Monitoring the operating health of a force sensor in a fluid infusion device

• US 9,770,553 B2
• Filed: 12/03/2013
• Issued: 09/26/2017
• Est. Priority Date: 12/22/2010
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Bazargan, Afshin, Vazquez, Pablo, Kow, Hsiao-Yu S., Monirabbasi, Salman, Hanson, Ian B.
• Primary Examiner(s): Bosworth, Kami A
• Application Number:
  US14/095,091
• Publication Number:
  US 20140094755A1
• Time in Patent Office: 1,393 Days
• CPC Class Codes: A61M 2005/16863 Occlusion detection
• CPC Class Codes: A61M 2205/332 Force measuring means
• CPC Class Codes: A61M 5/00 Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests vaccination appliances for veterinary use A61D1/025 ; tube connectors, tube couplings, valves or branch units specially adapted for medical use A61M39/00; containers specially adapted for medical or pharmaceutical purposes A61J1/00; combinations of vial and syringe for mixing or transferring their contents A61J1/20; holders for containers for collecting, storing or administering blood or medical fluids A61J1/16
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/16854 by monitoring line pressure

Abstract

A device for delivering fluid to a user includes a housing, a drive motor assembly in the housing, a force sensor, and an electronics module. The drive motor assembly regulates delivery of fluid by actuating a piston of a fluid reservoir, and the force sensor generates output levels in response to force imparted thereto during, for example, fluid delivery operations. The electronics module processes the output levels of the force sensor to assess the operating health of the force sensor, to check for occlusions in the fluid delivery path, and to monitor the seating status of the fluid reservoir.

Claims

1. A device for delivering fluid to a user, the device comprising:

a housing;

a drive motor assembly in the housing to regulate delivery of fluid by actuating a piston of a fluid reservoir;

a force sensor associated with the drive motor assembly to generate output levels in response to force imparted thereto, the force sensor located proximal to the drive motor assembly and between a proximal end of the drive motor assembly and a proximal end of the housing; and

an electronics module coupled to the force sensor to process the output levels to determine operating health of the force sensor, and the electronics module;

determines a rewind force measurement that indicates a rewind force imparted to the force sensor during a rewind operation;

compares the rewind force measurement to a first force measurement threshold; and

based on the comparison, initiates a corrective action based on the rewind force measurement being less than the first force measurement threshold.

2. The device of claim 1, wherein the corrective action is a user alert at the device when the rewind force measurement is less than the first force measurement threshold.

3. The device of claim 1, further comprising a memory element to store the first force measurement threshold.

4. The device of claim 1, wherein the electronics module:

determines a delivery force imparted to the force sensor during a delivery operation; and

initiates a corrective action when the delivery force is not within a specified range.

5. The device of claim 4, wherein the drive motor assembly includes a motor actuatable to drive the piston of the fluid reservoir, and the electronics module determines the delivery force imparted to the force sensor at each actuation of the motor during the delivery operation.

6. The device of claim 1, wherein the electronics module:

determines a plurality of calibration rewind force measurements imparted to the force sensor over a calibration period;

calculates a nominal rewind force from the plurality of calibration rewind force measurements; and

initiates a corrective action when the nominal rewind force is not within a specified range.

7. The device of claim 1, wherein the electronics module processes the output levels to determine if the force sensor is damaged or in poor health.

8. The device of claim 1, wherein the electronics module:

compares the rewind force measurement to a second force measurement threshold and initiates another corrective action, which is different than the corrective action, based on the rewind force measurement being greater than the second force measurement threshold.