Two-stage temperature control system, dialysis system and temperature control method for CRRT equipment

Abstract

The present invention discloses a two-stage temperature control system of a CRRT device, including a primary temperature control unit, a secondary temperature control unit and a neutralization temperature control system; the primary temperature control unit includes a primary container, a primary temperature control actuator and a primary flow pump, the primary container is used to accommodate a liquid bag, and the primary temperature control actuator is used to adjust the temperature of the liquid in the liquid bag; the primary flow pump is used to pump the liquid into the secondary temperature control unit; the secondary temperature control unit includes a secondary container, a secondary temperature control actuator and a secondary flow pump, the secondary container is used to accommodate the pumped liquid, and the secondary temperature control actuator is used to adjust the temperature of the liquid in the secondary container; the secondary flow pump is used to pump the liquid out of the secondary container; the neutralization temperature control system includes a neutralization container and a neutralization flow pump, the neutralization container is used to accommodate the neutralization liquid bag, the liquid inlet of the neutralization flow pump is connected to the neutralization liquid bag, and the liquid outlet is connected to the secondary container. The present invention also discloses a dialysis system and a temperature control method for a CRRT device, which can accurately control the temperature of the liquid by combining the secondary temperature control system and the neutralization temperature control.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and specifically relates to a two-stage temperature control system, a dialysis system and a temperature control method for CRRT equipment. Background Art

[0002] Continuous blood purification (CRRT) equipment is used for blood purification treatment of critically ill patients. The treatment time is generally more than 8 hours, and may even last for several days. The treatment process requires the consumption of a large amount of dialysate / replacement fluid. Studies have shown that patients are prone to hypothermia symptoms due to heat loss during treatment, which leads to temperature regulation disorders in patients, which is extremely detrimental to the stability of the patient's condition and may even lead to serious consequences. Therefore, the low-temperature or normal-temperature dialysate / replacement fluid must be heated to close to the patient's body temperature. Depending on the patient's condition, the target temperature for heating the treatment fluid is generally 33 to 39°C. The target temperature for heating the treatment fluid is set and adjusted according to the treatment prescription.

[0003] At present, there are two main schemes for dialysate / replacement fluid in CRRT equipment. In the first scheme, the liquid in the initial liquid packaging bag (dialysate / replacement fluid bag) flows into the heated liquid bag. There is a container with an openable and closed door to hold the liquid bag. There are heating plates on both sides to heat the liquid bag. The inside of the liquid bag is an S-shaped liquid path. The heating plates on both sides directly heat the dialysate in the liquid bag from 5-31°C to 37°C-38°C (human body temperature); there are temperature sensors to detect the temperature of the heating plate and the temperature of the liquid outlet after the liquid bag is heated, and the power of the heating plate is controlled by the detected temperature. The second scheme: The liquid in the initial liquid packaging bag (dialysate / replacement fluid bag) flows into the liquid bag, and the liquid bag is placed in a semi-wrapped container. The inner wall of the semi-wrapped container has a heating wire to heat the liquid bag. There are metal parts in contact with the outer wall of the liquid bag to indirectly measure the liquid temperature inside the liquid bag.

[0004] It can be seen that in the two existing main solutions, there is only one heat source to provide heating and feedback control for the liquid bag / liquid capsule, and both belong to a single-point heating control loop, such as Figure 6 As shown in the figure, the liquid is heated from the initial temperature to the target temperature in one heat source. The existing single-point heating control loop has the following shortcomings:

[0005] (1) When the temperature of the liquid is low, the heating plate will use high power for heating. However, in the existing solution, the liquid temperature is measured by contacting the outer surface of the liquid bag with the sensor, that is, the liquid temperature is measured indirectly through the liquid bag, which will result in a long temperature lag time, causing the liquid to easily overheat, that is, the temperature of the heated liquid exceeds the target temperature;

[0006] (2) When the flow rate of the liquid is large, due to the limited volume of the heating container, the fresh low-temperature liquid does not receive sufficient heat exchange, resulting in a low temperature at the liquid outlet. According to experimental tests, when the target temperature is set at 37°C, the actual heating temperature of the two CRRT models currently used in clinical practice is only 33-34°C (room temperature 27°C). The current equipment solutions cannot solve the problem of low temperature and overheating within the nominal flow range of the equipment.

[0007] like Figure 7 As shown in the figure, the temperature loss of a commercially available model at different flow rates was experimentally tested. At room temperature of 16°C, the temperature of the liquid in the liquid bag is close to 16°C. When the flow rate of the liquid pump is set to 3ml / min and 5ml / min, the temperature of the liquid corresponding to the heating plate temperature is measured respectively. From the measurement results, it can be concluded that an increase in the flow rate will lead to a decrease in the actual temperature of the liquid at the same heating plate temperature; and the maximum flow rate of the liquid pump can be set to 100ml / min, and a higher flow rate is likely to lead to a greater deviation in the actual temperature of the liquid. Summary of the invention

[0008] In view of this, the object of the present invention is to provide a two-stage temperature control system, a dialysis system and a temperature control method for a CRRT device, which can accurately control the liquid temperature by combining the two-stage temperature control system and the neutralization temperature control.

[0009] In order to achieve the above object, the present invention provides the following technical solutions:

[0010] The present invention firstly proposes a two-stage temperature control system for a CRRT device, comprising a primary temperature control unit, a secondary temperature control unit and a neutralization temperature control system;

[0011] The primary temperature control unit includes a primary container, a primary temperature control actuator and a primary flow pump. The primary container is used to hold the liquid bag, and the primary temperature control actuator is used to control the liquid temperature T in the liquid bag. 1 , and make the liquid temperature T 1 Located in the set preheating target temperature zone [T 11 ,T 12 ], the primary temperature control unit has a preheating temperature range [T 1a ,T 1b ], The primary flow pump is used to pump the preheated liquid into the secondary temperature control unit according to a set flow rate;

[0012] The secondary temperature control unit includes a secondary container, a secondary temperature control actuator and a secondary flow pump. The secondary container is used to contain a liquid capsule, which is used to contain the pumped liquid. The secondary temperature control actuator is used to control the liquid temperature T in the liquid capsule. 2 , and make the liquid temperature T 2Located in the set liquid supply target temperature zone [T 21 ,T 22 ], the secondary temperature control unit has a target temperature range [T 2a ,T 2b ], The secondary flow pump is used to pump the temperature-adjusted liquid out of the liquid capsule at a set flow rate;

[0013] The neutralization temperature adjustment system comprises a neutralization container and a neutralization flow pump, wherein the neutralization container is used to accommodate a neutralization liquid bag, the temperature of the liquid stored in the neutralization liquid bag is lower than the maximum temperature value of the target temperature range, and the liquid inlet of the neutralization flow pump is connected to the neutralization liquid bag, and the liquid outlet is connected to the liquid capsule;

[0014] The maximum temperature value of the preheating temperature range is within the target temperature range, and the minimum temperature value of the target temperature range is within the preheating temperature range; or, the maximum temperature value of the preheating temperature range is less than the minimum temperature value of the target temperature range; the secondary temperature regulating unit is used to heat the liquid and make the liquid temperature within the target temperature range; or,

[0015] The minimum temperature value of the preheating temperature range is within the target temperature range, and the maximum temperature value of the target temperature range is within the preheating temperature range; or, the minimum temperature value of the preheating temperature range is greater than the maximum temperature value of the target temperature range; the secondary temperature control unit is used to cool the liquid and make the liquid temperature within the target temperature range.

