JP2016182256A - Peritoneal dialyzer and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology to feed a peritoneal dialysis fluid more accurately.SOLUTION: A peritoneal dialyzer for heating a dialysis fluid supplied from a dialysate bag at a heating part, and injecting the heated dialysis fluid in the abdominal cavity includes: fluid feeding means for feeding the dialysis fluid by repetitively pressing a diaphragm pump; temperature measurement means for measuring the temperature of gas used for pressing the diaphragm pump; and calculation means for calculating a fluid amount fed by the fluid feeding means at least based on the temperature of gas measured by the temperature measurement means.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid feeding technique in a peritoneal dialysis device.

  In recent years, peritoneal dialysis apparatuses configured so that patients themselves can perform peritoneal dialysis at home or the like have become widespread. For example, Patent Document 1 discloses a peritoneal dialysis apparatus that uses a cassette in which a diaphragm for feeding peritoneal dialysis fluid and a heating tube are integrally formed. By the way, in peritoneal dialysis, accurately injecting an appropriate amount of peritoneal dialysis solution into the abdominal cavity of a patient is important for improving the therapeutic effect. Therefore, Patent Document 1 also discloses a method for measuring the amount of injected peritoneal dialysis fluid.

JP 2008-167935 A

  By the way, in recent years, in the peritoneal dialysis apparatus, application to the Tidal method and pediatric patients has been studied. When targeting these applications, the amount of peritoneal dialysis fluid injected into and discharged from the abdominal cavity is smaller than before, so the effect of the error in the amount of fluid delivered in the peritoneal dialysis device is relatively large. become. For this reason, it is expected to realize a technique capable of controlling the liquid feeding amount more accurately.

  This invention is made | formed in view of such a problem, and it aims at providing the technique which enables liquid delivery of a more accurate peritoneal dialysate.

  In order to solve the above-described problems, a peritoneal dialysis device according to the present invention has the following configuration. That is, in a peritoneal dialysis apparatus configured to heat dialysate supplied from a dialysate bag in a heating section and inject the warmed dialysate into the abdominal cavity, the dialysate is repeatedly pressed by a diaphragm pump. A liquid feeding means for sending the liquid, a temperature measuring means for measuring the temperature of the gas used to press the diaphragm pump, and a liquid feeding amount by the liquid feeding means based on at least the temperature of the gas measured by the temperature measuring means Calculating means for calculating.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which enables the liquid delivery of a more exact peritoneal dialysate can be provided.

It is a figure which shows the peritoneal dialysis apparatus and cassette which concern on 1st Embodiment. It is a figure explaining the connection structure of the liquid feeding path containing a cassette. It is a figure which shows an example of a structure of a flow-path switching part. It is a figure which shows the functional block of the peritoneal dialysis apparatus which concerns on 1st Embodiment. It is a figure which shows the cross section of the pump chamber which presses a diaphragm pump. It is a flowchart which shows the outline of the liquid feeding procedure of a dialysate. It is a figure explaining the liquid feeding error resulting from the amount of liquid feeding per pumping, and its reduction method. It is a figure which shows the state of the dialysate in the heating tube 103 accompanying a priming and a leak check exemplarily. It is a figure which shows the table containing a several parameter set illustratively.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are merely examples, and are not intended to limit the scope of the present invention.

(First embodiment)
As a first embodiment of the peritoneal dialysis apparatus according to the present invention, a peritoneal dialysis apparatus using a replaceable cassette will be described below as an example.

<1. Device configuration>
FIG. 1 is a diagram showing a peritoneal dialysis device and a cassette according to the first embodiment. Here, only the part related to the present invention will be described.

  The peritoneal dialyzer 100 is equipped with a cassette 101 for injecting peritoneal dialysate into the abdominal cavity. The peritoneal dialysis device 100 includes a cassette mounting unit 106, operation units 107a and 107b, and a display unit 108. The cassette 101 includes a diaphragm pump 102 that is a pump, a heating tube 103, a flow path switching unit 104, and a connection tube 105. Details of the connection tube 105 will be described later with reference to FIG.

