Methods and apparatuses for detecting medical device acceleration, temperature, and humidity conditions

• US 20080125701A1
• Filed: 11/29/2006
• Published: 05/29/2008
• Est. Priority Date: 11/29/2006
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Moberg, Sheldon B., Talbot, Cary D., Hanson, Ian B., Ireland, Jeffrey
• Granted Patent: US 7,704,227 B2
• Time in Patent Office: Days
• US Class Current: 604/67
• CPC Class Codes: A61B 2560/0242 adapted to measure environmental factors, e.g. temperature, pollution
• CPC Class Codes: A61B 2560/0276 Determining malfunction
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/4866 Evaluating metabolism A61B5/083 takes precedence
• CPC Class Codes: A61M 2005/14264 with means for compensating influence from the environment
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/3368 Temperature
• CPC Class Codes: A61M 2230/63 Motion, e.g. physical activity
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/172 electrical or electronic A61M5/16804, A61M5/16831 take precedence

Abstract

An ambulatory medical device for detecting acceleration, temperature, and/or humidity conditions in or around the medical device is provided. The medical device includes one or more acceleration, thermal, and/or humidity sensors which detect acceleration, temperature, and/or humidity conditions in or around the medical device. In response to detected conditions, the medical device may, among other things, alter the operation of the device, provide an alarm or warning to the user, or transmit data about the detected conditions to another device.

Claims

1. An external infusion device for infusing fluid into a person from a reservoir, comprising:

a housing adapted to be carried on an exterior of the person;

a drive mechanism contained in the housing and operatively coupled to the reservoir to deliver fluid from the reservoir into the person;

a processor contained in the housing;

an indicator operatively coupled to the processor and adapted to provide at least one of a visual indication, an audible indication, or a tactile indication to indicate information about the infusion device to the person; and

an acceleration sensor coupled to the processor and adapted to provide an acceleration output signal as a function of acceleration forces acting on the housing,

wherein the processor is adapted to control the infusion device in accordance with the acceleration output signal.

2. The external infusion device of claim 1, further comprising a memory contained in the housing and coupled to the processor, wherein the memory is adapted to store a predetermined acceleration threshold corresponding to an impact on the housing.

3. The external infusion device of claim 2, wherein if the acceleration output signal exceeds the predetermined acceleration threshold, the processor is adapted to control the infusion device by causing the indicator to provide an alarm or a warning to the person.

4. The external infusion device of claim 2, wherein if the acceleration output signal exceeds the predetermined acceleration threshold, the processor is adapted to control the infusion device by causing the drive mechanism to alter delivery of the fluid into the person.

5. The external infusion device of claim 2, further comprising a transmitter/receiver contained in the housing and coupled to the processor, wherein the transmitter/receiver is adapted to communicate with a remote device, and further wherein if the acceleration output signal exceeds the predetermined acceleration threshold, the processor is adapted to control the infusion device by causing the transmitter/receiver to send information about the impact to the remote device.

6. The external infusion device of claim 1, wherein the acceleration sensor is one of a piezoelectric accelerometer, a thermal accelerometer, a servo accelerometer, a strain gauge accelerometer, a capacitance accelerometer, a MEMS accelerometer, a resonance shift accelerometer, and a piezoresistive accelerometer.

7. The external infusion device of claim 1, wherein the acceleration sensor is an impact switch disposed within the housing.

8. The external infusion device of claim 7, wherein the impact switch comprises:

an electrical input and an electrical output;

an electrically conductive seismic mass having a pivot end and a free end, the mass being electrically coupled to the electrical output and being pivotably mounted to the housing at the pivot end for movement in a first closing contact direction; and

a first electrically conductive latch adapted to releasably hold the free end of the mass, the first latch being electrically coupled to the electrical input,

wherein the mass is adapted to move in the first closing contact direction and the first latch is adapted to hold the free end of the mass such that a circuit between the electrical input and the electrical output is closed to provide the acceleration output signal when a first predetermined acceleration force acts on the housing.

9. The external infusion device of claim 8, wherein the conductive seismic mass comprises:

an electrically conductive arm member having a proximate end and a distal end, the arm member being pivotably coupled to the housing at the proximate end; and

an electrically conductive plug mounted on the distal end of the arm, the plug being electrically coupled to the arm and adapted to be releasably secured by the first latch.

