Syringe pump rapid occlusion detection system

• US 8,182,461 B2
• Filed: 11/04/2003
• Issued: 05/22/2012
• Est. Priority Date: 11/04/2003
• Status: Active Grant

• Current Assignee: Smiths Medical ASD, Inc. (Smiths Group International Holdings Ltd.)
• Original Assignee: Smiths Medical ASD, Inc. (Smiths Group International Holdings Ltd.)
• Inventors: Pope, Brian, Liu, Zhan
• Primary Examiner(s): Sirmons, Kevin C
• Assistant Examiner(s): GILBERT, ANDREW M
• Application Number:
  US10/700,738
• Publication Number:
  US 20050096593A1
• Time in Patent Office: 3,122 Days
• Field of Search: 604 65- 67, 604/890.1
• US Class Current: 604/503
• CPC Class Codes: A61M 2005/16863 Occlusion detection
• CPC Class Codes: A61M 2205/3569 sublocal, e.g. between console and disposable
• CPC Class Codes: A61M 2205/505 Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 5/1452 pressurised by means of pistons
• CPC Class Codes: A61M 5/16854 by monitoring line pressure
• CPC Class Codes: A61M 5/16859 Evaluation of pressure response, e.g. to an applied pulse
• CPC Class Codes: A61M 5/5086 for indicating if defective, used, tampered with or unsterile

Abstract

An apparatus, method and program product detects an occlusion in a fluid line by determining if a relationship between force measurements departs from an expected relationship.

Claims

1. A method of automatically detecting an occlusion in a fluid line of a syringe pump, the syringe pump including a housing adapted to support a syringe containing a plunger moveable inside the syringe by pushing an end of a plunger with a pusher to expel fluid from an outlet of the syringe into a fluid line connected to the outlet and configured to carry the fluid under pressure to a patient, the method comprising:

mounting the syringe onto the housing with the plunger end extended;

coupling the pusher to the end of the plunger;

initiating a pumping sequence to cause the fluid to flow into the fluid line;

during the pumping sequence, using a sensor to determine a first instantaneous force value F1 indicative of force in the fluid line at instantaneous time T1;

during the pumping sequence, determining a second instantaneous force value F2 indicative of force in the fluid line at instantaneous time T2; and

providing an indication of the occlusion if a slope calculated by dividing a difference between the second instantaneous force value F2 and the first instantaneous force value F1 by a difference between instantaneous time T1 and instantaneous time T2 departs from an expected slope relationship.

2. The method of automatically detecting an occlusion of claim 1, further comprising providing no occlusion indication where the calculated slope does not depart from the expected slope relationship.

3. The method of automatically detecting an occlusion of claim 1, further comprising determining a steady state condition.

4. The method of automatically detecting an occlusion of claim 1, further comprising determining a time window defining at least one of time T1 and time T2.

5. The method of automatically detecting an occlusion of claim 1, wherein providing the indication of the occlusion further includes determining the expected slope relationship.

6. The method of automatically detecting an occlusion of claim 1, wherein providing the indication of the occlusion further includes determining a trial slope using at least one of the first and second instantaneous force values.

7. The method of automatically detecting an occlusion of claim 1, wherein providing the indication of the occlusion further includes determining an occlusion slope.

8. The method of automatically detecting an occlusion of claim 1, wherein providing the indication of the occlusion further includes comparing the expected slope relationship to the calculated slope.

9. The method of automatically detecting an occlusion of claim 1, wherein providing the indication of the occlusion further includes comparing an occlusion slope to a trial slope.

10. The method of automatically detecting an occlusion of claim 1, further comprising shifting a time window to obtain an additional instantaneous force value.

11. The method of automatically detecting an occlusion of claim 1, further comprising canceling the indication of the occlusion in response to a comparison between a trial slope and a cancellation slope.

12. A method of automatically detecting an occlusion in a fluid line of a medical pumping system, the fluid line being configured to carry fluid under pressure between a fluid source and a patient, the method comprising:

during a pumping sequence, determining a first instantaneous force value F1 indicative of force in the fluid line at instantaneous time T1;

during the pumping sequence, determining a second instantaneous force value F2 indicative of force in the fluid line at instantaneous time T2; and

providing an indication of the occlusion if a slope calculated by dividing a difference between the second instantaneous force value F2 and the first instantaneous force value F1 by a difference between instantaneous time T1 and instantaneous time T2 departs from an expected slope relationship.

13. The method of automatically detecting an occlusion of claim 12, further comprising providing no occlusion indication where the calculated slope does not depart from the expected slope relationship.

14. The method of automatically detecting an occlusion of claim 12, further comprising determining a steady state condition.

