Method and System for Shape-Memory Alloy Wire Control

• US 20150231329A1
• Filed: 10/06/2014
• Published: 08/20/2015
• Est. Priority Date: 09/29/2005
• Status: Active Grant

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Murphy, Colin H., Kamen, Dean, Kerwin, John M., Gray, Larry B.
• Granted Patent: US 9,687,602 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61M 2005/14268 with a reusable and a disposable component
• CPC Class Codes: A61M 2205/0266 Shape memory materials
• CPC Class Codes: A61M 2205/0294 Piezoelectric materials
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3375 Acoustical, e.g. ultrasonic, measuring means
• CPC Class Codes: A61M 2205/3546 Range
• CPC Class Codes: A61M 2205/3576 with non implanted data transmission devices, e.g. using external transmitter or receiver
• CPC Class Codes: A61M 2205/8237 Charging means
• CPC Class Codes: A61M 2206/22 eliminating pulsatile flows, e.g. by the provision of a dampening chamber
• CPC Class Codes: A61M 2209/045 for filling, e.g. for filling reservoirs
• CPC Class Codes: A61M 5/14224 Diaphragm type
• CPC Class Codes: A61M 5/14248 of the skin patch type
• CPC Class Codes: A61M 5/14586 pressurised by means of a flexible diaphragm
• CPC Class Codes: A61M 5/16809 by repeated filling and emptying of an intermediate volume pressure infusion using positive displacement pumps A61M5/142
• CPC Class Codes: A61M 5/16886 for measuring fluid flow rate, i.e. flowmeters
• CPC Class Codes: A61M 5/172 electrical or electronic A61M5/16804, A61M5/16831 take precedence
• CPC Class Codes: G01F 13/006 measuring volume in function of time
• CPC Class Codes: G01F 25/0092 for metering by volume
• CPC Class Codes: G01F 3/20 having flexible movable walls, e.g. diaphragms, bellows
• CPC Class Codes: G05D 7/0635 : by action on throttling means G05D7/0688, G05D7/0694 take precedence
• CPC Class Codes: G05D 7/0641 : using a plurality of throttling means G05D7/067 takes precedence
• CPC Class Codes: G05D 7/0676 : by action on flow sources G05D7/0688, G05D7/0694 take precedence

Abstract

A method for controlling a device using a shape-memory alloy wire is disclosed. The method includes determining an ontime for the shape-memory alloy wire based on a target volume to be pumped by a pump plunger, determining the temperature of the shape-memory alloy wire and adjusting the ontime based on the temperature of the shape-memory alloy wire.

Claims

1. A shape-memory alloy wire actuation system comprising:

at least one shape-memory alloy wire;

a valve member connected to the at least one shape-memory alloy wire wherein the shape-memory alloy wire, when actuated, actuates the valve member;

a controller for controlling the ontime of the at least one shape-memory alloy wire; and

a temperature sensor for determining the temperature of the shape-memory alloy wire, wherein the controller determines the ontime based on the temperature of the shape-memory alloy wire before actuation.

2. The system of claim 1, further comprising:

a reservoir upstream from the valve member, wherein the valve member controls the flow of fluid from a reservoir to a exit.

3. The system of claim 1, wherein the temperature sensor is a thermistor.

4. The system of claim 1, wherein the temperature sensor is located adjacent to the shape-memory alloy wire.

5. The system of claim 2, further comprising:

a volume measurement assembly upstream from the valve member, the volume measurement assembly comprising a volume sensor chamber wherein the fluid from the reservoir enters the volume sensor chamber and wherein the volume measurement assembly determines to volume of fluid in the volume sensor chamber.

6. A shape-memory alloy wire pumping system comprising:

a pump plunger wherein the pump plunger effectuates the pumping of fluid from a reservoir;

at least one shape-memory alloy wire connected to the pump plunger wherein the shape-memory alloy wire, when actuated, actuates the pump plunger;

a controller for controlling the ontime of the at least one shape-memory alloy wire; and

a temperature sensor for determining the temperature of the shape-memory alloy wire, wherein the controller determines the ontime based on the temperature of the shape-memory alloy wire before actuation.

7. The system of claim 6, further comprising wherein the temperature sensor is a thermistor.

8. The system of claim 7, wherein the temperature sensor is located adjacent to the shape-memory alloy wire.

9. The system of claim 6, further comprising:

a volume measurement assembly downstream from the pump plunger, the volume measurement assembly comprising a volume sensor chamber wherein the fluid from the reservoir enters the volume sensor chamber and wherein the volume measurement assembly determines to volume of fluid in the volume sensor chamber.