Hemodialysis machine waterway system and temperature control method thereof

Abstract

The invention discloses a hemodialysis machine waterway system and a temperature control method.The hemodialysis machine waterway system comprises a water inlet cavity, a heating cavity, a floater chamber, a balance cavity and a dialysis pipeline, a water inlet of the water inlet cavity is used for being connected with a purified water source, and the water inlet cavity, the heating cavity, the floater chamber and the balance cavity are sequentially connected through the water inlet pipeline; a dialysate inlet of the balance cavity is connected with a dialysate outlet of the dialysate pump, a water outlet of the dialysis machine is connected with a liquid inlet of the dialysis pipeline through a peripheral pipeline, a liquid outlet of the dialysis pipeline is connected with a waste liquid pipeline, and the waste liquid pipeline is provided with a waste liquid outlet; and the water inlet cavity, the floater chamber and the dialysis machine water outlet are respectively provided with a temperature sensor. The heating power of the heating cavity is controlled by calculating the target temperature of the floater chamber, and then fine control over the temperature of the waterway system is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of water temperature regulation, and in particular to a water circuit system of a hemodialysis machine and a temperature control method thereof. Background Art

[0002] During the dialysis process, a large amount of dialysate exchanges substances with the patient's blood. If the dialysate temperature is too low, the patient's body heat will be taken away, causing the patient's body temperature to drop, and symptoms such as chills and discomfort will occur. Therefore, heating the dialysate to an appropriate temperature can prevent the patient's body temperature from dropping excessively, maintain the patient's body temperature in a relatively stable state, and improve the patient's comfort during the dialysis process. And the appropriate temperature can make the solutes in the dialysate diffuse better into the blood, and it is also beneficial for the metabolic waste in the blood to diffuse into the dialysate, thereby improving the efficiency and effectiveness of dialysis.

[0003] However, during the treatment process of the hemodialysis machine, the water does not flow at a constant speed, but in a pulsed manner. In addition, since the water outlet is far away from the heating chamber, it is relatively difficult to control the temperature of the remote water outlet using the traditional PID (Proportion Integration Differentiation) algorithm.

[0004] In short, heating the dialysate is an important part of the dialysis process, which plays a vital role in maintaining the patient's body temperature and ensuring the dialysis effect. How to ensure uniform heating of the water circuit of the hemodialysis machine while avoiding temperature fluctuations is a problem that technicians in this field need to solve. Summary of the invention

[0005] In order to overcome the problems in the prior art, the object of the present invention is to provide a water circuit system of a hemodialysis machine and a temperature control method thereof, which can ensure accurate control of the water circuit temperature of the hemodialysis machine.

[0006] To achieve the above-mentioned purpose, the present invention provides a water system for a hemodialysis machine, comprising a water inlet chamber, a heating chamber, a float chamber, a balancing chamber and a dialysis pipeline, wherein the water inlet of the water inlet chamber is used to be connected to a pure water source, the water inlet chamber, the heating chamber, the float chamber and the balancing chamber are connected in sequence through the water inlet pipeline, the water outlet of the balancing chamber is connected to the water outlet of the dialysis machine through a long pipeline, the water outlet of the dialysis machine is connected to the liquid inlet of the dialysis pipeline connected to the peripheral pipeline, the liquid outlet of the dialysis pipeline is connected to the waste liquid pipeline, and the waste liquid pipeline is provided with a waste liquid outlet; the water inlet chamber, the float chamber and the water outlet of the dialysis machine are respectively provided with temperature sensors.

[0007] Specifically, a flow pump and a degassing pump are provided between the float chamber and the balance chamber, the flow pump is used to provide power for the liquid, and the degassing pump is used to remove bubbles remaining in the water inlet pipeline.

[0008] Specifically, a heat exchanger is provided between the water inlet chamber and the heating chamber, the waste liquid pipeline passes through the heat exchanger, and the waste liquid in the waste liquid pipeline and the pure water in the water inlet pipeline exchange heat energy in the heat exchanger; a water inlet valve is provided at the water inlet of the water inlet chamber.

[0009] The present invention also provides a method for controlling the water circuit temperature of a hemodialysis machine, which is applied to the water circuit system of the hemodialysis machine as described above, and the steps include:

[0010] S1: Establish a neural network PID model, the upper computer sends the flow rate F and target temperature Tm4 of the dialysis pipeline, obtains the actual temperature T2 of the float chamber, the ambient temperature T0, the distance L1 from the float chamber to the water outlet of the dialysis machine, and the distance L2 from the water outlet of the dialysis machine to the dialysis pipeline, selects the heat dissipation A according to the actual temperature T2 of the float chamber and the ambient temperature T0, selects the first temperature coefficient ΔC1 and the second temperature coefficient ΔC2 according to the flow rate F, and calculates the target temperature Tm2 of the float chamber and the target temperature Tm3 of the water outlet of the dialysis machine respectively;

