JP6974723B2 - Dissolver - Google Patents

Description

The present invention relates to a dissolving device for preparing a stock solution for dialysis by dissolving a powdered drug for dialysis with water.

Conventionally, in dialysis facilities such as hospitals that perform artificial dialysis, powdered dialysis drug (hereinafter, also simply referred to as “powdered drug”) is dissolved in water to prepare a stock solution for dialysis, and a dialysate supply device or the like is supplied. (Patent Document 1). The dissolution device has a dissolution unit, a water supply unit that supplies water to the dissolution unit, and a drug supply unit that supplies powdered drug to the dissolving unit. Perform a dissolution operation to prepare. The undiluted dialysis solution prepared in the dissolution section is once stored in a storage tank and then supplied to a dialysate supply device. The stock solution for dialysis supplied to the dialysate supply device is mixed and diluted in the dialysate supply device to form a dialysate, and then supplied to the dialysate device.

The dissolving device is an electric concentration detecting means for detecting the concentration of the undiluted solution for dialysis prepared by the dissolving operation because it has a simple structure, is easy to handle, has few factors of fluctuation in measured values, and is highly reliable. A conductivity meter is provided. Then, in the melting operation, when the electric conductivity of the solution detected by the electric conductivity meter reaches the target value, the supply of the powdered medicine from the medicine supply unit is terminated.

2007-117886 Publication No.

However, in the conventional dissolution apparatus as described above, for example, when the agent A (the powdered agent of the liquid A of the dialysate) is mixed with the agent B (the powdered agent of the liquid B of the dialysate), the electrolyte component and the non-electrolyte component are mixed. When the content of the non-electrolyte component of the agent A, which has been made into a single agent, is high, or when deposits such as silica adhere to the surface of the electrode of the electric conductivity meter and the sensitivity of the electric conductivity meter decreases. , The powdered drug may continue to be supplied without the electrical conductivity reaching the target value. This is due to the following reasons. That is, the measurement of the electric conductivity of the electrolyte solution by the electric conductivity meter is roughly performed by measuring the current due to the movement of ions in the electrolyte solution when a voltage is applied between the pair of electrodes. The electrical conductivity of the electrolyte solution depends on the concentration of the electrolyte, but the presence of undissolved electrolytes or non-electrolytes in the electrolyte solution hinders the movement of ions between the electrodes. As the current becomes difficult to flow, the electrical conductivity becomes low. In addition, even if an deposit adheres to the surface of the electrode, it becomes difficult for the current to flow, so that the electric conductivity detected by the electric conductivity meter becomes low. The target value of the electric conductivity in the melting operation is set assuming that each of the above-mentioned events does not occur. Therefore, when each of the above-mentioned events occurs, the electric conductivity detected by the electric conductivity meter does not reach the target value even if the electrolyte component of the powdered drug actually reaches a predetermined concentration. As a result, the powdered drug will continue to be supplied without the electric conductivity reaching the target value.

Therefore, conventionally, an upper limit of the supply time of the powdered drug is set, and when the upper limit time is exceeded, the supply of the powdered drug is stopped and an alarm is issued. However, when the upper limit time is exceeded, the electrolyte component of the powdered drug may already be in a supersaturated state. In addition to the automatic supply function that automatically controls the supply of powdered chemicals based on the detection results of the electric conductivity meter, the display related to the detection results of the electric conductivity meter (electrical conductivity value, solution concentration conversion value, etc.) There is a dissolving device having a manual supply function that manually controls the supply of the powdered drug based on the above. In such a melting device, even if the supply of the powdered drug is stopped after the upper limit time is exceeded, the electric conductivity has not reached the target value, so that the operator manually supplies the powdered drug in an attempt to reach this value. This may continue and the electrolyte component of the powdered drug may become supersaturated.

As described above, when the electrolyte component of the powdered drug becomes supersaturated, the undissolved powdered drug may clog the piping or the like in the dissolving device. When the piping or the like is clogged with the powdered chemicals, it takes time and effort to remove the clogged powdered chemicals and recover.

Therefore, an object of the present invention is to provide a dissolving device capable of preventing excessive supply of dialysis powder and preventing problems such as clogging of piping in the dissolving device with undissolved dialysis powder. To provide.

The above object is achieved by the melting apparatus according to the present invention. In summary, the present invention comprises a dissolving section, a water supply section for supplying water to the dissolving section, a drug supply section for supplying a dialysis powder drug to the dissolving section, and the drug being dissolved in water at the dissolving section. A dissolving device having an electric conductivity meter that detects the electric conductivity of the prepared solution and a control unit that controls the drug supply unit based on the electric conductivity of the solution detected by the electric conductivity meter. In the dissolving operation of dissolving the drug in water in the dissolving unit, the control unit determines the electric conductivity of the solution before the electric conductivity of the solution detected by the electric conductivity meter reaches a target value. A melting device characterized in that the supply of the drug from the drug supply unit is stopped when it is detected that the direction of change has changed from the increasing direction to the decreasing direction or the electrical conductivity has stopped increasing. Is.