[0016] Further, the maximum temperature value of the preheating temperature range is within the target temperature range, and the minimum temperature value of the target temperature range is within the preheating temperature range; or, the minimum temperature value of the preheating temperature range is within the target temperature range, and the maximum temperature value of the target temperature range is within the preheating temperature range;

[0017] The absolute value of the difference between the minimum temperature value of the target temperature range and the minimum temperature value of the preheating temperature is 2-3°C, and the absolute value of the difference between the maximum temperature value of the target temperature range and the maximum temperature value of the preheating temperature is 2-3°C.

[0018] Further, the maximum temperature value of the preheating temperature range is less than the minimum temperature value of the target temperature range, and the absolute value of the difference between the maximum temperature value of the preheating temperature range and the minimum temperature value of the target temperature is less than 3°C; or, the minimum temperature value of the preheating temperature range is greater than the maximum temperature value of the target temperature range; the absolute value of the difference between the minimum temperature value of the preheating temperature range and the maximum temperature value of the target temperature is less than 3°C.

[0019] Furthermore, the first-level temperature control unit also includes a first temperature sensor arranged at the liquid outlet of the first-level container or liquid bag and a second temperature sensor arranged on the first-level temperature control actuator; the first temperature sensor is used to measure the liquid temperature in the liquid bag, and the second temperature sensor is used to measure the temperature of the first-level temperature control actuator.

[0020] Furthermore, the primary temperature control unit further includes a primary temperature control unit, which receives the temperature data measured by the first temperature sensor and the second temperature sensor and controls the output power of the primary temperature control actuator. The principle is:

[0021]

[0022] Among them: U 1 (t) is the output power of the first-stage temperature control actuator; kp 1 is the first proportionality coefficient; T I is the first integral time constant; T D is the first differential time constant; t is time; err 1 (t) is the PID feedback adjustment deviation of the primary temperature control unit, and:

[0023] err 1 (t) = r 1 (t)―y 1 (t)

[0024] Where: r 1 (t) is the temperature of the liquid in the fluid bag measured by the first temperature sensor; 1 (t) is the temperature of the primary temperature control actuator measured by the second temperature sensor.

[0025] Furthermore, the secondary temperature control unit also includes a third temperature sensor arranged at the liquid outlet of the liquid sac and a fourth temperature sensor arranged on the secondary temperature control actuator; the third temperature sensor is used to measure the temperature of the liquid in the liquid sac, and the fourth temperature sensor is used to measure the temperature of the secondary temperature control actuator.

[0026] Furthermore, the secondary temperature control unit further includes a secondary temperature control unit, which receives the temperature data measured by the third temperature sensor and the fourth temperature sensor and controls the output power of the secondary temperature control actuator. The principle is:

[0027]

[0028] Among them: U 2 (t) is the output power of the secondary temperature control actuator; kp 2 is the second proportionality coefficient; T′I is the second integral time constant; T′ D is the second differential time constant; t is time; err 2 (t) is the PID feedback adjustment deviation of the secondary temperature control unit, and:

[0029] err 2 (t) = r 2 (t)―y 2 (t)

[0030] Where: r 2 (t) is the liquid temperature in the liquid bag measured by the third temperature sensor; 2 (t) is the temperature of the secondary temperature control actuator measured by the fourth temperature sensor.

[0031] Furthermore, the secondary temperature control unit also includes a secondary temperature control control unit, which receives the temperature data measured by the third temperature sensor, and sets the heating temperature of the secondary temperature control actuator and keeps it stable according to the set target temperature and liquid supply flow rate of the liquid supplied from the secondary temperature control unit to the rear end until the set target temperature and / or liquid supply flow rate changes, and the secondary temperature control unit resets the heating temperature of the secondary temperature control actuator and keeps it stable.

[0032] Furthermore, the neutralization and temperature adjustment system further comprises a neutralization and temperature adjustment actuator, a fifth temperature sensor, a sixth temperature sensor and a neutralization and temperature adjustment control unit, wherein the fifth temperature sensor is used to measure the temperature of the liquid in the neutralization liquid bag, the sixth temperature sensor is used to measure the temperature of the neutralization and temperature adjustment actuator, and the neutralization and temperature adjustment control unit receives the temperature data measured by the fifth temperature sensor and the sixth temperature sensor, and controls the output power of the neutralization and temperature adjustment actuator so that the temperature of the liquid in the neutralization liquid bag is maintained within the set liquid supply target temperature zone [T 21 ,T 22 ]Inside.

[0033] The present invention also proposes a dialysis system, comprising a dialyzer, wherein the dialyzer is provided with a blood inlet, a blood outlet, a dialysate inlet and a waste fluid outlet, wherein the blood inlet is connected to an arterial line, the blood outlet is connected to a venous line, the dialysate inlet is connected to a dialysate supply system, and / or the arterial line and / or the venous line are provided with a replacement fluid inlet, the replacement fluid inlet is connected to a replacement fluid supply system, a dialysate temperature control system is provided in the dialysate supply system, and / or a replacement fluid temperature control system is provided in the replacement fluid supply system, and both the dialysate temperature control system and the replacement fluid temperature control system adopt the secondary temperature control system of the CRRT equipment as described in any one of claims 1 to 9.

[0034] The present invention also proposes a two-stage temperature adjustment method for a CRRT device, wherein the device sets the target temperature zone of the liquid supply according to the target temperature of the liquid supply set by the user. 21 ,T 22 ] and the preheating target temperature zone [T 11 ,T 12 ]; The temperature adjustment process includes the following steps:

[0035] Step S1: placing the liquid bag in a primary container;

[0036] Step S2: The primary temperature control unit detects the temperature of the liquid in the liquid bag and makes a judgment based on the working state of the equipment: if the temperature control system of the equipment is in the liquid supply preparation state, or the temperature control system is in the liquid supply state but the temperature of the liquid in the liquid bag exceeds the preheating safety temperature limit, then the temperature is adjusted according to steps S21 to S24; if the temperature control system of the equipment is in the liquid supply state, and the temperature of the liquid in the liquid bag is within the preheating safety temperature limit, then step S3 is performed, and the temperature of the liquid retained in the liquid bag is adjusted according to steps S21 to S24 at the same time;

[0037] Step S21: Use the primary temperature control actuator to control the temperature of the liquid in the fluid bag, and after setting the time interval, execute step S22;

[0038] Step S22: Determine the temperature of the liquid in the fluid bag T 1 Is it within the set preheating target temperature zone: If yes, execute step S24; if not, then: if the liquid temperature T 1 Less than the minimum temperature T of the preheating target temperature zone 11 , execute step S21; if the temperature of the liquid in the liquid bag is T 1 Greater than the maximum temperature value T of the preheating target temperature zone 12 , execute step S23;

