JP6537863B2 - Peritoneal dialysis device and control method thereof - Google Patents

Description

  The present invention relates to fluid delivery technology in a peritoneal dialysis device.

  In recent years, a peritoneal dialysis apparatus configured to allow a patient to perform peritoneal dialysis at home or the like has become widespread. For example, Patent Document 1 discloses a peritoneal dialysis device using a cassette integrally formed with a diaphragm and a heating tube for feeding peritoneal dialysis fluid. By the way, in peritoneal dialysis, correctly injecting an appropriate amount of peritoneal dialysate into the abdominal cavity of a patient is important to improve the therapeutic effect. Therefore, Patent Document 1 also discloses a method of measuring the amount of peritoneal dialysate infused.

JP, 2008-167935, A

  By the way, in recent years, in the peritoneal dialysis apparatus, application to the Tydahl method and a pediatric patient is being considered. When these applications are targeted, the amount of inflow and discharge of peritoneal dialysis fluid into the abdominal cavity is smaller than before, so the influence of the error in the flow rate in the peritoneal dialysis device is relatively large. become. Therefore, the realization of a technology capable of controlling the amount of liquid delivery more accurately is expected.

  The present invention has been made in view of such problems, and it is an object of the present invention to provide a technique that enables more accurate delivery of peritoneal dialysate.

  In order to solve the above-mentioned problems, the peritoneal dialysis apparatus according to the present invention has the following configuration. That is, in a peritoneal dialysis apparatus configured to heat the dialysate supplied from the dialysate bag in the heating unit and inject the heated dialysate into the abdominal cavity, the heating unit is configured to press the diaphragm pump. After completion of at least one of the priming operation of filling the dialysate or the leak check operation of inspecting the dialysate leak in the fluid feed path from the diaphragm to the heating unit, A pretreatment means is controlled to move at least a part to a predetermined place other than the heating part (but excluding injection into the abdominal cavity), and the dialysate is heated after the movement by the pretreatment means. Control means to start the injection into the abdominal cavity via the part.

  According to the present invention, it is possible to provide a technique that enables more accurate delivery of peritoneal dialysate.

It is a figure which shows the peritoneal dialysis apparatus and cassette which concern on 1st Embodiment. It is a figure explaining the connection composition of the liquid transport way 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 heating tube 103 accompanying priming and a leak check illustratively. It is a figure showing an example a table containing a plurality of parameter sets.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The following embodiment is merely an example and is 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 as an example.

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

  The peritoneal dialysis device 100 is mounted with a cassette 101 for injecting peritoneal dialysis fluid into the abdominal cavity. In addition, 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 which 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, to input a start instruction when the user (patient) starts the peritoneal dialysis, and an end instruction when the peritoneal dialysis is ended. The display unit 108 reports information to the user (patient), and reports, for example, the operation state of the peritoneal dialysis apparatus 100. Here, the operating state indicates, for example, a state such as an injection process for injecting dialysate into the abdominal cavity or a process for discharging the dialysate from the abdominal cavity during, for example, completion.

  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 that pumps dialysate by expanding / contracting. The diaphragm pump 102 is housed in a sealed state by the flange member, and is depressurized / pressed by being externally depressurized and pressurized by air pressure. In addition to the air pressure, a piston or the like may be disposed on the surface of the diaphragm pump 102, and by pulling and pushing these, pressure and pressure can also be applied. Thereby, the diaphragm pump 102 is configured to expand when it is pressurized and to be contracted when it is pressed, in order to supply the dialysate. The operation of the diaphragm pump 102 in accordance with the pressure and pressure will be described later with reference to FIG.

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

  The flow path switching unit 104 switches the flow path of the dialysate in the tubes provided 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 disposed in the peritoneal dialysis device 100. The flow path switching unit 104 mainly switches to a flow path for liquid injection processing or liquid discharge processing. For example, in the case of injecting a dialysate contained in a dialysate bag described later, the flow path for injection treatment is a dialysis catheter connected to the dialysate bag, the diaphragm pump 102, the heating tube 103, and the cassette 101. It becomes a channel 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 tube for drainage treatment 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 the flow path from 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. In addition, this blocking is also performed in a priming operation of filling the dialysate into the heating tube 103 and a leak check operation of detecting leakage of dialysate in the flow path. In addition, although the flow-path switching part 104 which opens or interrupts | blocks a flow path is demonstrated as what is formed of a clamp here, the flow-path switching part 104 is a structure which switches a flow path by another method. Good.

