Determining the absence or presence of fluid in a dialysis system

• US 8,836,519 B2
• Filed: 05/10/2012
• Issued: 09/16/2014
• Est. Priority Date: 05/12/2011
• 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: Wright, Nigel, Magargi, Samuel Ernest III, Zang, Michael John, Winniewicz, Regis Joseph Jr., Beri, Joseph Stephen, Zatezalo, Douglas Mark, Fox, Ronald Robert, Harbaugh, Jeremy Thomas, Monahan, Tom
• Primary Examiner(s): HOFSASS, JEFFERY A
• Application Number:
  US13/468,288
• Publication Number:
  US 20120285870A1
• Time in Patent Office: 859 Days
• Field of Search: 340/603, 340/608, 604/65, 604/67, 210/645, 210/646, 128/DIG.13
• US Class Current: 340/603
• CPC Class Codes: A61K 33/26 Iron; Compounds thereof
• CPC Class Codes: A61K 38/1816 Erythropoietin [EPO]
• 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 1/155 with treatment-fluid pumping means or components thereof
• CPC Class Codes: A61M 1/1561 at least one cassette surface or portion thereof being flexible, e.g. the cassette having a rigid base portion with preformed channels and being covered with a foil
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/342 Adding solutions to the blood, e.g. substitution solutions for preventing coagulation A61M1/3672
• CPC Class Codes: A61M 1/3424 Substitution fluid path
• CPC Class Codes: A61M 1/3431 upstream of the filter
• CPC Class Codes: A61M 1/3462 Circuits for the preparation thereof
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/14 Detection of the presence or absence of a tube, a connector or a container in an apparatus
• CPC Class Codes: A61M 2205/15 Detection of leaks
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/3375 Acoustical, e.g. ultrasonic, measuring means
• CPC Class Codes: A61M 2205/3576 with non implanted data transmission devices, e.g. using external transmitter or receiver
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2205/582 by tactile feedback
• CPC Class Codes: A61M 2205/583 : by visual feedback
• CPC Class Codes: G01N 2291/022 : Liquids
• CPC Class Codes: G01N 2291/024 : Mixtures
• CPC Class Codes: G01N 2291/048 : Transmission, i.e. analysed material between transmitter and receiver
• CPC Class Codes: G01N 2291/102 : one emitter, one receiver
• CPC Class Codes: G01N 2291/2698 : Other discrete objects, e.g. bricks
• CPC Class Codes: G01N 29/02 : Analysing fluids using acoustic emission techniques G01N29/14 ; constructional or flow details for analysing fluids G01N29/222; optoacoustic fluid cells G01N29/2425
• CPC Class Codes: G01N 29/04 : Analysing solids using acoustic emission techniques G01N29/14
• CPC Class Codes: G01N 29/4427 : with stored values, e.g. threshold values

Abstract

This disclosure relates to detecting fluid in medical tubing. In certain aspects, a method is performed by a data processing apparatus. The method includes controlling repetitive activation of the ultrasonic transmitter. The method also includes receiving a signal from the ultrasonic receiver during an activation of the ultrasonic transmitter. The method also includes determining that fluid is absent or present in a portion of the medical fluid tube based on a comparison between the signal and a threshold value.

Claims

1. A dialysis system comprising:

a dialysis machine;

a control unit;

a medical fluid tube connected to the dialysis machine;

an ultrasonic transmitter positioned adjacent to the medical fluid tube;

an ultrasonic receiver positioned adjacent to the medical fluid tube configured to receive one or more signals in response to the activation of the ultrasonic transmitter; and

a computer storage medium encoded with computer program instructions that when executed by the dialysis system, causes the dialysis system to perform operations comprising;

controlling repetitive activation of the ultrasonic transmitter, wherein controlling repetitive activation of the ultrasonic transmitter comprises, for each repetition;

activating the ultrasonic transmitter for a first period of 2 to 15 milliseconds; and

deactivating the ultrasonic transmitter for a second period of 998 to 985 milliseconds;

receiving a signal from the ultrasonic receiver during an activation of the ultrasonic transmitter; and

determining that fluid is absent or present in a portion of the medical fluid tube based on a comparison between the signal and a threshold value.

2. The system of claim 1, wherein the computer storage medium is further encoded with computer program instructions that when executed by the dialysis system, causes the dialysis system to perform operations comprising:

storing an indicator of the absence or presence of fluid in a data structure, the data structure storing a plurality of indicators determined during previous activations of the ultrasonic transmitter.

