Granted Patent B2

US 8,852,164 · App. 13/011,384 · Granted Oct 7, 2014

Inventors: Colin H. Murphy (Cambridge, MA); Dean Kamen (Bedford, NH); John M. Kerwin (Manchester, NH); Larry B. Gray (Memmack, NH)

Assignee: DEKA Products Limited Partnership

Abstract

Claims (11)

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.

Assignments (1)

Continuity (20)