15. The method of automatically detecting an occlusion of claim 14, wherein determining the steady state condition further includes determining a steady state startup time period.

16. The method of automatically detecting an occlusion of claim 15, wherein determining the steady state condition further includes determining a startup time limit.

17. The method of automatically detecting an occlusion of claim 15, wherein determining the steady state condition further includes determining a startup fluid volume.

18. The method of automatically detecting an occlusion of claim 12, wherein determining at least one of the first and second instantaneous force values further includes using a sensor.

19. The method of automatically detecting an occlusion of claim 12, wherein determining at least one of the first and second instantaneous force values further includes determining a count indicative of the at least one of the first and second instantaneous force values.

20. The method of automatically detecting an occlusion of claim 19, further comprising adjusting at least one of time T1 and time T2 to avoid fractioning the count.

21. The method of automatically detecting an occlusion of claim 19, further comprising using a transducer to generate the count.

22. The method of automatically detecting an occlusion of claim 12, further comprising determining a time window defining at least one of time T1 and time T2.

23. The method of automatically detecting an occlusion of claim 12, wherein providing the indication of the occlusion further includes generating an alarm.

24. The method of automatically detecting an occlusion of claim 12, wherein providing the indication of the occlusion further includes determining the expected slope relationship.

25. The method of automatically detecting an occlusion of claim 12, wherein providing the indication of the occlusion further includes determining a trial slope using at least one of the first and second instantaneous force values.

26. The method of automatically detecting an occlusion of claim 12, wherein providing the indication of the occlusion further includes determining an occlusion slope.

27. The method of automatically detecting an occlusion of claim 12, wherein providing the indication of the occlusion further includes comparing the expected slope relationship to the calculated slope.

28. The method of automatically detecting an occlusion of claim 12, wherein providing the indication of the occlusion further includes comparing an occlusion slope to a trial slope.

29. The method of automatically detecting an occlusion of claim 12, further comprising shifting a time window to obtain an additional instantaneous force value.

30. The method of automatically detecting an occlusion of claim 12, further comprising canceling the indication of the occlusion in response to a comparison between a trial slope and a cancellation slope.

31. The method of automatically detecting an occlusion of claim 12, wherein determining the first instantaneous force value further includes altering delivery of the fluid.

32. The method of automatically detecting an occlusion of claim 12, wherein determining the first instantaneous force value further includes altering delivery of the fluid in response to comparing the first instantaneous force value to a bolus occlusion limit.

33. The method of automatically detecting an occlusion of claim 32, wherein determining the first instantaneous force value further includes resuming delivery of the fluid after a delay time.

34. The method of automatically detecting an occlusion of claim 32, wherein determining the first instantaneous force value further includes resuming delivery of the fluid in response to comparing the first instantaneous force value to a bolus occlusion limit.

35. The method of automatically detecting an occlusion of claim 12, wherein providing the indication of the occlusion further includes initiating a remedial action.

36. A syringe pumping system, comprising:

a syringe configured to contain fluid and including an outlet;

a housing adapted to support the syringe;

a plunger having an end and configured to move within the syringe;

a pusher adapted to attach to and push the end of the plunger so as to cause the fluid to exit out of the outlet of syringe;

a fluid line connected to the outlet of the syringe and configured to carry the fluid under force to a patient;

a sensor for determining at least first and second instantaneous force values F1 and F2 indicative of the force between the syringe and the patient taken at instantaneous times T1 and T2, respectively; and

a processor in communication with the pusher, the processor being configured to execute program code that determines if a slope calculated by dividing a difference between the second instantaneous force value F2 and the first instantaneous force value F1 by a difference between instantaneous time T1 and instantaneous time T2 departs from an expected slope relationship.

37. The syringe pumping system of claim 36, wherein the program code initiates providing an indication of an occlusion if the calculated slope departs from the expected slope relationship.

38. The syringe pumping system of claim 36, wherein the program code initiates determining a time window defining at least one of time T1 and time T2.

39. The syringe pumping system of claim 36, wherein the program code initiates determining the expected slope relationship.

40. The syringe pumping system of claim 36, wherein the expected slope relationship includes an occlusion slope.

41. The syringe pumping system of claim 36, wherein the program code initiates comparing the expected slope relationship to the calculated slope.

42. The syringe pumping system of claim 36, wherein the program code initiates comparing an occlusion slope to a trial slope.

43. The syringe pumping system of claim 36, wherein the program code initiates determining a third instantaneous force value indicative of a force between the fluid source and the patient taken at times T2 and T3, respectively.

44. The syringe pumping system of claim 36, wherein the program code initiates determining a third instantaneous force value indicative of a force between the fluid source and the patient taken at times T1 and T3, wherein T3 is subsequent to T2.

