Fluid delivery device with autocalibration

• US 7,727,181 B2
• Filed: 04/13/2005
• Issued: 06/01/2010
• Est. Priority Date: 10/09/2002
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Rush, Benjamin M.
• Primary Examiner(s): Lucchesi; Nicholas D
• Assistant Examiner(s): BERDICHEVSKY, AARTI
• Application Number:
  US11/105,711
• Publication Number:
  US 20050235732A1
• Time in Patent Office: 1,875 Days
• Field of Search: 604/65, 604/122, 604/134, 604/67, 417/322, 73/11.6
• US Class Current: 604/67
• CPC Class Codes: A61M 2205/0288 Electro-rheological or magneto-rheological materials
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/702 automatically during use
• CPC Class Codes: A61M 5/14216 Reciprocating piston type
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: F04B 2205/09 Flow through the pump
• CPC Class Codes: F04B 43/043 Micropumps
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: F04B 51/00 Testing machines, pumps, or pumping installations
• CPC Class Codes: F05C 2251/08 Shape memory
• CPC Class Codes: G01F 1/708 Measuring the time taken to traverse a fixed distance
• CPC Class Codes: G01F 11/029 provided with electric controlling means G01F11/022 and G01F11/024 take precedence
• CPC Class Codes: G01F 25/0084 for measuring volume
• CPC Class Codes: G01F 25/10 of flowmeters
• CPC Class Codes: G05D 7/0694 by action on throttling means or flow sources of very small size, e.g. microfluidics microvalves F16K99/0001; microstructural devices per se B81B

Abstract

A micro fluid delivery device is particularly useful in medical applications. The device may be worn or carried by the user and may deliver drugs or other medicaments to the user or patient. The device has a control system that accepts input from the user and controls all aspects of operation of the device. The control system measures the output of the pump and adjusts the output of the pump to achieve the desired dosage rate and size. This eliminates differences from pump to pump that result from inevitable variations in the manufacturing of such small scale affordable devices.

Claims

1. A method, comprising:

providing a disposable component comprising a pump element;

providing a durable component comprising a microprocessor and a shape memory element, the disposable component configured to mate and operate with the durable component;

when the disposable component is mated with the durable component, initiating the flow of a liquid through a portion of the disposable component with a known volume using, at least in part, the shape memory element, wherein the shape memory element is operatively coupled to the pump element and is configured to move the pump element from a first position to a second position to initiate flow of the liquid;

determining the time to pump the liquid through the known volume of the portion of the disposable component using, at least in part, a plurality of sensors, wherein each of the plurality of sensors have a plurality of electrodes configured to detect an interruption of a flow stream of the liquid through the known volume portion of the disposable component; and

determining the volume of a dose based at least in part on the determined time to pump the known volume.

2. The method of claim 1, wherein the liquid is insulin.

3. The method of claim 1, wherein initiating the flow of the liquid includes modifying the temperature of the shape memory element.

4. The method of claim 1, further comprising creating a ratio of the determined dose volume to an expected dose volume.

5. The method of claim 4, further comprising modifying a frequency of dosage delivery based upon the ratio.

6. The method of claim 1, including modifying a delivery profile based at least in part on the determined dose volume.

7. The method of claim 6, wherein modifying the delivery profile includes modifying the timing of a subsequent determined dose volume.

8. The method of claim 1, further comprising determining a flow characteristic of the liquid substantially simultaneously with the determining the time to pump the liquid through the known volume of the portion of the disposable component.

9. The method of claim 8, wherein the flow characteristic of liquid corresponds to a voltage of a reaction rate associated with a component of the fluid.

10. A method, comprising:

providing a piston in a first portion of a pumping mechanism;

providing a control unit including a processor in a second portion of the pumping mechanism;

initiating pumping of a plurality of doses using, at least in part, a shape memory element, wherein the shape memory element is operatively coupled to the piston and is configured to move the piston between a plurality of positions within the first portion of the pumping mechanism when pumping the plurality of doses;

measuring the plurality of doses;

comparing one or more of the measured doses to an expected value of one or more doses;

calculating a ratio based upon the comparing the one or more of the measured doses to the expected value of the one or more doses; and

applying the calculated ratio to a subsequent dose when delivering the subsequent dose.

11. The method of claim 10, wherein the plurality of doses includes plurality of insulin doses.

12. The method of claim 10, further comprising modifying a frequency of dosage delivery based upon the comparison.

13. The method of claim 10, including modifying the pumping of the plurality of doses based at least in part on the compared one or more of the measured doses to the expected value of the one or more doses.

14. The method of claim 10, including providing one or more feedback control signals to the control unit based, at least in part, on the measured plurality of doses.

15. The method of claim 14, wherein the one or more feedback control signals includes one or more of measured volume of the one or more of the plurality of doses, or measured time duration of the one or more of the plurality of doses.

16. The method of claim 10, wherein measuring the plurality of doses comprises determining a flow rate of the plurality of doses and substantially simultaneously determining a flow characteristic of the plurality of doses.

17. The method of claim 16, wherein the characteristic of the plurality of doses corresponds to a voltage of a reaction rate associated with a component of a liquid of each of the plurality of doses.

18. A method, comprising:

pumping a liquid using, at least in part, a shape memory element, wherein the shape memory element is operatively coupled to a pumping element;

detecting arrival of the liquid at a first sensor, wherein the first sensor includes a plurality of electrodes;

detecting arrival of the liquid at a second sensor, wherein the second sensor includes a plurality of electrodes;

measuring the time elapsed from the arrival of the liquid at the first sensor to the arrival of the liquid at the second sensor;

determining a flow characteristic of the liquid substantially simultaneously with the measuring of the time elapsed from the arrival of the liquid at the first sensor to the arrival of the liquid at the second sensor;

calculating a volumetric flow rate of the dispensing device; and

adjusting the volumetric flow rate of the dispensing of the device, based at least in part on the measured time and on the determined flow characteristic of the liquid.

19. The method of claim 18, wherein the liquid includes insulin.

20. The method of claim 18, wherein one or more of the first or the second sensors includes an electrode in fluid contact with the liquid.

21. The method of claim 18, wherein the plurality of electrodes of the first sensor and the plurality of electrodes of the second sensor are configured to detect at least one of a presence of a liquid for each of the plurality of doses and produce a signal indicative of a flow rate of the liquid or, detect an interruption in a flow stream of the liquid.

22. The method of claim 18, wherein the flow characteristic of the liquid corresponds to a voltage of a reaction rate associated with a component of the liquid.

23. The method of claim 18, wherein pumping the liquid includes modifying the temperature of the shape memory element.

24. The method of claim 23, wherein modifying the temperature of the shape memory element includes applying an electrical current to the shape memory element.