Method and system for shape-memory alloy wire control

• US 8,852,164 B2
• Filed: 01/21/2011
• Issued: 10/07/2014
• Est. Priority Date: 02/09/2006
• 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.
• Primary Examiner(s): BERDICHEVSKY, AARTI
• Application Number:
  US13/011,384
• Publication Number:
  US 20110300001A1
• Time in Patent Office: 1,355 Days
• Field of Search: 604/65, 604/67, 604506-508, 604/513, 604/890.1
• US Class Current: 604/506
• 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 method for controlling a device using a shape-memory alloy wire comprising:

a controller determining an ontime for the shape-memory alloy wire in the device based on a target volume to be pumped by a pump plunger in the device;

the controller determining a temperature of the shape-memory alloy wire;

the controller adjusting the ontime for the shape-memory alloy wire based on the temperature of the shape-memory alloy wire;

actuating the shape-memory alloy wire to effectuate the pumping of a volume of fluid by the pump plunger from a reservoir to a volume sensor chamber;

measuring the volume of fluid pumped using a volume sensor assembly;

determining the difference between the target volume and the volume of fluid pumped; and

if the volume of fluid pumped is greater than or less than the target volume, updating the ontime.

2. The method of claim 1 wherein determining the temperature of the shape-memory alloy wire further comprising:

determining the time elapsed since an actuation of the shape-memory alloy; and

using the time elapsed, determining a predictive temperature of the shape-memory alloy wire.