Medical fluid sensing and concentration determination in a fluid cartridge with multiple passageways, using a radio frequency device situated within a magnetic field

• US 9,566,377 B2
• Filed: 03/15/2013
• Issued: 02/14/2017
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius Medical Care AG)
• Original Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius Medical Care AG)
• Inventors: Jones, Ross Peter, Chopra, Pranav, Menzies, Rupert, Tuckwell, Mark David, Crnkovich, Martin Joseph, Jensen, Lynn, Kalaskar, Shashikant Dattatraya
• Primary Examiner(s): Bass, Dirk
• Assistant Examiner(s): BREWSTER, HAYDEN R
• Application Number:
  US13/836,597
• Publication Number:
  US 20140263064A1
• Time in Patent Office: 1,432 Days
• Field of Search: 73/614.1, 738/65
• US Class Current: 1/1
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61M 1/152 Details related to the interface between cassette and machine
• CPC Class Codes: A61M 1/154 with sensing means or components thereof
• CPC Class Codes: A61M 1/1562 Details of incorporated reservoirs
• CPC Class Codes: A61M 1/1565 Details of valves
• CPC Class Codes: A61M 1/1607 before use, i.e. upstream of dialyser
• CPC Class Codes: A61M 1/1609 after use, i.e. downstream of dialyser
• CPC Class Codes: A61M 1/3609 Physical characteristics of the blood, e.g. haematocrit, urea
• CPC Class Codes: A61M 1/3621 Extra-corporeal blood circuits single-needle circuits A61M1/30
• CPC Class Codes: A61M 1/36222 Details related to the interface between cassette and machine
• CPC Class Codes: A61M 1/36224 with sensing means or components thereof
• CPC Class Codes: A61M 1/36226 Constructional details of cassettes, e.g. specific details on material or shape
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/70 with testing or calibration facilities
• CPC Class Codes: A61M 2230/20 Blood composition characteristics
• CPC Class Codes: G01N 24/08 by using nuclear magnetic resonance G01N24/12 takes precedence
• CPC Class Codes: G01R 33/302 Miniaturized sample handling arrangements for sampling small quantities, e.g. flow-through microfluidic NMR chips
• CPC Class Codes: G01R 33/34053 Solenoid coils; Toroidal coils
• CPC Class Codes: G01R 33/383 : using permanent magnets

Abstract

This disclosure relates to medical fluid sensors and related systems and methods. In certain aspects, a method includes reading an indicia of a medical fluid cartridge to determine a volume of a fluid passageway of the medical fluid cartridge indicated by the indicia, receiving radio frequency energy generated by excited atoms in medical fluid in the fluid passageway of the medical fluid cartridge, and determining a concentration of a substance in the medical fluid based on the determined volume of the fluid passageway of the medical fluid cartridge indicated by the indicia and the received radio frequency energy generated by the excited atoms in the medical fluid in the fluid passageway of the medical fluid cartridge.

Claims

1. A method comprising:

reading an indicia of a medical fluid cartridge to determine a volume of a first fluid passageway of the medical fluid cartridge indicated by the indicia;

removeably positioning the medical fluid cartridge in a first magnetic field, such that the first fluid passageway is positioned within a radio frequency device in the magnetic field, and a second fluid passageway of the medical fluid cartridge is positioned within the magnetic field and outside the radio frequency device;

flowing dialysis fluid in the second fluid passageway, the first magnetic field aligning atoms of a substance of the dialysis fluid in the second fluid passageway;

flowing the dialysis fluid from the second fluid passageway into the first fluid passageway;

transmitting radio frequency energy to the dialysis fluid in the first fluid passageway using the radio frequency device, the radio frequency energy changing the alignment of the atoms of the substance of the dialysis fluid, the atoms of the substance generating a second magnetic field in the first fluid passageway;

receiving radio frequency energy generated by the atoms of the substance in the dialysis fluid in the first fluid passageway of the medical fluid cartridge, the radio frequency device receiving the radio frequency energy; and

determining a concentration of the substance in the dialysis fluid in the first fluid passageway based on the determined volume of the first fluid passageway of the medical dialysis fluid cartridge indicated by the indicia and the received radio frequency energy generated by the atoms of the substance of the dialysis fluid in the first fluid passageway of the medical fluid cartridge.

2. The method of claim 1, further comprising determining an actual volume of the first fluid passageway of the medical fluid cartridge and applying the indicia to the medical fluid cartridge, the indicia being indicative of the determined actual volume of the first fluid passageway of the medical fluid cartridge.

3. The method of claim 2, wherein determining the actual volume of the first fluid passageway of the medical fluid cartridge comprises measuring the actual volume of the first fluid passageway of the medical fluid cartridge.

4. The method of claim 1, wherein the indicia of the medical fluid cartridge is read by a machine.

5. The method of claim 1, wherein the machine is a barcode reader and the indicia is a barcode.

6. The method of claim 1, wherein the radio frequency energy generated by the atoms of the substance of the dialysis fluid in the first fluid passageway of the medical fluid cartridge is received by a sensor assembly comprising the radio frequency device.

7. The method of claim 6, wherein prior to determining the concentration of the substance in the dialysis fluid, the sensor assembly is used to determine a concentration of the substance in a reference fluid in a reference fluid cartridge and the sensor assembly is calibrated based on the determined concentration of the substance in the reference fluid in the reference fluid cartridge.

8. The method of claim 7, wherein calibrating the sensor assembly comprises comparing the concentration of the substance in the reference fluid in the reference fluid cartridge as determined by the sensor assembly to a known concentration of the substance in the reference fluid in the reference fluid cartridge.

9. The method of claim 1, further comprising flowing the dialysis fluid in the first and second passageways, the dialysis fluid flowing (i) through the second fluid passage way, (ii) into the first fluid passageway, and (iii) through the first fluid passageway.

10. The method of claim 1, wherein applying the radio frequency energy to the dialysis fluid in the first fluid passageway of the medical fluid cartridge comprises activating the radio frequency device.

11. The method of claim 10, wherein the radio frequency device is a radio frequency coil.

12. The method of claim 1, further comprising adjusting the concentration of the substance in the dialysis fluid if the determined concentration of the substance in the dialysis fluid falls outside of a desired range.

13. The method of claim 1, wherein the dialysis fluid is blood.

14. The method of claim 1, wherein the dialysis fluid is dialysate.

15. The method of claim 1, wherein the substance is sodium.