387 B2
• Filed: 03/20/2001
• Issued: 06/24/2003
• Est. Priority Date: 03/20/2001
• Status: Expired due to Term

• Current Assignee: TherOx Incorporated (Asahi Kasei Corporation)
• Original Assignee: TherOx Incorporated (Asahi Kasei Corporation)
• Inventors: Derek, Daw J., Patterson, William R., Watson, Gregory P., Zalesky, Paul J., Divino, Vincent Jr., Myrick, Stephen E., Creech, Jeffrey L.
• Primary Examiner(s): Bennett, Henry
• Assistant Examiner(s): Basichas, Alfred
• Application Number:
  US09/813,068
• Publication Number:
  US 20020138034A1
• Time in Patent Office: 826 Days
• Field of Search: 604/4.01, 604/6.14, 604/6.16, 422/44, 422/45, 128/200.14, 128/200.19, 128/200.21, 128/200.22, 261/DIG.28, 261/75, 261/78.1, 261/78.2
• US Class Current: 604/6.14
• CPC Class Codes: A61M 1/32 Oxygenators without membranes
• 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 1/36224 with sensing means or components thereof
• CPC Class Codes: A61M 1/362262 Details of incorporated reservoirs
• CPC Class Codes: A61M 1/362265 Details of valves
• CPC Class Codes: A61M 1/3623 Means for actively controlling temperature of blood
• CPC Class Codes: A61M 1/3626 Gas bubble detectors
• CPC Class Codes: A61M 1/3663 Flow rate transducers; Flow integrators

Abstract

A system utilizes an oxygenation device to generate a gas-enriched physiologic fluid and to combine it with a bodily fluid to create a gas-enriched bodily fluid. The oxygenation device may take the form of a disposable cartridge, which is placed within an enclosure. An electronic controller manages various aspects of the system, such as the production of gas-enriched fluids, flow rates, bubble detection, and automatic operation and shut down.

Claims

1. A system for enriching a bodily fluid with a gas, the system comprising:

a pump system adapted to transmit a bodily fluid from a patient;

a gas-enriching device operatively coupled to the pump system to receive the bodily fluid, the gas-enriching device combining the bodily fluid with a gas to form a gas-enriched bodily fluid;

a bubble detector arranged to detect bubbles in the gas-enriched bodily fluid;

a controller adapted to control the pump system and the gas-enriching device automatically;

an enrichment device to form a gas-enriched physiologic fluid, and a mixing device to mix the gas-enriched physiologic fluid with the bodily fluid to form the gas-enriched bodily fluid; and

wherein the enrichment device comprises an atomizing chamber adapted to receive the gas through a gas inlet, and an atomizer disposed within the atomizing chamber, the atomizer adapted to receive physiologic fluid and to atomize the physiologic fluid upon delivery into the atomizing chamber to form the gas-enriched physiologic fluid.

2. The system, as set forth in claim 1, wherein the pump system comprises:

a pump adapted to pump the bodily fluid through a tube; and

a flow meter adapted to sense flow of the bodily fluid through the tube, the flow meter generating an actual flow rate signal correlative to flow through the tube, wherein the controller is operatively coupled to the pump and to the flow meter, the controller adapted to receive the actual flow rate signal and to control the pump to maintain a desired rate of flow through the tube.

3. The system, as set forth in claim 2, wherein the pump comprises:

a peristaltic pump.

4. The system, as set forth in claim 2, wherein the flow meter comprises:

a flow transducer adapted to be operatively coupled to the tube, the flow transducer adapted to deliver to the flow meter a flow signal correlative to flow through the tube.

5. The system, as set forth in claim 2, comprising:

a flow setting device operatively coupled to the pump to set the desired rate of flow through the tube.

6. The system, as set forth in claim 5, wherein the flow setting device comprises:

a display illustrating the desired flow rate; and

a user-actuatable input operatively coupled to the display to adjust the desired flow rate illustrated by the display.

7. The system, as set forth in claim 5, wherein the flow setting device comprises:

a personality module having a memory adapted to store the desired flow rate and to deliver the desired flow rate signal to the controller.

8. The system, as set forth in claim 7, wherein the desired flow rate stored in the personality module comprises a desired range of flow rates.

9. The system, as set forth in claim 1, wherein the gas-enriching device comprises a disposable cartridge adapted to be placed in an enclosure.

10. The system, as set forth in claim 9, wherein the cartridge comprises:

a housing;

an enrichment device disposed in the housing to form a gas-enriched physiologic fluid; and

a mixing device disposed in the housing to mix the gas-enriched physiologic fluid with the bodily fluid to form the gas-enriched bodily fluid.

11. The system, as set forth in claim 10, wherein the enrichment device comprises:

an atomizing chamber adapted to receive the gas through a gas inlet; and

an atomizer disposed within the atomizing chamber, the atomizer adapted to receive physiologic fluid and to atomize the physiologic fluid upon delivery into the atomizing chamber to form the gas-enriched physiologic fluid.