[0011] S2: The neural network PID model controls the heating of the heating chamber according to the float target temperature Tm2, ​​and the upper computer marks the float chamber target temperature value Tm2last=Tm2, the dialysis machine outlet temperature target value Tm3last=Tm3, the dialysis pipeline target temperature Tm4last=Tm4, and the flow rate Flast=F;

[0012] S3: Regularly collect the actual temperature T2 of the float chamber and the actual temperature T3 of the water outlet of the dialysis machine, calculate the temperature error value △eT2 of the float chamber and the temperature error value ΔeT3 of the water outlet of the dialysis machine respectively, set the target temperature error value range, and judge whether the actual temperature T2 of the float chamber or the actual temperature T3 of the water outlet of the dialysis machine exceeds the target temperature error value range. If so, execute step S4, if not, repeat step S3; judge whether the upper computer sends a new dialysis pipeline target temperature Tm4 and flow rate F, if so, execute S5, if not, repeat step S3;

[0013] S4: Calculate a new float chamber target temperature Tm2 according to the float chamber temperature error value ΔeT2 or the dialysis machine outlet temperature error value ΔeT3, and then execute step S2.

[0014] S5: Calculate the target temperature compensation value and flow temperature compensation value of the dialysis pipeline according to the new dialysis pipeline target temperature Tm4 and flow F sent by the host computer, adjust and calculate the new float chamber target temperature Tm2 according to the dialysis pipeline target temperature and flow, and then execute step S2.

[0015] Specifically, in step S1, the method for respectively calculating the target temperature Tm2 of the float chamber and the target temperature Tm3 of the water outlet of the dialysis machine is:

[0016] S11: Obtain the actual temperature T2 of the float chamber 7, the ambient temperature T0, the flow rate F, the distance L1 from the float chamber 7 to the water outlet 11 of the dialyzer, and the distance L2 from the water outlet 11 of the dialyzer to the dialyzer pipeline 12. First, select a suitable heat dissipation A by looking up the table according to the actual temperature T2 of the float chamber 7 and the ambient temperature T0, and then select a suitable first temperature coefficient ΔC1 and a second temperature coefficient ΔC2 according to the flow rate F, and calculate the temperature compensation value Tc between the target temperature Tm3 of the water outlet 11 of the dialyzer and the target temperature Tm4 of the dialyzer pipeline 12. The formula is: Tc = (L2 / L1)*A*ΔC2;

[0017] S12: Obtain the target temperature Tm4 of the dialysis pipeline, and calculate the target temperature Tm3 of the dialysis machine outlet, which is expressed by the formula: Tm3 = Tm4 + Tc;

[0018] S13: According to the target temperature Tm3 of the water outlet of the dialysis machine, the heat dissipation A and the first temperature coefficient ΔC1, the target temperature Tm2 of the float chamber is calculated, Tm2=Tm3+A*ΔC1.

[0019] Specifically, in step S3, the method for calculating the float chamber temperature error value ΔeT2 is as follows: obtaining the last target temperature Tm2last of the float chamber, collecting the actual temperature T2 of the float chamber, and calculating the float chamber temperature error value ΔeT2, the formula is: ΔeT2=Tm2last-T2; the method for calculating the dialysis machine water outlet temperature error value ΔeT3 is as follows: obtaining the last target temperature Tm3last of the dialysis machine water outlet, collecting the actual temperature T3 of the dialysis machine water outlet, and calculating the dialysis machine water outlet temperature error value ΔeT3, the specific formula is: ΔeT3=Tm3last-T3.

[0020] 7. A method for controlling the water circuit temperature of a hemodialysis machine according to claim 4, characterized in that, in the step S4, according to the float chamber temperature error value ΔeT2, a method for calculating a new float chamber target temperature Tm2 is: obtaining the last float chamber target temperature Tm2last and the float chamber temperature error value ΔeT2, and calculating the adjusted float chamber target temperature Tm2, ​​and the specific formula is: Tm2=Tm2last+ΔeT2; according to the dialysis machine outlet temperature error value ΔeT3, a method for calculating a new float chamber target temperature Tm2 is: obtaining the last float chamber target temperature Tm2last, and calculating the adjusted float chamber target temperature Tm2, ​​and the specific formula is: Tm2=Tm2last+ΔeT3.

[0021] Specifically, the specific method of step S5 is:

[0022] S51: Compare the current dialysis pipeline 12 temperature target value Tm4 with the previous Tm4last to determine whether there is a change. If so, execute step S52; if not, execute step S54.

[0023] S52: Calculate the difference between the new dialysis tubing 12 target temperature Tm4 issued this time and the dialysis tubing 12 target temperature Tm4last issued last time, and obtain the dialysis tubing 12 target temperature compensation value ΔAdjust, which is expressed as: ΔAdjust = Tm4-Tm4last. S53: Obtain the last float chamber 7 target temperature Tm2Last and the dialysis tubing 12 temperature error compensation value ΔAdjust, and calculate the new float chamber 7 target temperature Tm2, ​​which is expressed as: Tm2 = Tm2last+ΔAdjust.

