Medical fluid cassette leak detection methods and devices

Patent metadata

Field	Value
Publication number	US-11262270-B2
Application number	US-202016745820-A
Country	US
Kind code	B2
Filing date	Jan 17, 2020
Priority date	Mar 14, 2013
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

A method is provided for detecting leaks in a disposable medical fluid cassette that includes a base and a flexible membrane attached to the base in such a way that the base and the flexible membrane cooperate to at least partially form a fluid passageway. The method includes applying a first force to the flexible membrane, measuring a first physical property of a system that includes the medical fluid cassette a medical fluid pumping machine, removing the first force from the flexible membrane, applying a second force to the flexible membrane, measuring a second physical property of the system, and determining whether the medical fluid cassette leaks based on a comparison of the first physical property and the second physical property.

First claim

What is claimed is:

1. A medical fluid pumping machine configured to receive a disposable medical fluid cassette, the medical fluid cassette comprising a base and a flexible membrane attached to the base in such a way that the base and the flexible membrane cooperate to at least partially form a fluid passageway, the medical fluid pumping machine comprising:
a compartment that receives the medical fluid cassette;
a pressure applicator configured to apply a force to the medical fluid cassette when the medical fluid cassette is disposed within the compartment;
a processer configured to:
control the pressure applicator in such a way that a first force is applied to the flexible membrane when the medical fluid cassette is disposed within the compartment;
measure a first pressure resulting from the application of the first force to the flexible membrane while the first force is applied to the flexible membrane;
control the pressure applicator in such a way that the first force is removed from the flexible membrane when the medical fluid cassette is disposed within the compartment;
control the pressure applicator in such a way that a second force is applied to the flexible membrane when the medical fluid cassette is disposed within the compartment;
measure a second pressure resulting from the application of the second force to the flexible membrane while the second force is applied to the flexible membrane; and
determine whether the medical fluid cassette comprises a leak based on a comparison of the first pressure and the second pressure.

2. The medical pumping machine of claim 1 , wherein controlling the pressure applicator in such a way that a first force is applied to the flexible membrane and controlling the pressure applicator in such a way that a first force is applied to the flexible membrane comprises advancing the pressure applicator towards the flexible membrane until the pressure applicator reaches a predetermined position.

3. The medical pumping machine of claim 1 , further comprising at least one position sensor configured to measure a position of the pressure applicator within the compartment.

4. The medical pumping machine of claim 1 , further comprising at least one pressure sensor configured to measure the first pressure and the second pressure.

5. The medical pumping machine of claim 1 , wherein determining whether the medical fluid cassette comprises a leak comprises:
determining a difference between the first pressure and the second pressure; and
determining whether the difference exceeds a threshold difference.

6. The medical pumping machine of claim 1 , further comprising
a door that is configured to selectively close the compartment and retain the medical fluid cassette within the compartment; and
an inflatable bladder disposed on an inside surface of the door and configured such that:
when inflated while the medical fluid cassette is within the compartment, the inflatable bladder is configured to compress the medical fluid cassette; and
when deflated while the medical fluid cassette is within the compartment, the inflatable bladder is configured to contract against the inside surface of the door and generate a space between the inflatable bladder and the medical fluid cassette, wherein the processer is further configured to deflate the door bladder between controlling the pressure applicator in such a way that the first force is removed from the flexible membrane and controlling the pressure applicator in such a way that the second force is applied to the flexible membrane.

Assignees

• Fresenius Medical Care Holdings Inc

Inventors

• Plahey Kulwinder S
• Zhu Jie
• Ly Tri
• Ohline Robert Matthew
• Crawford William Scott

Classifications

• G01M3/36

  by detecting change in dimensions of the structure being tested · CPC title

• A61M1/28

  Peritoneal dialysis {; Other peritoneal treatment, e.g. oxygenation} · CPC title

• A61M2205/15

  Detection of leaks · CPC title

• G01M3/3218 Primary

  for flexible or elastic containers · CPC title

• A61M5/142

  Pressure infusion, e.g. using pumps · CPC title