Method of controlling a dialysis apparatus

• US 20050061740A1
• Filed: 10/01/2002
• Published: 03/24/2005
• Est. Priority Date: 10/02/2001
• Status: Active Grant

• Current Assignee: Gambro Lundia AB (Baxter International Inc.)
• Original Assignee: Gambro Lundia AB (Baxter International Inc.)
• Inventors: Sternby, Jan, Felding, Anders
• Granted Patent: US 7,494,590 B2
• Time in Patent Office: Days
• US Class Current: 210/637
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1603 Regulation parameters
• CPC Class Codes: A61M 1/1611 Weight of the patient
• CPC Class Codes: A61M 1/1613 Profiling or modelling of patient or predicted treatment evolution or outcome
• CPC Class Codes: A61M 1/34 Filtering material out of the blood by passing it through a membrane, i.e. hemofiltration or diafiltration
• CPC Class Codes: A61M 1/3403 Regulation parameters
• CPC Class Codes: A61M 1/341 by measuring the filtrate rate or volume
• CPC Class Codes: A61M 1/3441 Substitution rate control as a function of the ultrafiltration rate
• CPC Class Codes: A61M 2205/33 Controlling, regulating or measuring
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: B01D 61/32 Controlling or regulating

Abstract

The present invention relates to a method of controlling a dialysis apparatus, which can be used for e.g. hemodialysis, hemodiafiltration or hemofiltration. Numerous alarms occur during treatments creating additional workloads for the operator. The present method of controlling the apparatus allows an automatic switch form a first control mode to another, thus allowing the treatment to continue without operator interference.

Claims

1. Method of controlling a dialysis apparatus comprising the steps of:

observing at least two parameters related to the dialysis,

determine a range of acceptable values for said parameters

controlling one of said parameters,

switching to controlling one of the other of said parameters when one of the other of said parameters is outside the respective range of acceptable values.

2. Method according to claim 1, wherein the controlled parameter is controlled so as to maintain a predetermined value or follow a predetermined profile

3. Method according to claim 1 or 2, wherein said dialyses apparatus is suitable for hemodialysis, and/or hemodiafiltration and/or hemofiltration.

4. Method according to any of the preceding claims, in which said at least two parameters comprise transmembrane pressure and ultrafiltration flow rate.

5. Method according to claims 1 to 3, in which said at least two parameters comprise transmembrane pressure and replacement fluid flow rate.

6. Method according to claims 1 to 3, in which said at least two parameters comprise blood pressure and blood flow rate.

7. Method according to claims 1 to 3, in which said at least two parameters comprise dialysate flow rate and dialysate temperature.

8. Method according to any of the proceeding claims, comprising the step of selecting an initial parameter to be controlled, if a switch from controlling said initial parameter to controlling another parameter has taken place, returning to said initial control parameter after a predetermined time span since said switch or when the initial control parameter has returned below its threshold or other predetermined value.

9. Method of controlling a dialysis apparatus for or comprising the steps of:

causing the flow of blood on one side of a semi permeable membrane,

causing the flow of dialysate at the other side of said semi permeable membrane,

observing the transmembrane pressure,

observing the ultrafiltration flow rate,

defining a threshold value for the transmembrane pressure,

defining a threshold value for the ultrafiltration flow rate,

controlling either the transmembrane pressure or the ultrafiltration flow rate so as to maintain a predetermined value or follow a predetermined profile,

switching from controlling transmembrane pressure to controlling ultrafiltration flow rate, when the ultrafiltration flow rate threshold is exceeded and switching from controlling ultrafiltrate flow rate to controlling transmembrane pressure when the transmembrane pressure threshold is exceeded.

10. Method of controlling a dialysis apparatus for or comprising the steps of:

causing the flow of blood on one side of a semi permeable membrane,

causing the flow of dialysate at the other side of said semi permeable membrane,

providing replacement fluid at a certain rate,

observing the transmembrane pressure,

observing the replacement fluid rate,

defining a threshold value for the transmembrane pressure,

defining a threshold value for the replacement fluid rate,

controlling either the transmembrane pressure or the replacement fluid rate so as to maintain a predetermined value or follow a predetermined profile,

switching from controlling transmembrane pressure to controlling replacement fluid rate, when the replacement fluid flow rate threshold is exceeded and switching from controlling replacement fluid flow rate to controlling transmembrane pressure when the transmembrane pressure threshold is exceeded.

11. Apparatus for hemodialysis, hemodiafiltration or hemofiltration comprising

a dialysate flow path,

a blood flow path,

a dialyser having a semi permeable membrane, a fist compartment on one side of said semi permeable membrane coupled into said dialysate flow path and a second compartment on the other side of said membrane coupled in said blood flow path,

means for measuring the transmembrane pressure,

means for measuring the volume or flow rate of ultrafiltration liquid,

means for regulating the transmembrane pressure,

means for regulating the ultrafiltration flow rate,

control means for selectively controlling either transmembrane pressure or ultrafiltration flow rate,

means for setting and storing threshold values for transmembrane pressure and ultrafiltration flow rate,

selection means for switching from controlling transmembrane pressure to controlling ultrafiltration flow rate, when the ultrafiltration flow rate threshold is exceeded and switching from controlling ultrafiltration flow rate to controlling transmembrane pressure when the transmembrane pressure threshold is exceeded.

12. Apparatus for hemodiafiltration or hemofiltration comprising

a dialysate flow path,

a blood flow path,

a dialyser having a semi permeable membrane, a fist compartment on one side of said semi permeable membrane coupled into said dialysate flow path and a second compartment on the other side of said membrane coupled in said blood flow path,

means for measuring the transmembrane pressure,

means for providing a replacement fluid flow at a certain flow rate,

means for regulating the transmembrane pressure,

means for regulating the replacement fluid flow rate,

control means for selectively controlling either transmembrane pressure or replacement fluid flow rate,

means for setting and storing threshold values for transmembrane pressure and replacement fluid flow rate,

selection means for switching from controlling transmembrane pressure to controlling replacement fluid flow rate, when the replacement fluid flow rate threshold is exceeded and switching from controlling replacement fluid flow rate to controlling transmembrane pressure when the transmembrane pressure threshold is exceeded.