  The constituent materials of the above-described diaphragm pump 102, heating tube 103, and tubes disposed around the cassette 101 are soft resins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate co-polymer, for example. Polyolefins such as polymer (EVA), polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, poly- (4-methylpentene-1), ionomer, acrylic resin, polyethylene terephthalate (PET), polybutylene terephthalate Various thermoplastic elastomers such as polyesters such as PBT), styrenes, polyolefins, polyvinyl chlorides, polyurethanes, polyesters, and polyamides, silicone resins, polyurethanes, or the like 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 for explaining a connection configuration of a liquid delivery path including a cassette. Here, in addition to the configuration described in FIG. 1, elements connected to the connection tube 105 will be described. Therefore, the same elements as in FIG. 1 are assigned the same reference numerals and descriptions thereof will be omitted.

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

  The flow path switching unit 104 is provided with a plurality of openings, and the clamp of the peritoneal dialysis device 100 is operated in a state where the cassette 101 is attached to the peritoneal dialysis device 100, so that the openings are inserted. As a result, predetermined positions of the liquid injection path and the drainage path in the flow path switching unit 104 are clamped.

  FIG. 3 is a diagram showing an example of the configuration of the flow path switching unit. In FIG. 3, rectangles indicated by C1 to C8 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 points 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, with the cassette 101 attached to the peritoneal dialysis apparatus 100, the pumping operation of the peritoneal dialysis apparatus 100 is pumped to cause the diaphragm pump 102 to repeat expansion / contraction, ie, a pump chamber including the diaphragm pump 102. The inside will be repeatedly changed between the pressurized state and the depressurized state. As a result, the delivery of the dialysate is controlled.

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

  The heating tube 103 is disposed outside the cassette 101 through an opening. Thus, the surface heater of the peritoneal dialysis device 100 can heat the heating tube 103 in a state where the cassette 101 is attached to the peritoneal dialysis device 100.

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

  The peritoneal dialysis apparatus 100 includes a CPU 401, operation units 107a and 107b, a power supply circuit 403, a flow control unit 404, a storage unit 405, a flow 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 centrally controls each functional block by executing a control program stored in the storage unit 405, for example.

  As illustrated in FIG. 1, the operation units 107 a and 107 b are disposed on the outer surface of the peritoneal dialysis device 100, receive an input from the operator, and notify the CPU 401. For example, the operation units 107a and 107b are used by the operator to instruct the start of treatment when starting peritoneal dialysis. The power supply circuit 403 supplies power to the CPU 401. The flow rate control unit 404 controls the diaphragm pump 102 to feed a dialysate of a predesignated amount (target liquid delivery 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 flow path switching unit 104 to control the flow path of the dialysate. The heater control unit 409 controls the temperature of the heater 411. The pumping operation unit 410 controls the pressure and pressure on the diaphragm pump 102 by depressurizing or pressurizing the pump chamber including the diaphragm pump 102 to control the delivery of the dialysate. Therefore, the flow rate control unit 404 instructs the pumping operation unit 410 to control the pressure and pressure of the diaphragm pump 102 in accordance with the amount of dialysate to be supplied 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 measuring unit 406 calculates and integrates the amount of dialysate delivered from the diaphragm pump 102 for each pressing from the start of infusion of dialysate into the abdominal cavity to the end of infusion.

  Further, signals from the temperature sensor 412 and the air bubble sensor 413 disposed in the cassette 101 are input to the CPU 401. The temperature sensor 412 is one or more temperature sensors disposed 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 (the temperature before heating) of the dialysate sent from the dialysate bag to the diaphragm, and the fluid sent from the heating tube to the dialysis catheter 201 Measure the temperature of the treated dialysate (the temperature after heating). As the temperature sensor 412, it is desirable to use a thermopile type infrared sensor (non-contact type temperature sensor) having a very high response speed. Thus, the heater control unit 409 can control the temperature of the heater with high accuracy. The air 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 air bubbles in the dialysate.

<2. General operation of device>
As described above, the peritoneal dialysis device 100 transfers the dialysate by changing the inside of the pump chamber including the diaphragm pump 102 between the pressurized state and the depressurized state. For example, when the liquid injection processing is performed, first, the switching control unit 408 sets the dialysate bag 203a and the diaphragm pump 102 to be in communication with each other by 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 while the diaphragm pump 102 and the heating tube 103 are in communication with each other 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 the liquid is fed.

<2.1. Calculation of liquid transfer amount>
The flow rate measuring unit 406 of the peritoneal dialysis device 100 derives the amount of the sent dialysate by calculation according to the pumping operation of the diaphragm pump 102 while performing the dialysate injection process. This is derived according to Boyle-Charles's law. A method of measuring the amount of dialysate sent from the diaphragm pump 102 will be described with reference to FIG.