[0039] Step S23: turn off the primary temperature control actuator, set the time interval, and then execute step S22;

[0040] Step S24: determine whether the difference between the temperature of the primary temperature control actuator and the temperature of the liquid in the liquid bag is within the steady-state temperature error range: if so, it indicates that the temperature of the liquid in the liquid bag has reached a stable state, and step S2 is executed; if not, step S21 is executed;

[0041] Step S3: pumping the liquid in the fluid bag into the liquid bag in the secondary container according to the set flow rate;

[0042] Step S4: The secondary temperature control unit detects the temperature of the liquid in the liquid capsule and makes a judgment based on the working state of the device: if the temperature control system of the device is in the liquid supply preparation state, or the temperature control system is in the liquid supply state but the temperature of the liquid in the liquid capsule exceeds the liquid supply safety temperature limit, then the temperature is adjusted according to steps S41 to S44; if the temperature control system of the device is in the liquid supply state, and the temperature of the liquid in the liquid capsule is within the liquid supply safety temperature limit, then step S5 is performed, and the temperature of the liquid retained in the liquid capsule is adjusted according to steps S41 to S44 at the same time;

[0043] Step S41: Determine whether the temperature of the liquid in the liquid capsule is within the set liquid supply target temperature zone: if so, execute step S44; if not, then: if the temperature of the liquid in the liquid capsule is T 2 Less than the minimum temperature value T of the target temperature zone of the liquid supply 21 The secondary temperature control actuator is a heating device, or the liquid temperature in the liquid capsule is T 2 Greater than the maximum temperature value T of the target temperature zone of the liquid supply 22 If the secondary temperature control actuator is a cooling device, execute step S42; if the liquid temperature in the liquid capsule is greater than the maximum temperature value T of the target temperature zone of the liquid supply 22 , and the secondary temperature control actuator is a heating device, or the liquid temperature in the liquid capsule is lower than the minimum temperature value T of the target temperature zone of the liquid supply 21 If the secondary temperature control actuator is a cooling device, execute step S43;

[0044] Step S42: using the secondary temperature control actuator to control the temperature of the liquid in the liquid capsule, after setting the time interval, executing step S41;

[0045] Step S43: turn off the secondary temperature control actuator, set the time interval, and then execute step S41;

[0046] Step S44: determine whether the difference between the temperature of the secondary temperature control actuator and the temperature of the liquid in the liquid capsule is within the steady-state temperature error range: if so, it indicates that the temperature of the liquid in the secondary container has reached a stable state, and step S4 is executed; if not, step S41 is executed;

[0047] Step S5: Pumping the liquid out of the liquid bag according to the set flow rate.

[0048] Furthermore, in step S43, after the secondary temperature control actuator is turned off, the neutralization flow pump is started to pump the liquid in the neutralization liquid bag into the liquid capsule.

[0049] The beneficial effects of the present invention are:

[0050] The two-stage temperature control system of the CRRT device of the present invention is provided with a two-stage temperature control unit including a primary temperature control unit and a secondary temperature control unit. Thus, a large-capacity liquid bag is placed in a primary container, and the liquid in the liquid bag is temperature-controlled by a primary temperature control actuator, so that the primary temperature control unit reaches a steady state, and the temperature of the liquid in the liquid bag is maintained within a preheating temperature range close to a target temperature range; then, the liquid in the liquid bag is pumped into the liquid bag at a set flow rate through a primary flow pump, and the liquid in the liquid bag is temperature-controlled by a secondary temperature control actuator, so that the temperature of the liquid in the liquid bag is within a target temperature range. range; since the temperature of the liquid pumped into the secondary temperature control unit is close to or within the target temperature range, the secondary temperature control unit can quickly reach a steady state under different flow rates; in particular, if the secondary temperature control unit overheats, the liquid in the neutralization liquid bag is pumped into the liquid bag through the neutralization flow pump to achieve the purpose of rapid neutralization and cooling, and at the same time, the secondary temperature control unit can also quickly regain a steady state; in summary, the two-stage temperature control system of the CRRT equipment of the present invention can accurately control the liquid temperature by combining the secondary temperature control system and the neutralization temperature control. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0052] Figure 1 This is the schematic diagram of the two-stage temperature control system of the CRRT equipment;

[0053] Figure 2 It is the schematic diagram of the neutralization and temperature control system;

[0054] Figure 3 This is the schematic diagram of PID feedback control;

[0055] Figure 4 This is a schematic diagram of the dialysis system;

[0056] Figure 5 This is a flow chart of the two-stage temperature control method for CRRT equipment;

[0057] Figure 6 It is the schematic diagram of the existing single-point heating control loop;

[0058] Figure 7 This is a graph showing the relationship between the liquid flow rate and liquid temperature of a certain type of CRRT equipment used clinically.

[0059] Description of reference numerals:

[0060] 10-primary temperature control unit; 11-primary container; 12-primary temperature control actuator; 13-primary flow pump; 14-first temperature sensor; 15-second temperature sensor; 16-primary temperature control unit; 17-fluid bag;

[0061] 20-secondary temperature control unit; 21-secondary container; 22-secondary temperature control actuator; 23-secondary flow pump; 24-third temperature sensor; 25-fourth temperature sensor; 26-secondary temperature control unit; 27-liquid capsule;

[0062] 30-dialyzer; 31-dialysis fluid supply system; 32-replacement fluid supply system; 33-arterial line; 34-blood pump; 35-waste pump; 36-waste bag; 37-venous line;

[0063] 40-neutralization and temperature control system; 41-neutralization container; 42-neutralization flow pump; 43-neutralization liquid bag; 44-neutralization and temperature control actuator; 45-fifth temperature sensor; 46-sixth temperature sensor; 47-neutralization and temperature control control unit. DETAILED DESCRIPTION

[0064] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0065] 1. Two-stage temperature control system of CRRT equipment

[0066] During clinical CRRT treatment, medical staff set the target temperature for fluid heating according to the treatment prescription. The allowable setting range of the target temperature is determined by the equipment manufacturer during the equipment design phase based on clinical needs and implemented through appropriate software and hardware.

[0067] like Figure 1 As shown, the two-stage temperature control system of the CRRT device of this embodiment includes a primary temperature control unit 10, a secondary temperature control unit 20 and a neutralization temperature control system 40. The primary temperature control unit has a preheating temperature range [T 1a ,T 1b ], the secondary temperature control unit has a target temperature range [T 2a ,T 2b ], these are parameters determined by the hardware and software of the device, reflecting the performance attributes of the device. The target temperature range [T 2a ,T 2b ] For normal operation of the heating system, the user is allowed to set the target temperature range for the liquid supply, and the preheating temperature range [T 1a ,T 1b ] is the preheating temperature range allowed for the first-level temperature control unit to preheat the liquid.

[0068] The target temperature zone for liquid supply is the allowable deviation range set manually by the user or automatically generated by the device according to the target temperature for liquid supply set by the user, and is the temperature control reference of the secondary temperature control unit 20. According to the set target temperature for liquid supply, the user manually sets or the device automatically sets the preheating temperature value, and the device automatically generates a preheating temperature zone with a certain deviation from the preheating temperature value according to the set preheating temperature value, as the temperature control reference of the primary temperature control unit 10.

