Occlusion detection for a fluid infusion device

• US 9,050,406 B2
• Filed: 04/19/2013
• Issued: 06/09/2015
• Est. Priority Date: 12/22/2010
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Kow, Hsiao-Yu S., Bazargan, Afshin, Hanson, Ian B., Vazquez, Pablo, Alderete, Juan M. Jr., Monirabbasi, Salman
• Primary Examiner(s): BERDICHEVSKY, AARTI
• Application Number:
  US13/866,240
• Publication Number:
  US 20130245595A1
• Time in Patent Office: 781 Days
• US Class Current: 1/1
• CPC Class Codes: A61M 2005/16863 Occlusion detection
• CPC Class Codes: A61M 2205/332 Force measuring means
• CPC Class Codes: A61M 5/14 Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
• CPC Class Codes: A61M 5/142 Pressure infusion, e.g. using pumps
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/1452 pressurised by means of pistons
• 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
• CPC Class Codes: A61M 5/5086 for indicating if defective, used, tampered with or unsterile
• CPC Class Codes: G01F 13/00 Apparatus for measuring by volume and delivering fluids or fluent solid materials, not provided for in the preceding groups
• CPC Class Codes: G01L 1/26 Auxiliary measures taken, or devices used, in connection with the measurement of force, e.g. for preventing influence of transverse components of force, for preventing overload

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 method of detecting occlusions in a fluid path of a fluid infusion device having a drive motor assembly that actuates a fluid reservoir by applying actuation force to a piston of the fluid reservoir, the method comprising:

initiating a fluid delivery action intended to deliver an amount of fluid from the fluid reservoir;

determining measures of fluid pressure in the fluid path for the fluid delivery action;

indicating an occlusion when a first rate of change of the measures of fluid pressure is greater than or equal to first threshold value, the first rate of change based upon a first measurement window; and

indicating an occlusion when both;

(a) a second rate of change of the measures of fluid pressure is greater than or equal to a second threshold value, the second rate of change based upon a second measurement window; and

(b) a current measure of fluid pressure is greater than or equal to a threshold force value.

2. The method of claim 1, wherein:

the first measurement window represents a first delivery time, relative to a reference time;

the second measurement window represents a second delivery time, relative to the reference time; and

the first delivery time is longer than the second delivery time.

3. The method of claim 1, wherein the first threshold value is greater than the second threshold value.

4. The method of claim 1, wherein if the second rate of change of the measures of fluid pressure is less than the second threshold value and the current measure of fluid pressure is less than the threshold force value, the method further comprises:

determining if more delivery strokes are needed to deliver the amount of fluid from the fluid reservoir.

5. The method of claim 1, wherein determining measures of fluid pressure in the fluid path further comprises determining measures of actuation force using a force sensor that indicates the fluid pressure in the fluid path.

6. The method of claim 1, wherein:

the first measurement window represents a first delivered volume, relative to a reference volume; and

the second measurement window represents a second delivered volume, relative to the reference volume.

7. The method of claim 6, wherein the first delivered volume is greater than the second delivered volume.

8. The method of claim 1, further comprising the step of initiating corrective action for the fluid infusion device when an occlusion is indicated.

9. The method of claim 8, wherein initiating corrective action further comprises:

generating an alert or alarm at the fluid infusion device.

10. The method of claim 1, wherein the second measurement window size varies as a function of the measures of fluid pressure in the fluid path.

11. The method of claim 10, wherein the second measurement window size decreases as the measures of fluid pressure in the fluid path increase.

12. A method of detecting occlusions in a fluid path of a fluid infusion device having a drive motor assembly that actuates a fluid reservoir by applying actuation force to a piston of the fluid reservoir, the method comprising:

initiating a fluid delivery action intended to deliver an amount of fluid from the fluid reservoir;

determining measures of fluid pressure in the fluid path for the fluid delivery action;

indicating an occlusion when a first rate of change of the measures of fluid pressure is greater than or equal to first threshold value, the first rate of change based upon a first measurement window that represents a first delivered volume, relative to a reference volume; and

indicating an occlusion when both;

(a) a second rate of change of the measures of fluid pressure is greater than or equal to a second threshold value, the second rate of change based upon a second measurement window that represents a second delivered volume, relative to the reference volume; and

(b) a current measure of fluid pressure is greater than or equal to a threshold force value.

13. The method of claim 12, wherein the first delivered volume is greater than the second delivered volume.

14. The method of claim 12, wherein the first threshold value is greater than the second threshold value.

15. The method of claim 12, further comprising the step of initiating corrective action for the fluid infusion device when an occlusion is indicated.

16. The method of claim 12, wherein the second measurement window size decreases as the measures of fluid pressure in the fluid path increase.

17. The method of claim 12, wherein determining measures of fluid pressure in the fluid path further comprises determining measures of actuation force using a force sensor that indicates the fluid pressure in the fluid path.