10. The external infusion device of claim 8, wherein the impact switch further comprises:

a second electrically conductive latch adapted to releasably hold the free end of the mass, the second latch being electrically coupled to the electrical input,

wherein the mass is further pivotably mounted to the housing at the pivot end for movement in a second closing contact direction, and

wherein the mass is adapted to move in the second closing contact direction and the second latch is adapted to hold the free end of the mass such that a circuit between the electrical input and the electrical output is closed to provide the acceleration output signal when a second predetermined acceleration force acts on the housing.

11. The external infusion device of claim 7, wherein the impact switch comprises:

a switch electrical input and a switch electrical output;

an electrically conductive seismic mass having a pivot end and a free end, the mass being electrically coupled to the switch electrical output and being pivotably mounted to the housing at the pivot end for movement in a first closing contact direction; and

a first electromagnet adapted to generate a first magnetic field to releasably hold the free end of the mass, the first electromagnet being electrically coupled to the switch electrical input,

wherein the mass is adapted to move in the first closing contact direction and the first magnetic field generated by the first electromagnet is adapted to hold the free end of the mass such that a circuit between the electrical input and the electrical output is closed to provide the acceleration output signal when a first predetermined acceleration force acts on the housing.

12. The external infusion device of claim 11, wherein the first electromagnet is electrically coupled to a magnet electrical input and a magnet electrical output, and wherein the impact switch further comprises:

a reset switch having an open position and a closed position, the reset switch being adapted to electrically connect the magnet electrical input to the magnet electrical output such that the first magnetic field collapses and the free end of the mass is released when the reset switch is in the closed position.

13. The external infusion device of claim 11, wherein the conductive seismic mass comprises:

an electrically conductive arm member having a distal end and a proximate end, the arm member being pivotably coupled to the housing at the proximate end; and

an electrically conductive contact member mounted on the distal end of the arm, the contact member being electrically coupled to the arm member and adapted to be held by the first magnetic field generated by the first electromagnet.

14. The external infusion device of claim 11, wherein the impact switch further comprises:

a second electromagnet adapted to generate a second magnetic field to releasably hold the free end of the mass, the second electromagnet being electrically coupled to the switch electrical input,

wherein the mass is further pivotably mounted to the housing at the pivot end for movement in a second closing contact direction, and

wherein the mass is adapted to move in the second closing contact direction and the second magnetic field generated by the second electromagnet is adapted to hold the free end of the mass such that a circuit between the electrical input and the electrical output is closed to provide the acceleration output signal when a second predetermined acceleration force acts on the housing.

15. The external infusion device of claim 7, wherein the impact switch comprises:

an electrical input and an electrical output;

an electrically conductive seismic mass having an anchored end and a free end, the mass being electrically coupled to the electrical output, the mass being coupled to the housing at the anchored end and adapted for resilient deflection in a first closing contact direction; and

a first electrically conductive contact fixedly mounted adjacent to the mass, the first contact being electrically coupled to the electrical input,

wherein the mass is adapted to deflect in the first closing contact direction from a first position to a second position, touch the first contact, and return from the second position to the first position such that a circuit between the electrical input and the electrical output is closed to provide the acceleration output signal when a first predetermined acceleration force acts on the housing.

16. The external infusion device of claim 15, wherein the conductive seismic mass comprises:

an electrically conductive arm member having a proximate end and a distal end, the arm member being coupled to the housing at the proximate end and adapted for resilient deflection in the first closing contact direction; and

an electrically conductive impact head mounted on the distal end of the arm member, the impact head being electrically coupled to the arm member,

wherein the arm member is adapted to deflect from the first position to the second position, the impact head is adapted to touch the first contact, and the arm member is adapted to return from the second position to the first position when the first predetermined acceleration force acts on the housing.

17. The external infusion device of claim 15, wherein the impact switch further comprises:

a second electrically conductive contact fixedly mounted adjacent to the seismic mass, the second contact being electrically coupled to the electrical input,

wherein the mass is further adapted for resilient deflection in a second closing contact direction, and

wherein the mass is adapted to deflect in the second closing contact direction from the first position to a third position, touch the second contact, and return from the third position to the first position such that a circuit between the electrical input and the electrical output is closed to provide the acceleration output signal when a second predetermined acceleration force acts on the housing.