[0024] Step S54: compare the flow F sent this time with the flow Flast sent last time to determine whether the flow F has changed. If so, execute S55; if not, execute step S2.

[0025] Step S55: Obtain the flow rate F sent this time and the last flow rate Flast, and select a suitable flow rate temperature compensation value ΔTF according to different flow rate switches.

[0026] Step S56: Add the flow compensation value and the last issued target temperature Tm2last to obtain a new target temperature Tm2 of the float chamber 7, and then execute step S2.

[0027] Specifically, the heat dissipation A is the water temperature reduction at a distance L1 from the float chamber to the water outlet of the dialysis machine under the conditions of the actual temperature T2 of the float chamber, the flow rate F and the ambient temperature T0; the first temperature coefficient ΔC1 is the temperature compensation coefficient for the distance L1 from the float chamber to the water outlet of the dialysis machine under different flow rates; the second temperature coefficient ΔC2 is the temperature compensation coefficient for the distance from the water outlet of the dialysis machine to the dialysis pipeline L2 under different flow rates.

[0028] Specifically, the calculation method of the ambient temperature T0 is: when starting up, collect the water inlet temperature T1, the float chamber temperature T2, and the dialysis machine outlet temperature T3. The ambient temperature is the average of the three temperatures, and the formula is: T0 = (T1 + T2 + T3) / 3.

[0029] The present invention obtains the target temperature and heat dissipation of the dialysis pipeline by means of negative feedback regulation, and negatively feedback calculates the target temperature of the dialysis machine water outlet and float chamber, thereby overcoming the influence of the heat dissipation problem of the long peripheral pipeline on the target temperature. The present invention uses a neural network PID algorithm to finely control the power of the heating chamber, and responds to the external environment regulation in a timely manner to ensure the stability of the water temperature. Further, a negative feedback mechanism is adopted to adjust the float chamber temperature through the outlet temperature feedback, thereby stabilizing the outlet temperature. When the dialysis pipeline temperature is adjusted multiple times, the present invention adopts a fast adjustment algorithm, and the heating chamber can respond quickly to adjust the power to keep the water temperature in the hemodialysis machine stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structure of a water system of a hemodialysis machine provided in Example 1 of the present invention;

[0031] Figure 2 An overall flow chart of temperature control of a water system of a hemodialysis machine provided in Example 1 of the present invention;

[0032] Description of the drawings: 1. Water inlet valve, 2. Water inlet chamber, 3. Waste liquid outlet, 4. Dialysis liquid pump, 5. Heat exchanger, 6. Heating chamber, 7. Float chamber, 8. Flow pump, 9. Degassing pump, 10. Balance chamber, 11. Dialysis machine water outlet, 12. Dialysis pipeline. DETAILED DESCRIPTION

[0033] Example 1

[0034] A water system for a hemodialysis machine, such as Figure 1 As shown, it includes a water inlet chamber 2, a heating chamber 6, a float chamber 7, a balance chamber 10 and a dialysis pipeline 12. The water inlet of the water inlet chamber 2 is used to connect to a pure water source, and a water inlet valve 1 is provided between the water inlet chamber 2 and the water source. The water inlet chamber 2, the heating chamber 6, the float chamber 7, and the balance chamber 10 are connected in sequence through a water inlet pipeline. The dialysate inlet of the balance chamber 10 is connected to the outlet of the dialysate pump 4. The outlet of the balance chamber 10 is connected to the dialyzer outlet 11 through a long pipeline. The peripheral pipeline of the dialyzer outlet 11 is connected to the inlet of the dialysis pipeline 12. The outlet of the dialysis pipeline 12 is connected to the waste liquid pipeline, and the waste liquid pipeline is provided with a waste liquid outlet 3. The water inlet chamber 2, the float chamber outlet 7, and the dialyzer outlet 11 are respectively provided with temperature collectors.

[0035] A flow pump 8 and a degassing pump 9 are provided between the float chamber 7 and the balance chamber 10. The flow pump 9 is used to provide power for the liquid, and the degassing pump 9 is used to remove bubbles remaining in the water inlet pipeline.

[0036] A heat exchanger 5 is provided between the water inlet chamber 2 and the heating chamber 6 . The waste liquid pipeline passes through the heat exchanger 5 . The waste liquid in the waste liquid pipeline and the pure water in the water inlet pipeline perform heat exchange in the heat exchanger 5 .

[0037] The specific working principle is as follows: the flow pump 8 draws away the pure water in the float chamber 7, the water level in the float chamber 7 becomes low, and the float valve and the water inlet valve 1 of the float chamber are automatically opened, and the pure water enters the heating chamber 6 and is heated to the target temperature. The flow pump 8 controls the hot water to enter the float chamber 7 in a pulsed manner, and the hot water is mixed in the float chamber 7 to make the temperature of the hot water in the float chamber 7 balanced. The degassing pump 9 is used to remove impurities in the water, stabilize the flow of the water channel, and avoid heating instability due to excessive gas in the water channel. Then the hot water and the dialysate output by the dialysate pump 4 enter the balance chamber 10 together to mix into a dialysate mixture, and the dialysate mixture flows from the dialyzer outlet 11 through the peripheral pipeline to the dialysate pipeline 12 to perform hemodialysis on the patient. The dialysate waste liquid generated after the hemodialysis is completed passes through the heat exchanger 5, and the residual heat of the dialysate waste liquid is heat exchanged with the pure water, and finally flows out through the waste liquid outlet 3.

