JPH056466B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a dialysis fluid production device that mixes dialysis concentrate and water.

BACKGROUND OF THE INVENTION In a dialysate production apparatus of the type shown in Johnsson U.S. Pat. No. 4,371,185 (which is incorporated herein by reference), water is heated, air is separated, and It is mixed with dialysis concentrate to provide a continuous supply of dialysate to the patient's dialyzer. In such devices, dialysate is typically pumped to a junction in the main delivery line and mixed with water. A conductivity detection cell is used on the downstream side to detect the conductivity of the mixed solution passing through the conductivity detection cell (conductivity is related to the concentration of dialysate components in the water). The pump for dialysis concentrate is controlled using the rate in the control loop. When the device is sterilized or cleaned for use on another patient, the hydraulic circuit of the dialysate production device is flushed with a disinfectant or disinfectant.

(Means for Solving the Problems) It has been found that the safety of the dialysate production apparatus can be further improved (for example, the addition of harmful chemicals can be prevented) by using a positive displacement pump. The positive displacement pump has a constant displacement per stroke and is capable of pumping concentrate into a main feed line carrying water. Positive displacement pumps are controlled by a feedback loop using a concentration sensor and controller downstream of the main feed line. The controller is adapted to compare the stroke ratio of the pump to a predetermined range of operating stroke ratios.

In a preferred embodiment, the concentration sensor is a conductivity sensor. The concentrate pump can also be connected to either a source of concentrate or a source of cleaning chemicals. The predetermined operating stroke ratio range for the concentrate does not include the cleaning chemical pump ratio required to achieve the conductivity set point.

Other advantages and features of the invention will become apparent from the following description of preferred embodiments of the invention, as well as from the claims.

A preferred embodiment will now be described.

(Example) Structure Please refer to the drawings. Illustrated dialysate manufacturing apparatus 10
comprises a main feed line 12 having an end 14 communicating with a water supply and another end connected to an inlet 16 of a dialyzer 18 for dialyzing the patient's blood. The dialyzer 18 includes a blood inlet 20 and a blood outlet 22 connected to the patient, and a dialysate outlet 24. The concentrate feed line 26 is connected at one end to a confluence 28 of the main feed line 12 and at the other end for communication with either a dialysis concentrate (acetate) container 36 or a cleaning fluid (disinfectant) container 38 . , a connector 30 that can be disconnected from the attachment part 32 of the container 36 and connected to the attachment part 34 of the container 38 is provided.

The concentrate feed pipe 26 is provided with a positive displacement diaphragm pump 40 that has a constant discharge amount per stroke. Merging section 28 of main feed pipe 12
On the downstream side there is a mixing chamber 42 and a conductivity detection cell 44.
is provided. The pump 40 has a sensor 44
controlled by a feedback loop based on the sensed conductivity. This feedback loop is represented in the figure by a dotted line 46 extending to the controller 48 and a dotted line 47 extending to the pump 40. The controller 48 includes a comparator that represents the stroke ratio (strokes/time) of the pump 40 (i.e., the rate of pulses sent to the pump 40 via line 47) and a predetermined range of operating stroke ratios. It is designed to compare with the limit value.

The device 10 also includes a heat exchanger, an air separator with a heater (which balances the flow into and out of the dialyzer, and manages ultrafiltration).
It is equipped with an equilibrium chamber, a separate conductivity sensing cell and a PH sensor. All these are not shown.
The device further includes a second concentrate delivery line (equipped with a pump and vessel connector) and a junction, as well as a mixing chamber and a conductivity sensing cell. All of this is upstream from the confluence 28, and this separate feed line is used to add bicarbonate and the acid is added through line 26, using a solution of bicarbonate and acid instead of acetate. be able to.

