Medical fluid cassette leak detection methods and devices

Patent metadata

Field	Value
Publication number	US-12061135-B2
Application number	US-202217667673-A
Country	US
Kind code	B2
Filing date	Feb 9, 2022
Priority date	Mar 14, 2013
Publication date	Aug 13, 2024
Grant date	Aug 13, 2024

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 position of the pressure applicator within the compartment 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 position of the pressure applicator within the compartment 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 position and the second position.

2. The medical pumping machine of claim 1 , further comprising at least one pressure sensor configured to measure the force applied by the applicator to the medical fluid cassette.

3. 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 second force is applied to the flexible membrane comprises advancing the pressure applicator into the flexible membrane until a predetermine pressure within the medical fluid cassette is reached.

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

5. The medical fluid pumping machine of claim 1 , further comprising a vacuum source controllable by the processor and disposed within the compartment in a manner such that, when activated while the medical fluid cassette is within the compartment, the vacuum source is configured to apply a force to the flexible membrane, wherein the processor is further configured to change a spacing between the flexible membrane and the base by activating the vacuum source.

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

7. The medical pumping machine of claim 6 , wherein the at least one position sensor comprises at least one position encoder.

Assignees

• Fresenius Medical Care Holdings Inc

Inventors

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

Classifications

• A61M2205/3331

  Pressure; Flow · CPC title

• A61M2205/123

  with incorporated reservoirs · CPC title

• A61M2205/121

  interface between cassette and base · CPC title

• A61M2205/07

  having air pumping means · CPC title

• A61M1/288

  Priming (priming in extracorporeal blood circuits A61M1/3643) · CPC title