Method of determining system volume of a dialysis machine

• US 6,280,634 B1
• Filed: 06/09/2000
• Issued: 08/28/2001
• Est. Priority Date: 12/09/1996
• Status: Expired due to Term

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Aksys Ltd.
• Inventors: Maliekkal, Shincy, Wiebenson, Derek, Brose, Tom L., Shah, Dilip H.
• Primary Examiner(s): KIM, SUN U
• Application Number:
  US09/590,812
• Time in Patent Office: 445 Days
• Field of Search: 210/646, 210/647, 210/739, 210/746, 738/61, 738/610.8
• US Class Current: 210/739
• CPC Class Codes: A61L 2/04 Heat A61L2/08 takes precedence
• CPC Class Codes: A61L 2/18 Liquid substances or solutions comprising solids or dissolved gases
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1601 Control or regulation
• 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 1/1649 with pulsatile dialysis fluid flow
• CPC Class Codes: A61M 1/165 with a dialyser bypass on the dialysis fluid line
• CPC Class Codes: A61M 1/1656 Apparatus for preparing dialysates
• CPC Class Codes: A61M 1/1658 Degasification
• CPC Class Codes: A61M 1/166 Heating for sterilisation A61M1/1686
• CPC Class Codes: A61M 1/1662 with heat exchange between fresh and used dialysate
• CPC Class Codes: A61M 1/1666 by dissolving solids
• CPC Class Codes: A61M 1/1668 Details of containers
• CPC Class Codes: A61M 1/1672 using membrane filters, e.g. for sterilising the dialysate
• CPC Class Codes: A61M 1/1682 both machine and membrane module, i.e. also the module blood side
• CPC Class Codes: A61M 1/1684 Checking the module characteristics before reuse
• CPC Class Codes: A61M 1/1686 by heat
• CPC Class Codes: A61M 1/1688 with recirculation of the sterilising fluid
• CPC Class Codes: A61M 1/169 using chemical substances
• CPC Class Codes: A61M 1/1692 : Detection of blood traces in dialysate
• CPC Class Codes: A61M 1/1694 : with recirculating dialysing liquid
• CPC Class Codes: A61M 1/28 : Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 1/3434 : with pre-dilution and post-dilution
• CPC Class Codes: A61M 1/3437 : downstream of the filter, e.g. post-dilution with filtrate
• CPC Class Codes: A61M 1/3462 : Circuits for the preparation thereof
• CPC Class Codes: A61M 1/3465 : using dialysate as substitution fluid
• CPC Class Codes: A61M 1/3626 : Gas bubble detectors
• CPC Class Codes: A61M 1/3627 : Degassing devices; Buffer reservoirs; Drip chambers; Blood filters
• CPC Class Codes: A61M 1/3629 : degassing by changing pump speed, e.g. during priming
• CPC Class Codes: A61M 1/3639 : Blood pressure control, pressure transducers specially adapted therefor
• CPC Class Codes: A61M 1/3641 : Pressure isolators
• CPC Class Codes: A61M 1/3643 : Priming, rinsing before or after use
• CPC Class Codes: A61M 1/3644 : Mode of operation
• CPC Class Codes: A61M 1/3646 : Expelling the residual body fluid after use, e.g. back to the body
• CPC Class Codes: A61M 1/3647 : with recirculation of the priming solution
• CPC Class Codes: A61M 1/3649 : using dialysate as priming or rinsing liquid
• CPC Class Codes: A61M 1/365 : through membranes, e.g. by inverted trans-membrane pressure [TMP]
• CPC Class Codes: A61M 2205/12 : with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/15 : Detection of leaks
• CPC Class Codes: A61M 2205/17 : with redundant control systems
• CPC Class Codes: A61M 2205/3317 : Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3324 : PH measuring means
• CPC Class Codes: A61M 2205/3382 : Upper level detectors
• CPC Class Codes: A61M 2205/3386 : Low level detectors
• CPC Class Codes: A61M 2205/505 : Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
• CPC Class Codes: A61M 2205/6072 : Bar codes
• CPC Class Codes: A61M 2205/705 : Testing of filters for leaks
• CPC Class Codes: A61M 2205/707 : Testing of filters for clogging
• CPC Class Codes: A61M 2205/7554 : with means for unclogging or regenerating filters
• CPC Class Codes: A61M 2205/7581 : with means for switching over to a fresh filter on clogging or saturation
• CPC Class Codes: A61M 2206/11 : Laminar flow
• CPC Class Codes: A61M 39/16 : having provision for disinfection or sterilisation A61M39/143 takes precedence; methods or apparatus for disinfection or sterilisation A61L2/00
• CPC Class Codes: B01D 2311/04 : Specific process operations in the feed stream; Feed pretreatment
• CPC Class Codes: B01D 2311/10 : Temperature control
• CPC Class Codes: B01D 2321/08 : Use of hot water or water vapor
• CPC Class Codes: B01D 61/02 : Reverse osmosis; Hyperfiltration ; Nanofiltration
• CPC Class Codes: B01D 61/025 : Reverse osmosis; Hyperfiltration
• CPC Class Codes: B01D 61/04 : Feed pretreatment
• CPC Class Codes: B01D 61/12 : Controlling or regulating
• CPC Class Codes: B01D 65/022 : Membrane sterilisation
• CPC Class Codes: B01D 65/102 : Detection of leaks in membranes
• CPC Class Codes: C02F 1/441 : by reverse osmosis
• CPC Class Codes: F16K 17/0453 : the member being a diaphragm

Abstract

A method of calibrating a dialysis machine to determine the volume of a dialysate flow path of the machine including a dialysate preparation tank includes the steps of introducing a known quantity of electrically conductive chemicals into the dialysate preparation tank, filling the dialysate solution flow path with water, mixing the chemicals with water to form a solution, measuring the conductivity of the solution, calculating the system volume (V_sys) according to the relation: V_sys=M/(a₁r+b₁) where M is the mass in grams of the chemicals, a₁ and b₁ are a coefficient of linearity and a constant of linearity, respectively, for the chemicals and r is the measured conductivity of the solution.

Claims

1. A method of calibrating a dialysis machine to determine the volume of a dialysate flow path of said machine, said dialysate solution flow path including a dialysate preparation tank, comprising the steps of:

introducing a known quantity of electrically conductive chemicals into said dialysate preparation tank;

filling said dialysate solution flow path with water;

mixing said chemicals with said water to form a solution;

measuring the conductivity of said solution; and

calculating said system volume (V_sys) according to the relation;

2. The method of claim 1, wherein said method is performed at the time of manufacture of said dialysis machine.

3. The method of claim 1, wherein said method is performed after the time of manufacture of said dialysis machine and after said dialysis machine has been shipped to a place of use of said machine, and after a component of said dialysis flow path has been replaced.

4. The method of claim 1, wherein said electrically conductive chemicals comprise a batch quantity of a dialysis solution chemical or chemicals.