  FIG. 5 is a view showing a cross section of a pump chamber 510 for applying pressure and pressure to the diaphragm pump. In the tube 501, as indicated by the arrow 504, the flow of the dialysate 503 changes depending on whether it is supplied or delivered.

  FIG. 5A shows that the dialysate 503 is filled in the diaphragm pump 102. The filling of the dialysate 503 is performed by depressurizing the diaphragm pump 102 by decompressing the pump chamber 510 in a state where the diaphragm pump 102 and the dialysate bag 203 a are in communication with each other. The diaphragm pump 102 includes a membrane 502 formed of a soft material. Therefore, when the dialysate 503 is filled in the diaphragm pump 102, as shown in FIG. 5A, the volume in the diaphragm pump 102 increases and the volume in the pump chamber 510 increases because the membrane 502 expands. It becomes V1.

  When the dialysate 503 is filled, the diaphragm pump 102 is pressed by applying a 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 with each other. The dialysate 503 is fed to the heating tube 103 through the tube in the portion 104.

  FIG. 5B shows a state after the dialysate 503 filled in the diaphragm pump 102 is fed. When the pressure P 1 is applied, the membrane 502 is pushed toward the inside of the diaphragm pump 102 filled with the dialysate 503 to deliver the dialysate 503 in the direction of 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. 5 (b).

  Here, the conditional expression V1 <V2 holds. Also, according to Boyle-Charles's law, PV / T is always constant. Here, assuming that the temperature (absolute temperature) near the diaphragm pump 102 at the time of performing peritoneal dialysis is substantially constant, the 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 that has been sent. Specifically, the flow rate measuring unit 406 measures the pressure using a pressure sensor while the liquid delivery by pumping is performed. As described above, the pressure P1 is a pressure at the time of pressurization in a state in which 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 the state where all the dialysate 503 in the diaphragm pump 102 has flowed out. Therefore, when the pressure sensor detects the pressure P2, the measuring unit 407 measures that the dialysate 503 having a volume corresponding to the volume in the diaphragm pump 102 has been fed.

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

<3. Outline of liquid transfer control>
FIG. 6 is a flowchart showing an outline of a dialysate delivery procedure. In the procedure described below, the CPU 401 performs overall control. In the following processing, the connection settings of the device (the connection of the dialysate bag 203a and the dialysis catheter 201 to the cassette 101 and the setting of the cassette 101 to the peritoneal dialysis device 100) and the liquid transfer setting from the user (liquid transfer) Setting of the amount of dialysate to be performed, etc. is completed, and it 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 heating tube 103 with the dialysate. Specifically, the switching control unit 408 is controlled to set the path to the heating tube 103 in the flow path switching unit 104. Thereafter, the pump operation unit 410 is controlled to press the diaphragm pump 102 to fill the heating tube 103 with the dialysate.

  In step S602, the CPU 401 controls so as to perform a leak check operation for checking a dialysate leak in the fluid delivery path from the diaphragm pump 102 to the heating tube 103. Specifically, the pump operation unit 410 is controlled to further press the diaphragm pump 102 to push the dialysate into the heating tube 103. If a leak is detected in the leak check operation, the process ends in error. Steps S601 and S602 may be performed in 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 delivery by pumping of the diaphragm pump 102. Specifically, the switching control unit 408 is controlled to set the flow path switching unit 104 so that the diaphragm pump 102 and the dialysate bag 203 a communicate with each other. Thereafter, the pump operating unit 410 is controlled to draw the dialysate into the diaphragm pump 102. Furthermore, the switching control unit 408 is controlled to set a path to the dialysis catheter 201 through 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 flow rate of the liquid by the pumping operation in step S603. Specifically, the pressure of the diaphragm pump 102 is monitored to calculate the amount of dialysate sent. As mentioned above, this calculation is made according to Boyle-Charles's law. In the second and subsequent loops via S605, an integrated value obtained by adding the amount of liquid sent in the current loop to the amount of dialysate sent in the preceding loop is calculated together.

  In step S605, the CPU 401 determines whether or not the dialysis fluid of the fluid delivery target amount has been delivered. If the dialysis fluid of the target fluid delivery volume has been delivered, the fluid delivery processing is terminated, and if not, the process proceeds to S603.

In this way, the target amount of dialysate to be delivered will be infused into the patient's peritoneal cavity. By the way, the liquid transfer procedure shown in FIG. 6 includes some operations that may cause a liquid transfer error. Specifically, it is considered that a feeding error may occur at the following three points.
(I) Pumping error (S603) A liquid transfer error caused by the liquid transfer amount per one time.
(II) An error caused by the dialysate injected into the heating tube 103 in the priming (S601) and the leak check (S602).
(III) Calculation of the amount of liquid transfer depending on temperature non-uniformity (S604) Error.