45. A pumping system, comprising:

a fluid source;

a fluid line configured to carry fluid under pressure between the fluid source and a patient;

a sensor for determining at least first and second instantaneous force values F1 and F2 indicative of the force between the fluid source and the patient taken at instantaneous times T1 and T2, respectively;

a pump configured to generate a force between the fluid source and the patient; and

a processor in communication with the pump, the processor being configured to execute program code that determines if a slope calculated by dividing a difference between the second instantaneous force value F2 and the first instantaneous force value F1 by a difference between instantaneous time T1 and instantaneous time T2 departs from an expected slope relationship.

46. The pumping system of claim 45, wherein the program code initiates providing an indication of an occlusion if the calculated slope departs from the expected slope relationship.

47. The pumping system of claim 45, wherein the program code initiates determining a steady state condition.

48. The pumping system of claim 45, wherein the program code initiates determining a count indicative of the at least one of the first and second instantaneous force values.

49. The pumping system of claim 45, further comprising a transducer configured to generate a count from at least one of the first and second instantaneous force values.

50. The pumping system of claim 45, wherein the program code initiates determining a time window defining at least one of time T1 and time T2.

51. The pumping system of claim 45, wherein the program code initiates determining the expected slope relationship.

52. The pumping system of claim 45, wherein a relationship between the first and second instantaneous force values includes a trial slope.

53. The pumping system of claim 45, wherein the expected slope relationship includes an occlusion slope.

54. The pumping system of claim 45, wherein the program code initiates comparing the expected slope relationship to the calculated slope.

55. The pumping system of claim 45, wherein the program code initiates comparing an occlusion slope to a trial slope.

56. The pumping system of claim 45, wherein the program code initiates shifting a time window to obtain an additional instantaneous force value.

57. The pumping system of claim 45, wherein the program code initiates canceling the indication of the occlusion in response to a comparison between a trial slope and a cancellation slope.

58. The pumping system of claim 45, wherein the program code initiates altering delivery of the fluid.

59. The pumping system of claim 45, wherein the program code initiates altering delivery of the fluid in response to comparing the first instantaneous force value to a bolus occlusion limit.

60. The pumping system of claim 59, wherein the program code initiates resuming delivery of the fluid after a delay time.

61. The pumping system of claim 59, wherein the program code initiates resuming delivery of the fluid in response to comparing the first instantaneous force value to a bolus occlusion limit.

62. The pumping system of claim 45, wherein the program code initiates determining a third instantaneous force value indicative of a force between the fluid source and the patient taken at times T2 and T3, respectively.

63. The pumping system of claim 45, wherein the program code initiates determining a third instantaneous force value indicative of a force between the fluid source and the patient taken at times T1 and T3, wherein T3 is subsequent to T2.

64. A pumping system, comprising:

a fluid source;

a fluid line configured to carry fluid under force between the fluid source and a patient;

a sensor for determining at least first and second instantaneous force values F1 and F2 indicative of the force between the fluid source and the patient taken at instantaneous times T1 and T2, respectively;

a pump configured to generate the force between the fluid source and the patient; and

a processor in communication with the pump, the processor being configured to execute program code that initiates altering delivery of the fluid in response to determining that a slope calculated by dividing a difference between the second instantaneous force value F2 and the first instantaneous force value F1 by a difference between instantaneous time T1 and instantaneous time T2 deviates from an expected value.

65. The pumping system of claim 64, wherein the program code initiates determining if a bolus infusion is being delivered.

66. The pumping system of claim 64, wherein the program code initiates resuming the delivery of the fluid after a delay period.

67. The pumping system of claim 64, wherein the program code initiates resuming the delivery of the fluid at a reduced infusion rate.

68. A syringe pumping system, comprising:

a syringe configured to contain fluid and including an outlet;

a housing adapted to support the syringe;

a plunger having an end and configured to move within the syringe;

a pusher adapted to attach to and push the end of the plunger so as to cause the fluid to exit out of the outlet of syringe;

a fluid line connected to the outlet of the syringe and configured to carry the fluid under force to a patient;

a sensor for determining at least first and second instantaneous force values F1 and F2 indicative of the force between the fluid source and the patient taken at instantaneous times T1 and T2, respectively; and

a processor in communication with the pusher, the processor being configured to execute program code that initiates altering delivery of the fluid in response to determining that a slope calculated by dividing a difference between the second instantaneous force value F2 and the first instantaneous force value F1 by a difference between instantaneous time T1 and instantaneous time T2 deviates from an expected value.

69. The pumping system of claim 68, wherein the program code initiates determining if a bolus infusion is being delivered.

70. The pumping system of claim 68, wherein the program code initiates resuming the delivery of the fluid after a delay period.