According to the present invention, it is possible to prevent an excessive supply of the dialysis powder drug and prevent problems such as clogging of the piping in the dissolving device with the undissolved dialysis powder drug.

It is a schematic diagram which shows the schematic structure of the melting apparatus which concerns on one Example of this invention. It is a graph for demonstrating the change of electric conductivity when the agent A is added to water. It is a graph for demonstrating an example of the measurement result of the electric conductivity at the time of a normal operation in a melting operation, and at the time of occurrence of a trouble. It is a flowchart which shows the outline of the procedure of control of a melting operation in Example 1. FIG. It is a flowchart which shows the outline of the procedure of control of a melting operation in Example 2. FIG.

Hereinafter, the melting apparatus according to the present invention will be described in more detail with reference to the drawings.

[Example 1]
1. 1. Configuration of Dissolving Device FIG. 1 is a schematic diagram showing a schematic configuration of the melting device 1 of this embodiment. In this embodiment, the dissolving device 1 prepares a stock solution A (one of the stock solutions for dialysis) which is a concentrated solution in which the agent A for dialysate is dissolved.

The dissolution device 1 has a dissolution tank 2, a storage tank 3 for accommodating the stock solution A sent from the dissolution tank 2, and a hopper 4 for supplying the agent A to the dissolution tank 2. An inlet pipe 18 through which water (RO water) supplied to the dissolution tank 2 passes is connected to the dissolution tank 2. The inlet pipe 18 is provided with an inlet pump 6 which is a liquid feeding pump and an inlet valve 7 which is a solenoid valve. Further, one end of an outlet pipe line 20 through which the undiluted solution A discharged from the dissolution tank 2 passes is connected to the bottom of the dissolution tank 2. The other end of the outlet pipeline 20 is connected to the storage tank 3, and the circulation pipeline 19 is connected in the middle. The outlet pipe 20 is an outlet pipe 20a from one end connected to the melting tank 2 to the connection point of the circulation pipe line 19 and an outlet from the connection point of the circulation pipe line 19 to the other end connected to the storage tank 3. It is composed of a pipeline 20b. The outlet pipe 20a is provided with an outlet pump 8 which is a liquid feeding pump, and the outlet pipe 20b is provided with an outlet valve 10 which is a solenoid valve. The recirculation pipeline 19 recirculates the liquid discharged from the dissolution tank 2 through the outlet pipeline 20a to the dissolution tank 2. The recirculation pipeline 19 is provided with a recirculation flow path valve 9 which is a solenoid valve. Further, an electric conductivity meter 30 is installed in the circulation pipe line 19. The electric conductivity meter 30 detects the electric conductivity of the liquid flowing in the circulation pipe line 19. The stock solution A prepared in the dissolution tank 2 is sent to the storage tank 3 through the outlet pipe line 20. A supply pipeline 21 through which the undiluted solution A discharged from the storage tank 3 passes is connected to the bottom of the storage tank 3. The supply pipe line 21 is provided with a supply pump 11 which is a liquid feed pump and a supply valve 12 which is a solenoid valve. The supply pipe line 21 is connected to a dialysate supply device (not shown) outside the dissolution device 1.

Further, the melting device 1 has a water receiving tank 5 for accommodating water to be supplied to the melting tank 2. The inlet pipeline 18 for supplying water to the dissolution tank 2 is connected to the bottom of the water receiving tank 5. Water is supplied to the water receiving tank 5 from an RO water producing device (not shown) outside the dissolving device 1 via a water supply pipe line 27. Further, the water receiving tank 5 can be supplied with a disinfectant solution from an external disinfectant solution supply source (not shown) of the dissolution device 1 via a water supply pipe line 27. The water supply pipeline 27 has a water supply valve 15 that controls the supply of water from the RO water production apparatus, a disinfectant liquid supply pump 16 that supplies the disinfectant liquid from the disinfectant liquid supply source, and a disinfectant that controls the supply of the disinfectant liquid. A liquid supply valve 17 is provided.

Further, drainage pipes 24 and 25 for drainage during cleaning and the like are connected to the outlet pipe 20 and the supply pipe 21, respectively, and drainage as an electromagnetic valve is connected to these drainage pipes 24 and 25, respectively. Valves 13 and 14 are provided, respectively. Further, overflow pipes 22, 23, and 26 for discharging the overflowed liquid are connected to the dissolution tank 2, the storage tank 3, and the water receiving tank 5, respectively. The drainage pipes 24 and 25 and the overflow pipes 22, 23 and 26 are connected to the drainage port 28, respectively.