  Therefore, in the following, a method for reducing the liquid transfer error will be described with respect to these three points.

<3.1. (I) Reduction of liquid transfer error caused by the amount of liquid transfer per pumping (S603)>
As described above, the peritoneal dialysis device 100 pumps the target amount of dialysis fluid 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 transfer is the volume in the diaphragm pump 102.

  Fig.7 (a) is a figure explaining the sending error resulting from the sending amount per pumping (S603). In this case, the amount smaller than the liquid transfer target value by the amount of liquid transfer equivalent to one press (in this case, 18 mL, which is the volume in the diaphragm pump 102) is set as the threshold, and the liquid transfer integrated value exceeds the threshold. The example in the control which determines the following 1 press as the last press is shown. In the case of such control, in the case of the liquid delivery pattern shown in the “worst case” in the upper part of FIG. 7A, an excess of about 18 mL of liquid delivery will occur.

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

  FIG. 7B is a view for explaining control for reducing the liquid feeding error. As shown in the figure, a first threshold value smaller than the liquid delivery target value by a predetermined amount is set, and when the first threshold value is exceeded, the pressure on the diaphragm pump 102 is the first pressure amount in the preceding pressure The second pressing amount (here, a pressing amount of 4 mL) is changed to a second pressing amount (here, a pressing amount of 18 mL). In addition, in consideration of the responsiveness of the diaphragm pump 102 and the like, the amount is 2 to 10 times the amount of liquid transfer by the second pressing amount from the liquid supply target value (7.5 times in FIG. 7 (b) It is good to set as a 1st threshold value a few value only). On the other hand, the first threshold may be set as a value (for example, 80% of the target value) depending on the liquid delivery target value.

  After the change to the second pressing amount, as in the case of FIG. 7A, the second threshold value is the amount that is the smallest of the liquid sending amount equivalent to one pressing (here, 4 mL) from the liquid sending target value. If the liquid transfer integrated value exceeds the second threshold value, the subsequent one press is determined as the last press.

  By performing such control, the minimum unit of liquid transfer becomes smaller, and as a result, the liquid transfer error is reduced. For example, in the above example, the maximum value of the liquid transfer error is reduced from 18 mL (the "worst case" in the upper row of FIG. 7A) to 4 mL (the "worst case" in the upper row of FIG. 7B) become. Moreover, before changing to the second pressing amount, the liquid feeding speed is the same as in the conventional case, and after changing to the second pressing amount at which the liquid feeding speed decreases, it takes only a short time. Has the advantage of not requiring a long time.

  In the above description, it has been described that 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 designated liquid delivery target amount is small, and the pressing amount may not be changed when the liquid delivery target amount is large (for example, 1000 mL or more). For example, when the liquid delivery target amount is equal to or more than the predetermined amount, the pressure on the diaphragm pump is not changed to the second pressing amount even when the liquid delivery integrated value exceeds the first threshold. If the integrated liquid value exceeds the third threshold value which is smaller than the liquid transfer target amount by the third predetermined amount, the subsequent one press is determined as the final press, and after the final press is completed, the press control is performed. Stop it. Here, the third predetermined amount is set to the same amount as the amount of the dialysate to be delivered by the first pressing amount.

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

  FIG. 8 is a view exemplarily showing the state of the dialysate in the heating tube 103 accompanying the priming (S601) and the leak check (S602). In addition, the black rectangle of the flow-path switching part 104 in FIG. 8 has shown that the closure of the tube is performed 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 dialysis tube is further pressurized and pushed into the heating tube 103. become. Therefore, when the pump (S603) is started after the leak check, the amount of the dialysate remaining in the heating tube 103 is excessively increased. Although not all of the volume (for example, 40 mL) of the heating tube 103 is an error, the dilation fluid equivalent amount to the heating tube 103 by pressurization of the leak check (S602) can be obtained from the heating tube 103 through the dialysis catheter 201 As soon as the blocking of the path to the blood vessel is released, the internal pressure of the heating tube 103 is likely to cause the dialysate to leak into the dialysis catheter 201. For example, 10 to 20 mL of dialysate leaks, leading to excess delivery.