[0069] As a safety control parameter, the liquid supply safety temperature limit refers to the temperature range that will not cause damage to the rear-end liquid circuit or the patient. This temperature range includes the target temperature range. The liquid supply safety temperature limit is a safety temperature limit that requires absolute control, so it can be reasonably set by the equipment manufacturer. When the liquid temperature exceeds the liquid supply safety temperature, the liquid supply system will not supply liquid to the rear-end circuit, and the equipment can issue a prompt or alarm at this time. The equipment preheating safety temperature limit is automatically generated by the equipment according to the set target temperature. It is the safe temperature of the liquid after the first-level temperature adjustment and is the basis for the rear-end temperature control. Avoid excessively high or low temperatures that cannot be quickly corrected in the secondary temperature adjustment unit 20, causing potential damage to the patient or the rear-end liquid circuit. It is easy to understand that the preheating safety temperature limit includes the preheating temperature range.

[0070] In this embodiment, the primary temperature control unit 10 includes a primary container 11, a primary temperature control actuator 12 and a primary flow pump 13. The primary container 11 is used to contain or place a liquid bag 17, the primary temperature control actuator 12 is used to control the temperature of the liquid in the liquid bag 17 and make the liquid temperature within the set preheating temperature range, and the primary flow pump 13 is used to pump the preheated liquid into the liquid bag 27 of the secondary temperature control unit 20 according to the set flow rate. In this embodiment, the primary container 11 is a tray and is used to place the liquid bag 17. Of course, in other embodiments, the primary container 11 can also be set as a box or other structure for storing the liquid bag 17, which will not be repeated. The primary temperature control actuator 12 can be a common electric heating plate.

[0071] In this embodiment, the primary temperature control unit 10 further includes a first temperature sensor 14 disposed at the liquid outlet of the primary container 11 or the liquid bag 17 and a second temperature sensor 15 disposed on the primary temperature control actuator 12. Specifically, the first temperature sensor 14 is used to measure the temperature of the liquid in the liquid bag 17, and the second temperature sensor 15 is used to measure the temperature of the primary temperature control actuator 12. The primary temperature control unit of this embodiment further includes a primary temperature control control unit 16, which receives the temperature data measured by the first temperature sensor 14 and the second temperature sensor 15, and controls the output power of the primary temperature control actuator 12. The control mode of the primary temperature control unit 16 adopts PID feedback control, and the principle is:

[0072]

[0073] Among them: U 1 (t) is the output power of the primary temperature control actuator 12; kp 1 is the first proportionality coefficient; T I is the first integral time constant; T D is the first differential time constant; t is time; err 1 (t) is the PID feedback adjustment deviation of the primary temperature control unit 10, and:

[0074] err 1 (t) = r 1 (t)―y 1 (t)

[0075] Where: r 1 (t) is the liquid temperature in the liquid bag 17 measured by the first temperature sensor 14; y 1 (t) is the temperature of the primary temperature control actuator 12 measured by the second temperature sensor 15 .

[0076] In this embodiment, the secondary temperature control unit 20 includes a secondary container 21, a secondary temperature control actuator 22 and a secondary flow pump 23. The secondary container 21 is used to contain a liquid capsule 27, which is used to contain the pumped liquid. The secondary temperature control actuator 22 is used to control the temperature of the liquid in the liquid capsule 27 and make the liquid temperature within the set target temperature range; the secondary flow pump 23 is used to pump the liquid after temperature control out of the liquid capsule 27 according to the set flow rate. In this embodiment, the secondary container 21 can be a semi-open temperature control device in a box shape, sleeve shape or other shape for containing the liquid capsule 27. The volume of the liquid capsule 27 is smaller than the liquid bag 17 used in the primary temperature control unit 10. The liquid capsule 27 can also be replaced by a heating liquid bag with a smaller volume than the liquid bag 17. If the secondary temperature control unit 20 is used for secondary heating, the secondary temperature control actuator 22 can be a common electric heating plate; if the secondary temperature control unit 20 is used for cooling, the secondary temperature control actuator 22 can be a refrigeration device such as a semiconductor refrigerator.

[0077] Specifically, the secondary temperature control unit 20 also includes a third temperature sensor 24 disposed at the liquid outlet of the liquid capsule 27 and a fourth temperature sensor 25 disposed on the secondary temperature control actuator 22; the third temperature sensor 24 is used to measure the liquid temperature in the liquid capsule 27, and the fourth temperature sensor 25 is used to measure the temperature of the secondary temperature control actuator 22. The secondary temperature control unit 20 of this embodiment also includes a secondary temperature control unit 26, which receives the temperature data measured by the third temperature sensor 24 and the fourth temperature sensor, and controls the output power of the secondary temperature control actuator 22. Specifically, the control method of the secondary temperature control unit 26 adopts PID feedback control, and the principle is:

[0078]

[0079] Where: Y 2 (t) is the output power of the secondary temperature control actuator 22; kp 2 is the second proportionality coefficient; T′ I is the second integral time constant; T′ D is the second differential time constant; t is time; err 2 (t) is the PID feedback adjustment deviation of the secondary temperature control unit 20, and:

[0080] err 2 (t) = r 2 (t)―y 2 (t)

[0081] Where: r 2 (t) is the liquid temperature in the liquid capsule 27 measured by the third temperature sensor 24; y 2 (t) is the temperature of the secondary temperature control actuator 22 measured by the fourth temperature sensor 24 .

[0082] Specifically, the principle of PID feedback control is as follows Figure 3 As shown, the PID feedback control controls the temperature control actuator (the primary temperature control actuator 12 and the secondary temperature control actuator 22) through the error signal. The control model of the PID feedback control includes the addition results of the three links of proportion, integration and differentiation. The continuous state formula of the PID feedback control is:

[0083]

[0084] Where: U(t) is the output power of the temperature control actuator; kp is the first proportional coefficient; T I is the first integral time constant; T D is the first differential time constant; t is time; err(t) is the PID feedback regulation deviation, and:

[0085] err(t)=r(t)―y(t)

[0086] Where: r(t) is the liquid temperature; y(t) is the temperature of the thermostatic actuator.

[0087] According to the continuous state formula of PID feedback control, it can be directly concluded that PID feedback control is actually a control process of the deviation. In this embodiment, the PID control quantity is the actual power of the thermostat actuator, but the actual power of the thermostat actuator includes other influencing factors, such as: the power dissipation P of the air lossThe heating yield η belongs to the proportional control part of PID. The change of temperature difference and the residual temperature of the thermostat actuator have a comprehensive impact on the integral and differential control part of PID, which affects the trend judgment and overshoot control. For example, the reduction of temperature difference and the increase of residual temperature of the thermostat actuator show a trend close to the result of overheating. In order to avoid overshoot, the output power needs to be reduced in advance.