Here, in this embodiment, the agent A is dissolved in water by the dissolution tank 2, the outlet pipe line 20a, the outlet pump 8, the ring flow path valve 9, the circulation pipe line 19, and the like, and the A stock solution is one of the stock solutions for dialysis. The melting unit 61 for preparing the above is configured. Further, in the present embodiment, the water supply section 62 for supplying water to the melting section 61 is configured by the water receiving tank 5, the inlet pipeline 18, the inlet pump 6, the inlet valve 7, and the like. Further, in this embodiment, the hopper 4 constitutes a drug supply unit 63 that supplies the agent A to the dissolution unit 61. Further, in this embodiment, the electric conductivity meter 30 detects the electric conductivity of the solution in which the agent A is dissolved in water in the dissolving portion 61.

Further, the melting device 1 is provided with a control unit 50 that collectively controls the operation of the melting device 1. The control unit 50 includes a controller 51 including an arithmetic control element and the like, a storage unit 52 including a ROM, RAM, and the like. The control unit 50 controls the operation of each pump, each valve, the hopper 4, and the like of the dissolution device 1 according to the program and data stored in the storage unit 52 by the controller 51 to prepare the A stock solution, and dialysis as a supply target. The undiluted solution A is supplied to the liquid supply device. Further, the melting device 1 is provided with an operation unit 40. The operation unit 40 is provided with an input unit 41 for the operator to input various settings to the control unit 50, and a display unit 42 for displaying various information. In this embodiment, the operation unit 40 is configured as a touch panel type operation panel having the functions of the input unit 41 and the display unit 42.

A The stock solution is prepared as follows. Unless otherwise specified, the drain valves 13 and 14 and the disinfectant solution supply valve 17 are closed, the disinfectant solution supply pump 16 is stopped, and water to the water receiving tank 5 is opened and closed by the water supply valve 15. It is assumed that the water supply is appropriately performed and that the water receiving tank 5 contains a sufficient amount of water.

First, with the outlet valve 10 closed and the outlet pump 8 stopped, the inlet valve 7 is opened, the inlet pump 6 is operated, and water is supplied from the water receiving tank 5 to the melting tank 2 through the inlet pipeline 18. Will be done. After that, when the float switch F1 that detects the water level of the liquid (water) in the dissolution tank 2 inputs the detection signal to the control unit 50, the inlet valve 7 is closed, the inlet pump 6 is stopped, and the ring flow path valve 9 is stopped. Is opened and the outlet pump 8 is operated. As a result, the water in the dissolution tank 2 is circulated and stirred through the outlet pipe line 20a and the circulation pipe line 19.

Subsequently, the supply of the agent A from the hopper 4 to the dissolution tank 2 is started. Agent A is a powdered agent containing sodium chloride, potassium chloride, calcium chloride, magnesium chloride, sodium acetate, glacial acetic acid, and glucose (dextrose) in a predetermined ratio. Agent A is stirred and mixed in the dissolution tank 2 by circulating water. At this time, the electric conductivity of the liquid flowing in the circulation pipe 19 is detected by the electric conductivity meter 30 installed in the circulation pipe 19, and the detection signal is input to the control unit 50.

As will be described in detail later, the control unit 50 controls the hopper 4 based on the electric conductivity detected by the electric conductivity meter 30 in the following manner, and the agent A is dissolved in water in the dissolving unit 61. Let the melting operation be performed. That is, the detection signal of the electric conductivity meter 30 is input to the controller 51 through predetermined signal processing such as amplification and A / D conversion in the control unit 50. In the storage unit 52 of the control unit 50, the target value of the electric conductivity corresponding to the predetermined concentration of the agent A in the stock solution A is stored. The controller 51 controls the hopper 4 to appropriately supply the agent A, compares the detected value of the electric conductivity meter 30 with the target value, and detects that the detected value has reached the target value. The supply of agent A by the hopper 4 is stopped. As a result, the A stock solution containing the A agent having a predetermined concentration is prepared. In this example, a predetermined amount of A stock solution is prepared by this one dissolution operation.

When the A stock solution is prepared in this way, the outlet pump 8 is stopped. Then, the stock solution A in the dissolution tank 2 is sent to the storage tank 3 through the outlet pipeline 20 by closing the ring flow path valve 9 and opening the outlet valve 10 and operating the outlet pump 8. Then, when substantially all of the A stock solution in the dissolution tank 2 is sent to the storage tank 3, the above-mentioned preparation operation of the A stock solution is repeated.