18. The external infusion device of claim 7, wherein the impact switch comprises:

an electrical input and an electrical output;

an electrically conductive seismic mass having an anchored end and a free end, the mass being electrically coupled to the electrical output, the mass being coupled to the housing at the anchored end and adapted for resilient deflection in a plurality of directions;

a plurality of electrically conductive contact surfaces fixedly mounted adjacent to the mass, each of the contact surfaces being electrically coupled to the electrical input,

wherein the arm member is adapted to deflect in one of the plurality of directions from a first position to a second position, touch one of the plurality of contact surfaces, and return from the second position to the first position such that a circuit between the electrical input and the electrical output is closed to provide the acceleration output signal when a predetermined acceleration force in one of the plurality of directions acts on the housing.

19. The external infusion device of claim 18, wherein the seismic mass comprises:

an electrically conductive arm member having an anchored end and a free end, the arm member being coupled to the housing at the anchored end and adapted for resilient deflection in the plurality of directions; and

an electrically conductive impact head mounted on the free end of the arm member, the impact head being electrically coupled to the arm member,

wherein the arm member is adapted to deflect in one of the plurality of directions from the first position to the second position, the impact head is adapted to touch one of the plurality of contact surfaces, and the arm member is adapted to return from the second position to the first position such that a circuit between the electrical input and the electrical output is closed to provide the acceleration output signal when a predetermined acceleration force in one of the plurality of directions acts on the housing.

20. The external infusion device of claim 18, wherein the plurality of electrically conductive contact surfaces are mounted to form an enclosure generally surrounding at least a portion of the seismic mass.

21. The external infusion device of claim 1, wherein the processor is further adapted to determine whether the person is engaging in a physical activity based on the acceleration output signal.

22. The external infusion device of claim 21, further comprising a memory contained in the housing and coupled to the processor, wherein the memory is adapted to store a predetermined acceleration force corresponding to a physical activity of the person, and the processor determines that the person is engaging in the physical activity if the acceleration output signal exceeds the predetermined acceleration force.

23. The external infusion device of claim 21, further comprising a memory contained in the housing and coupled to the processor, wherein the memory is adapted to store a pattern of acceleration forces corresponding to a physical activity of the person, and the processor determines that the person is engaging in the physical activity if the acceleration output signal corresponds to the pattern of acceleration forces.

24. The external infusion device of claim 21, wherein if the processor determines that the person is engaging in a physical activity, the processor is adapted to control the infusion device by causing the indicator to notify the person about the physical activity.

25. The external infusion device of claim 21, wherein if the processor determines that the person is engaging in a physical activity, the processor is adapted to control the infusion device by causing the drive mechanism to alter delivery of the fluid into the person from a current delivery rate to a modified delivery rate.

26. The external infusion device of claim 25, wherein the processor is adapted to control the infusion device by causing the drive mechanism to automatically alter delivery of the fluid into the person from the current delivery rate to the modified delivery rate.

27. The external infusion device of claim 26, further comprising an input device coupled to the processor and adapted to receive input from the person about the modified delivery rate, wherein the processor is adapted to control the infusion device by causing the drive mechanism to automatically alter delivery of the fluid into the person from the current delivery rate to the modified delivery rate based on the input from the person.

28. The external infusion device of claim 25, further comprising an input device coupled to the processor and adapted to receive input from the person associated with the modified delivery rate, wherein the processor is adapted to control the infusion device by causing the drive mechanism to alter delivery of the fluid into the person from the current delivery rate to the modified delivery rate in response to the input by the person.

29. The external infusion device of claim 25, wherein the processor is adapted to control the infusion device by applying a time delay between determining that the person is engaging in the physical activity and causing the drive mechanism to alter delivery of the fluid into the person from the current delivery rate to the modified delivery rate.

30. The external infusion device of claim 21, wherein the processor is further adapted to determine whether the person has stopped engaging in the physical activity based on the acceleration output signal.