12. The system, as set forth in claim 10, wherein the mixing device comprises:

a mixing chamber having a fluid inlet and a fluid outlet; and

a fluid delivery device disposed within the mixing chamber in a predetermined relationship with the fluid inlet, the fluid delivery device adapted to receive the gas-enriched physiologic fluid from the atomizing chamber and to deliver the gas-enriched fluid into the mixing chamber to mix with the bodily fluid entering the mixing chamber through the fluid inlet to form the gas-enriched bodily fluid.

13. The system, as set forth in claim 10, wherein the cartridge comprises:

a fluid supply device disposed in the housing to supply a physiologic fluid to the enrichment device.

14. The system, as set forth in claim 13, wherein the fluid supply device comprises:

a fluid supply chamber having a fluid inlet and a fluid outlet; and

a pump disposed within the fluid supply chamber, the pump adapted to draw a physiologic fluid into the fluid supply chamber through the fluid inlet in the fluid supply chamber and to deliver the physiologic fluid to the enrichment device through the fluid outlet in the fluid supply chamber.

15. The system, as set forth in claim 13, wherein the cartridge comprises:

a valve assembly disposed in the housing, the valve assembly having valves to control flow of the physiologic fluid between the fluid supply device and the enrichment device and to control flow of the gas-enriched physiologic fluid between the enrichment device and the mixing device.

16. The system, as set forth in claim 10, wherein the enclosure comprises:

a receiving chamber sized to accept the cartridge therein;

a first level sensor arranged to determine fluid level in the enrichment device;

a second level sensor arranged to determine a low fluid level in the mixing device; and

a third level sensor arranged to determine a high fluid level in the mixing device.

17. The system, as set forth in claim 15, wherein the enclosure comprises:

a receiving chamber sized to accept the cartridge therein; and

a valve actuation assembly adapted to actuate the valves of the valve assembly.

18. The system, as set forth in claim 9, wherein the enclosure comprises:

a door having a lock to secure the cartridge within the enclosure.

19. The system, as set forth in claim 1, wherein the bubble detector comprises:

an ultrasonic transducer pair comprising a transmitting transducer and a receiving transducer, the ultrasonic transducer pair being positionable to sense bubbles in a fluid flow;

a transducer driver operatively coupled to the transmitting transducer to cause the transmitting transducer to deliver a pulsed ultrasonic signal across the fluid flow to the receiving transducer;

a signal conditioner operatively coupled to the receiving transducer to receive the pulsed ultrasonic signal from the receiving transducer, the signal conditioner conditioning the pulsed ultrasonic signal to produce a conditioned signal; and

a signal processor operatively coupled to the signal conditioner to receive the conditioned signal, the signal processor determining information correlative to bubbles in the fluid flow in response to the conditioned signal.

20. The system, as set forth in claim 19, wherein the pulsed ultrasonic signal delivered by the transmitting transducer comprises a frequency range of 3 MHz to 4 MHz and a pulse rate of about 3 KHz to 40 KHz.

21. The system, as set forth in claim 19, wherein the signal conditioner comprises:

a detector adapted to detect the amount of ultrasonic energy of the pulsed ultrasonic signal received by the receiving transducer.

22. The system, as set forth in claim 19, wherein the signal conditioner comprises:

an analog-to-digital converter adapted to convert the amount of ultrasonic energy detected by the detector into a digital signal.

23. The system, as set forth in claim 19, wherein the signal processor comprises a buffer adapted to hold multiple digital signals.

24. The system, as set forth in claim 23, wherein a reduction in the digital signal as compared to previously recorded digital signals or an average of previously recorded digital signals is correlative to bubbles in the fluid flow.

25. The system, as set forth in claim 19, wherein the signal processor comprises a digital signal processor.

26. The system, as set forth in claim 25, wherein the digital signal processor is adapted to detect and count each bubble in the fluid flow.

27. The system, as set forth in claim 25, wherein the digital signal processor determines the volume of each bubble in the fluid flow.

28. The system, as set forth in claim 27, wherein the digital signal processor converts the volume of each bubble in the fluid flow to a volume of each bubble when it reaches a patient.

29. The system, as set forth in claim 25, wherein the digital signal processor determines an accumulated volume of bubbles in the fluid flow over a given period of time.

30. The system, as set forth in claim 29, wherein the signal processor initiates the stop signal in response to the accumulated volume of bubbles exceeding a predetermined limit, the stop signal being delivered to the controller to cause the controller to cease operation of the pump system and the gas-enriching device.

31. The system, as set forth in claim 1, wherein the controller comprises:

a first sensor assembly arranged to monitor the pump system, the first sensor assembly delivering at least one first signal correlative to operation of the pump system;

a second sensor assembly arranged to monitor the gas-enriching device, the second sensor assembly delivering at least one second signal correlative to operation of the gas-enriching device;

a signal processor operatively coupled to the first sensor assembly and to the second sensor assembly to receive the at least one first signal and the at least one second signal, the signal processor delivering at least one pump system control signal in response to the at least one first signal, the pump system adjusting its operation in response to receiving the at least one pump system control signal from the signal processor, and the signal processor delivering at least one gas-enrichment control signal in response to the at least one second signal; and

an actuation assembly arranged to adjust operation of the gas-enriching device in response to receiving the at least one gas-enrichment signal from the signal processor.