[0038] Example 2

[0039] A method for controlling the water circuit temperature of a hemodialysis machine is applied to a water circuit system of a hemodialysis machine as described in the above embodiment 1. Figure 2 As shown, including:

[0040] Step S1: Establish a neural network PID model. The host computer sends the flow rate F and target temperature Tm4 of the dialysis pipeline, obtains the actual temperature T2 of the float chamber, the ambient temperature T0, the distance L1 from the float chamber to the water outlet of the dialysis machine, and the distance L2 from the water outlet of the dialysis machine to the dialysis pipeline. According to the actual temperature T2 of the float chamber and the ambient temperature T0, the heat dissipation A is selected. According to the flow rate F, the first temperature coefficient ΔC1 and the second temperature coefficient ΔC2 are selected, and the target temperature Tm2 of the float chamber and the target temperature Tm3 of the water outlet of the dialysis machine are calculated respectively.

[0041] Specifically, the target temperature Tm4 of the dialysis tubing 12 sent by the host computer has a temperature parameter range of 34°C-39°C, and a flow parameter range of 300mL / min-800mL / min. The temperature that the machine can directly collect closest to the dialysis tubing 12 is the temperature of the dialysis machine outlet 11. In order to accurately control the temperature of the dialysis tubing 12, it is necessary to calculate the target temperature Tm3 of the dialysis machine outlet 11, and then calculate the target temperature Tm2 of the float chamber 7 based on the target temperature Tm3 of the dialysis machine outlet 11. Finally, the heating chamber 6 is controlled by the neural network PID model for heating.

[0042] The method for respectively calculating the target temperature Tm2 of the float chamber 7 and the target temperature Tm3 of the water outlet of the dialysis machine is:

[0043] Step S11: Obtain the actual temperature T2 of the float chamber 7, the ambient temperature T0, the flow rate F, the distance L1 from the float chamber 7 to the water outlet 11 of the dialyzer, and the distance L2 from the water outlet 11 of the dialyzer to the dialyzer pipeline 12. First, select a suitable heat dissipation A by looking up the table according to the actual temperature T2 of the float chamber 7 and the ambient temperature T0, and then select a suitable first temperature coefficient ΔC1 and a second temperature coefficient ΔC2 according to the flow rate F, and calculate the temperature compensation value Tc between the target temperature Tm3 of the water outlet 11 of the dialyzer and the target temperature Tm4 of the dialyzer pipeline 12. The formula is: Tc = (L2 / L1)*A*ΔC2;

[0044] Specifically, in the embodiment, the dialysis machine has three flow gears, namely F1, F2, and F3. The heat dissipation A, the first temperature coefficient ΔC1, and the second temperature coefficient ΔC2 are calculated based on a large number of previous experimental results.

[0045] The heat dissipation A is the distance L1 from the float chamber 7 to the water outlet 11 of the dialysis machine, the flow rate is F1, and the actual temperature T2 of the float chamber 7 is X m and the ambient temperature T0 is Y n The water temperature reduction under the condition of ; the calculation method of heat dissipation A is as follows:

[0046] Obtain multiple groups of actual temperature T2 of the float chamber 7, ambient temperature T0 and temperature of the water outlet 11 of the dialysis machine, and express the actual temperature T2 of the float chamber 7 as X m ,m=1,2,…,M,M is the total sample size of the actual temperature T2 of the float chamber 7, m is the mth sample in the M sample size, and the ambient temperature T0 is expressed as Y n ,n=1,2,…,N,N is the total sample size of the ambient temperature T0, n is the nth sample in the N sample size. m 、Ambient temperature T0 is Y n In the case of, calculate the water temperature drop from the float chamber 7 to the dialysis machine outlet 11, that is, the heat dissipation A, and obtain the matrix set of heat dissipation A:

[0047]

[0048] Thus, a matrix set of heat dissipation A is obtained when the flow rate is F1, and the host computer establishes a lookup table of heat dissipation A according to the matrix set of heat dissipation A.

[0049] The first temperature compensation coefficient ΔC1 is a temperature compensation coefficient for the heat dissipation A when the flow rate is F1, F2, or F3 at a distance L1 from the float chamber 7 to the water outlet 12 of the dialyzer.

[0050] Specifically, since the heat dissipation A is calculated under the flow rate F1, the temperature compensation coefficient ΔC under the flow rate F1 is directly recorded as 1F1 is 1.

