DETERMINING DIALYSIS TREATMENT EFFECTIVENESS

• US 20130053651A1
• Filed: 08/22/2011
• Published: 02/28/2013
• Est. Priority Date: 08/22/2011
• 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: Wang, Fei, Wang, Aiyuan, Tarn, Jeffrey
• Granted Patent: US 9,155,823 B2
• Time in Patent Office: Days
• US Class Current: 600/301
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1601 Control or regulation
• CPC Class Codes: A61M 1/1603 Regulation parameters
• CPC Class Codes: A61M 1/1611 Weight of the patient
• CPC Class Codes: A61M 1/28 Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 2202/0498 Urea
• CPC Class Codes: A61M 2205/15 Detection of leaks
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/505 Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: B01D 61/30 Accessories; Auxiliary operation
• CPC Class Codes: B01D 61/32 Controlling or regulating

Abstract

A method performed on a dialysis machine includes receiving a first value that represents a pre-dialysis body weight of a patient and receiving a second value that represents a volume of liquid (V) inside a body of the patient. The method also includes administering dialysis to the patient, calculating an instantaneous body weight (W) of the patient based at least in part on the first value, determining a length of time (t) for which the dialysis was administered to the patient, determining a dialyzer clearance (K) associated with the dialysis, and calculating, based at least in part on the length of time, the instantaneous body weight, the volume, and the dialyzer clearance, a urea reduction ratio (URR) associated with the dialysis.

Claims

1. A method performed on a dialysis machine, the method comprising:

receiving a first value that represents a pre-dialysis body weight of a patient;

receiving a second value that represents a volume of liquid (V) inside a body of the patient;

administering dialysis to the patient;

calculating an instantaneous body weight (W) of the patient based at least in part on the first value;

determining a length of time (t) for which the dialysis was administered to the patient;

determining a dialyzer clearance (K) associated with the dialysis; and

calculating, based at least in part on the length of time, the instantaneous body weight, the volume, and the dialyzer clearance, a urea reduction ratio (URR) associated with the dialysis.

2. The method of claim 1, further comprising presenting a graphical representation of the urea reduction ratio on a display associated with the dialysis machine.

3. The hemodialysis machine of claim 1, further comprising determining an ultrafiltrate value (UF) associated with the dialysis.

4. The method of claim 3, wherein calculating an instantaneous body weight of the patient comprises subtracting the ultrafiltrate value from the first value.

5. The method of claim 1, wherein calculating the urea reduction ratio comprises iteratively evaluating an algorithm.

6. The method of claim 5, wherein calculating the urea reduction ratio further comprises providing an estimated value for the urea reduction ratio.

7. The method of claim 5, wherein the algorithm is represented by the expression:

URR=URR−

f(URR)/f′

(URR).

8. The method of claim 7, further comprising evaluating f(URR) according to the expression:

K*t/V+ln((1−

URR)−

0.008*t)−

(0.5+3.5*URR)*0.55*UF/W.

9. The method of claim 7, wherein calculating the urea reduction ratio further comprises iteratively evaluating the expression URR=URR−

f(URR)/f′

(URR) until a predetermined condition is satisfied.

10. The method of claim 9, wherein the predetermined condition is represented by the expression:

|f(URR)/f′

(URR)|<

0.01

11. The method of claim 1, further comprising evaluating the expression Kt/V to provide a Kt/V value.

12. The method of claim 11, further comprising receiving a signal on the dialysis machine to cause a display of the dialysis machine to toggle between a presentation of the urea reduction ratio and the Kt/V value.

13. A dialysis machine comprising:

one or more processing devices; and

one or more memory devices comprising instructions that, when executed by the one or more processing devices, cause the one or more processing devices to perform operations comprising;

receiving a first value that represents a pre-dialysis body weight of a patient;

receiving a second value that represents a volume of liquid (V) inside a body of the patient;

administering dialysis to the patient;

calculating an instantaneous body weight (W) of the patient based at least in part on the first value;

determining a length of time (t) for which the dialysis was administered to the patient;

determining a dialyzer clearance (K) associated with the dialysis; and

calculating, based at least in part on the length of time, the instantaneous body weight, the volume, and the dialyzer clearance, a urea reduction ratio (URR) associated with the dialysis.

14. One or more computer storage devices storing instructions that, when executed by one or more processing devices, cause the one or more processing devices to perform operations comprising:

receiving a first value that represents a pre-dialysis body weight of a patient;

receiving a second value that represents a volume of liquid (V) inside a body of the patient;

administering dialysis to the patient;

calculating an instantaneous body weight (W) of the patient based at least in part on the first value;

determining a length of time (t) for which the dialysis was administered to the patient;

determining a dialyzer clearance (K) associated with the dialysis; and

calculating, based at least in part on the length of time, the instantaneous body weight, the volume, and the dialyzer clearance, a urea reduction ratio (URR) associated with the dialysis.