Monitoring the seating status of a fluid reservoir in a fluid infusion device

• US 8,556,856 B2
• Filed: 05/14/2012
• Issued: 10/15/2013
• 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
• Primary Examiner(s): BERDICHEVSKY, AARTI
• Application Number:
  US13/470,787
• Publication Number:
  US 20120226234A1
• Time in Patent Office: 519 Days
• Field of Search: 604/131, 604/151
• US Class Current: 604/151
• CPC Class Codes: A61M 2005/16863 Occlusion detection
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/332 Force measuring means
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient
• 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 reservoir cavity within the housing to accommodate fluid reservoirs;

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; and

an electronics module coupled to the force sensor to process the output levels to determine a seating status of the fluid reservoir in the reservoir cavity, wherein the electronics module;

determines a measure of actuation force imparted to the force sensor during operation of the drive motor assembly;

compares the measure of actuation force to an amount of force that is less than normally expected actuation forces of the device, wherein the amount of force is indicative of an unseated state of the fluid reservoir; and

generates indicia of an unseated reservoir condition when the measure of actuation force is less than the amount of force.

2. The device of claim 1, wherein the electronics module generates a user alert at the device when the output levels indicate an unseated state of the fluid reservoir in the reservoir cavity.

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

obtains measures of actuation force imparted to the force sensor for a number of consecutive fluid delivery pulses;

calculates a pulse-to-pulse difference between two consecutive fluid delivery pulses, the pulse-to-pulse difference based on respective measures of actuation force for the two consecutive fluid delivery pulses; and

initiates corrective action for the fluid infusion device when the pulse-to-pulse difference is greater than a threshold amount of force.

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

confirms initial seating of the fluid reservoir in the reservoir cavity; and

initiates corrective action for the device when the measure of actuation force is less than the amount of force.

5. The device of claim 4, further comprising a memory element coupled to the electronics module to store the amount of force as a fixed quantity during an operating lifespan of the device.

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

obtains a baseline actuation force imparted to the force sensor, after initial seating and priming of the fluid reservoir;

determines a measured actuation force imparted to the force sensor, the measured actuation force corresponding to a designated delivery stroke of the drive motor assembly; and

generates the indicia of the unseated reservoir condition when the measured actuation force is less than the baseline actuation force by at least a predetermined amount.

7. The device of claim 6, further comprising a memory element coupled to the electronics module to store the baseline actuation force.

8. The device of claim 7, wherein the electronics module updates the baseline actuation force as a function of the measured actuation force when the measured actuation force is not less than the baseline actuation force by at least the predetermined amount.