SENSING A STATUS OF AN INFUSER BASED ON SENSING MOTOR CONTROL AND POWER INPUT

• US 20140330240A1
• Filed: 05/03/2013
• Published: 11/06/2014
• Est. Priority Date: 05/03/2013
• Status: Active Grant

• Current Assignee: West Pharma. Services IL, Ltd. (West Pharmaceutical Services Incorporated)
• Original Assignee: Medimop Medical Projects Ltd. (West Pharmaceutical Services Incorporated)
• Inventors: CABIRI, Oz, FILMAN, Reuven Y.
• Granted Patent: US 9,889,256 B2
• Time in Patent Office: Days
• US Class Current: 604/500
• CPC Class Codes: A61M 2005/16863 Occlusion detection
• CPC Class Codes: A61M 2205/70 with testing or calibration facilities
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/16831 Monitoring, detecting, signalling or eliminating infusion flow anomalies low-level float-valves causing cut-off A61M5/40; indicating or recording presence, absence or direction of flow in general G01P13/0066
• CPC Class Codes: A61M 5/172 electrical or electronic A61M5/16804, A61M5/16831 take precedence

Abstract

A status of a battery operated infuser may be detected by measuring a controlled input parameter. The measurement may be used to determine a magnitude of the input parameter and a parameter of the control. For example, control of power input to a motor may be by pulse density modulation. An integral of current over time may sever as a measure of current magnitude and pulse density. The result of the integral may be used to determine the status of the injector. The status may include normal functions for example start of pumping and/or malfunctions such as occlusion or drive disengagement.

Claims

1. A method of determining a status of a battery operated drug infusing device comprising:

controlling the device based on a performance of the device;

measuring an input parameter of the device, and

ascertaining a status of the device dependent on both

a magnitude of said input parameter and

said controlling.

2. The method of claim 1, wherein

said performance of the device includes a cumulative movement of the device and

said controlling includes limiting a time of current input to the device and

said measuring includes measuring a magnitude of said current input to the device over time and

said ascertaining includes combining said magnitude and said time of said current input to the device to determine a combined measure and wherein said ascertaining is based on a value of said combined measure.

3. The method of claim 2, wherein said cumulative movement includes a number of revolutions during a time period.

4. The method of claim 3, wherein said limiting includes limiting a pulse density of said current input in said time period.

5. The method of claim 2, wherein said combined measure includes a product of said current magnitude over said time.

6. The method of claim 1, wherein said controlling affects said input parameter.

7. The method of claim 6, wherein a result of said measuring serves as a proxy for a parameter of said controlling.

8. The method of claim 7, wherein a time dependence of said measured input parameter serves as said proxy for said parameter of said controlling.

9. The method of claim 8, wherein said ascertaining includes determining a combined measure of said input parameter magnitude over time.

10. The method of claim 9, wherein said combined measure includes a product of said input parameter magnitude and said time.

11. The method of claim 1, wherein said controlling includes pulse density modulation and said ascertaining depends on said pulse density.

12. The method of claim 1, wherein said controlling includes a feedback loop.

13. The method of claim 1, wherein said controlling includes a negative feedback loop.

14. The method of claim 1, wherein said status includes at least one element selected from the group consisting of, a blockage, a disengagement, changing of an active mechanical part, discharging medicine, and not discharging.

15. The method of claim 1, wherein said input parameter is magnitude of current and wherein said controlling includes:

counting a number of rotations wherein said number of rotations is proportional to a cumulative discharge of the device, and

cutting off said current when said number reaches a threshold.

16. The method of claim 15, wherein a rate of said counting is less than four times a sampling rate of said measuring.

17. The method of claim 1, wherein said input parameter is unregulated.

18. The method of claim 1, wherein said controlling includes temporarily cutting off said input parameter.

19. A drug infusion device comprising:

a DC power source;

an actuator;

a performance sensor operationally coupled to an output of said actuator;

a controller which adjusts a power input of said actuator according to an output of said performance sensor;

an input sensor operationally coupled to said power input;

a processor which ascertains the status of the device dependent on said adjusting based on an output of said sensor.

20. The drug infusion device of claim 19, wherein said performance sensor includes a revolution counter.

21. The drug infusion device of claim 19, wherein said actuator includes a DC motor.

22. The drug infusion device of claim 21, further comprising:

a pulse density circuit, and wherein said adjusting is by pulse density modulation.

23. The drug infusion device of claim 22, wherein said sensor is a current sensor and said power input includes a current.

24. The drug infusion device of claim 23, wherein said processor computes an product of a magnitude of said current over time and wherein said ascertaining is dependent on said product.