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Publication numberCA2718306 A1
Publication typeApplication
Application numberCA 2718306
Publication date26 Oct 2006
Filing date13 Apr 2006
Priority date13 Apr 2005
Also published asCA2604498A1, CA2604498C, CA2718306C, CN101189431A, CN101189431B, EP1877662A2, EP1877662A4, US7922458, US7993108, US7993109, US8029245, US8029250, US8047812, US20050238503, US20090105648, US20090105649, US20090112156, US20090112165, US20090163869, US20120083730, WO2006113521A2, WO2006113521A3
Publication numberCA 2718306, CA 2718306 A1, CA 2718306A1, CA-A1-2718306, CA2718306 A1, CA2718306A1
InventorsBenjamin M. Rush, Christopher V. Reggiardo, Arthur E. Anderson Iii
ApplicantAbbott Diabetes Care Inc, Benjamin M. Rush, Christopher V. Reggiardo, Arthur E. Anderson Iii
Export CitationBiBTeX, EndNote, RefMan
External Links: CIPO, Espacenet
Variable volume, shape memory actuated insulin dispensing pump
CA 2718306 A1
Abstract
A portable pumping system provides insulin or other drugs to a user. A shape memory element is used to actuate the pump and an intelligent system controls the actuator in order to minimize stresses within the system and provide accurate and reliable dosage delivery. The control system utilizes various types of feedback to monitor and optimize the position of the pumping mechanisms.
Physical design aspects also minimize stress and the combination of the physical design aspects and the intelligent operation of the system results in a lightweight and cost effective pump that may be used in a disposable fashion if desired.
Description  available in
Claims(25)
1. A method of pumping a liquid, comprising:
applying at least one electrical pulse to a shape memory alloy to overcome a bias force of a first spring coupled to the shape memory alloy to move a piston by a predetermined distance, the piston movement corresponding to a pumping cycle;
detecting a stressed state of the shape memory alloy resulting from the shape memory alloy overcoming a bias force of a second spring coupled to the shape memory alloy;
detecting an occlusion by monitoring a rate of change of a position of the piston over a time period using an encoding grid disposed on the piston and comparing the monitored rate of change of the position of the piston to a predetermined rate of change of the position of the piston over the time period, wherein the predetermined rate of change of the position of the piston is based, at least in part, on the at least one electrical pulse applied to the shape memory alloy; and modifying the at least one electrical pulse when at least one of the stressed state is detected or the occlusion is detected.
2. The method of claim 1, further comprising determining a position of the piston using the encoding grid and comparing the determined position to a predetermined position, wherein the predetermined position is associated with the pumping cycle.
3. The method of claim 2, wherein comparing the monitored position of the piston to the predetermined position includes determining whether the pumping cycle has completed.
4. The method of claim 3, wherein the occlusion is detected when the pumping cycle has not completed.
5. The method of claim 2, wherein the pumping cycle includes movement of a predetermined dose of fluid.
6. The method of claim 5, wherein the fluid includes insulin.
7. The method of claim 2, wherein determining a position of the piston using an encoding grid comprises measuring the capacitance between a stationary conductive element and a conductive portion of the encoding grid.
8. The method of claim 1 wherein the encoding grid comprises a plurality of conductive portions and nonconductive portions and wherein each of the plurality of conductive portions and nonconductive portions are arranged in a plurality of patterns on the grid to indicate a plurality of positions of the piston.
9. The method of claim 1, including generating an output signal when the occlusion is detected.
10. The method of claim 9, including providing the output signal to a display.
11. The method of claim 1, wherein a spring constant of the second spring is greater than a spring constant of the first spring.
12. The method of claim 1, wherein modifying the at least one electrical pulse when the stress state is detected includes reducing a level of the at least one electrical pulse to prevent the stress state from occurring:
13. An apparatus, comprising:
a pump component;
a microprocessor; and a drive circuit operatively coupled to the microprocessor and the pump component, the drive circuit including a shape memory alloy operatively coupled to the pump component and configured to move the pump component in a predetermined direction, the drive circuit further including a first spring coupled to the shape memory alloy and the pump component, and a second spring coupled to the shape memory alloy;

wherein the microprocessor is configured to:

control the drive circuit to apply at least one electrical pulse to the shape memory alloy to overcome a bias force of the first spring to move the pump component by a predetermined distance, the movement of the pump component corresponding to a pump cycle;
detect a stressed state of the shape memory alloy resulting from the shape memory alloy overcoming a bias force of the second spring;
detect an occlusion by monitoring a rate of change of a position of the pump component over a time period using an encoding grid disposed on the pump component and comparing the monitored rate of change of the pump component to a predetermined rate of change of the position of the pump component over the time period, wherein the predetermined rate of change of the position of the pump component is based, at least in part, on the at least one electrical pulse applied to the shape memory alloy; and modify the at least one electrical pulse when at least one of the stressed state is detected or the occlusion is detected.
14. The apparatus of claim 13, wherein the microprocessor is configured to determine a position of the pump component using the encoding grid and compare the determined position of the pump component to a predetermined position, wherein the predetermined position is associated with the pump cycle.
15. The apparatus of claim 14, wherein determining a position of the pump component using an encoding grid comprises measuring the capacitance between a stationary conductive element and a conductive portion of the encoding grid.
16. The apparatus of claim 14, wherein the microprocessor determines whether the pump cycle has completed.
17. The apparatus of claim 14, wherein the microprocessor detects the occlusion when the pump cycle has not completed.
18. The apparatus of claim 14, wherein the pump cycle includes movement of a predetermined dose of fluid.
19. The apparatus of claim 18, wherein the fluid includes insulin.
20. The apparatus of claim 13, wherein the microprocessor is configured to generate an output signal when the occlusion is detected.
21. The apparatus of claim 20, including a display configured to output the generated output signal.
22. The apparatus of claim 13, wherein the predetermined direction includes a first direction and a second direction, wherein one of the first direction or the second direction is associated with a direction of fluid delivery.
23. The apparatus of claim 13, wherein a spring constant of the second spring is greater than a spring constant of the first spring.
24. The apparatus of claim 13, wherein the encoding grid comprises a plurality of conductive portions and nonconductive portions and wherein each of the plurality of conductive portions and nonconductive portions are arranged in a plurality of patterns on the grid to indicate a plurality of positions of the pump component.
25. The apparatus of claim 13, wherein modifying the at least one electrical pulse when the stress state is detected includes causing the microprocessor to reduce a level of the at least one electrical pulse to prevent the stress state from occurring.
Classifications
International ClassificationF04B49/06, F04B53/14, F04B13/00, A61M5/142, F04B9/00, F15B15/28, A61M, F04B17/00, F04B23/08, F04B35/04, F04B43/04, G01F25/00, G01F1/708, F04B1/00, F04B17/04, F04B51/00, G01F11/02
Cooperative ClassificationF04B23/02, F05C2251/08, F04B17/00, F04B35/04, F04B9/02, A61M2205/702, F04B2201/0201, A61M2205/0288, F04B35/00, A61M5/14244, F04B9/00, A61M5/14216, A61M2205/0266, A61M2205/3317, G01F11/021, F03G7/065, F04B49/065
European ClassificationF04B9/00, A61M5/142G2, A61M5/142P, F04B35/00, F04B35/04, F03G7/06B, F04B9/02, F04B23/02, G01F11/02B, F04B17/00, F04B49/06C
Legal Events
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18 Oct 2010EEERExamination request