  The cassette 101 is mounted on the cassette mounting unit 106. The operation units 107a and 107b are used, for example, for inputting a start instruction when the user (patient) starts peritoneal dialysis and an end instruction when ending the peritoneal dialysis. The display unit 108 notifies the user (patient) of information, and for example, notifies the operating state of the peritoneal dialysis device 100. Here, the operating state indicates, for example, a state in which the injection process for injecting the dialysate into the abdominal cavity or the drainage process for discharging the dialysate from the abdominal cavity is completed.

  The cassette 101 includes a diaphragm pump 102, a heating tube 103, a flow path switching unit 104, and a connection tube 105.

  The diaphragm pump 102 functions as a pump for feeding dialysate by expanding / contracting. The diaphragm pump 102 is housed in a sealed state by a flange member, and is tensioned and pressed by being decompressed and pressurized by air pressure from the outside. In addition to the air pressure, a piston or the like is arranged on the surface of the diaphragm pump 102, and it can be tensioned and pressed by pulling and pushing them. Thus, the diaphragm pump 102 is configured to expand when pressurized and to contract when pressed to deliver dialysate. The operation of the diaphragm pump 102 accompanying tension and pressing will be described later with reference to FIG.

  The heating tube 103 heats the dialysate flowing through the heating tube 103. Specifically, the warming tube 103 warms the dialysate by being sandwiched by a heater disposed in the peritoneal dialysis apparatus 100. In the heating tube 103, for example, a maximum of about 40 mL of dialysate is accommodated.

  The channel switching unit 104 switches the dialysate channel in a tube stretched around the cassette 101. For example, the flow path is switched by pressing one or more portions of the tube in the flow path switching unit 104 with one or more clamps arranged in the peritoneal dialysis device 100. Mainly, the flow path switching unit 104 switches to a flow path for liquid injection processing or drainage processing. For example, when injecting a dialysate contained in a dialysate bag, which will be described later, the flow path for the liquid injection process is a dialysate bag, a diaphragm pump 102, a heating tube 103, and a dialysis catheter connected to the cassette 101. It becomes a flow path that leads in order. On the other hand, the flow path for drainage treatment is a flow path that leads in the order of the dialysis catheter, the drainage treatment tube of the flow path switching unit 104, the diaphragm pump 102, and the drainage treatment tank 202 described later.

  Furthermore, the flow path switching unit 104 opens or blocks a flow path through which the peritoneal dialysate flows from the heating tube 103 to the tube. For example, the flow channel switching unit 104 opens the flow channel when performing peritoneal dialysis, and blocks the flow channel after the peritoneal dialysis is completed. This blocking is also performed in a priming operation for filling the heating tube 103 with dialysate and a leak check operation for detecting a leak of dialysate in the flow path. Here, the flow path switching unit 104 that opens or blocks the flow path is described as being formed by a clamp, but the flow path switching unit 104 may be configured to switch the flow path by other methods. Good.

  Constituent materials for the above-described diaphragm pump 102, heating tube 103, and tube stretched around the cassette 101 are soft resins such as polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-vinyl acetate. Polyolefin such as polymer (EVA), polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, poly- (4-methylpentene-1), ionomer, acrylic resin, polyethylene terephthalate (PET), polybutylene terephthalate ( PBT) and other polyesters, styrene-based, polyolefin-based, polyvinyl chloride-based, polyurethane-based, polyester-based, polyamide-based and other thermoplastic elastomers, silicone resins, polyurethanes, etc. Copolymer, blend that, mentioned polymer alloy or the like, can be used singly or in combination of two or more of these (e.g., a laminate of two or more layers).

  FIG. 2 is a diagram illustrating a connection configuration of a liquid supply path including a cassette. Here, in addition to the structure demonstrated in FIG. 1, the element connected to the connection tube 105 is demonstrated. Therefore, the same elements as those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.

  A dialysis catheter 201, dialysate bags 203 a and 203 b, and a drainage treatment tank 202 are connected to the cassette 101 through a connection tube 105. Dialysis catheter 201 is a tube having one end connected to cassette 101 and the other end configured to be connected to abdominal cavity 204. The cassette 101 performs a liquid injection process for injecting a dialysate into the abdominal cavity 204 and a drainage process for discharging the dialysate from the abdominal cavity 204 through the dialysis catheter 201. The dialysate bags 203a, 203b contain dialysate that is injected into the abdominal cavity 204 of the patient. The drainage treatment tank 202 stores used dialysate discharged from the abdominal cavity 204 of the patient.