Further, the stock solution A in the storage tank 3 is supplied to the dialysate supply device through the supply line 21 by opening the supply valve 12 and operating the supply pump 11. In the dialysate supply device, the B stock solution prepared by another dissolution device and the A stock solution prepared by the dissolution device 1 of this example are diluted and mixed with water (RO water), and dialysis at a predetermined concentration is performed. Prepare the solution. The stock solution B is a concentrated solution in which the agent B for dialysate is dissolved, and the agent B is a powdered agent of sodium hydrogen carbonate.

2. 2. Electrical Conductivity of Agent A Solution Next, the change in electrical conductivity of the solution when Agent A is added to water will be described. FIG. 2 shows the osmotic pressure after diluting the prepared solution 35 times, the electrical conductivity of the prepared solution, and the prepared solution diluted 35 times when the agent A was added to water. It is a graph which shows the relationship with the glucose concentration after the dilution. After each addition of Agent A, the mixture was stirred for 3 minutes and then sampled to measure osmotic pressure, electrical conductivity and glucose concentration. As the agent A, Kindary 2E (manufactured by Fuso Pharmaceutical Indus, Ltd.) was used.

As can be seen from FIG. 2, when the agent A is added to water, the electric conductivity and the glucose concentration of the solution increase almost linearly, respectively. However, when the agent A is further added, the glucose concentration of the solution continues to increase almost linearly, whereas the direction of change in the electric conductivity of the solution changes from the increasing direction to the decreasing direction. This is because, in the case of Agent A, the electrolyte component becomes supersaturated and the undissolved electrolyte component increases, and the non-electrolyte component increases, so that the current becomes difficult to flow and the electric conductivity becomes low. It depends.

FIG. 3 is a schematic graph showing an example of the relationship between the elapsed time and the electric conductivity of the prepared solution when the dissolving operation of dissolving the agent A in water is performed in the dissolving apparatus 1. The solid line in FIG. 3 shows the relationship during normal operation. Further, the broken line in FIG. 3 indicates the sensitivity of the electric conductivity meter, for example, when the agent B is mixed with the agent A, when the content of the non-electrolyte component of the agent A is high, or when the deposits adhere to the surface of the electrode. Shows the relationship when is reduced.

As shown by the solid line in FIG. 3, in this embodiment, when the dissolution operation is started, the electric conductivity of the solution is lower than the target value of the electric conductivity according to the predetermined A agent concentration of the A stock solution. Agent A is continuously supplied until the continuous powder injection stop value set for the electric conductivity is reached (continuous powder injection period). Then, after the electric conductivity of the solution reaches the continuous powder injection stop value, the agent A is supplied intermittently (intermittent powder injection period), and when the electric conductivity of the solution reaches the target value, The supply of agent A is terminated.

On the other hand, for example, when the agent B is mixed with the agent A, the content of the non-electrolyte component of the agent A is high, or the sensitivity of the electric conductivity meter is lowered due to the adhesion of deposits on the surface of the electrode. The electric conductivity of the solution detected by the electric conductivity meter 30 is lower than that in normal operation in which these events do not occur. The reason is as described above. Therefore, as shown by the broken line in FIG. 3, the electric conductivity of the solution does not reach the target value even if the agent A is supplied, and when the agent A is continuously supplied, the agent A becomes supersaturated. Due to the influence of some electrolyte components, precipitation of mixed B agent, non-electrolyte components supplied in excess, etc., the direction of change in the electric conductivity decreases from the increasing direction before the electric conductivity reaches the target value. It changes in the direction (see Fig. 2). As a result, the agent A will continue to be supplied without the electric conductivity of the solution reaching the target value. In particular, as shown by the broken line in FIG. 3, when the direction of change in the electric conductivity changes from the increasing direction to the decreasing direction before the electric conductivity of the solution reaches the continuous powder injection stop value, A. Even after a part of the electrolyte component of the agent becomes supersaturated, the agent A will continue to be supplied.

Therefore, conventionally, an upper limit of the supply time of the agent A is set, and when the upper limit time is exceeded, the supply of the agent A is stopped and an alarm is issued. However, for example, when the direction of change in the electric conductivity changes from the increasing direction to the decreasing direction before the electric conductivity of the solution reaches the continuous powder injection stop value as described above, the upper limit time is exceeded. At this point, some electrolyte components of Agent A may already be in a supersaturated state. Further, in the case of a dissolving device having a manual supply function for manually controlling the supply of the A agent, even if the supply of the A agent is stopped after the upper limit time is exceeded, the operation is performed in an attempt to reach the target value of the electric conductivity. A person may continue to manually supply Agent A. Also in this case, the agent A is excessively supplied, and a part of the electrolyte component of the agent A becomes supersaturated. In this way, when a part of the electrolyte component of the agent A becomes supersaturated, the undissolved agent A may clog the piping (for example, the outlet pipe line 20a, the circulation pipe line 19) in the dissolving device. .. When the pipe is clogged with the agent A in this way, it takes time and effort to remove the clogged agent A and recover.

