Variable volume, shape memory actuated insulin dispensing pump

• US 8,047,812 B2
• Filed: 12/29/2008
• Issued: 11/01/2011
• Est. Priority Date: 10/09/2002
• Status: Expired due to Term

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories)
• Inventors: Reggiardo, Christopher V., Rush, Benjamin M., Anderson, Arthur E. III
• Primary Examiner(s): Kramer; Devon C
• Assistant Examiner(s): KASTURE, DNYANESH G
• Application Number:
  US12/345,591
• Publication Number:
  US 20090105649A1
• Time in Patent Office: 1,037 Days
• Field of Search: 417/44.1, 417/12, 417/199.2, 417/200, 417/321, 417/410.1, 222/52, 222/63, 318/117, 605/27, 605/28
• US Class Current: 417/321
• CPC Class Codes: A61M 2205/0266 Shape memory materials
• 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: F03G 7/065 using a shape memory element
• CPC Class Codes: F04B 17/00 Pumps characterised by combination with, or adaptation to, specific driving engines or motors
• CPC Class Codes: F04B 2201/0201 Position of the piston
• CPC Class Codes: F04B 23/02 having reservoirs
• CPC Class Codes: F04B 35/00 Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for
• CPC Class Codes: F04B 35/04 the means being electric
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: F04B 9/00 Piston machines or pumps characterised by the driving or driven means to or from their working members
• CPC Class Codes: F04B 9/02 the means being mechanical
• CPC Class Codes: F05C 2251/08 Shape memory
• CPC Class Codes: G01F 11/021 of the piston type G01F11/04 takes precedence

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.

Claims

1. A pumping system comprising:

a chamber;

a first piston within the chamber;

a shape memory element within the chamber that changes length when a current flows through the shape memory element;

the shape memory element moving the first piston between a first physical limit defined by a first portion of the chamber and second physical limit defined by a second portion of the chamber, such that when the first piston is at the first physical limit the chamber is filled with fluid and when the first piston is at the second physical limit the chamber is discharged of fluid;

at least a first switch disposed at the at least one of the first physical limit and the second physical limit that indicates when the first piston is in contact with the at least one of the first physical limit and the second physical limit;

a second piston coupled to the shape memory element that moves to accommodate changes in the shape memory element and reduce stress on the pumping system; and

a processor programmed to measure a first time period, wherein the first time period is the time it takes for the first piston to move between the first physical limit and the second physical limit, to compare the first time period to a predetermined time period, and to determine that the pumping system is not primed when the first time period is below the predetermined time period by a threshold amount of time.

2. The pumping system of claim 1, wherein the second piston is configured to move between a third physical limit defined by a third portion of the chamber and a fourth physical limit defined by a fourth portion of the chamber.

3. The pumping system of claim 2, further comprising at least a second switch disposed at one of the third physical limit or the fourth physical limit to indicate that the second piston is in contact with the one of the third physical limit or the fourth physical limit.

4. The pumping system of claim 3, further comprising circuitry configured to detect a condition of the second switch.

5. The pumping system of claim 4, wherein the circuitry is configured to detect a stressed state of the pumping system.

6. The pumping system of claim 5, wherein the circuitry is configured to discontinue the current through the shape memory element when the stressed state of the pumping system is detected.

7. The pumping system of claim 1, further comprising circuitry configured to detect a condition of the first switch.

8. The pumping system of claim 7, wherein the circuitry is configured to detect a malfunction of the pump when the first piston does not contact the first switch disposed at the at least one of the first physical limit and the second physical limit after the current has been applied to the shape memory element.

9. The pumping system of claim 8, wherein the circuitry is configured to discontinue the current through the shape memory element when the malfunction is detected.

10. The pumping system of claim 1, wherein at least one of the first portion of the chamber and the second portion of the chamber comprises at least a portion of a side wall of the chamber, wherein the portion of the side wall of the chamber partially narrows a width of the chamber.

11. A method for pumping a fluid from a pump, comprising:

moving a first piston in a chamber between a first physical limit defined by a first portion of the chamber and a second physical limit defined by a second portion of the chamber, wherein the first piston is moved from the first physical limit to the second physical limit by a shape memory element that expands and contracts when a pulse is applied to the shape memory element;

drawing fluid into the chamber when the first piston moves towards the first physical limit;

expelling fluid from the chamber when the first piston moves towards the second physical limit;

detecting when the first piston is in contact with the at least one of the first physical limit and the second physical limit using at least a first switch disposed at least at one of the first physical limit and the second physical limit;

moving a second piston between a third physical limit defined by a third portion of the chamber and a fourth physical limit defined by a fourth portion of the chamber, wherein the second piston is moved between the third physical limit and the fourth physical limit by the shape memory element to accommodate changes in the shape memory element and reduce stress on the shape memory element; and

measuring a first time period, wherein the first time period is the time it takes for the first piston to move between the first physical limit and the second physical limit;

comparing the first time period to a predetermined time period; and

determining that the pump is not primed when the first time period is below the predetermined time period by a threshold amount of time.

12. The method of claim 11, further comprising detecting a condition of at least a second switch disposed at the at least one of the third physical limit and the fourth physical limit.

13. The method of claim 12 wherein detecting a condition of the second switch includes detecting a stressed state of the shape memory element when the second piston is not in contact with the second switch.

14. The method of claim 13, further comprising discontinuing the current through the shape memory element when the stressed state is detected.

15. The method of claim 11, further comprising detecting a condition of the first switch.

16. The method of claim 15, further comprising detecting a malfunction when the first piston does not contact the first switch disposed at the at least one of the first physical limit and the second physical limit after the current has been applied to the shape memory element.

17. The method of claim 16, further comprising discontinuing the current through the shape memory element when the malfunction is detected.

18. The method of claim 15, further comprising detecting a malfunction when the first piston does not contact the first switch disposed at the at least one of the first physical limit and the second physical limit during a complete pump cycle after applying the current to the shape memory element.

19. The method of claim 18, further comprising outputting a notification of the detected malfunction.

20. The method of claim 11, wherein at least one of the first portion of the chamber and the second portion of the chamber comprises at least a portion of a side wall of the chamber, wherein the portion of the side wall of the chamber partially narrows a width of the chamber.