3. The system of claim 2, wherein the computer storage medium is further encoded with computer program instructions that when executed by the dialysis system, causes the dialysis system to perform operations comprising:

raising an alarm upon determining that each indicator in the data structure indicates that fluid was absent from the portion of the medical fluid tube.

4. The system of claim 1, wherein the first period is 5 milliseconds and the second period is 995 milliseconds.

5. The system of claim 1, wherein the medical fluid tube has an outer diameter of less than 0.128 inch.

6. The system of claim 1, wherein the medical fluid tube has an inner diameter of less than 0.031 inch.

7. The system of claim 1, wherein the signal is a measure of voltage.

8. The system of claim 7, wherein the threshold value is a first value if fluid was determined to be present during the previous activation of the ultrasonic transmitter;

the threshold is a second value if the fluid was previously determined to be absent during the previous activation of the ultrasonic transmitter; and

the first value is greater than the second value.

9. A computer-implemented method comprising:

on a control unit of a dialysis machine;

controlling, on a processor of the control unit, repetitive activation of an ultrasonic transmitter, wherein controlling repetitive activation of the ultrasonic transmitter comprises, for each repetition;

activating the ultrasonic transmitter for a first period of 2 to 15 milliseconds; and

deactivating the ultrasonic transmitter for a second period of 998 to 985 milliseconds;

receiving, by the processor of the control unit, a signal from an ultrasonic receiver during an activation of the ultrasonic transmitter; and

determining, by the processor of the control unit, that fluid is absent or present in a portion of a medical fluid tube of a drug delivery device based on a comparison between the signal and a threshold value.

10. The method of claim 9 further comprising:

storing an indicator of the absence or presence of fluid in a data structure, the data structure storing a plurality of indicators determined during previous activations of the ultrasonic transmitter.

11. The method of claim 10, further comprising:

raising an alert upon determining that each indicator in the data structure indicates that fluid was absent from the portion of the medical fluid tube.

12. The method of claim 9, wherein the first period is 5 milliseconds and the second period is 995 milliseconds.

13. The method of claim 9, wherein the medical fluid tube has an outer diameter of less than 0.128 inch.

14. The method of claim 9, wherein the medical fluid tube has an inner diameter of less than 0.031 inch.

15. The method of claim 9, wherein the signal is a measure of voltage.

16. The method of claim 15, wherein the threshold value is a first value if fluid was determined to be present during the previous activation of the ultrasonic transmitter;

the threshold is a second value if the fluid was previously determined to be absent during the previous activation of the ultrasonic transmitter; and

the first value is greater than the second value.

17. A dialysis system comprising:

a dialysis machine;

a control unit;

an ultrasonic transmitter;

an ultrasonic receiver; and

a computer storage medium encoded with computer program instructions that when executed by the dialysis system, causes the dialysis system to perform operations comprising;

controlling repetitive activation of the ultrasonic transmitter, wherein controlling repetitive activation of the ultrasonic transmitter comprises, for each repetition;

activating the ultrasonic transmitter for a first period of 2 to 15 milliseconds; and

deactivating the ultrasonic transmitter for a second period of 998 to 985 milliseconds;

receiving a signal from the ultrasonic receiver during an activation of the ultrasonic transmitter; and

determining that fluid is absent or present in a portion of a medical fluid tube based on a comparison between the signal and a threshold value.

18. The system of claim 17, wherein the computer storage medium is further encoded with computer program instructions that when executed by the dialysis system, causes the dialysis system to perform operations comprising:

storing an indicator of the absence or presence of fluid in a data structure, the data structure storing a plurality of indicators determined during previous activations of the ultrasonic transmitter.

19. The system of claim 18, wherein the computer storage medium is further encoded with computer program instructions that when executed by the dialysis system, causes the dialysis system to perform operations comprising:

raising an alarm upon determining that each indicator in the data structure indicates that fluid was absent from the portion of the medical fluid tube.

20. The system of claim 17, wherein the first period is 5 milliseconds and the second period is 995 milliseconds.

21. The system of claim 17, wherein the signal is a measure of voltage.

22. The system of claim 21, wherein the threshold value is a first value if fluid was determined to be present during the previous activation of the ultrasonic transmitter;

the threshold is a second value if the fluid was previously determined to be absent during the previous activation of the ultrasonic transmitter; and

the first value is greater than the second value.