3. 3. Control of melting operation Next, control of the melting operation in this embodiment will be described.

In this embodiment, in the dissolving operation of dissolving the agent A in water in the dissolving unit 61, the electric conductivity of the solution detected by the electric conductivity meter 30 corresponds to the predetermined concentration of the agent A in the stock solution A. If it is detected that the direction of change in the electric conductivity has changed from the increasing direction to the decreasing direction before reaching the target value, the supply of the agent A from the hopper 4 is stopped. In particular, in this embodiment, the control unit 50 performs the melting operation before the electric conductivity of the solution detected by the electric conductivity meter 30 reaches the continuous powder injection stop value as a reference value lower than the above target value. When it is detected that the direction of change in the electric conductivity has changed from the increasing direction to the decreasing direction, the supply of the agent A from the hopper 4 is stopped. Here, in the present embodiment, the control unit 50 is a hopper in the melting operation after the electric conductivity of the solution detected by the electric conductivity meter 30 reaches the continuous powder injection stop value and before the target value is reached. The supply amount of the A agent from 4 per unit time is the supply of the A agent from the hopper 4 before the electric conductivity of the solution detected by the electric conductivity meter 30 reaches the continuous powder injection stop value. Make it smaller than the amount. Then, the control unit 50 detects that the direction of change in the electric conductivity has changed from the increasing direction to the decreasing direction in the melting operation, and notifies the abnormality when the supply of the agent A from the hopper 4 is stopped. Perform processing. Further, when the process of notifying the abnormality is performed, the process of prohibiting the supply of the drug from the drug supply unit 63 may be performed.

FIG. 4 is a flowchart showing an outline of the procedure for controlling the melting operation in this embodiment. In this embodiment, it is detected that the direction of change in the electric conductivity changes from the increasing direction to the decreasing direction during the continuous powder injection period of the agent A. _{Further, in this embodiment, the maximum value (X max} ) of the electric conductivity in a predetermined period before a predetermined time from the present is obtained, and the current electric conductivity (X) decreases with respect to the _{maximum value (X max).} In this case (when _{the sign of the value of XX max} becomes negative), it is determined that the direction of change in electrical conductivity has changed from the increasing direction to the decreasing direction.

The definition of each symbol in FIG. 4 will be described. "P" is a target value [mS / cm] of electrical conductivity according to a predetermined concentration of the A agent in the A stock solution (for example, 194 mS / cm when the A agent is Rinpack TA-3 (manufactured by Nipro)). cm). “O” is an offset value [mS / cm] of the target value P of the electric conductivity (for example, −0.3 mS / cm in the case of Rinpack TA-3). This offset value is provided because it takes a certain time for the electric conductivity to fully increase after the agent A is supplied. “X” is the current measured value of electrical conductivity [mS / cm]. "X _max " is the maximum value [mS / cm] of the electric conductivity between 12 seconds and 6 seconds before the present time. "P1" is a continuous powder injection stop value [mS / cm] which is a reference value of the electric conductivity for stopping the control of continuously supplying the agent A (for example, 187 mS / cm in the case of Rinpack TA-3). cm). In this embodiment, the procedure shown in FIG. 4 (measurement of electrical conductivity X) is performed at intervals of about 0.3 seconds. However, this measurement interval depends on the processing speed of the sequencer and the like, and is not limited to the value of this embodiment. “P”, “O”, and “P1” are stored in advance in the storage unit 52 of the control unit 50, and “X _max ” is obtained by the controller 51 of the sequential control unit 50 and stored in the control unit 50. It is stored in the part 52.

When the melting operation is started, the control unit 50 determines whether or not the current measured value of electrical conductivity has reached the target value (whether or not X ≧ P + O is satisfied) (S101). When the control unit 50 determines “No” in S101, it determines whether or not the current measured value of electric conductivity has reached the continuous powder injection stop value (whether or not X <P1 is satisfied) (whether or not X <P1 is satisfied). S102). When the control unit 50 determines “Yes” in S102, whether or not the current measured value of electrical conductivity is smaller than the maximum value of electrical conductivity in a predetermined period before a predetermined time from the present (X <X _max) . Whether or not it is satisfied) is determined (S103). When the control unit 50 determines "No" in S103, the control unit 50 continuously drives the drive motor of the hopper 4 to continuously supply the agent A (S104).

