Implantable pump impeller thermal knockdown

Patent metadata

Field	Value
Publication number	US-10744247-B2
Application number	US-201715719719-A
Country	US
Kind code	B2
Filing date	Sep 29, 2017
Priority date	Sep 29, 2016
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

The present invention relates to kits and methods for calibrating a pump through performance of a thermal knockdown process including demagnetization of an impeller of the pump where the impeller is separate from the pump. By heat treating the impeller, a property of magnetic interaction of the pump is reduced in a repeatable manner. A kit includes a pump with impeller, a controller and an oven. The method generally involves an iterative process of testing the pump for a property related to magnetic interaction of the elements of the pump, removing the impeller from the pump, heating the impeller under controlled conditions, then placing the impeller back into the pump to repeat the test performed initially.

First claim

What is claimed is:

1. A method of modifying a back electromotive force related to a magnetic interaction between at least one blood pump including a stator and an impeller with permanent magnetization having a first voltage, comprising:
heating the impeller outside of the at least one blood pump for a first heating cycle at a first treatment temperature between 60 and 95 degrees Celsius until the back electromotive force reaches a second voltage lower than the first voltage;
measuring a back electromotive force voltage related to magnetic interaction between the impeller and the stator; and
if the second voltage of the back electromotive force related to magnetic interaction after the first heating cycle is greater than a predetermined target voltage of the back electromotive force, heating the impeller for a second heating cycle at a second treatment temperature between 60 and 95 degrees Celsius that is higher than the first treatment temperature.

2. The method of claim 1 , wherein the second voltage of the back electromotive force equals the predetermined target voltage after the second heating cycle.

3. The method of claim 1 , wherein the first treatment temperature of the first heating cycle is maintained until a temperature of the impeller is substantially equal to the first treatment temperature.

4. The method of claim 1 , wherein the first treatment temperature is at least 73 degrees Celsius.

5. The method of claim 1 , wherein the second treatment temperature is approximately 75 degrees Celsius.

Assignees

• Heartware Inc

Inventors

• Wolman Justin
• Reyes Carlos
• Casas Fernando

Classifications

• F04D29/18 Primary

  Rotors (specially for elastic fluids F04D29/26) · CPC title

• A61M60/538

  Regulation using real-time blood pump operational parameter data, e.g. motor current · CPC title

• A61M60/515

  Regulation using real-time patient data · CPC title

• A61M60/422 Primary

  the force acting on the blood contacting member being electromagnetic, e.g. using canned motor pumps · CPC title

• A61M60/216

  including a rotating member acting on the blood, e.g. impeller · CPC title