[0088] Temperature control is limited by the following factors: Power dissipation P of the air loss ; Heating yield η, heating yield η is the combination of temperature control actuator efficiency and thermal efficiency. In unit time t seconds, the liquid of mass m is heated from the initial temperature T 1 Heating to T 2 , the required power P w For: P w =mC P (T 2 ―T 1 ), where: C P is the specific heat capacity of the liquid. Therefore, the required output power is: P n =P w +P loss , the actual power of the thermostat actuator is The actual power P of the thermostatic actuator decreases as the difference between the actual liquid temperature and the target temperature decreases.

[0089] That is, at a large flow rate, the liquid flows rapidly in the pipeline, and the heat of the heating wire must pass through three layers of barriers: insulating silicone, temperature control actuator (metal plate), and wall material of the liquid circuit before it can be transferred to the liquid. At this time, the control of integration and differentiation has reached the extreme value, the entire system has reached a steady state, and there is a steady-state error. Experimental measurements show that under the conditions of a blood flow of 500mL / min and a liquid pump flow of 50mL / min, the temperature of the liquid is only 34°C (room temperature 27°C), and the steady-state error is 3-4°C. Therefore, in this embodiment, a primary temperature control unit 10 is used to control the temperature of the liquid within a preheating temperature range close to the target temperature range, and the temperature difference between the target temperature and the preheating temperature is compensated by a secondary temperature control unit 20, which makes up for the defect of a large error between the actual temperature of the liquid and the theoretical temperature caused by thermal conductivity.

[0090] The neutralization and temperature control system 40 of this embodiment includes a neutralization container 41 and a neutralization flow pump 42. The neutralization container 41 is used to accommodate a neutralization liquid bag 43. The temperature of the liquid stored in the neutralization liquid bag 43 is lower than the maximum temperature value of the target temperature range. The liquid inlet of the neutralization flow pump 42 is connected to the neutralization liquid bag 43, and the liquid outlet is connected to the liquid capsule 27. Specifically, when the secondary temperature control unit 20 is overheated, the neutralization flow pump 42 is started to pump the liquid in the neutralization liquid bag 43 into the liquid capsule 27 to achieve the purpose of rapid neutralization and cooling. In one implementation of this embodiment, the neutralization container 41 has no temperature regulation function, and the neutralization liquid bag 43 stores liquid at room temperature. When the secondary temperature control unit 20 is overheated, rapid neutralization and cooling can be performed. In another implementation of this embodiment, the neutralization and temperature control system 40 also includes a neutralization and temperature control actuator 44, a fifth temperature sensor 45, a sixth temperature sensor 46 and a neutralization and temperature control control unit 47, such as Figure 2 As shown. Specifically, the fifth temperature sensor 45 is used to measure the temperature of the liquid in the neutralization liquid bag 43, the sixth temperature sensor 46 is used to measure the temperature of the neutralization temperature control actuator 44, and the neutralization temperature control unit 47 receives the temperature data measured by the fifth temperature sensor 45 and the sixth temperature sensor 46, and controls the output power of the neutralization temperature control actuator 47 so that the liquid temperature in the neutralization liquid bag 43 is maintained within the set neutralization temperature range. Specifically, the neutralization temperature control actuator 47 uses a PID feedback control method to control the output power of the neutralization temperature control actuator 47. The principle is the same as that of the primary temperature control system 10 and the secondary temperature control system 20, and will not be repeated. In this way, the liquid temperature in the neutralization liquid bag 43 can be maintained within the set temperature range, that is, the liquid temperature in the neutralization liquid bag 43 is more stable, and the secondary temperature control unit 20 can be better neutralized and cooled. In particular, the maximum temperature value of the neutralization temperature range should be lower than the maximum temperature value of the target temperature range.

[0091] Specifically, the preheating temperature range and the target temperature range can be determined according to the liquid heating control strategy determined by the product design and functional requirements of the CRRT equipment and implemented through product manufacturing.

[0092] The first method: the maximum temperature value of the preheating temperature range is within the target temperature range, and the minimum temperature value of the target temperature range is within the preheating temperature range. For example, if the preheating temperature range is 30-36°C and the target temperature range is 33-39°C, the maximum temperature value of the preheating temperature range, 36°C, is within the target temperature range, 33-39°C, and the minimum temperature value of the target temperature range, 33°C, is within the preheating temperature range, 30-36°C. The absolute value of the difference between the minimum temperature value of the target temperature range and the minimum temperature value of the preheating temperature is 2-3°C, and the absolute value of the difference between the maximum temperature value of the target temperature range and the maximum temperature value of the preheating temperature is 2-3°C. In this embodiment, the absolute value of the difference between the minimum temperature value of the target temperature range and the minimum temperature value of the preheating temperature is 3°C, and the absolute value of the difference between the maximum temperature value of the target temperature range and the maximum temperature value of the preheating temperature is 3°C. For example, when the target temperature of the liquid supply set by the user is 37°C, the device uses the primary temperature control unit 10 to control the temperature of the liquid in the liquid bag 17 within the range of 34-35°C, and then uses the secondary temperature control unit 20 to control the temperature of the liquid pumped into the secondary container 21 within the range of 36-38°C. That is, the secondary temperature control unit 20 at this time is used to heat the liquid and make the liquid temperature within the target temperature range of the liquid supply.

[0093] The second way: the maximum temperature value of the preheating temperature range is less than the minimum temperature value of the target temperature range. For example, if the preheating temperature range is 32-35°C and the target temperature range is 36-39°C, the maximum temperature value of the preheating temperature range of 35°C is less than the minimum temperature value of the target temperature range of 36°C. The absolute value of the difference between the maximum temperature value of the preheating temperature range and the minimum temperature value of the target temperature is less than 3°C; in this embodiment, the absolute value of the difference between the maximum temperature value of the preheating temperature range and the minimum temperature value of the target temperature is 1°C. For example, when the user sets the target temperature of the liquid supply to 36°C, the first-level temperature control unit 10 is used to control the temperature of the liquid in the liquid bag 17 within the range of 33-35°C, and then the second-level temperature control unit 20 is used to control the temperature of the liquid pumped into the liquid capsule 27 within the range of 35.5-36.5°C. That is, the second-level temperature control unit 20 at this time is used to heat the liquid and make the liquid temperature within the target temperature zone of the liquid supply.

[0094] The third way: the minimum temperature value of the preheating temperature range is within the target temperature range, and the maximum temperature value of the target temperature range is within the preheating temperature range. For example, the preheating temperature range is 36-42°C, and the target temperature range is 33-39°C. The minimum temperature value of the preheating temperature range, 36°C, is within the target temperature range of 33-39°C, and the maximum temperature value of the target temperature range, 39°C, is within the preheating temperature range of 36-42°C. The absolute value of the difference between the minimum temperature value of the target temperature range and the minimum temperature value of the preheating temperature is 2-3°C, and the absolute value of the difference between the maximum temperature value of the target temperature range and the maximum temperature value of the preheating temperature is 2-3°C. In this embodiment, the absolute value of the difference between the minimum temperature value of the target temperature range and the minimum temperature value of the preheating temperature is 3°C, and the absolute value of the difference between the maximum temperature value of the target temperature range and the maximum temperature value of the preheating temperature is 3°C. For example, when the target temperature of the liquid supply set by the user is 39° C., the primary temperature control unit 10 is used to control the temperature of the liquid in the liquid bag 17 within the range of 40-41° C., and then the secondary temperature control unit 20 is used to control the temperature of the liquid pumped into the secondary container 21 within the range of 38.5-39.5° C. That is, the secondary temperature control unit 20 is used to cool the liquid and make the liquid temperature within the target temperature range of the liquid supply.