  The flow path switching unit 104 is provided with a plurality of openings. When the cassette 101 is attached to the peritoneal dialysis device 100, the clamp of the peritoneal dialysis device 100 is operated, so that the openings are passed through the openings. Thus, predetermined positions of the liquid injection path and the liquid discharge path in the flow path switching unit 104 are clamped.

  FIG. 3 is a diagram illustrating an example of the configuration of the flow path switching unit. In FIG. 3, rectangles indicated by C <b> 1 to C <b> 8 indicate positions where the occlusion is controlled by the clamp of the peritoneal dialysis device 100. A predetermined flow path is set by simultaneously closing one or more of C1 to C8 by the clamp.

  The diaphragm pump 102 is configured to be tensioned and pressed from the outside through an opening provided in the cassette 101. Thus, when the cassette 101 is mounted on the peritoneal dialysis device 100, the pumping operation portion of the peritoneal dialysis device 100 is pumped to cause the diaphragm pump 102 to repeat expansion / contraction, that is, a pump chamber including the diaphragm pump 102. The inside is repeatedly changed between a pressurized state and a reduced pressure state. As a result, the dialysate feeding is controlled.

  Both ends of the channel of the heating tube 103 are connected to the channel switching unit 104. Here, the dialysate of the flow path switching unit 104 is injected into the heating tube 103 through one end that is an inlet, and returns to the flow path switching unit 104 through the other end that is an outlet.

  Note that the heating tube 103 is disposed outside the cassette 101 so as to be exposed through an opening. Thereby, the surface heater of the peritoneal dialysis apparatus 100 can heat the heating tube 103 in a state where the cassette 101 is mounted on the peritoneal dialysis apparatus 100.

  FIG. 4 is a functional block diagram of the peritoneal dialysis device according to the first embodiment. Here, only the main functional blocks of the peritoneal dialysis device 100 are described, but other functional blocks may be included.

  The peritoneal dialysis device 100 includes a CPU 401, operation units 107a and 107b, a power supply circuit 403, a flow rate control unit 404, a storage unit 405, a flow rate measurement unit 406, a switching control unit 408, a heater control unit 409, a heater 411, and a pumping operation unit 410. Including. The CPU 401 performs overall control of each functional block by executing a control program stored in the storage unit 405, for example.

  As shown in FIG. 1, the operation units 107 a and 107 b are arranged on the outer surface of the peritoneal dialysis device 100, receive input from the operator, and notify the CPU 401. For example, the operation units 107a and 107b are used to instruct the start of treatment by the operator when starting peritoneal dialysis. The power supply circuit 403 supplies power to the CPU 401. The flow rate controller 404 controls the diaphragm pump 102 to feed a dialysate of a predetermined amount (a liquid feed target amount). The storage unit 405 stores in advance various control programs executed by the CPU 401 and parameters necessary for performing peritoneal dialysis.

  The switching control unit 408 controls the channel of the dialysate by controlling the channel switching unit 104. The heater control unit 409 controls the temperature of the heater 411. The pumping operation unit 410 controls the pressure and pressure applied to the diaphragm pump 102 by reducing or pressurizing the pump chamber including the diaphragm pump 102, thereby controlling the dialysate feeding. Therefore, the flow control unit 404 instructs the pumping operation unit 410 to control the tension / pressure of the diaphragm pump 102 according to the amount of dialysate to be sent during peritoneal dialysis.

  According to the first embodiment, the flow rate measuring unit 406 measures the amount of dialysate injected into the abdominal cavity. For example, the flow rate measurement unit 406 calculates and integrates the amount of dialysate sent from the diaphragm pump 102 for each press from the start to the end of injection of dialysate into the abdominal cavity.