  Therefore, as shown in states 803 to 804 in FIG. 8, the dialysate remaining in the heating tube 103 is aspirated by the diaphragm pump 102, and the aspirated dialysate is dialyzed from the dialysate bag 203a or the diaphragm pump 102. The fluid is sent to the fluid delivery path to the fluid bag 203a. That is, the dialysate remaining in the heating tube 103 is moved to another place that does not affect the liquid transfer control. When the dialysate remaining in the heating tube 103 is aspirated by the diaphragm pump 102, as shown in the state 803, through an outlet different from the inlet where the dialysate is injected by priming and leak check. It is good to aspirate.

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

  Further, since the liquid transfer error is reduced, it may be performed after the leak check (if the order of the priming operation and the leak check operation is reversed). If only one of the priming operation and the leak check operation is to be performed, the operation may be performed after those operations.

  Although in the state 803 of FIG. 8 an example is shown in which the aspirated dialysate is moved to the dialysate bag 203 a, the dialysate may be controlled to move to another place, for example, the drainage processing tank 202.

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

<3.3. (III) Calculation of liquid transfer amount depending on temperature non-uniformity (S604) Reduction of error>
As described with reference to FIG. 5, the flow rate measurement 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 transfer amount was calculated as being constant. However, in practice, 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. Therefore, in the calculation formula that assumes that the temperature around the diaphragm pump 102 is constant, there may occur an unacceptable error in the calculation of the liquid transfer amount. For example, it is known that an error of about 5% occurs 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.).

Therefore, as the temperature related to the diaphragm pump 102,
· Temperature of gas pressing the diaphragm (Tt) (temperature of gas stored in 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 measurement unit 406 corrects and calculates the amount of liquid transfer based on these temperatures.

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

  In this case, it is assumed that pressure (P) × volume (V) = constant, and the amount of liquid transfer calculated has the following calculation error.

Calculation error = K x (Te-Tt) + L x Tt + c (Equation 1)
(K, L, c are predetermined constants)
This equation can be written as an equation for Te and Tt: Calculation error = a × Te + b × Tt + c (Equation 2)
(A, b, c are predetermined constants)
It becomes.

  Therefore, the set of values of a, b and c may be obtained in advance experimentally and stored in advance as a parameter set in the storage unit 405 such as a ROM. Then, the flow rate measurement unit 406 substitutes the measured temperature (Te and Tt) and a predetermined parameter set into (Eq. 2) to calculate a calculation error, and pressure (P) × volume (V) = constant It is preferable to calculate a more accurate liquid transfer amount by performing a correction operation to correct (compensate) the liquid transfer amount calculated when it is assumed.

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

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

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

  In the first embodiment, three techniques for liquid transfer error reduction 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 flow-path switching part 107a, 107b operation part 401 CPU
403 power supply circuit 404 flow control unit 405 storage unit 406 flow measurement unit 408 switching control unit 409 heater control unit 410 pumping operation unit 411 heater 412 temperature sensor 412 bubble sensor

Claims (5)

A peritoneal dialysis apparatus configured to heat dialysate supplied from a dialysate bag in a heating unit and inject the heated dialysate into the peritoneal cavity,
After completion of at least one of the priming operation of pressing the diaphragm pump to fill the heating unit with dialysate or the leak check operation of inspecting the dialysate leak in the liquid feeding path from the diaphragm pump to the heating unit , a pre-processing means wherein at least a portion of the predetermined location outside the pressurized temperature portion moves to so that the control of dialysate present in the heating zone,
After the movement by the preprocessing means, the dialysate have a, a feeding means for controlling to start the injection into the peritoneal cavity through the heating unit,
The peritoneal dialysis device , wherein the predetermined place is the dialysate bag or a fluid delivery path from the diaphragm pump to the dialysate bag . The pretreatment means sucks at least a part of the dialysate present in the heating unit using the diaphragm pump, and sends the sucked dialysate to the predetermined place using the diaphragm pump. The peritoneal dialysis device according to claim 1, characterized in that: The peritoneal dialysis device according to claim 2, wherein the pretreatment means executes suction of dialysate from the heating unit and delivery of dialysate to the predetermined place a plurality of times. The heating unit has an inlet that is an inlet of dialysate and an outlet that is an outlet of dialysate,
In the priming operation and the leak check operation, the pre-processing unit sends dialysate to the heating unit via the inlet, and the outlet unit is used to suction dialysate from the heating unit. The peritoneal dialysis device according to claim 2 or 3, wherein the dialysate is aspirated from the heating unit via the passage. The diaphragm pump, the inlet portion, the outlet portion, a connection tube to the dialysate bag, and a connection tube to the abdominal cavity are connected via a flow path switching portion capable of setting a flow path by pressing one or more places by a clamp. The peritoneal dialysis device according to claim 4 , wherein the peritoneal dialysis device is connected.

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