[0051] Calculate the temperature compensation coefficient ΔC when the flow rate is F2 1F2 The method is:

[0052] When the flow rate is F2 and the actual temperature T2 of the float chamber 7 is X m 、Ambient temperature T0 is Y n In the case of, calculate the water temperature drop from the float chamber 7 to the dialysis machine outlet 11, that is, the heat dissipation A', and obtain the matrix set of heat dissipation A':

[0053]

[0054] Calculate the difference ΔA' between the heat dissipation A and A' when the flow rate is F1 and the flow rate is F2. The formula is:

[0055]

[0056] The temperature compensation coefficient ΔC 1F2 Take the average value of all values ​​within the difference ΔA' between the heat dissipation A and A', and the formula is expressed as:

[0057]

[0058] Thus, the temperature compensation coefficient ΔC for the heat dissipation A at the flow rate F2 is obtained: 1F2 .

[0059] Calculate the temperature compensation coefficient ΔC when the flow rate is F3 1F3 The method is:

[0060] When the flow rate is F3 and the actual temperature T2 of the float chamber 7 is X m 、Ambient temperature T0 is Y n In the case of, the water temperature drop from the float chamber 7 to the dialysis machine outlet 11 is calculated, that is, the heat dissipation A", and the matrix set of heat dissipation A" is obtained:

[0061]

[0062] The difference ΔA” between the heat dissipation A and A” when the flow rate is F3 and the flow rate is F1 is calculated as follows:

[0063]

[0064] The temperature compensation coefficient ΔC 1F3 Take the average value of all values ​​within the difference ΔA” between the heat dissipation A and A”, and the formula is expressed as:

[0065]

[0066] Thus, the temperature compensation coefficient ΔC for the heat dissipation A at the flow rate F3 is obtained: F3 .

[0067] The first compensation coefficient set ΔC1={ΔC 1F1 , ΔC 1F2 , ΔC 1F3};

[0068] At this point, the calculation of the first compensation coefficient ΔC1 is completed, and the first compensation coefficient ΔC1 and its triggering condition are input into the host computer.

[0069] The second temperature compensation coefficient ΔC2 is a temperature compensation coefficient for the heat dissipation A at different flow rates at a distance L2 from the water outlet 11 of the dialysis machine to the dialysis pipeline 12 .

[0070] Specifically, the method for calculating the second temperature coefficient ΔC2 is:

[0071] According to the first temperature compensation coefficient ΔC1 and the ratio of the distance L2 from the dialysis machine outlet 11 to the dialysis pipeline 12 to the distance L1 from the float chamber 7 to the dialysis machine outlet 12, it can be obtained that when the flow rates are F1, F2, and F3 respectively, the second temperature compensation coefficient ΔC2 at the distance L2 from the dialysis machine outlet 11 to the dialysis pipeline 12 also includes ΔC 2F1 , ΔC 2F2 , ΔC 2F3 , the formulas are expressed as: That is, the second compensation coefficient set ΔC2 = {ΔC 2F1 , ΔC 2F2 , ΔC 2F3};

[0072] At this point, the calculation of the second compensation coefficient ΔC2 is completed, and the triggering condition of the second compensation coefficient ΔC2 is input into the host computer.

[0073] Among them, the calculation method of the ambient temperature is: when the dialysis machine is just turned on, the water inlet chamber temperature sensor, the float chamber temperature sensor, and the dialysis machine outlet temperature sensor are collected respectively to obtain the actual temperature T1 of the water inlet chamber 2, the actual temperature T2 of the float chamber 7, and the actual temperature T3 of the dialysis machine outlet 12, and the average value of the three temperatures is calculated to obtain the ambient temperature T0 = (T1+T2+T3) / 3.

[0074] Step S12: Calculate the target temperature Tm3 of the dialysis machine outlet 11 according to the target temperature Tm4 of the dialysis pipeline 12, which is expressed by the formula: Tm3 = Tm4 + Tc;

[0075] Step S13: Calculate the target temperature Tm2 of the float chamber 7 according to the target temperature Tm3 of the water outlet 11 of the dialysis machine, the heat dissipation A and the first temperature coefficient ΔC1, where Tm2=Tm3+A*ΔC1.

[0076] Step S2: The neural network PID model controls the heating of the heating chamber 6 according to the target temperature Tm2 of the float 7, and the upper computer marks the target temperature value Tm2last=Tm2 of the float chamber 7, the target temperature value Tm3last=Tm3 of the dialysis machine outlet 11, the target temperature Tm4last=Tm4 of the dialysis pipeline 12, and the flow rate Flast=F;

[0077] Specifically, the neural network PID model calculates the heating power according to the target temperature Tm2 to control the operation of the heating chamber 6. After the heating of the heating chamber 6 is completed, the hot water is pulsed to the float chamber 7 under the action of the flow of the flow pump 8. A float valve is provided in the float chamber 7. When the water level drops, the float valve automatically opens. When the water level rises to a suitable position, the float valve automatically closes, thereby achieving the effect of controlling the water inlet.