  Further, the CPU 401 receives signals from the temperature sensor 412 and the bubble sensor 413 arranged in the cassette 101. The temperature sensor 412 is one or more temperature sensors arranged in the peritoneal dialysis device 100. For example, in order to appropriately control the temperature of the dialysate injected into the abdominal cavity, the temperature of the dialysate sent from the dialysate bag to the diaphragm (the temperature before heating), the solution sent from the heating tube to the dialysis catheter 201 Measure the temperature of the dialysate (temperature after heating). As the temperature sensor 412, it is desirable to use a thermopile infrared sensor (non-contact type temperature sensor) having a very fast response speed. Thereby, the heater control unit 409 can control the temperature of the heater with high accuracy. The bubble sensor 413 is disposed on the inlet side and the outlet side of the dialysate in the flow path switching unit 104 and detects bubbles in the dialysate.

<2. General operation of the device>
As described above, the peritoneal dialysis device 100 feeds the dialysate by changing the inside of the pump chamber including the diaphragm pump 102 between a pressurized state and a reduced pressure state. For example, when performing the liquid injection process, first, the switching control unit 408 sets the dialysate bag 203a and the diaphragm pump 102 to communicate with each other through the flow path switching unit 104, and the pumping operation unit 410 performs pressure reduction. . Thereby, the dialysate flows into the diaphragm pump 102 from the dialysate bag 203a. Next, the switching control unit 408 applies pressure in a state where the diaphragm pump 102 and the heating tube 103 are communicated by the flow path switching unit 104. As a result, the dialysate accumulated in the diaphragm pump 102 is pushed out to the heating tube 103, and liquid feeding is performed.

<2.1. Calculation of liquid delivery amount>
The flow rate measurement unit 406 of the peritoneal dialysis device 100 derives the amount of dialysate sent by calculation in accordance with the pumping operation of the diaphragm pump 102 during the injection process of the dialysate. This is derived according to Boyle-Charles' law. With reference to FIG. 5, a method for measuring the amount of dialysate sent from diaphragm pump 102 will be described.

  FIG. 5 is a view showing a cross section of a pump chamber 510 that tensions and presses the diaphragm pump. In the tube 501, as indicated by an arrow 504, the flow of the dialysate 503 varies depending on whether it is supplied or sent.

  FIG. 5A shows a state in which the dialysis fluid 503 is filled in the diaphragm pump 102. The filling of the dialysate 503 is performed by increasing the pressure of the diaphragm pump 102 by reducing the pressure of the pump chamber 510 in a state where the diaphragm pump 102 and the dialysate bag 203a are in communication. The diaphragm pump 102 includes a film 502 formed of a soft material. Therefore, when the dialysate 503 is filled in the diaphragm pump 102, as shown in FIG. 5A, the membrane 502 expands, so that the volume in the diaphragm pump 102 increases and the volume in the pump chamber 510 becomes V1.

  When the dialysate 503 is filled, the flow is switched by pressing the diaphragm pump 102 by applying pressure (air pressure) P1 to the pump chamber 510 in a state where the diaphragm pump 102 and the heating tube 103 are in communication. The dialysate 503 is fed to the heating tube 103 through the tube in the unit 104.

  FIG. 5B shows a state after the dialysate 503 filled in the diaphragm pump 102 is fed. When the pressure P1 is applied, the membrane 502 is pushed toward the inside of the diaphragm pump 102 filled with the dialysate 503, and sends out the dialysate 503 toward the tube in the flow path switching unit 104. Further, as the position of the membrane 502 moves, the volume in the pump chamber 510 becomes V2 as shown in FIG. 5B.

  Here, the conditional expression V1 <V2 holds. Also, according to Boyle-Charles' law, PV / T is always constant. Here, assuming that the temperature (absolute temperature) near the diaphragm pump 102 during peritoneal dialysis is substantially constant, PV becomes constant (Boil's law). That is, when the volume in the pump chamber 510 increases from V1 to V2, the pressure P1 decreases to the pressure P2.

  Using this principle, the flow rate measuring unit 406 derives the amount of dialysate sent. A specific procedure will be described. The flow rate measuring unit 406 measures the pressure using a pressure sensor while liquid feeding by pumping is being performed. As described above, the pressure P1 is the pressure at the time of pressurization while the dialysate 503 is filled in the diaphragm pump 102. Further, the pressure P2 is a pressure that is lower than the pressure P1 in a state where the dialysate 503 in the diaphragm pump 102 has completely flowed out. Therefore, when the pressure sensor detects the pressure P2, the measurement unit 407 measures that the dialysate 503 having a volume corresponding to the volume in the diaphragm pump 102 has been sent.