Operation In operation, water is flowed from end 14 into feed line 12 and dialysis concentrate is pumped to junction 28 by pump 40. At this junction 28, the water is initially mixed with the concentrate. Further stirring is performed within the mixing chamber 42. The mixing chamber 42 is equipped with an exhaust port connected to a vacuum pump (not shown) to remove gases escaping from the solution.
The mixed dialysis concentrate/aqueous solution flows from the mixing chamber 42 through the conductivity sensing cell 44 and from the conductivity sensing cell to the dialysis side of the dialysis membrane of the dialyzer 18. The conductivity sensed by sensor 44 is fed back and used to control pump 40 to obtain a conductivity that matches a predetermined dialysis concentration. The stroke ratio of pump 40 is automatically monitored by controller 48, which continuously compares the monitored stroke ratio to a predetermined operating stroke range at a particular concentration.

When transferred to a different patient, the hydraulic circuit is flushed with water and flushed with cleaning fluid. Some of the cleaning fluid may remain in the circuit for a period of time. As used herein, "cleaning fluid" refers to a disinfectant, disinfectant, or other chemical that can be flushed through a device system. For example, as shown in the drawings, after connecting the connector 30 to the attachment portion 34 of the container 38, the system using the pump 40 is cleaned with the disinfectant in the container 38.

Continuous monitoring of stroke volume by controller 48 prevents the inadvertent use of inappropriate chemicals that may meet conductivity settings and be harmful to the patient. For example, a dialysis concentrate is pumped, the dialysis concentrate and water are mixed at a ratio of 1:34, and the conductivity of the resulting solution is used as a set value. When the pump operates at a stroke ratio of 1:20, the controller 48 issues an alarm (not shown) as the limit value has been exceeded.
is given an output and an alarm is sounded. To pump the disinfectant and bring the conductivity closer to the set point,
It is necessary to pump at a higher stroke ratio than that associated with a 1:20 mix ratio.

Another advantage is that loop 46 automatically compensates for changes in concentrate concentration within container 36.

Other embodiments of the invention are within the scope of the claims.

[Brief explanation of drawings]

The drawing is a schematic explanatory diagram of a dialysate manufacturing apparatus according to the present invention. DESCRIPTION OF SYMBOLS 10... Dialysate manufacturing device, 12... Main feed piping, 14... Piping end, 16... Dialyzer inlet, 18... Dialyzer, 20... Blood inlet of dialyzer, 22 ...Blood outlet of the dialyzer, 24...
Dialysate outlet, 26...Concentrate feed piping, 28
... Merging section, 30 ... Connector, 32, 34 ...
Attachment part, 36... Dialysis concentrate container, 38... Disinfectant container, 40... Pump, 42... Mixing chamber, 44
...Conductivity detection cell, 46, 47...Wiring, 48
……controller.

Claims (1)

[Scope of Claims] 1. A dialysate manufacturing device for mixing dialysis concentrate and water, the device having: one end communicating with a water supply source and a dialyzer for dialyzing the blood of a patient; a main feed line having another end for supplying fluid; one end communicating with a source of dialysis concentrate; A concentrate feed pipe having another end capable of adding concentrate to water; a positive displacement pump located in the middle of the concentrate feed pipe and having a constant discharge amount per stroke; and the merging section. A concentration sensor located in the middle of the main feed pipe downstream from the pump, for sending a control signal to the pump to obtain a predetermined concentration for pumping the concentrated liquid; and a controller for comparing the stroke ratio of the pump with a limit value representing a range of operating stroke ratios, the controller being configured to provide an output to alarm means when the stroke ratio of the pump exceeds the limit value. Dialysate manufacturing equipment. 2. In the dialysate manufacturing apparatus according to claim 1, the concentration sensor is a conductivity sensor having a certain conductivity setting value, and this conductivity setting value corresponds to the predetermined concentration. The dialysate production equipment associated with the value. 3. In the dialysate manufacturing apparatus according to claim 2, the one end of the concentrate feed pipe is disconnected from the dialysis concentrate supply source and connected to the cleaning fluid supply source. A dialysate having a connectable connector and a limit value representing a range of predetermined operating stroke ratios for said concentrate that does not include the resulting ratio of said conductivity set point by pumping said wash fluid. Manufacturing equipment.