SYRINGE PUMP RAPID OCCLUSION DETECTION SYSTEM

• US 20120245525A1
• Filed: 06/07/2012
• Published: 09/27/2012
• 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
• Granted Patent: US 8,900,213 B2
• Time in Patent Office: Days
• US Class Current: 604/152
• 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 and method for detecting an occlusion in a downstream fluid line of a medical pump in relation to increased pressure in the downstream fluid line between the beginning and the end of each interval of a series of intervals of operation of the pump even if one or more intervals between the first and last intervals does not reflect such an increase in pressure in the downstream fluid line.

Claims

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

operating the medical pumping system to carry fluid under pressure in the downstream fluid line over a series of intervals having a first interval, a last interval, and a plurality of intervals therebetween; and

determining an occlusion exists if, for each of the first interval, the last interval, and all but at least one of the plurality of intervals, an instantaneous pressure indicative of force in the downstream fluid line at the end of the interval is greater than an instantaneous pressure indicative of force in the downstream fluid line at the beginning of the interval.

2. The method of claim 1, wherein the series of intervals comprises consecutive intervals.

3. The method of claim 1, wherein the count value of a counter is incremented if an instantaneous pressure indicative of force in the downstream fluid line at the end of an interval of the series of intervals is greater than an instantaneous pressure indicative of force in the downstream fluid line at the beginning of that interval.

4. The method of claim 3, wherein the count value of a the counter is not incremented if an instantaneous pressure indicative of force in the downstream fluid line at the end of an interval of the plurality of intervals is not greater than an instantaneous pressure indicative of force in the downstream fluid line at the beginning of that interval.

5. The method of claim 4, wherein an occlusion is determined if the last interval results in the count value of the counter reaching an expected value.

6. The method of claim 3, wherein the count value of the counter is reset to zero if an instantaneous pressure indicative of force in the downstream fluid line at the end of an interval of the plurality of intervals is not greater than an instantaneous pressure indicative of force in the downstream fluid line at the beginning of that interval.

7. The method of claim 1, wherein the medical pumping system is a 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 downstream fluid line connected to the outlet and configured to carry the fluid under pressure to a patient, the method further comprising mounting the syringe onto the housing with the plunger end extended, coupling the pusher to the end of the plunger, and operating the medical pump to cause the pusher to push the end of the plunger whereby to cause fluid under pressure to be carried in the downstream fluid line over the series of intervals.

8. The method of claim 1, wherein determining an occlusion exists further requires that the instantaneous pressure indicative of force in the downstream fluid line at the beginning of the first interval is less than the instantaneous pressure indicative of force in the downstream fluid line at the end of the last interval.

9. The method of claim 1, wherein a new series of intervals is begun if an instantaneous pressure indicative of force in the downstream fluid line at the end of an interval of one of such intervals is not greater than an instantaneous pressure indicative of force in the downstream fluid line at the beginning of that interval.

10. The method of claim 1 wherein determining an occlusion exists even if none of the plurality of intervals has an instantaneous pressure indicative of force in the downstream fluid line at the end of the interval greater than an instantaneous pressure indicative of force in the downstream fluid line at the beginning of the interval.

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

operating the medical pumping system to carry fluid under pressure in the downstream fluid line over a series of intervals having a first interval, a last interval, and at least one interval therebetween; and

determining an occlusion exists if, for each of the first interval and the last interval while ignoring the at least one interval therebetween, an instantaneous pressure indicative of force in the downstream fluid line at the end of the interval is greater than an instantaneous pressure indicative of force in the downstream fluid line at the beginning of the interval.

12. The method of claim 11, wherein the series of intervals comprises consecutive intervals.

13. The method of claim 11, wherein the count value of a counter is incremented for each of at least the first and last intervals if an instantaneous pressure indicative of force in the downstream fluid line at the end of each such interval is greater than an instantaneous pressure indicative of force in the downstream fluid line at the beginning of that interval.

14. The method of claim 13, wherein an occlusion is determined if the last interval results in the count value of the counter reaching an expected value.

15. The method of claim 11, wherein the medical pumping system is a 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 downstream fluid line connected to the outlet and configured to carry the fluid under pressure to a patient, the method further comprising mounting the syringe onto the housing with the plunger end extended, coupling the pusher to the end of the plunger, and operating the medical pump to cause the pusher to push the end of the plunger whereby to cause fluid under pressure to be carried in the downstream fluid line over the series of intervals.

16. The method of claim 11, wherein determining an occlusion exists further requires that the instantaneous pressure indicative of force in the downstream fluid line at the beginning of the first interval is less than the instantaneous pressure indicative of force in the downstream fluid line at the end of the last interval.

17. The method of claim 11, wherein a new series of intervals is begun if an instantaneous pressure indicative of force in the downstream fluid line at the end of the at least one interval is not greater than an instantaneous pressure indicative of force in the downstream fluid line at the beginning of that interval.

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

initiating a pumping sequence to cause the fluid to flow into the downstream fluid line with the patient at an elevation;

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

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

providing an indication of the occlusion if a relationship between the first and second force values departs from an expected relationship unless the relationship departs from an expected relationship as a result of a change in elevation of the patient.

19. A medical pumping system for pumping fluid under pressure through a downstream fluid line configured to carry fluid under pressure between a fluid source and a patient, the system comprising:

a pump configured to force fluid from a fluid source under pressure into a downstream fluid line;

a sensor for determining force values indicative of the force in said downstream fluid line;

a processor in communication with the pump, the processor being configured to execute program code that operates the pump to force fluid under pressure in said downstream fluid line over a series of intervals having a first interval, a last interval, and a plurality of intervals therebetween; and

wherein the processor is further configured to execute program code to provide an indication of an occlusion if, for each of the first interval, the last interval, and all but at least one of the plurality of intervals, an instantaneous pressure indicative of force in said downstream fluid line at the end of the interval is greater than an instantaneous pressure indicative of force in said downstream fluid line at the beginning of the interval.