  For example, the peritoneal dialysis device 100 stores the pressure P1 in the storage unit 405 in advance as 140 mmHg (18.7 kPa) and the pressure P2 as 50 mmHg (6.7 kPa). Therefore, the flow rate measuring unit 406 measures a change in pressure between the stored pressure P1 and pressure P2.

<3. Outline of liquid feeding control>
FIG. 6 is a flowchart showing an outline of a dialysate feeding procedure. The CPU 401 performs overall control of the procedure described below. The following processing includes apparatus connection settings (dialysis solution bag 203a, connection of dialysis catheter 201 to cassette 101 and setting of cassette 101 to peritoneal dialysis apparatus 100) and liquid supply settings from the user (liquid supply). The setting of the amount of dialysate to be performed, etc.) is completed, and is started based on the start instruction of the dialysis operation by the operation of the operation units 107a and 107b by the user.

  In step S601, the CPU 401 controls to perform a priming operation for filling the warming tube 103 with the dialysate. Specifically, the switching control unit 408 is controlled, and the path to the heating tube 103 is set in the flow path switching unit 104. Thereafter, the pumping operation unit 410 is controlled to press the diaphragm pump 102 and fill the warming tube 103 with the dialysate.

  In step S <b> 602, the CPU 401 controls to perform a leak check operation for inspecting leakage of dialysate in the liquid supply path from the diaphragm pump 102 to the heating tube 103. Specifically, the pumping operation unit 410 is controlled to further press the diaphragm pump 102 and push the dialysate toward the heating tube 103. If a leak is detected in the leak check operation, the process ends with an error. Note that step S601 and step S602 may be performed in the reverse order, or one of them may be performed.

  In step S <b> 603, the CPU 401 controls the pumping operation unit 410 to perform liquid feeding by pumping of the diaphragm pump 102. Specifically, the switching control unit 408 is controlled so that the diaphragm pump 102 and the dialysate bag 203a communicate with each other in the flow path switching unit 104. Thereafter, the pumping operation unit 410 is controlled to suck the dialysate into the diaphragm pump 102. Further, the switching control unit 408 is controlled to set a route to the dialysis catheter 201 via the heating tube 103 in the flow path switching unit 104. Thereafter, the pumping operation unit 410 is controlled to press the pumping of the diaphragm pump 102.

  In step S604, the CPU 401 calculates the liquid feeding amount by the pumping operation in S603. Specifically, the pressure of the diaphragm pump 102 is monitored, and the amount of dialysate sent is calculated. As described above, this calculation is performed according to Boyle-Charles' law. In the second and subsequent loops via S605, an integrated value obtained by adding the amount of dialysate fed up to the preceding loop to the amount of fluid fed in the current loop is also calculated.

  In step S605, the CPU 401 determines whether or not a target amount of dialysate has been supplied. When the dialysate of the target liquid supply amount is supplied, the liquid supply process is terminated, and when it is not supplied, the process proceeds to S603.

In this way, a target amount of dialysate is injected into the abdominal cavity of the patient. Incidentally, the liquid feeding procedure shown in FIG. 6 includes operations that may cause some liquid feeding errors. Specifically, it is considered that liquid feeding errors can occur at the following three points.
(I) Pumping (S603) A liquid feeding error caused by a liquid feeding amount per one time.
(II) Error due to the dialysate injected into the heating tube 103 in the priming (S601) and leak check (S602).
(III) Liquid feed amount calculation depending on temperature non-uniformity (S604) error.

  Therefore, a method for reducing the liquid feeding error with respect to these three points will be described below.

<3.1. (I) Pumping (S603) Reduction of liquid feeding error due to liquid feeding amount per time>
As described above, the peritoneal dialysis device 100 sends a target amount of dialysate to the patient's abdominal cavity by repeatedly pressing the diaphragm pump 102 of the cassette 101. Therefore, as shown in FIG. 5, the minimum unit of liquid feeding is the volume in the diaphragm pump 102.