[0095] The fourth way: the minimum temperature value of the preheating temperature range is greater than the maximum temperature value of the target temperature range. For example, the preheating temperature range is 39-41°C, and the target temperature range is 36-38°C. The minimum temperature value of the preheating temperature range of 39°C is greater than the maximum temperature value of the target temperature range of 38°C. The absolute value of the difference between the minimum temperature value of the preheating temperature range and the maximum temperature value of the target temperature is less than 3°C; in this embodiment, the absolute value of the difference between the minimum temperature value of the preheating temperature range and the maximum temperature value of the target temperature is 1°C. For example, when the user sets the target temperature of the liquid supply to 37°C, at this time, the first-level temperature control unit 10 is used to control the temperature of the liquid in the liquid bag 17 within the range of 39-40°C, and then the second-level temperature control unit 20 is used to control the temperature of the liquid pumped into the second-level container 21 within the range of 36.5-37.5°C. That is, the second-level temperature control unit 20 at this time is used to cool the liquid and make the liquid temperature within the target temperature range.

[0096] 2. Dialysis System

[0097] like Figure 4As shown, this embodiment also proposes a dialysis system, including a dialyzer 30, the interior of which is divided into a blood chamber and a dialysate chamber by a hollow fiber dialysis membrane, the blood chamber of the dialyzer 30 is provided with a blood inlet and a blood outlet, the dialysate chamber is provided with a dialysate inlet and a waste liquid outlet, wherein the blood inlet is connected to an arterial line 34, and the blood outlet is connected to a venous line 37, thereby forming an extracorporeal blood circuit, and a blood pump 34 is provided on the arterial line 34. The dialysate inlet of the dialyzer 30 is connected to a dialysate supply system 31, the arterial line 34 and / or the venous line 37 are provided with a replacement fluid inlet, and the replacement fluid inlet is connected to a replacement fluid supply system 32, i.e., a replacement fluid supply structure of a pre-dilution or post-dilution or mixed dilution treatment mode in clinical practice. Specifically, the dialysate supply system 31 of this embodiment is provided with a dialysate temperature control system, and the replacement fluid supply system 32 is provided with a replacement fluid temperature control system. Both the dialysate temperature control system and the replacement fluid temperature control system adopt the secondary temperature control system of the CRRT equipment described above in this embodiment.

[0098] Specifically, the dialysate supply system 31 and the replacement fluid supply system 32 both include a supply pipe set. The supply pipe set and the liquid bag 17 are both disposable consumables, and cooperate with the liquid temperature control system of the CRRT device to form a dialysate supply system or a replacement fluid supply system. The primary flow pump, the secondary flow pump, and the neutralization flow pump can all be peristaltic pumps. The supply pipe set includes a liquid inlet, a liquid capsule 27, and a pump tube, and the liquid inlet, the liquid capsule 27, and the pump tube are connected by a pipeline. The liquid inlet of the supply pipe set is connected to the liquid bag 17 arranged in the primary container, and the liquid capsule 27 is arranged in the secondary container 21. The pump tube corresponds to each peristaltic pump one by one, and the rotor roller of the peristaltic pump squeezes and releases the pump tube to promote the flow of liquid. A waste liquid pump 35 and a waste liquid bag 36 are connected to the dialysate outlet of the dialyzer 30 of this embodiment.

[0099] Specifically, the primary temperature control unit 10 of the dialysate temperature control system and the replacement fluid temperature control system is set as an integral or split setting. When the primary temperature control unit 10 of the dialysate temperature control system and the replacement fluid temperature control system is set as an integral unit, the liquid bag of the dialysate supply system 31 and the liquid bag of the replacement fluid supply system 32 are both placed in the same primary container, and are preheated to the same set preheating temperature range at the same time, and then pumped into their respective independent secondary temperature control units 20 to adjust the temperature to the target temperature range. In this embodiment, the primary temperature control unit 10 of the dialysate temperature control system and the replacement fluid temperature control system is set as a split setting, so that the two primary temperature control units 10 can be used to preheat and adjust the liquid bag of the dialysate supply system 31 and the liquid bag of the replacement fluid supply system 32 to the set preheating temperature range.

[0100] 3. Two-stage temperature control method for CRRT equipment

[0101] like Figure 5As shown, a two-stage temperature adjustment method for a CRRT device in this embodiment, firstly, the device sets a target temperature zone [T 21 ,T 22 ] and preheating target temperature zone [T 11 ,T 12 ], and then adjust the temperature. The temperature adjustment process includes the following steps:

[0102] Step S1: placing the fluid bag 17 in the primary container 11.

[0103] Step S2: The primary temperature control unit 10 detects the temperature of the liquid in the liquid bag 17, and makes a judgment based on the working state of the equipment: if the temperature control system of the equipment is in the liquid supply preparation state, or the temperature control system is in the liquid supply state but the temperature of the liquid in the liquid bag 17 exceeds the preheating safety temperature limit, the temperature is adjusted according to steps S21 to S24; if the temperature control system of the equipment is in the liquid supply state, and the temperature of the liquid in the liquid bag 17 is within the preheating safety temperature limit, step S3 is performed, and the temperature of the liquid retained in the liquid bag 17 is adjusted according to steps S21 to S24.

[0104] Step S21: Use the primary temperature control actuator 12 to control the temperature of the liquid in the liquid bag 17. After setting the unit time interval, execute step S22.

[0105] Step S22: Determine the temperature T of the liquid in the liquid bag 17 1 Is it within the set preheating target temperature zone: If yes, execute step S24; if no, then: if the liquid temperature T in the liquid bag 17 1 Less than the minimum temperature T of the preheating target temperature zone 11 , execute step S21; if the temperature of the liquid in the liquid bag 17 is T 1 Greater than the maximum temperature value T of the preheating target temperature zone 12 , execute step S23.

[0106] Step S23: turn off the primary temperature control actuator 12, set the unit time interval, and then execute step S22.

[0107] Step S24: determine whether the difference between the temperature of the primary temperature control actuator 12 and the temperature of the liquid in the liquid bag 17 is within the steady-state temperature error range: if so, it indicates that the primary temperature control unit 10 has reached a steady state, and step S2 is executed; if not, step S21 is executed;

[0108] Step S3: using the primary flow pump 13 to pump the liquid in the liquid bag 17 into the liquid capsule 21 at a set flow rate.

