Syringe pump rapid occlusion detection system

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 F 1 indicative of force in the fluid line at instantaneous time T 1 ;

during the pumping sequence, determining a second instantaneous force value F 2 indicative of force in the fluid line at instantaneous time T 2 ; and

providing an indication of the occlusion if a slope calculated by dividing a difference between the second instantaneous force value F 2 and the first instantaneous force value F 1 by a difference between instantaneous time T 1 and instantaneous time T 2 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 T 1 and time T 2 .

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 F 1 indicative of force in the fluid line at instantaneous time T 1 ;

during the pumping sequence, determining a second instantaneous force value F 2 indicative of force in the fluid line at instantaneous time T 2 ; and

providing an indication of the occlusion if a slope calculated by dividing a difference between the second instantaneous force value F 2 and the first instantaneous force value F 1 by a difference between instantaneous time T 1 and instantaneous time T 2 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 T 1 and time T 2 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 T 1 and time T 2 .

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 F 1 and F 2 indicative of the force between the syringe and the patient taken at instantaneous times T 1 and T 2 , 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 F 2 and the first instantaneous force value F 1 by a difference between instantaneous time T 1 and instantaneous time T 2 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 T 1 and time T 2 .

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 T 2 and T 3 , 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 T 1 and T 3 , wherein T 3 is subsequent to T 2 .

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 F 1 and F 2 indicative of the force between the fluid source and the patient taken at instantaneous times T 1 and T 2 , 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 F 2 and the first instantaneous force value F 1 by a difference between instantaneous time T 1 and instantaneous time T 2 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 T 1 and time T 2 .

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 T 2 and T 3 , 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 T 1 and T 3 , wherein T 3 is subsequent to T 2 .

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 F 1 and F 2 indicative of the force between the fluid source and the patient taken at instantaneous times T 1 and T 2 , 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 F 2 and the first instantaneous force value F 1 by a difference between instantaneous time T 1 and instantaneous time T 2 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 F 1 and F 2 indicative of the force between the fluid source and the patient taken at instantaneous times T 1 and T 2 , 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 F 2 and the first instantaneous force value F 1 by a difference between instantaneous time T 1 and instantaneous time T 2 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.