  FIG. 7A is a diagram for explaining a liquid feeding error caused by a liquid feeding amount per pumping (S603). Here, when the amount that is smaller by the amount corresponding to the amount of the liquid that is pressed once (18 mL that is the volume in the diaphragm pump 102) is set as the threshold value from the target value of the liquid supply, and the integrated value of the liquid supply exceeds the threshold value In the following, an example in the control of determining the subsequent one press as the final press is shown. In the case of such control, in the case of the liquid feeding pattern shown by the “worst case” in the upper part of FIG. 7A, approximately 18 mL of liquid feeding excess occurs.

  For example, by using a diaphragm pump having a small volume, it is possible to reduce the liquid feeding error, but in that case, it takes a longer time to complete the liquid feeding. Therefore, here, it is considered to reduce the pressing amount of the diaphragm pump 102 and reduce the liquid feeding amount per time. The control of the pressing amount of the diaphragm pump 102 is realized, for example, by changing the opening time of the valve that connects the positive pressure tank and the pump chamber (that is, the length of one pressing period).

  FIG. 7B is a diagram for explaining the control for reducing the liquid feeding error. As shown in the figure, a first threshold value that is smaller by a predetermined amount than the liquid delivery target value is set, and when the first threshold value is exceeded, the pressure on the diaphragm pump 102 is changed to the first pressure amount in the preceding pressure. The pressure is changed to a second pressing amount (here, a pressing amount equivalent to 4 mL) smaller than (the pressing amount corresponding to 18 mL here). In consideration of the responsiveness of the diaphragm pump 102 and the like, the liquid feed target value is twice to ten times the liquid feed amount by the second pressing amount (7.5 times in FIG. 7B). ) Is preferably set as a first threshold value. On the other hand, the first threshold value may be set as a value depending on the liquid supply target value (for example, 80% of the target value).

  After the change to the second pressing amount, similarly to the case of FIG. 7A, an amount that is smaller by the amount corresponding to the amount of one pressing (four mL in this case) than the target value is set to the second threshold value. When the integrated liquid feeding value exceeds the second threshold value, the subsequent pressing is determined as the last pressing.

  By performing such control, the minimum unit of liquid feeding becomes small, and as a result, liquid feeding error is reduced. For example, in the above example, the maximum value of the liquid feeding error is reduced from 18 mL (the “worst case” in the upper part of FIG. 7A) to 4 mL (the “worst case” in the upper part of FIG. 7B). become. Further, before the change to the second pressing amount, the liquid feeding speed is the same as the conventional one, and after the change to the second pressing amount where the liquid feeding speed decreases, it is a short time, so the liquid feeding is completed. There is an advantage that it does not take a long time.

  In the above description, the first threshold value is set, and when the first threshold value is exceeded, the second pressing amount is changed. However, the above-described control may be performed only when the specified liquid supply target amount is small, and the pressing amount may not be changed when the liquid supply target amount is large (for example, 1000 mL or more). For example, when the liquid supply target amount is a predetermined amount or more, even if the liquid supply integrated value exceeds the first threshold value, the pressure on the diaphragm pump is not changed to the second press amount, and the liquid supply target value is not changed to the second press amount. When the liquid integrated value exceeds a third threshold value that is smaller than the liquid supply target amount by a third predetermined amount, the subsequent pressing is determined as the last pressing, and after the last pressing is completed, the pressing control is performed. Stop. Here, the third predetermined amount is set to the same amount as the amount of dialysate delivered by the first pressing amount.

<3.2. (II) Reduction of error due to dialysate injected into heating tube 103 in priming (S601) and leak check (S602)>
As described above, the peritoneal dialysis device 100 performs priming (S601) and leak check (S602) prior to feeding the dialysate to the abdominal cavity of the patient.

  FIG. 8 is a diagram exemplarily showing the state of the dialysate in the heating tube 103 accompanying priming (S601) and leak check (S602). In addition, the black rectangle of the flow path switching unit 104 in FIG. 8 indicates that the tube is closed by the clamp.