[0078] Step S3: Regularly collect the actual temperature T2 of the float chamber 7 and the actual temperature T3 of the water outlet 11 of the dialyzer, respectively calculate the temperature error value ΔeT2 of the float chamber 7 and the temperature error value ΔeT3 of the water outlet 11 of the dialyzer, set the target temperature error value range, and determine whether the actual temperature T2 of the float chamber 7 or the actual temperature T3 of the water outlet 11 of the dialyzer exceeds the target temperature error value range. If so, execute step S4, if not, repeat step S3; determine whether the upper computer sends a new target temperature Tm4 and flow rate F of the dialyzer pipeline 12, if so, execute S5, if not, repeat step S3;

[0079] Specifically, the method for calculating the temperature error value ΔeT2 of the float chamber 7 is as follows:

[0080] The last target temperature Tm2last of the float chamber 7 is obtained, the actual temperature T2 of the float chamber 7 is collected, and the temperature error value ΔeT2 of the float chamber 7 is calculated, and the formula is: ΔeT2=Tm2last-T2.

[0081] The specific method for calculating the temperature error value ΔeT3 of the dialysis machine water outlet 11 is:

[0082] The last target temperature Tm3last of the dialysis machine water outlet 11 is obtained, the actual temperature T3 of the dialysis machine water outlet 11 is collected, and the temperature error value ΔeT3 of the dialysis machine water outlet 11 is calculated. The specific formula is: ΔeT3=Tm3last-T3.

[0083] Step S4: Calculate a new target temperature Tm2 of the float chamber 7 according to the temperature error value ΔeT2 of the float chamber 7 or the temperature error value ΔeT3 of the water outlet 11 of the dialysis machine, and then execute step S2.

[0084] Specifically, in step S4, according to the temperature error value ΔeT2 of the float chamber 7, a method for calculating a new target temperature Tm2 of the float chamber 7 is as follows:

[0085] According to the last target temperature Tm2last of the float chamber 7 and the temperature error value ΔeT2 of the float chamber 7, the adjusted target temperature Tm2 of the float chamber 7 is calculated, and the specific formula is: Tm2=Tm2last+ΔeT2.

[0086] According to the temperature error value ΔeT3 of the dialysis machine water outlet 11, the method for calculating the new target temperature Tm2 of the float chamber 7 is:

[0087] According to the last target temperature Tm2last of the float chamber 7 and the temperature error value ΔeT3 of the water outlet 11 of the dialysis machine, the adjusted target temperature Tm2 of the float chamber 7 is calculated, and the specific formula is: Tm2=Tm2last+ΔeT3.

[0088] S5: Calculate the target temperature compensation value and flow temperature compensation value of the dialysis pipeline according to the new dialysis pipeline target temperature Tm4 and flow F sent by the host computer, adjust and calculate the new float chamber target temperature Tm2 according to the dialysis pipeline target temperature and flow, and then execute step S2.

[0089] According to treatment needs, when the target temperature Tm4 and flow rate F of the dialysis line 12 need to be changed again during the operation of the hemodialysis machine, in order to make the water temperature quickly reach the target temperature without drastic fluctuations or temperature overcharging, the present invention adopts a fast adjustment algorithm, and the specific steps are as follows:

[0090] Step S51: Compare the current target temperature value Tm4 of the dialysis pipeline 12 with the previous Tm4last to determine whether there is a change. If so, execute step S52; otherwise, execute step S54.

[0091] Step S52: Calculate the difference between the new target temperature Tm4 of the dialysis tubing 12 issued this time and the target temperature Tm4last of the dialysis tubing 12 issued last time to obtain the target temperature compensation value ΔAdjust of the dialysis tubing 12, which is expressed by the formula: ΔAdjust=Tm4-Tm4last.

[0092] Step S53: Obtain the last target temperature Tm2Last of the float chamber 7 and the temperature error compensation value ΔAdjust of the dialysis pipeline 12, and calculate the new target temperature Tm2 of the float chamber 7, which is expressed by the formula: Tm2=Tm2last+ΔAdjust.

[0093] Step S54: compare the flow F sent this time with the flow Flast sent last time to determine whether the flow F has changed. If so, execute S55; if not, execute step S2.

[0094] Step S55: Obtain the flow rate F sent this time and the last flow rate Flast, and select a suitable flow rate temperature compensation value ΔTF according to different flow rate switches.

[0095] Specifically, in this embodiment, the dialysis machine has three flow rates, namely F1, F2, and F3. The flow temperature compensation value ΔTF is calculated based on the previous experimental data. The specific method is as follows:

[0096] The actual temperature of the float chamber is a fixed value, and when the ambient temperature T0 is T 01 In the case of , the actual temperature of the water outlet when the flow rate is F1 is ΔT1F1, the flow rate is switched to F2, the actual temperature of the water outlet is ΔT1F2, and the outlet temperature difference P1 is calculated after the flow rate is switched from F1 to F2.

[0097] Change the ambient temperature T0 to T 02 When the flow rate is F1, the actual temperature of the water outlet is ΔT2F1. When the flow rate is switched to F2, the actual temperature of the water outlet is ΔT2F2. The outlet temperature difference P2 is calculated after the flow rate is switched from F1 to F2.

