Dialysis system with radio frequency device within a magnet assembly for medical fluid sensing and concentration determination

Patent metadata

Field	Value
Publication number	US-10371775-B2
Application number	US-201715449127-A
Country	US
Kind code	B2
Filing date	Mar 3, 2017
Priority date	Mar 15, 2013
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

This disclosure relates to medical fluid sensors and related systems and methods. In certain aspects, a method includes using a medical fluid pump of a medical fluid pumping machine, such as a hemodialysis machine, to deliver medical fluid to a first portion of a cartridge that is positioned within a magnetic field, exciting atoms in the medical fluid in the first portion of the cartridge by applying radio frequency energy to the medical fluid in the first portion of the cartridge, receiving radio frequency energy generated by the excited atoms in the medical fluid in the first portion of the cartridge, and determining a concentration of a substance in the medical fluid based on the received radio frequency energy generated by the excited atoms in the medical fluid in the first portion of the cartridge.

First claim

What is claimed is:

1. A dialysis system comprising:
a magnet assembly that generates a magnetic field, the magnet assembly defining an opening;
a radio frequency device disposed in the opening of the magnet assembly, the radio frequency device defining a first cavity configured to receive a first section of a first portion of a cartridge, the first cavity being internal to the radio frequency device, and a second cavity being defined between the radio frequency device and the magnet assembly such that the second cavity is outside of the radio frequency device, the second cavity being configured to receive a second section of the first portion of the cartridge; and
a dialysis fluid pump that is operable to pump dialysis fluid to the first portion of the cartridge when the first section of the first portion of the cartridge is disposed in the first cavity and the second section of the first portion of the cartridge is disposed in the second cavity,
wherein the radio frequency device is operable to receive radio frequency energy generated by excited atoms in the dialysis fluid in the first portion of the cartridge when the first and second sections of the first portion of the cartridge are disposed in the first and second cavities, respectively, and dialysis fluid has been pumped to the first portion of the cartridge.

2. The dialysis system of claim 1 , wherein the radio frequency device is further operable to apply radio frequency energy to dialysis fluid in the first portion of the cartridge to excite the atoms in the dialysis fluid in the first portion of the cartridge.

3. The dialysis system of claim 2 , wherein the radio frequency device is a radio frequency coil.

4. The dialysis system of claim 1 , further comprising a controller in communication with the radio frequency device, the controller being configured to determine a concentration of a substance in the dialysis fluid based on the received radio frequency energy generated by the excited atoms in the dialysis fluid in the first portion of the cartridge.

5. The dialysis system of claim 4 , wherein the controller is configured to determine the concentration of the substance in the dialysis fluid as a function of (i) the radio frequency energy generated by the excited atoms in the dialysis fluid in the first portion of the cartridge and (ii) a volume of the first portion of the cartridge.

6. The dialysis system of claim 1 , further comprising the cartridge.

7. The dialysis system of claim 6 , wherein the first section of the first portion of the cartridge defines a first meandering fluid passageway, and the first portion of the cartridge is configured to be disposed within the opening of the magnet assembly.

8. The dialysis system of claim 7 , wherein the cartridge is configured such that the first meandering fluid passageway is disposed in the first cavity outside the radio frequency device when the first portion of the cartridge is disposed in the opening of the magnet assembly.

9. The dialysis system of claim 6 , wherein the second section of the first portion of the cartridge defines a second meandering fluid passageway.

10. The dialysis system of claim 9 , wherein the cartridge defines a fluid inlet port via which the dialysis fluid enters the cartridge, the fluid inlet port having a first flow area and the second meandering fluid passageway having a second flow area that is smaller than the first flow area.

11. The dialysis system of claim 6 , wherein the cartridge comprises a second portion configured to be positioned outside the radio frequency device when the first section of the first portion of the cartridge is disposed in the first cavity and the second section of the first portion of the cartridge is disposed in the second cavity.

12. The dialysis system of claim 11 , wherein the second portion of the cartridge is configured to be positioned at least partially outside the magnet assembly when the first section of the first portion of the cartridge is disposed in the first cavity and the second section of the first portion of the cartridge is disposed in the second cavity.

13. The dialysis system of claim 11 , wherein the second portion of the cartridge defines a fluid passageway that bypasses the first portion of the cartridge.

14. The dialysis system of claim 13 , wherein the fluid passageway of the second portion of the cartridge is a substantially straight fluid passageway.

15. The dialysis system of claim 1 , wherein the dialysis fluid pump is a blood pump.

16. The dialysis system of claim 1 , wherein the dialysis fluid pump is a dialysate pump.

Assignees

• Fresenius Medical Care Holdings Inc

Inventors

• Jones Ross Peter
• Crnkovich Martin Joseph
• Wang Fei
• Folden Thomas Irvin
• Jensen Lynn
• Kalaskar Shashikant Dattatraya

Classifications

• A61M2205/3331

  Pressure; Flow · CPC title

• A61M1/267

  used for pumping · CPC title

• A61M2205/6072

  Bar codes · CPC title

• G01R33/34053

  Solenoid coils; Toroidal coils · CPC title

• G01N24/08 Primary

  by using nuclear magnetic resonance (G01N24/12 takes precedence) · CPC title