On the other hand, when the control unit 50 determines "Yes" in S103, the control unit 50 stops the drive motor of the hopper 4 and stops the supply of the agent A (S105). Then, the control unit 50 determines that an abnormality in which the electric conductivity decreases has occurred (S106), and shifts to an alarm process for notifying the abnormality (S107). In the alarm processing, the display unit 42 of the operation unit 40 displays a candidate for the cause of the abnormality, displays a message prompting the user to visually check the piping, etc., and removes undissolved powder chemicals from the piping. It is possible to display a message prompting that. In the alarm process, the lamp is turned on, a voice such as a buzzer or an announcement is generated, and information for notifying an abnormality to an external device (personal computer or the like) communicably connected to the melting device 1 is transmitted. It may be something like that. Further, when the dissolving device 1 has the manual supply function of the agent A, the control unit 50 prevents the agent A from being supplied by the manual supply function in addition to or instead of the alarm processing in S107. Prohibition processing can be performed. The prohibition of the supply of the agent A by this manual supply function indicates that the control unit 50 has visually confirmed, for example, a predetermined input in the input unit 41 of the operation unit 40 by the operator, piping, or the like. It may be canceled according to the detection result of opening / closing of.

Further, when the control unit 50 determines "No" in S102, the control unit 50 switches the drive of the drive motor of the hopper 4 from continuous drive to intermittent drive (S108). If the control unit 50 determines "Yes" in S101, the control unit 50 stops the drive motor of the hopper 4 and ends the supply of the agent A (ends the melting operation) (S109).

_{In this embodiment, the current measured value X of the electric conductivity is compared with the maximum value X max} of the electric conductivity in a predetermined period before a predetermined time from the present, and the following method is exemplified as a modification. can. For example, when the maximum value between 8 seconds ago and 4 seconds ago is M1 and the maximum value between the present and 4 seconds ago is M0, M0 decreases with respect to M1 (the value of M0-M1). When the sign becomes negative), it may be determined that the direction of change in the electric conductivity has changed from the increasing direction to the decreasing direction. In addition, the electric conductivity is measured at regular intervals (for example, every 4 seconds), and when the sign of the differential value becomes negative, it is determined that the direction of change in the electric conductivity has changed from the increasing direction to the decreasing direction. You may.

As described above, in this embodiment, the direction of change in the electric conductivity changed from the increasing direction to the decreasing direction during the continuous powder injection period of the agent A in which the pipe is likely to be clogged with the undissolved powder agent. It is possible to detect that and stop the supply of the agent A. As a result, it is possible to prevent an excessive supply of the agent A and prevent problems such as clogging of the piping in the dissolving apparatus 1 with the undissolved agent A.

[Example 2]
Next, another embodiment of the present invention will be described. The basic configuration and operation of the melting apparatus of this embodiment are the same as those of the first embodiment. Therefore, in the dissolution apparatus of the present embodiment, the elements having the same or corresponding functions or configurations as those of the dissolution apparatus of the first embodiment are designated by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted.

FIG. 5 is a flowchart showing an outline of the procedure for controlling the melting operation in this embodiment. In this embodiment, it is detected that the direction of change in the electric conductivity changes from the increasing direction to the decreasing direction regardless of whether the agent A is in the continuous powder injection period or the intermittent powder injection period. Further, in this embodiment, it obtains the moving average of the measured values of a predetermined number of electrical conductivity was measured every predetermined time, the current moving average relative previous moving average _{(X n-1) (X} n) There when decreased (when the sign of X n _{-X n-1} value becomes negative), the direction of the electrical conductivity change is determined to have changed in the decreasing direction from the increasing direction.

The definition of each symbol in FIG. 5 will be described. "P" is the target value of electrical conductivity (for example, 194 mS / cm when the agent A is Rinpack TA-3), and "O" is the offset value (for example, -0.3 mS when the agent A is Rinpack TA-3). / Cm), "X" are the current measured values of electrical conductivity, which are the same as those described in Example 1, respectively. “P1” is the value of the electric conductivity (for example, 192.0 mS / cm in the case of Rinpack TA-3) that does not execute the determination process of the decreasing direction of the electric conductivity, and “X _n ” is the moving average of this time. The values [mS / cm] and "X _n-1 " are the values of the previous moving average [mS / cm]. In this embodiment, the measurement interval Tx of the electric conductivity is 4 seconds, and the interval Tc for performing the procedure shown in FIG. 5 (confirmation of the decrease in the electric conductivity) is 4 seconds. Further, in this embodiment, the number of measured values of the electric conductivity for obtaining the moving average is five. That is, the moving average _Xn this time is the average value of the measured values of the electric conductivity at present, 4 seconds ago, 8 seconds ago, 12 seconds ago, and 16 seconds ago. Further, the previous moving average _Xn-1 is an average value of the measured values of the electric conductivity 4 seconds ago, 8 seconds ago, 12 seconds ago, 16 seconds ago, and 20 seconds ago. “P”, “O”, and “P1” are stored in advance in the storage unit 52 of the control unit 50, and “X _n ” and “X _n-1 ” are obtained by the controller 51 of the sequential control unit 50. It is stored in the storage unit 52 of the control unit 50.