[0098] Repeat the above process to obtain the outlet temperature difference set P = {P1, P2, ...Pn} after the flow rate switches from F1 to F2 under different ambient temperatures; take the median of the set P as the flow temperature compensation value ΔTF1 after the flow rate switches from F1 to F2.

[0099] By repeating the above process, we can obtain the flow temperature compensation value ΔTF2 after the flow switches from F2 to F3 and the flow temperature compensation value ΔTF3 after the flow switches from F1 to F3 under different ambient temperatures, and the flow temperature compensation value set ΔTF = {ΔTF1, ΔTF2, ΔTF3}; when the dialysis machine is working, the appropriate ΔTF can be selected according to the flow F issued this time and the last flow Flast.

[0100] Step S56: Calculate the new target temperature Tm2 of the float chamber 7, which is expressed by the formula: Tm2=Tm2last+ΔTF, and then execute step S2.

Claims

1. A hemodialysis machine water system, comprising a water inlet chamber, a heating chamber, a float chamber, a balance chamber and a dialysis pipeline, wherein the water inlet of the water inlet chamber is used to be connected to a pure water source, the water inlet chamber, the heating chamber, the float chamber and the balance chamber are sequentially connected through the water inlet pipeline, and the dialysate inlet of the balance chamber is connected to the dialysate pump outlet, characterized in that: The water outlet of the balancing chamber is connected to the water outlet of the dialyzer through a long pipeline, the water outlet of the dialyzer is connected to the peripheral pipeline connected to the liquid inlet of the dialysis pipeline, the liquid outlet of the dialysis pipeline is connected to the waste liquid pipeline, and the waste liquid pipeline is provided with a waste liquid outlet; the water inlet chamber, float chamber and water outlet of the dialyzer are respectively provided with temperature sensors.

2. A hemodialysis machine water system as claimed in claim 1, characterized in that: A flow pump and a degassing pump are provided between the float chamber and the balance chamber. The flow pump is used to provide power for the liquid, and the degassing pump is used to remove bubbles remaining in the water inlet pipeline.

3. A hemodialysis machine water system as claimed in claim 1, characterized in that: A heat exchanger is provided between the water inlet chamber and the heating chamber, the waste liquid pipeline passes through the heat exchanger, and the waste liquid in the waste liquid pipeline and the pure water in the water inlet pipeline exchange heat energy in the heat exchanger; a water inlet valve is provided at the water inlet of the water inlet chamber.

4. A method for controlling the water circuit temperature of a hemodialysis machine, applied to a water circuit system of a hemodialysis machine as described in any one of claims 1 to 3, characterized in that the steps include: S1: Establish a neural network PID model, the upper computer sends the flow rate F and target temperature Tm4 of the dialysis pipeline, obtains the actual temperature T2 of the float chamber, the ambient temperature T0, the distance L1 from the float chamber to the water outlet of the dialysis machine, and the distance L2 from the water outlet of the dialysis machine to the dialysis pipeline, selects the heat dissipation A according to the actual temperature T2 of the float chamber and the ambient temperature T0, selects the first temperature coefficient ΔC1 and the second temperature coefficient ΔC2 according to the flow rate F, and calculates the target temperature Tm2 of the float chamber and the target temperature Tm3 of the water outlet of the dialysis machine respectively; S2: The neural network PID model controls the heating of the heating chamber according to the target temperature Tm2 of the float chamber, and the upper computer marks the target temperature value Tm2last=Tm2 of the float chamber, the target value Tm3last=Tm3 of the water outlet temperature of the dialysis machine, the target temperature Tm4last=Tm4 of the dialysis pipeline, and the flow rate Flast=F; S3: Regularly collect the actual temperature T2 of the float chamber and the actual temperature T3 of the water outlet of the dialysis machine, calculate the temperature error value △eT2 of the float chamber and the temperature error value ΔeT3 of the water outlet of the dialysis machine respectively, set the target temperature error value range, and judge whether the actual temperature T2 of the float chamber or the actual temperature T3 of the water outlet of the dialysis machine exceeds the target temperature error value range. If so, execute step S4, if not, repeat step S3; judge whether the upper computer sends a new dialysis pipeline target temperature Tm4 and flow rate F, if so, execute S5, if not, repeat step S3; S4: Calculate a new float chamber target temperature Tm2 according to the float chamber temperature error value ΔeT2 or the dialysis machine outlet temperature error value ΔeT3, and then execute step S2; S5: Calculate the target temperature compensation value and flow temperature compensation value of the dialysis pipeline according to the new dialysis pipeline target temperature Tm4 and flow F sent by the host computer, adjust and calculate the new float chamber target temperature Tm2 according to the dialysis pipeline target temperature and flow, and then execute step S2.

