Cleaning Of Dialyser Compartments And Blood Lines Of Artificial Kidney Machine

Abstract

A system for supplying a blood dialyser with dialysing fluid with connections enabling the system to be connected with the dialyser blood compartment, so that after a dialysing treatment, the supply system can be used to supply washing and sterilizing liquid both to the blood compartment and the dialysate compartment of the dialyser.

Description

This invention relates to artificial kidney machines for blood dialysis. Such machines comprise a dialyser, which may take a number of forms such as parallel flow, coil or capillary type of dialyser, and systems for pumping the blood and dialysing fluid or dialysate through the dialyser.

After a dialysis treatment has been completed using a machine of the above type, it is necessary to wash and sterilize the entire machine system including the dialyser compartments, in preparation for a subsequent dialysis treatment. It is an object of the present invention to provide a novel method and means for cleaning and sterilizing the blood and dialysate compartments of a dialyser after use.

According to the invention, after a dialysis treatment, we connect the blood compartment of a dialyser to the dialysate production and supply system of the machine and utilize the system to supply liquid to both the blood and dialysate compartments of the dialyser for washing and/or sterilizing purposes.

According to a further feature of the invention, we provide the dialysate production and supply system of an artificial kidney machine with connections enabling the system to be connected with a blood circuit of a dialyser so that liquid from the supply system can be delivered to the dialyser blood compartment for washing and/or sterilizing purposes after completion of a dialysis treatment.

The invention will now be described by way of an example with reference to the accompanying drawing which is a circuit diagram of an artificial kidney machine.

The machine comprises a dialysate production and delivery system A and a dialyser B which may be of the parallel flow, coil or capillary type. System A includes a dialysate production arrangement 1 not shown in detail in the drawing but comprising conventional mainswater and dialysate mixing and concentration control means 1 and conventional mixture heating means 1', the arrangement 1, 1' supplying dialysate to the base of a first header tank 2 from where the dialysate circulates through a de-aerating conventional circuit 3 and is pumped into a second header tank 4 linked to the first tank as shown. (Tanks 2 and 4 could be combined into a single partitioned tank). Tank 4 has an overflow 5 leading into a third tank 6 on a lower level, tank 6 itself having an overflow 7 going to drain. A connection 8 from tank 4 leads to the dialysate compartment or compartments of the dialyser and during a dialysis treatment, dialysate is constantly drawn through the dialyser from tank 4 by a pump 9 and discharged to the drain, the dialysate supply being continuously replenished by the production system, which is run so that tanks 2, 4 and 6 are all kept flushed with liquid. Further, during dialysis, the blood compartment or compartments of the dialyser continuously receive blood from a patient through a blood circuit comprising an intravascular needle fitting, a supply line 10 and blood pump 11, the blood being returned to the patient from the dialysis through a further blood line 12 and needle fitting. Thus during dialysis, dialysate is continuously pumped through the dialysate compartment(s) of the dialyser while a patients blood is continuously circulated by the blood circuit, through the blood compartment(s) of the dialyser.

When dialysis has been completed, first the needle through which blood passes from the patient is removed from the patient and this end of the blood circuit is connected to a saline supply so that continued operation of the blood pump 11 returns all the patients blood from within the dialyser at which stage the blood inlet needle is removed from the patient. The blood circuit is then purged of saline after which the opposite ends of the blood circuit lines 10 and 12 (previously connected to the patients blood supply) are attached to connections 13 and 14 respectively, leading to and from tanks 4 and 6. By this means, continued operation of the blood pump 11 causes dialysate from the supply system A to be circulated through the blood circuit for washing purposes. By suitable operation of pumps 9 and 11, both the blood circuit and the dialysate circuit, including the dialyser compartments can be flushed with dialysing fluid and subsequently with pure water by shutting off the supply of dialysate concentrate.

Finally, after the system has been thoroughly flushed with water, the circuits can be charged with a sterilizing medium, by the introduction of a sterilizing concentrate such as formalin concentrate from a supply 15 to the tank 2 by the operation of a pump 16 and continued operation of pumps 9 and 11 for a time sufficient fully to circulate the sterilizing mixture. Alternatively, the sterilizing medium may be introduced by venturi means and it could be introduced into the line 1 instead of into the tank 2.

It will be appreciated that the invention provides an in situ method of washing both the blood and dialysate compartments of the dialyser utilizing the dialysate supply system of the machine. Moreover, the invention provides a method of distributing a concentrated toxic sterilizing solution, such as a formalin solution, after dilution, to the dialyser without the necessity of handling the concentrated solution and without the effects of having toxic vapours from the solution within the system environment. This is of particular importance for individuals with sensitive skins.

It will also be appreciated that while the invention has been described in relation to one particular form of dialysate supply system, it is also applicable to other forms of supply system.

Claims

I claim:

1. A method of washing a blood dialyser of an artificial kidney machine of the type having a supply system which produces dialysate by mixing water with metered quantities of dialysate concentrate and heats and deaerates the resultant mixture, said dialyser having a blood compartment and a dialysate compartment, said method comprising the steps of:

a. connecting the blood compartment of said dialyser to said dialysate supply system of said machine, and

b. using liquid from said supply system to wash both the blood and dialysate compartments of said dialyser.

2. A method as recited in claim 1 wherein the step of connecting the blood compartment of said dialyser to said dialysate supply system is accomplished by connecting ends of a blood circuit, said ends previously having been attached to a patient's blood supply, containing said blood compartment and a blood pump to said dialysate supply system so that said blood pump circulates liquid from said supply system through said blood circuit.

3. A method as recited in claim 1 wherein the washing liquid for both said compartments of said dialyser initially comprises dialysate.

4. A method as recited in claim 3 wherein the method comprises the additional step of washing both said compartments of said dialyser with pure heated and deaerated water from said supply system after said washing with dialysate.

5. A method as recited in claim 1 wherein the method comprises the additional step of providing a sterilizing medium to said supply system to supply said sterilizing medium to both said compartments of said dialyser after said washing of said compartments.

6. A dialysate supply system for an artificial kidney machine with a dialyser having a blood circuit including blood supply lines and blood and dialysate compartments, said supply system comprising means for producing dialysate by mixing water with metered quantities of dialysate concentrate and heating and deaerating the mixture, and connection means for connecting said supply system with said dialyser blood circuit so that after a blood dialysate treatment liquid from said supply system can be delivered to said dialyser blood compartment for washing said compartment.

7. A system as claimed in claim 6, including a pair of dialysate header tanks in liquid-flow communication wherein said connection means comprise a connection leading into each tank.

8. A system as claimed in claim 7, wherein one of said tanks is an overflow tank from the other of said tanks.

9. A system as claimed in any of claims 6 including means for introducing a sterilizing medium into the system and hence into said blood and dialysate compartments of said dialyser.