AMBULATORY INFUSION DEVICE WITH SENSOR TESTING UNIT

• US 20100264931A1
• Filed: 04/16/2010
• Published: 10/21/2010
• Est. Priority Date: 04/16/2009
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics International AG (Roche Holding AG)
• Inventors: Schrotberger, Reto, Muri, Alex, Lindegger, Stefan
• Granted Patent: US 8,373,421 B2
• Time in Patent Office: Days
• US Class Current: 324/511
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/168 Means for controlling media flow to the body or for metering media to the body, e.g. drip meters, counters ; Monitoring media flow to the body flow control in general G05D7/00
• CPC Class Codes: G01R 31/40 Testing power supplies testing photovoltaic devices H02S50/10

Abstract

An ambulatory infusion device for infusion of a liquid drug into a patient'"'"'s body over an extended period of time and methods thereof are disclosed. The device includes a sensor assembly, which produces a sensor assembly output based on an infusion characteristic of the ambulatory infusion device and based on a supply voltage/current, and a supply unit which is coupled to a sensor of the sensor assembly and generates the supply voltage/current. A sensor testing unit detects a failure of the sensor assembly, wherein the sensor testing unit is coupled to the sensor assembly and the supply unit, and the sensor testing unit carries out a sensor testing sequence. The sensor testing sequence includes controlling the supply unit so as to produce a variation of the supply voltage/current, and determining whether the variation of the supply voltage/current produces a corresponding variation of the sensor assembly output.

Claims

1. An ambulatory infusion device for infusion of a liquid drug into a patient'"'"'s body over an extended period of time, the ambulatory infusion device comprising:

a sensor assembly having a sensor, wherein the sensor assembly produces a sensor assembly output based on an infusion characteristic of the ambulatory infusion device and based on a supply voltage/current;

a supply unit, wherein the supply unit is coupled to the sensor and generates the supply voltage/current; and

a sensor testing unit which detects a failure of the sensor assembly, wherein the sensor testing unit is coupled to the sensor assembly and the supply unit, and the sensor testing unit carries out a sensor testing sequence, the sensor testing sequence comprising;

controlling the supply unit so as to produce a variation of the supply voltage/current, and

determining whether the variation of the supply voltage/current produces a corresponding variation of the sensor assembly output.

2. The ambulatory infusion device of claim 1, wherein the infusion characteristic is a pressure of the liquid drug or a characteristic corresponding to the pressure of the liquid drug.

3. The ambulatory infusion device of claim 1, wherein the supply unit comprises a variable voltage supply or a variable current supply.

4. The ambulatory infusion device of claim 1, wherein the variation of the supply voltage/current comprises two or more discrete levels of the supply voltage/current.

5. The ambulatory infusion device of claim 1, wherein the variation of the supply voltage/current comprises two discrete levels of the supply voltage/current, a first discrete level and a second discrete level.

6. The ambulatory infusion device of claim 5, wherein the first discrete level is about two times higher than the second discrete level.

7. The ambulatory infusion device of claim 5, wherein the supply unit comprises at least one dropping resistor used for producing the second discrete level.

8. The ambulatory infusion device of claim 1, wherein the supply unit generates a continuously variable supply voltage/current.

9. The ambulatory infusion device of claim 1, wherein determining whether the variation of the supply voltage/current produces a corresponding variation of the sensor assembly output comprises determining whether the corresponding variation of the sensor assembly output is proportional to the variation of the supply voltage/current.

10. The ambulatory infusion device of claim 1, wherein determining whether the variation of the supply voltage/current produces a corresponding variation of the sensor assembly output comprises determining whether the corresponding variation of the sensor assembly output falls within an expected range.

11. The ambulatory infusion device of claim 1, wherein the sensor comprises at least one force-sensitive resistor, pressure-sensitive a resistor, or strain gauge.

12. The ambulatory infusion device of claim 1, wherein the sensor testing unit measures a value of the supply voltage/current.

13. The ambulatory infusion device of claim 1, wherein determining whether the variation of the supply voltage/current produces a corresponding variation of the sensor assembly output comprises averaging two or more samples of the sensor assembly output.

14. The ambulatory infusion device of claim 1, wherein the sensor testing unit comprises a microcontroller having an analog-to-digital converter, the sensor assembly output is coupled to the analog-to-digital converter, and the analog-to-digital converter measures the corresponding variation of the sensor assembly output.

15. A method for detecting a failure of a sensor assembly of an ambulatory infusion device, wherein the sensor assembly comprises a sensor and produces a sensor assembly output based on an infusion characteristic of the ambulatory infusion device and based on a supply voltage/current coupled to the sensor, the method comprising:

producing a variation of the supply voltage/current, and

determining whether the variation of the supply voltage/current produces a corresponding variation of the sensor assembly output.

16. The method of claim 15, wherein producing a variation of the supply voltage/current comprises switching a value of the supply voltage/current between at least two discrete supply levels.

17. The method of claim 15, wherein determining whether the variation of the supply voltage/current produces a corresponding variation of the sensor assembly output comprises determining whether the corresponding variation of the sensor assembly output is proportional to the variation of the supply voltage/current.

18. The method of claim 15, wherein producing a variation of the supply voltage/current is performed such that the corresponding variation of the sensor assembly output is relatively large as compared to a variation of the sensor assembly output resulting from a variation of the infusion characteristic.

19. The method of claim 15, wherein acts of the method are carried out in defined time intervals prior to, during, or after drug administration by the ambulatory infusion device.

20. The method of claim 15, wherein the sensor comprises at least one force-sensitive, pressure-sensitive resistor, or strain gauge.