5. A method for controlling water circuit temperature of a hemodialysis machine according to claim 4, characterized in that: In step S1, the method for respectively calculating the target temperature Tm2 of the float chamber and the target temperature Tm3 of the water outlet of the dialysis machine is: S11: Obtain the actual temperature T2 of the float chamber, the ambient temperature T0, the flow rate F, the distance L1 from the float chamber to the water outlet 11 of the dialyzer, and the distance L2 from the water outlet of the dialyzer to the dialyzer pipeline. First, select the appropriate heat dissipation A according to the actual temperature T2 of the float chamber and the ambient temperature T0, and then select the appropriate first temperature coefficient ΔC1 and second temperature coefficient ΔC2 according to the flow rate F, and calculate the temperature compensation value Tc between the target temperature Tm3 of the water outlet of the dialyzer and the target temperature Tm4 of the dialyzer pipeline. The formula is: Tc = (L2 / L1)*A*ΔC2; S12: Obtain the target temperature Tm4 of the dialysis pipeline, and calculate the target temperature Tm3 of the dialysis machine outlet, which is expressed by the formula: Tm3 = Tm4 + Tc; S13: According to the target temperature Tm3 of the water outlet of the dialysis machine, the heat dissipation A and the first temperature coefficient ΔC1, the target temperature Tm2 of the float chamber is calculated, Tm2=Tm3+A*ΔC1.

6. A method for controlling water circuit temperature of a hemodialysis machine according to claim 4, characterized in that: In the step S3, the method for calculating the float chamber temperature error value ΔeT2 is specifically as follows: obtaining the last float chamber target temperature Tm2last, collecting the actual float chamber temperature T2, and calculating the float chamber temperature error value ΔeT2, the formula is: ΔeT2=Tm2last-T2; the method for calculating the dialysis machine water outlet temperature error value ΔeT3 is specifically as follows: obtaining the last dialysis machine water outlet target temperature Tm3last, collecting the dialysis machine water outlet actual temperature T3, and calculating the dialysis machine water outlet temperature error value ΔeT3, the specific formula is: ΔeT3=Tm3last-T3.

7. A method for controlling water circuit temperature of a hemodialysis machine according to claim 4, characterized in that: In the step S4, according to the float chamber temperature error value ΔeT2, the method for calculating the new float chamber target temperature Tm2 is: obtaining the last float chamber target temperature Tm2last and the float chamber temperature error value ΔeT2, and calculating the adjusted float chamber target temperature Tm2, ​​and the specific formula is: Tm2=Tm2last+ΔeT2; according to the dialysis machine outlet temperature error value ΔeT3, the method for calculating the new float chamber target temperature Tm2 is: obtaining the last float chamber target temperature Tm2last, and calculating the adjusted float chamber target temperature Tm2, ​​and the specific formula is: Tm2=Tm2last+ΔeT3.

8. A method for controlling water circuit temperature of a hemodialysis machine according to claim 4, characterized in that: The specific method of step S5 is: S51: Compare the current dialysis circuit temperature target value Tm4 with the previous Tm4last to determine whether there is a change. If so, execute step S52; if not, execute step S54; S52: Calculate the difference between the new dialysis tubing target temperature Tm4 issued this time and the dialysis tubing target temperature Tm4last issued last time to obtain the dialysis tubing target temperature compensation value ΔAdjust, which is expressed by the formula: ΔAdjust=Tm4-Tm4last; S53: Obtain the last float chamber target temperature Tm2Last and the dialysis line temperature error compensation value ΔAdjust, and calculate a new float chamber target temperature Tm2, ​​which is expressed by the formula: Tm2=Tm2last+ΔAdjust; Step S54: compare the flow rate F sent this time with the flow rate Flast sent last time to determine whether the flow rate F has changed. If so, execute S55; if not, execute step S2; Step S55: Obtain the flow rate F sent this time and the last flow rate Flast, and select a suitable flow rate temperature compensation value according to different flow rate switches; Step S56: Add the flow temperature compensation value ΔTF and the last issued target temperature Tm2last to obtain a new float chamber target temperature Tm2, ​​and then execute step S2.

9. A method for controlling water circuit temperature of a hemodialysis machine according to claim 4, characterized in that: The heat dissipation A is the water temperature reduction at the distance L1 from the float chamber to the water outlet of the dialysis machine under the conditions of the actual temperature T2 of the float chamber, the flow rate F and the ambient temperature T0; the first temperature coefficient ΔC1 is the temperature compensation coefficient for the distance L1 from the float chamber to the water outlet of the dialysis machine under different flow rates; the second temperature coefficient ΔC2 is the temperature compensation coefficient for the distance from the water outlet of the dialysis machine to the dialysis pipeline L2 under different flow rates.

10. A method for controlling water circuit temperature of a hemodialysis machine according to claim 9, characterized in that: The calculation method of the ambient temperature T0 is: when starting up the machine, collect the water inlet temperature T1, the float chamber temperature T2, and the dialysis machine outlet temperature T3. The ambient temperature is the average value of the three temperatures, and the formula is: T0 = (T1 + T2 + T3) / 3.

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