Simulation of patient drain phase in peritoneal dialysis

• US 8,521,482 B2
• Filed: 02/20/2009
• Issued: 08/27/2013
• Est. Priority Date: 02/20/2009
• Status: Active Grant

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Inventors: Akonur, Alp, Lo, Ying-Cheng
• Primary Examiner(s): Craig, Dwin M
• Application Number:
  US12/389,886
• Publication Number:
  US 20100217180A1
• Time in Patent Office: 1,649 Days
• Field of Search: 703/2
• US Class Current: 703/2
• CPC Class Codes: A61M 1/28 Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 1/282 Operational modes
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders

Abstract

A method of modeling a patient'"'"'s peritoneal dialysis drain phase includes (i) modeling a first segment of a drain phase curve as having a constant flowrate; (ii) modeling a second segment of a drain phase curve as having a decaying exponential flowrate; and (iii) incorporating a switching component into the first and second components so that (a) at a first time the first segment is active and while the second segment is inactive and (b) at a second time the first segment is inactive and while the second segment is active.

Claims

1. A method of modeling a patient'"'"'s peritoneal dialysis drain phase comprising:

determining a constant flowrate for the patient residing in a particular patient position;

modeling a first segment of a drain phase curve as having the constant flowrate;

modeling a second segment of a drain phase curve as having a decaying exponential flowrate;

incorporating a switching component into the first and second segments so that (i) at a first time the first segment is active while the second segment is inactive and (ii) at a second time the first segment is inactive while the second segment is active; and

programming a computer to use the modeled first and second drain phase segments for at least one of;

(i) determining a drain time for an automated peritoneal dialysis (“

APD”

) machine, (ii) determining a dwell time for the APD machine, (iii) determining a drain time for a continuous ambulatory peritoneal dialysis therapy, (iv) setting a low flowrate alarm in the APD machine, (v) setting a minimum drain volume percentage in the APD machine, (vi) determining a dwell time for use in kinetically modeling a patient, and (vii) preventing overfilling of the patient.

2. The method of claim 1, which includes determining the constant flowrate empirically.

3. The method of claim 1, wherein the particular patient position is one of standing, sitting or lying down.

4. The method of claim 1, which includes determining a time of transition from the first segment to the second segment for the switching component empirically.

5. The method of claim 1, which includes a patient specific constant used with the decaying exponential flowrate empirically.

6. The method of claim 1, which includes entering at least one of the drain time, dwell time and low flowrate alarm setting into the APD machine.

7. The method of claim 6, wherein the APD machine uses gravity for drain or pumps to drain.

8. The method of claim 1, which includes using the model to ensure that the drain flowrate does not fall below a certain level during therapy.

9. A model of a patient'"'"'s peritoneal dialysis drain phase produced via the method of claim 1.

10. A method of modeling a patient'"'"'s peritoneal dialysis drain phase comprising:

modeling a first segment of a drain phase curve as having a linear decrease in drain volume from the patient residing in a particular patient position;

modeling a second segment of a drain phase curve as having an exponentially decaying decrease in drain volume from the patient;

incorporating a switching component into the first and second segments so that (i) at a first time the first segment is active while the second segment is inactive and (ii) at a second time the first segment is inactive while the second segment is active; and

programming a computer to use the modeled first and second drain phase segments for at least one of;

(i) determining a drain time for an automated peritoneal dialysis (“

APD”

) machine, (ii) determining a dwell time for the APD machine, (iii) determining a drain time for a continuous ambulatory peritoneal dialysis therapy, (iv) setting a low flowrate alarm in the APD machine, (v) setting a minimum drain volume percentage in the APD machine, (vi) determining a dwell time for use in kinetically modeling a patient, (vii) preventing overfilling of the patient, and (viii) determining a time at which the patient'"'"'s drain volume is calculated to drop to a certain level as a drain phase duration for therapy.

11. The method of claim 10, which includes entering the time at which the patient'"'"'s drain volume is calculated to drop to a certain level as a drain phase duration for therapy into the APD machine.

12. The method of claim 10, which includes using the method to ensure that the certain level of drain volume removed over the drain phase duration is below a minimum drain volume level or percentage.

13. The method of claim 10, which includes using the method to ensure that the drain phase flowrate does not fall below a minimum level over the drain phase duration.

14. The method of claim 10, wherein the particular patient position is one of standing, sitting or lying down.

15. An apparatus for modeling a patient'"'"'s peritoneal dialysis drain phase comprising:

a computer; and

a non-transitory computer readable medium modified to yield an instantaneous drain volume remaining in a patient, V_D, which is equal to [V_D0−

Q_max*t]*Φ

+[V_D0*e<sup>−

α

t</sup>]*(1−

Φ

), wherein

V_D0 is an initial patient drain volume;

Q_max is a starting flowrate;

Φ

is a switching component;

α

is a decaying exponential constant; and

t is time, and

wherein the computer executes the computer readable medium and outputs the instantaneous drain volume.

16. The apparatus of claim 15, wherein V_D0 is estimated from a fill volume plus an expected amount of ultrafiltrate removed from the patient over a previous dwell phase.

17. The apparatus of claim 15, wherein Q_max is at least one of (i) patient specific, (ii) patient drain position specific, and (iii) determined empirically.

18. The apparatus of claim 15, wherein Φ

is either 1 or 0 depending on time t.

19. The apparatus of claim 18, wherein Φ

switches from 1 to 0 at a time t or a volume V_D that is determined empirically.

20. The apparatus of claim 15, wherein α

is at least one of (i) patient specific and (iii) determined empirically.

21. The apparatus of claim 15, wherein the computer readable medium is further modified to use V_D to at least one of:

(i) determine a drain time for an automated peritoneal dialysis (“

APD”

) machine;

(ii) determine a dwell time for the automated peritoneal dialysis (“

APD”

) machine;

(iii) determine a drain time for a continuous ambulatory peritoneal dialysis therapy;

(iv) set a low flowrate alarm in an APD machine;

(v) set a minimum drain volume percentage in the APD machine;

(vi) determine a dwell time for use in kinetically modeling a patient; and

(vii) prevent overfilling of the patient.