31. The external infusion device of claim 30, further comprising a memory contained in the housing and coupled to the processor, wherein the memory is adapted to store a predetermined acceleration force corresponding to a physical activity of the person, and the processor determines that the person has stopped engaging in the physical activity if the acceleration output signal drops below the predetermined acceleration force.

32. The external infusion device of claim 30, further comprising a memory contained in the housing and coupled to the processor, wherein the memory is adapted to store a pattern of acceleration forces corresponding to a physical activity of the person, and the processor determines that the person has stopped engaging in the physical activity if the acceleration output signal no longer corresponds to the pattern of acceleration forces.

33. The external infusion device of claim 30, wherein if the processor determines that the person has stopped engaging in the physical activity, the processor is adapted to control the infusion device by causing the indicator to notify the person about stopping the physical activity.

34. The external infusion device of claim 30, wherein if the processor determines that the person has stopped engaging in the physical activity, the processor is adapted to control the infusion device by causing the drive mechanism to return delivery of the fluid into the person from the modified delivery rate to the current delivery rate.

35. The external infusion device of claim 34, wherein the processor is adapted to control the infusion device by causing the drive mechanism to automatically return delivery of the fluid into the person from the modified delivery rate to the current delivery rate.

36. The external infusion device of claim 34, further comprising an input device coupled to the processor and adapted to receive input from the person, wherein the processor is adapted to control the infusion device by causing the drive mechanism to return delivery of the fluid into the person from the modified delivery rate to the current delivery rate in response to the input by the person.

37. The external infusion device of claim 34, wherein the processor is adapted to control the infusion device by applying a time delay between determining that the person has stopped engaging in the physical activity and causing the drive mechanism to return delivery of the fluid into the person from the modified delivery rate to the current delivery rate.

38. The external infusion device of claim 21, wherein if the processor determines that the person is engaging in a physical activity, the processor is adapted to control the infusion device by causing the drive mechanism to deliver the fluid into the person at a modified delivery rate after the physical activity while the person is sleeping.

39. The external infusion device of claim 21, further comprising a transmitter/receiver contained in the housing and coupled to the processor, wherein the transmitter/receiver is adapted to communicate with a remote device, and further wherein if the processor determines that the person is engaging in a physical activity, the processor is adapted to control the infusion device by causing the transmitter/receiver to send information about the physical activity of the person to the remote device.

40. The external infusion device of claim 39, wherein the information includes data about at least one of frequency, duration, and intensity of the physical activity of the person.

41. The external infusion device of claim 21, further comprising a memory contained in the housing and coupled to the processor, wherein the memory is further adapted to store data about at least one of frequency, duration, and intensity of the physical activity of the person.

42. An external ambulatory medical device for use on a person'"'"'s body, comprising:

a housing adapted to be carried on an exterior of the person'"'"'s body;

a processor contained in the housing;

an indicator operatively coupled to the processor and adapted to provide at least one of a visual indication, an audible indication, or a tactile indication to indicate information about the ambulatory medical device to the person; and

an acceleration sensor coupled to the processor and adapted to provide an acceleration output signal as a function of acceleration forces acting on the housing,

wherein the processor is adapted to control the ambulatory medical device and the indicator is adapted to indicate information about the ambulatory medical device based on the acceleration output signal.

43. The ambulatory medical device of claim 42, wherein the ambulatory medical device is an external infusion pump.

44. The ambulatory medical device of claim 42, wherein the ambulatory medical device is a glucose monitoring device.

45. The ambulatory medical device of claim 42, further comprising a transmitter/receiver contained in the housing and coupled to the processor, wherein the transmitter/receiver is adapted to communicate with a remote device, and further wherein the processor is adapted to control the ambulatory medical device by causing the transmitter/receiver to send information about the ambulatory medical device to the remote device based on the acceleration output signal.

46. The ambulatory medical device of claim 42, wherein the acceleration sensor is one of a piezoelectric accelerometer, a thermal accelerometer, a servo accelerometer, a strain gauge accelerometer, a capacitance accelerometer, a MEMS accelerometer, a resonance shift accelerometer, and a piezoresistive accelerometer.

47. The ambulatory medical device of claim 42, wherein the acceleration sensor is an impact switch disposed within the housing.