When the melting operation is started, the control unit 50 determines whether or not the current measured value of electrical conductivity has reached the target value (whether or not X ≧ P + O is satisfied) (S201). When the control unit 50 determines "No" in S201, whether or not the current measured value of the electric conductivity has reached the value of the electric conductivity that does not execute the determination process of the decreasing direction of the electric conductivity (X>). Whether or not P1 is satisfied) is determined (S202). When the control unit 50 determines “No” in S202, whether or not the current moving average of the measured value of the electric conductivity is smaller than the previous moving average (whether or not X _n <X _n-1 is satisfied). Is determined (S203). When the control unit 50 determines "No" in S203, the control unit 50 continuously or intermittently (intermittently) drives the drive motor of the hopper 4 to supply the agent A continuously or intermittently according to the value of X. (S204).

On the other hand, when the control unit 50 determines "Yes" in S203, the control unit 50 stops the drive motor of the hopper 4 and stops the supply of the agent A (S205). Then, the control unit 50 determines that an abnormality in which the electrical conductivity decreases has occurred (S206), and shifts to an alarm process for notifying the abnormality (S207). As described in the first embodiment, the control unit 50 can perform a prohibition process in S207 to prevent the supply of the agent A by the manual supply function in addition to or instead of the alarm process. ..

Further, when the control unit 50 determines "Yes" in S202, the control unit 50 continuously or intermittently drives the drive motor of the hopper 4 according to the value of X without performing the determination process of the decreasing direction. The agent is continuously or intermittently supplied (S204). For the sake of simplification, in FIG. 5, the drive motor of the hopper 4 is represented as the same step both continuously and intermittently. If the control unit 50 determines "Yes" in S201, the control unit 50 stops the drive motor of the hopper 4 to end the supply of the agent A (end the melting operation) (S208).

In this embodiment, the measurement interval of the electric conductivity is 4 seconds, and the number of the measured values of the electric conductivity for which the moving average is obtained is 5, but these are all limited to the values of the present embodiment. Rather, it can be appropriately set so that it can be detected with sufficient accuracy that the direction of change in electrical conductivity has changed from the increasing direction to the decreasing direction at the earliest possible time.

As described above, in this example, the direction of change in the electric conductivity changed from the increasing direction to the decreasing direction regardless of whether the agent A was in the continuous powder injection period or the intermittent powder injection period. Can be detected and the supply of the A agent can be stopped. This makes it possible to more reliably prevent the excessive supply of the A agent and prevent problems such as clogging of the piping in the dissolving apparatus 1 with the undissolved A agent.

[Other Examples]
Although the present invention has been described above with reference to specific examples, the present invention is not limited to the above-mentioned examples.

In the above-mentioned example, the dissolving device prepares the A stock solution which is a concentrated solution of the A agent of the dialysate, but it may prepare the B stock solution which is the concentrated solution of the B agent of the dialysate. good. Also in this case, for example, when the agent A is mixed with the agent B, or when the sensitivity of the electric conductivity meter is lowered due to the adhesion of deposits on the surface of the electrode, the electric conductivity does not reach the target value. It may continue to supply powdered medicine. Then, in that case, due to the influence of the supersaturated agent B or the agent B precipitated by the mixing of the agent A, the direction of change in the electric conductivity is increasing before the electric conductivity reaches the target value. It changes in the decreasing direction from. In addition, the dissolving device prepares the A stock solution from the A agent divided into two agents, the A-1 agent (the glucose component of the A agent is removed) and the A-2 agent (the glucose component of the A agent). You may. Conventionally, the A-1 agent is dissolved in water to prepare an A-1 agent solution having a predetermined concentration, and then the A-2 agent is added to this solution to contain the predetermined A-1 agent and the A-2 agent. A A method for preparing a stock solution to be prepared is known. In this case as well, the electric conductivity is the target value when the A-2 agent or the B agent is mixed with the A-1 agent, or when the sensitivity of the electric conductivity meter is lowered due to the adhesion of the deposit on the surface of the electrode. The powdered drug may continue to be supplied without reaching. Then, in that case, the electric conductivity is affected by the influence of a part of the electrolyte component of the supersaturated A-1 agent, the non-electrolyte component due to the mixing of the A-2 agent, the B agent precipitated by the mixing of the B agent, and the like. The direction of change in the electric conductivity changes from an increasing direction to a decreasing direction before the target value is reached. Therefore, by applying the present invention to the dissolution operation of the agent B and the dissolution operation of the agent A-1 in this way, as in the above-mentioned Examples, it is possible to prevent excessive supply of the powdered agent and to prevent the powdered agent from being dissolved. It is possible to prevent problems such as clogging of the piping inside the dissolving device with the powdered chemicals.