[0109] In step S4, the secondary temperature control unit 20 detects the temperature of the liquid in the liquid capsule 27, and makes a judgment based on the working state of the equipment: if the temperature control system of the equipment is in the liquid supply preparation state, or the temperature control system is in the liquid supply state but the temperature of the liquid in the liquid capsule 27 exceeds the preheating safety temperature limit, the temperature is adjusted according to steps S41 to S44; if the temperature control system of the equipment is in the liquid supply state, and the temperature of the liquid in the liquid capsule 27 is within the liquid supply safety temperature limit, step S5 is performed, and at the same time, the temperature of the retained liquid in the liquid capsule 27 is adjusted according to steps S41 to S44, so that the temperature of the liquid flowing out of the liquid capsule 27 is as close to the target temperature as possible.

[0110] Step S41: Determine whether the temperature of the liquid in the liquid capsule 27 is within the set liquid supply target temperature zone: If yes, execute step S44; if not, then: if the temperature of the liquid in the liquid capsule 27 is less than the minimum temperature value T of the liquid supply target temperature zone 21 The secondary temperature control actuator is a heating device, or the liquid temperature in the liquid capsule is T 2 Greater than the maximum temperature value T of the target temperature zone of the liquid supply 22 If the secondary temperature control actuator is a cooling device, step S42 is executed; if the liquid temperature in the liquid capsule 21 is greater than the maximum temperature value T of the target temperature zone of the liquid supply, 22 , and the secondary temperature control actuator is a heating device, or the liquid temperature in the liquid capsule is lower than the minimum temperature value T of the target temperature zone of the liquid supply 21 If the secondary temperature control actuator is a cooling device, execute step S43.

[0111] Step S42: Use the secondary temperature control actuator 22 to control the temperature of the liquid in the liquid capsule 27. After setting the unit time interval, execute step S41.

[0112] Step S43: turn off the secondary temperature control actuator 22, set the unit time interval, and then execute step S41. Specifically, in this embodiment, after turning off the secondary temperature control actuator 22, start the neutralization flow pump 42 to pump the liquid in the neutralization liquid bag 43 into the liquid bag 27 to achieve the purpose of rapid neutralization and cooling.

[0113] Step S44: Determine whether the difference between the temperature of the secondary temperature control actuator 22 and the temperature of the liquid in the liquid capsule 21 is within the steady-state temperature error range: if so, it indicates that the secondary temperature control unit 20 has reached a steady state, and execute step S4; if not, execute step S41.

[0114] Step S5: using the secondary flow pump 23 to pump the liquid out of the liquid bag 27 according to the set flow rate.

[0115] The liquid heating method of this embodiment is controlled in combination with the device status. Before dialysis treatment, the machine is in the treatment preparation stage (such as self-test or liquid heating), and the treatment has not yet started. At this time, the device has not issued an instruction to the temperature control system to supply liquid to the rear end flow path, so the liquid in the liquid bag can be slowly heated to the preheating temperature. When the device liquid supply system is in the state of supplying liquid to the rear end, such as in the pre-filling and exhausting stage of the extracorporeal blood circuit, the dialysate circuit and the dialyzer, or the treatment is terminated and the liquid bag is replaced and the treatment is continued, the device issues an instruction to supply liquid to the rear end flow path. At this time, the priority of supplying liquid to the rear end is higher. As long as the liquid is within the preheating safety temperature limit, liquid is supplied to the rear end, but at the same time, the liquid in the liquid bag and the liquid sac is also temperature-controlled so that the liquid temperature gradually reaches the set target temperature.

[0116] Specifically, the primary temperature control unit 10 includes a primary container 11, a primary temperature control actuator 12, a primary flow pump 13, a first temperature sensor 14, a second temperature sensor 15 and a primary temperature control unit 16. The primary container 11 is used to contain or place a liquid bag 17; the primary temperature control actuator 12 is used to control the temperature of the liquid in the liquid bag 17 and make the liquid temperature within the set preheating temperature range; the primary flow pump 13 is used to pump the preheated liquid into the liquid bag 27 of the secondary temperature control unit 20 according to the set flow rate; the first temperature sensor 14 is arranged at the liquid outlet of the primary container 11 or the liquid bag 17, and is used to measure the temperature of the liquid in the liquid bag 17; the second temperature sensor 15 is arranged on the primary temperature control actuator 12, and is used to measure the temperature of the primary temperature control actuator 12; the primary temperature control unit 16 receives the temperature data measured by the first temperature sensor 14 and the second temperature sensor 15, and controls the output power of the primary temperature control actuator 12. Specifically, the control method of the primary temperature control unit 16 adopts PID feedback control, and the principle is:

[0117]

[0118] Among them: U 1 (t) is the output power of the primary temperature control actuator 12; kp 1 is the first proportionality coefficient; T I is the first integral time constant; T D is the first differential time constant; t is time; err 1 (t) is the PID feedback adjustment deviation of the primary temperature control unit 10, and:

[0119] err 1 (t) = r 1 (t)―y 1 (t)

[0120] Where: r 1(t) is the liquid temperature in the liquid bag 17 measured by the first temperature sensor 14; y 1 (t) is the temperature of the primary temperature control actuator 12 measured by the second temperature sensor 15 .

[0121] Specifically, the secondary temperature control unit 20 includes a secondary container 21, a secondary temperature control actuator 22, a secondary flow pump 23, a third temperature sensor 24, a fourth temperature sensor 25 and a secondary temperature control unit 26. The secondary container 21 is used to contain a liquid capsule 27, which is used to contain the pumped liquid; the secondary temperature control actuator 22 is used to control the temperature of the liquid in the liquid capsule 27, and make the liquid temperature within the set target temperature range; the secondary flow pump 23 is used to pump the temperature-controlled liquid out of the liquid capsule 27 at a set flow rate; the third temperature sensor 24 is arranged at the liquid outlet of the liquid capsule 27, and is used to measure the temperature of the liquid in the liquid capsule 27; the fourth temperature sensor 25 is arranged on the secondary temperature control actuator 22, and is used to measure the temperature of the secondary temperature control actuator 22; the secondary temperature control unit 26 receives the temperature data measured by the third temperature sensor 24 and the fourth temperature sensor 25, and controls the output power of the secondary temperature control actuator 22. Specifically, the control method of the secondary temperature control unit 26 adopts PID feedback control, and the principle is:

[0122]

[0123] Among them: U 2 (t) is the output power of the secondary temperature control actuator 22; kp 2 is the second proportionality coefficient; T′ I is the second integral time constant; T′ D is the second differential time constant; t is time; err 2 (t) is the PID feedback adjustment deviation of the secondary temperature control unit 20, and:

[0124] err 2 (t) = r 2 (t)―y 2 (t)

[0125] Where: r 2 (t) is the liquid temperature in the liquid capsule 27 measured by the third temperature sensor 24; y 2 (t) is the temperature of the secondary temperature control actuator 22 measured by the fourth temperature sensor 24 .

[0126] Specifically, the principle of PID feedback control is as follows Figure 3As shown, the PID feedback control controls the temperature control actuator (the primary temperature control actuator 12 and the secondary temperature control actuator 22) through the error signal. The control model of the PID feedback control includes the addition results of the three links of proportion, integration and differentiation. The continuous state formula of the PID feedback control is:

[0127]

[0128] Where: U(t) is the output power of the temperature control actuator; kp is the first proportional coefficient; T I is the first integral time constant; T D is the first differential time constant; t is time; err(t) is the PID feedback regulation deviation, and:

[0129] err(t)=r(t)―y(t)

[0130] Where: r(t) is the liquid temperature; y(t) is the temperature of the thermostatic actuator.