32. The system, as set forth in claim 31, wherein the first sensor assembly comprises:

a flow transducer adapted to be operatively coupled to a tube carrying the bodily fluid, wherein the at least one first signal comprises a flow signal delivered from the flow transducer, the flow signal being correlative to flow through the tube.

33. The system, as set forth in claim 32, wherein the signal processor comprises a comparison device adapted to receive the flow signal and to compare the flow through the tube to the desired flow range.

34. The system, as set forth in claim 33, wherein the signal processor delivers an enable signal to the pump system in response to the flow signal being indicative of flow through the tube being within a desired flow range.

35. The system, as set forth in claim 33, wherein the signal processor delivers a disable signal to the pump system in response to the flow signal being indicative of flow through the tube being outside the desired flow range.

36. The system, as set forth in claim 33, comprising:

a first clamp adapted to be operatively coupled to a draw side of the tube; and

a second clamp adapted to be operatively coupled to a return side of the tube, wherein the signal processor closes the first clamp and the second clamp in response to the flow signal being outside the desired flow range.

37. The system, as set forth in claim 31, wherein the gas-enriching device comprises a cartridge adapted to be disposed in an enclosure,

wherein the cartridge comprises:

a housing;

a fluid supply device disposed in the housing to supply a physiologic fluid;

an enrichment device disposed in the housing and operatively couple to receive the physiologic fluid from the fluid supply device, the enrichment device converting the physiologic fluid to a gas-enriched physiologic fluid;

a mixing device disposed in the housing and operatively coupled to receive the gas-enriched physiologic fluid from the enrichment device and to receive the bodily fluid from the pump system, the mixing device adapted to mix the gas-enriched physiologic fluid with the bodily fluid to form the gas-enriched bodily fluid; and

a valve assembly disposed in the housing, the valve assembly having valves to control flow of the physiologic fluid between the fluid supply device and the enrichment device and to control flow of the gas-enriched physiologic fluid between the enrichment device and the mixing device;

and wherein the second sensor assembly comprises;

a transducer arranged to determine physiologic fluid supplied by the fluid supply device;

a first level sensor arranged to determine fluid level in the enrichment device;

a second level sensor arranged to determine a low fluid level in the mixing device; and

a third level sensor arranged to determine a high fluid level in the mixing device;

and wherein the actuation assembly comprises;

a valve actuation assembly disposed in the enclosure and adapted to actuate the valves of the valve assembly.

38. The system, as set forth in claim 2, wherein:

the bodily fluid is blood;

the pump is a blood pump; and

the system forms an automated blood pump circuit.

39. The circuit, as set forth in claim 38, wherein the blood pump comprises:

a peristaltic pump.

40. The circuit, as set forth in claim 38, wherein the flow meter comprises:

a flow transducer adapted to be operatively coupled to the tube, the flow transducer adapted to deliver to the flow meter a flow signal correlative to blood flow through the tube.

41. The circuit, as set forth in claim 38, comprising:

a flow setting device operatively coupled to the blood pump to set a desired rate of blood flow through the tube.

42. The circuit, as set forth in claim 41, wherein the flow setting device delivers a desired flow rate signal to the controller, and wherein the controller automatically adjusts the actual rate of flow through the tube to the desired flow rate in response to the desired flow rate signal and the actual flow rate signal.

43. The circuit, as set forth in claim 42, wherein the flow setting device comprises:

a display adapted to generate the desired flow rate signal correlative to the desired rate of blood flow through the tube.

44. The circuit, as set forth in claim 43, wherein the display comprises:

a digital panel illustrating the desired flow rate; and

a user-actuatable input operatively coupled to the digital panel to adjust the desired flow rate illustrated by the digital panel.

45. The circuit, as set forth in claim 42, wherein the flow setting device comprises:

a personality module having a memory adapted to store the desired flow rate and to deliver the desired flow rate signal to the controller.

46. The circuit, as set forth in claim 45, wherein the desired flow rate stored in the personality module comprises a desired range of flow rates.

47. The circuit, as set forth in claim 41, wherein the tube has a draw portion for drawing blood from a patient and a return portion for returning blood to a patient, the circuit comprising:

a draw tube clamp operatively coupled to the draw portion of the tube, the draw tube clamp being moveable between a clamped position and an unclamped position;

a return tube clamp operatively coupled to the return portion of the tube, the return tube clamp being moveable between a clamped position and an unclamped position; and

wherein the controller is operatively coupled to the draw tube clamp and the return tube clamp, the controller adapted to move the draw tube clamp and the return tube clamp between the respective clamped and unclamped positions.

48. The circuit, as set forth in claim 47, wherein the blood pump circuit comprises:

an extracorporeal circuit.