Further, in the above-described embodiment, when it is detected that the direction of change in the electric conductivity has changed from the increasing direction to the decreasing direction before the electric conductivity of the solution reaches the target value, the powdered drug is supplied. It stopped. On the other hand, from the viewpoint of stopping the supply of the powdered drug earlier, the electric conductivity of the solution changed from the increasing direction to the decreasing direction before reaching the target value. If it is detected that the electric conductivity does not increase before the detection of the above, the supply of the powdered drug may be stopped. That is, for example, in the case of the dissolution operation of the agent A, as can be seen from FIGS. 2 and 3, the electric conductivity of the solution reaches the target value due to the state of supersaturation of a part of the electrolyte component of the agent A. Before, the rate of increase (the ratio of the increase in electrical conductivity to the amount of powdered drug supplied) decreases, the increase ends, and the direction of change eventually becomes the decreasing direction. Therefore, if it is detected that the electric conductivity of the solution does not increase before the electric conductivity of the solution reaches the target value (or the reference value such as the continuous powder injection stop value lower than the target value), the drug is used. By stopping the supply of the powdered drug, the supply of the powdered drug can be stopped earlier. The reason why the electric conductivity of the solution does not increase is that, for example, the change width (increase width) of the representative value (average value, maximum value, etc.) in a predetermined period becomes less than or equal to the predetermined threshold value, and the change rate (increase rate). ) Is below a predetermined threshold, and so on. The fact that the electric conductivity does not increase means not only that the increase is completely completed, but also that the rate of increase is sufficiently smaller than that expected at normal times.

Further, in the above-described embodiment, the dissolution device is configured independently and the stock solution for dialysis is supplied to a separately prepared dialysate supply device. However, the dissolution device of the present invention is a dialysate supply device or a dialysis device. It may be integrated with, or it may be used as a set with a specific dialysate supply device or dialysate device. That is, the dissolving apparatus of the present invention can form a part of a dialysis system.

1 Dissolving device 2 Dissolving tank 3 Storage tank 4 Hopper 5 Water receiving tank 50 Control unit 61 Dissolving unit 62 Water supply unit 63 Drug supply unit

Claims (5)

Melting part and
A water supply unit that supplies water to the melting unit and
A drug supply unit that supplies powdered dialysis drug to the dissolution unit,
An electric conductivity meter that detects the electric conductivity of a solution in which the drug is dissolved in water at the dissolving part,
A control unit that controls the drug supply unit based on the electric conductivity of the solution detected by the electric conductivity meter, and a control unit.
In a melting device with
In the dissolving operation of dissolving the drug in water at the dissolving unit, the control unit changes the electric conductivity before the electric conductivity of the solution detected by the electric conductivity meter reaches a target value. A dissolving apparatus, characterized in that the supply of the drug from the drug supply unit is stopped when it is detected that the direction has changed from the increasing direction to the decreasing direction or the electrical conductivity has stopped increasing. In the melting operation, the control unit increases the direction of change in the electric conductivity before the electric conductivity of the solution detected by the electric conductivity meter reaches a reference value lower than the target value. The melting apparatus according to claim 1, wherein the supply of the drug from the drug supply unit is stopped when it is detected that the change in the direction of decrease or the electric conductivity does not increase. .. In the dissolution operation, the control unit receives the drug from the drug supply unit after the electric conductivity of the solution detected by the electric conductivity meter reaches the reference value and before the target value is reached. The supply amount per unit time is made smaller than the supply amount of the drug from the drug supply unit before the electric conductivity of the solution detected by the electric conductivity meter reaches the reference value. The melting apparatus according to claim 2, wherein the solution device is characterized by the above. The one according to any one of claims 1 to 3, wherein the control unit performs a process of notifying an abnormality when the supply of the drug from the drug supply unit is stopped in the dissolution operation. Melting device. Claims 1 to 4 are characterized in that the control unit performs a process of prohibiting the supply of the drug from the drug supply unit when the supply of the drug from the drug supply unit is stopped in the dissolution operation. The melting apparatus according to any one of the above.

Images