20. The system of claim 19, wherein the processor is further configured to execute program code that operates the pump to carry fluid under pressure in the downstream fluid line over the series of intervals comprising a series of consecutive intervals.

21. The system of claim 19 further comprising a counter, wherein the processor is further configured to execute program code to increment a count value of the counter if an instantaneous pressure indicative of force in said downstream fluid line at the end of an interval of the series of intervals is greater than an instantaneous pressure indicative of force in said downstream fluid line at the beginning of that interval.

22. The system of claim 21, wherein the processor is further configured to execute program code to not increment the count if an instantaneous pressure indicative of force in said downstream fluid line at the end of an interval of the series of intervals is not greater than an instantaneous pressure indicative of force in said downstream fluid line at the beginning of that interval.

23. The system of claim 22, wherein the processor is further configured to execute program code to determine an occlusion exists, if the last interval results in the count value of the counter reaching an expected value.

24. The system of claim 21, wherein the processor is further configured to execute program code to reset the count value of the counter to zero if an instantaneous pressure indicative of force in said downstream fluid line at the end of an interval of the plurality of intervals is not greater than an instantaneous pressure indicative of force in said downstream fluid line at the beginning of that interval.

25. The system of claim 19, wherein the medical pumping system is a syringe pump including a housing adapted to support a syringe and a pusher configured to push a plunger moveable inside said syringe to expel fluid from an outlet of said syringe into a downstream fluid line connected to said outlet and configured to carry fluid under pressure to a patient.

26. The system of claim 19, wherein the processor is further configured to execute program code to not determine an occlusion exists unless the instantaneous pressure indicative of force in said downstream fluid line at the beginning of the first interval is less than the instantaneous pressure indicative of force in said downstream fluid line at the end of the last interval.

27. The system of claim 19, wherein the processor is further configured to execute program code to initiate a new series of intervals if an instantaneous pressure indicative of force in said downstream fluid line at the end of an interval of one of such intervals is not greater than an instantaneous pressure indicative of force in said downstream fluid line at the beginning of that interval.

28. The system of claim 19 wherein the processor is further configured to execute program code to determine an occlusion exists even if none of the plurality of intervals has an instantaneous pressure indicative of force in said downstream fluid line at the end of the interval greater than an instantaneous pressure indicative of force in said downstream fluid line at the beginning of the interval.

29. A medical pumping system for pumping fluid under pressure through a downstream fluid line configured to carry fluid under pressure between a fluid source and a patient, the system comprising:

a pump configured to force fluid from a fluid source under pressure into a downstream fluid line;

a sensor for determining force values indicative of the force in said downstream fluid line;

a processor in communication with the pump, the processor being configured to execute program code that operates the pump to force fluid under pressure in said downstream fluid line over a series of intervals having a first interval, a last interval, and at least one interval therebetween; and

wherein the processor is further configured to execute program code to provide an indication of an occlusion, for each of the first interval and the last interval while ignoring at least one interval therebetween, if an instantaneous pressure indicative of force in said downstream fluid line at the end of the interval is greater than an instantaneous pressure indicative of force in said downstream fluid line at the beginning of the interval.

30. The system of claim 29, wherein the processor is further configured to execute program code that operates the pump to carry fluid under pressure in the downstream fluid line over the series of intervals comprising a series of consecutive intervals.

31. The system of claim 29 further comprising a counter, wherein the processor is further configured to execute program code to increment a count value of the counter if an instantaneous pressure indicative of force in said downstream fluid line at the end of an interval of the series of intervals is greater than an instantaneous pressure indicative of force in said downstream fluid line at the beginning of that interval.

32. The system of claim 31, wherein the processor is further configured to execute program code to determine an occlusion exists, if the last interval results in the count value of the counter reaching an expected value.

33. The system of claim 29, wherein the medical pumping system is a syringe pump including a housing adapted to support a syringe and a pusher configured to push a plunger moveable inside said syringe to expel fluid from an outlet of said syringe into a downstream fluid line connected to said outlet and configured to carry fluid under pressure to a patient.

34. The system of claim 29, wherein the processor is further configured to execute program code to not determine an occlusion exists unless the instantaneous pressure indicative of force in said downstream fluid line at the beginning of the first interval is less than the instantaneous pressure indicative of force in said downstream fluid line at the end of the last interval.

35. The system of claim 29, wherein the processor is further configured to execute program code to initiate a new series of intervals if an instantaneous pressure indicative of force in said downstream fluid line at the end of the at least one interval is not greater than an instantaneous pressure indicative of force in said downstream fluid line at the beginning of that interval.

36. A medical pumping system for pumping fluid under pressure through a downstream fluid line being configured to carry fluid under pressure between a fluid source and a patient at an elevation, the system comprising:

a pump configured to force fluid from a fluid source under pressure into a downstream fluid line;

a sensor for determining a first force value indicative of the force in said downstream fluid line at a first time, and second force value indicative of the force in said downstream fluid line at a second time;

a processor in communication with the pump, the processor being configured to execute program code that operates the pump to force fluid under pressure in said downstream fluid line; and

wherein the processor is further configured execute program code to declare an occlusion if a relationship between the first and second force values departs from an expected relationship, unless the relationship departs from an expected relationship as a result of a change in elevation of said patient.