  As described with reference to FIG. 6, in the priming (S601), the heating tube 103 is filled with the dialysate, and in the leak check (S602), the dialysate is further pressurized and pushed into the heating tube 103. become. Therefore, when pumping (S603) is started after the leak check, the amount of dialysate remaining in the heating tube 103 is excessively increased. Although not all of the capacity (for example, 40 mL) of the heating tube 103 is an error, the amount of dialysate equivalent to the heating tube 103 due to pressurization of the leak check (S602) is changed from the heating tube 103 to the dialysis catheter 201. As soon as the blockage of the route to the release is released, there is a high possibility that the dialysate leaks into the dialysis catheter 201 due to the internal pressure of the heating tube 103. For example, 10-20 mL of dialysate leaks, leading to excess liquid delivery.

  Therefore, as shown in states 803 to 804 in FIG. 8, the dialysate remaining in the heating tube 103 is sucked by the diaphragm pump 102, and the sucked dialysate is dialyzed from the dialysate bag 203 a or the diaphragm pump 102. The liquid is supplied to the liquid supply path to the liquid bag 203a. That is, the dialysate remaining in the heating tube 103 is moved to another place that does not affect the liquid feeding control. When the dialysate remaining in the heating tube 103 is sucked by the diaphragm pump 102, as shown in a state 803, the dialysate is injected through an outlet portion different from the inlet portion into which the dialysate has been injected by priming and leak check. Suction is good.

  As described above, when the volume of the diaphragm pump 102 (here 18 mL) is smaller than the capacity of the heating tube 103 (here 40 mL), the suction operation (state 803) and the liquid feeding operation (state 804) are executed a plurality of times. May be. However, it is not necessary to move all of the dialysate remaining in the heating tube 103, and if at least a part of the dialysate is moved, the liquid feeding error is reduced. Therefore, the suction operation (state 803) and the liquid feeding operation (state 804) are performed. ) May be controlled to be executed only once.

  Further, since the liquid feeding error is reduced, it may be executed after the priming or (when the order of the priming operation and the leak check operation is reversed) after the leak check. In the case where only one of the priming operation and the leak check operation is performed, the operation may be executed after those operations.

  In the state 803 in FIG. 8, an example is shown in which the sucked dialysate is moved to the dialysate bag 203a. However, control may be performed so as to move to another location, for example, the drainage treatment tank 202.

  By performing such control, it is possible to reduce the amount of dialysis fluid remaining in the heating tube 103 leaking out to the dialysis catheter 201, and as a result, liquid feeding error is reduced.

<3.3. (III) Calculation of liquid feeding amount depending on temperature non-uniformity (S604) Reduction of error>
As described with reference to FIG. 5, the flow rate measuring unit 406 assumes that the temperature (absolute temperature T) around the diaphragm pump 102 is uniform (constant), and pressure (P) × volume based on Boyle's law. (V) = The liquid feeding amount was calculated as constant. However, actually, the ambient temperature of the peritoneal dialysis device 100 changes depending on the season, time, or air conditioning. Further, along with the operation of the peritoneal dialysis device 100, the temperature in the device also changes. For this reason, in the calculation formula that assumes that the temperature around the diaphragm pump 102 is constant, there is a possibility that an unacceptable error may occur in the calculation of the liquid feeding amount. For example, when the temperature difference is 20 degrees (the positive pressure tank temperature is, for example, 10 ° C. and the dialysate temperature is, for example, 30 ° C.), it is known that an error of about 5% occurs.

Therefore, as the temperature related to the diaphragm pump 102,
-Temperature (Tt) of the gas that presses the diaphragm (temperature of the gas stored in the positive pressure tank)
Dialysate temperature (Te) before heating (temperature of dialysate supplied from the dialysate bag 203a to the diaphragm pump 102)
The flow rate measuring unit 406 corrects and calculates the liquid feeding amount based on these temperatures.

  Specifically, in order to acquire the temperature of the gas that presses the diaphragm, the temperature sensor 412 is further configured to include a temperature sensor that measures the temperature of the positive pressure tank used for pressing the diaphragm. In addition, about the dialysate temperature before a heating, it is good to use the existing temperature sensor utilized also in the heating control in the heater control part 409.

  In this case, the liquid supply amount calculated on the assumption that pressure (P) × volume (V) = constant has the following calculation error.

Calculation error = K × (Te−Tt) + L × Tt + c (Formula 1)
(K, L, and c are predetermined constants)
When this equation is written down as an equation relating to Te and Tt, calculation error = a × Te + b × Tt + c (Equation 2)
(A, b and c are predetermined constants)
It becomes.

