Methods and apparatuses for detecting occlusions in an ambulatory infusion pump

• US 8,668,672 B2
• Filed: 04/18/2012
• Issued: 03/11/2014
• Est. Priority Date: 10/29/1998
• Status: Expired due to Term

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Moberg, Sheldon B., Hanson, Ian B., Talbot, Cary D.
• Primary Examiner(s): FLICK, JASON E
• Application Number:
  US13/450,059
• Publication Number:
  US 20120215199A1
• Time in Patent Office: 692 Days
• Field of Search: 604/151
• US Class Current: 604/151
• CPC Class Codes: A61M 2005/14264 with means for compensating influence from the environment
• CPC Class Codes: A61M 2005/16863 Occlusion detection
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/332 Force measuring means
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/70 with testing or calibration facilities
• CPC Class Codes: A61M 5/14566 with a replaceable reservoir for receiving a piston rod of the pump
• 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 5/16854 by monitoring line pressure
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

An improved pump, reservoir and reservoir piston are provided for controlled delivery of fluids. A motor is operably coupled to a drive member, such as a drive screw, which is adapted to advance a plunger slide in response to operation of the motor. The plunger slide is removably coupled to the piston. Methods, systems, and articles of manufacture for automatically detecting an occlusion in a medication infusion pump are provided. The electrical current to an infusion pump may be measured. Based on measurements of one or more variables, such as force, the infusion pump detects whether there is an occlusion in the system. The methods of detecting occlusions may be dynamic.

Claims

1. A method of detecting an occlusion in an infusion pump having a reservoir and a drive mechanism that includes a motor and one or more drive train components for infusing fluid from the reservoir into a body of a user through delivery of one or more separate pulses of infusion fluid, wherein consecutive pulses of infusion fluid are separated by a period of time during which no fluid is infused into the user'"'"'s body, the method comprising:

during delivery of a single one of said one or more separate pulses of infusion fluid, periodically measuring the amount of force that is applied to a drive train component to obtain a series of measurements;

determining a peak value of the series of measurements;

selecting a second value within the series of measurements later in time than the peak value;

calculating a difference between the peak value and the second value; and

declaring an occlusion has occurred if the difference exceeds a threshold value.

2. The method of claim 1, wherein the applied force is measured continuously during delivery of the pulse delivery of said single one of said one or more separate pulses of infusion fluid.

3. The method of claim 1, wherein the threshold value is dynamically updated based on measurements of applied force during delivery of at least one pulse of infusion fluid that was delivered before delivery of said single one of said one or more separate pulses of infusion fluid.

4. The method of claim 1, wherein the threshold value is updated each time a new reservoir is loaded into the infusion pump and the infusion pump is primed.

5. The method of claim 1, wherein an alarm is activated if the difference exceeds the threshold value.

6. The method of claim 5, wherein the alarm is an audible alarm.

7. The method of claim 5, wherein the alarm is a tactile alarm.

8. The method of claim 5, wherein the alarm is a visible alarm.

9. The method of claim 1, wherein an alarm is activated if the difference exceeds a predetermined percentage of the threshold value, said percentage being less than 100%.

10. The method of claim 9, wherein the alarm is at least one of an audible alarm, a tactile alarm, and a visible alarm.