  Therefore, the set of values a, b, and c may be experimentally obtained in advance and stored in advance in the storage unit 405 such as a ROM as a parameter set. Then, the flow rate measurement unit 406 calculates a calculation error by substituting the measured temperature (Te and Tt) and a predetermined parameter set into (Expression 2), and pressure (P) × volume (V) = constant. It is preferable to perform a correction operation for correcting (compensating) the liquid supply amount calculated under the assumption, and to calculate a more accurate liquid supply amount.

  The set of values of a, b, and c varies depending on, for example, the change in the amount of liquid delivered per pumping described in section (3.1) above. Therefore, it is preferable to prepare a plurality of parameter sets corresponding to a plurality of different liquid feeding operations that the peritoneal dialysis device 100 has. When there are a plurality of types in the cassette 101, a parameter set may be prepared for each type of cassette.

  FIG. 9 exemplarily shows a state where the storage unit 405 stores a plurality of parameter sets in advance as a table.

  As described above, according to the first embodiment, it is possible to reduce the liquid feeding error that occurs in the liquid feeding procedure. As a result, it is possible to inject an appropriate amount of peritoneal dialysis solution into the patient's abdominal cavity more accurately, and it can be expected that the therapeutic effect is improved.

  In the first embodiment, three methods for reducing the liquid feeding error have been described, but these may be used in combination or may be used alone.

DESCRIPTION OF SYMBOLS 100 Peritoneal dialysis apparatus 101 Cassette 102 Diaphragm pump 103 Heating tube 104 Channel switching part 107a, 107b Operation part 401 CPU
403 Power supply circuit 404 Flow rate control unit 405 Storage unit 406 Flow rate measurement unit 408 Switching control unit 409 Heater control unit 410 Pumping operation unit 411 Heater 412 Temperature sensor 412 Bubble sensor

Claims (6)

A peritoneal dialysis device configured to heat dialysate supplied from a dialysate bag in a heating section and inject the warmed dialysate into the abdominal cavity,
A liquid-feeding means for sending dialysate by repeatedly pressing the diaphragm pump;
Temperature measuring means for measuring the temperature of the gas used for pressing the diaphragm pump;
Calculating means for calculating a liquid feeding amount by the liquid feeding means based on at least the temperature of the gas measured by the temperature measuring means;
A peritoneal dialysis device comprising: The peritoneal dialysis apparatus according to claim 1, wherein the temperature measuring means measures a temperature of a positive pressure tank storing the gas. A second temperature measuring means for measuring the temperature of the dialysate supplied from the dialysate bag to the diaphragm pump;
The calculating means calculates the amount of liquid fed by the liquid feeding means based on the temperature of the gas measured by the temperature measuring means and the temperature of the dialysate measured by the second temperature measuring means. The peritoneal dialysis apparatus according to claim 1 or 2. 4. The peritoneal dialysis device according to claim 3, wherein the temperature of the dialysate measured by the second temperature measuring means is also used in heating control in the heating unit. The liquid feeding means is configured to allow a plurality of different liquid feeding operations,
The peritoneal dialysis apparatus further comprises a storage means for storing a plurality of parameter sets corresponding to the plurality of liquid feeding operations,
The calculation means selects one parameter set from the plurality of parameter sets based on the type of liquid feeding operation in the liquid feeding means, and the selected one parameter set and the gas measured by the temperature measuring means 5. The peritoneal dialysis apparatus according to claim 3, wherein the amount of liquid fed by the liquid feeding unit is calculated based on the temperature and the temperature of the dialysate measured by the second temperature measuring unit. A method for controlling a peritoneal dialysis device configured to heat dialysate supplied from a dialysate bag in a heating unit and inject the warmed dialysate into the abdominal cavity,
A liquid-feeding step of sending the dialysate by repeatedly pressing the diaphragm pump;
A temperature measuring step for measuring the temperature of the gas used for pressing the diaphragm pump;
A calculation step for calculating a liquid feeding amount by the liquid feeding step based on at least the temperature of the gas measured by the temperature measuring step;
A method for controlling a peritoneal dialysis device.

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