[0131] According to the continuous state formula of PID feedback control, it can be directly concluded that PID feedback control is actually a control process of the deviation. In this embodiment, the PID control quantity is the actual power of the thermostat actuator, but the actual power of the thermostat actuator includes other influencing factors, such as: the power dissipation P of the air loss The heating yield η belongs to the proportional control part of PID. The change of temperature difference and the residual temperature of the thermostat actuator have a comprehensive impact on the integral and differential control part of PID, which affects the trend judgment and overshoot control. For example, the reduction of temperature difference and the increase of residual temperature of the thermostat actuator show a trend close to the result of overheating. In order to avoid overshoot, the output power needs to be reduced in advance.

[0132] Temperature control is limited by the following factors: Power dissipation P of the air loss ; Heating yield η, heating yield η is the combination of temperature control actuator efficiency and thermal efficiency. In unit time t seconds, the liquid of mass m is heated from the initial temperature T 1 Heating to T 2 , the required power P w For: P w =mC P (T 2 ―T 1 ), where: C P is the specific heat capacity of the liquid. Therefore, the required output power is: P n =P w +P loss , the actual power of the thermostat actuator is The actual power P of the thermostatic actuator decreases as the difference between the actual liquid temperature and the target temperature decreases.

[0133] That is, at a large flow rate, the liquid flows rapidly in the pipeline, and the heat of the heating wire must pass through the three barriers of insulating silica gel, thermostat actuator (metal plate), and liquid path material before it can be transferred to the liquid. At this time, the control of integration and differentiation has reached the extreme value, the entire system has reached a steady state, and there is a steady-state error. Experimental measurements show that under the conditions of a blood flow of 500mL / min and a liquid pump flow of 50mL / min, the temperature of the liquid is only 34°C (room temperature 27°C), and the steady-state error is 3-4°C. Therefore, in this embodiment, a primary thermostat unit 10 is used to control the temperature of the liquid within a preheating temperature range close to the target temperature range, and the temperature difference between the target temperature and the preheating temperature is compensated by the secondary thermostat unit 20, which makes up for the defect that there is a large error between the actual temperature of the liquid and the theoretical temperature caused by the thermal conductivity efficiency. Specifically, in this embodiment, when the primary thermostat unit 10 reaches a steady state, the difference between the temperature of the primary thermostat actuator 12 and the temperature of the liquid in the liquid bag 17 is 3-4°C. When the secondary temperature regulating unit 20 reaches a steady state, the difference between the temperature of the secondary temperature regulating actuator 22 and the temperature of the liquid in the liquid capsule 27 is 3-4°C.

[0134] Specifically, the preheating temperature range and the target temperature range can be determined according to the liquid heating control strategy determined by the product design and functional requirements of the CRRT equipment and implemented through product manufacturing.

[0135] The first method: the maximum temperature value of the preheating temperature range is within the target temperature range, and the minimum temperature value of the target temperature range is within the preheating temperature range. For example, if the preheating temperature range is 30-36°C and the target temperature range is 33-39°C, the maximum temperature value of the preheating temperature range, 36°C, is within the target temperature range, 33-39°C, and the minimum temperature value of the target temperature range, 33°C, is within the preheating temperature range, 30-36°C. The absolute value of the difference between the minimum temperature value of the target temperature range and the minimum temperature value of the preheating temperature is 2-3°C, and the absolute value of the difference between the maximum temperature value of the target temperature range and the maximum temperature value of the preheating temperature is 2-3°C. In this embodiment, the absolute value of the difference between the minimum temperature value of the target temperature range and the minimum temperature value of the preheating temperature is 3°C, and the absolute value of the difference between the maximum temperature value of the target temperature range and the maximum temperature value of the preheating temperature is 3°C. For example, when the target temperature of the liquid supply set by the user is 37°C, the device uses the primary temperature control unit 10 to control the temperature of the liquid in the liquid bag 17 within the range of 34-35°C, and then uses the secondary temperature control unit 20 to control the temperature of the liquid pumped into the liquid capsule 27 within the range of 36-38°C. That is, the secondary temperature control unit 20 at this time is used to heat the liquid and make the liquid temperature within the target temperature range of the liquid supply.

[0136] The second way: the maximum temperature value of the preheating temperature range is less than the minimum temperature value of the target temperature range. For example, if the preheating temperature range is 32-35°C and the target temperature range is 36-39°C, the maximum temperature value of the preheating temperature range of 35°C is less than the minimum temperature value of the target temperature range of 36°C. The absolute value of the difference between the maximum temperature value of the preheating temperature range and the minimum temperature value of the target temperature is less than 3°C; in this embodiment, the absolute value of the difference between the maximum temperature value of the preheating temperature range and the minimum temperature value of the target temperature is 1°C. For example, when the user sets the target temperature of the liquid supply to 36°C, the first-level temperature control unit 10 is used to control the temperature of the liquid in the liquid bag 17 within the range of 33-35°C, and then the second-level temperature control unit 20 is used to control the temperature of the liquid pumped into the liquid capsule 27 within the range of 35.5-36.5°C. That is, the second-level temperature control unit 20 at this time is used to heat the liquid and make the liquid temperature within the target temperature zone of the liquid supply.

[0137] The third way: the minimum temperature value of the preheating temperature range is within the target temperature range, and the maximum temperature value of the target temperature range is within the preheating temperature range. For example, the preheating temperature range is 36-42°C, and the target temperature range is 33-39°C. The minimum temperature value of the preheating temperature range, 36°C, is within the target temperature range of 33-39°C, and the maximum temperature value of the target temperature range, 39°C, is within the preheating temperature range of 36-42°C. The absolute value of the difference between the minimum temperature value of the target temperature range and the minimum temperature value of the preheating temperature is 2-3°C, and the absolute value of the difference between the maximum temperature value of the target temperature range and the maximum temperature value of the preheating temperature is 2-3°C. In this embodiment, the absolute value of the difference between the minimum temperature value of the target temperature range and the minimum temperature value of the preheating temperature is 3°C, and the absolute value of the difference between the maximum temperature value of the target temperature range and the maximum temperature value of the preheating temperature is 3°C. For example, when the target temperature of the liquid supply set by the user is 39° C., the primary temperature control unit 10 is used to control the temperature of the liquid in the liquid bag 17 within the range of 40-41° C., and then the secondary temperature control unit 20 is used to control the temperature of the liquid pumped into the liquid capsule 27 within the range of 38.5-39.5° C. That is, the secondary temperature control unit 20 is used to cool the liquid and make the liquid temperature within the target temperature range of the liquid supply.

[0138] The fourth way: the minimum temperature value of the preheating temperature range is greater than the maximum temperature value of the target temperature range. For example, the preheating temperature range is 39-41°C, and the target temperature range is 36-38°C. The minimum temperature value of the preheating temperature range, 39°C, is greater than the maximum temperature value of the target temperature range, 38°C. The absolute value of the difference between the minimum temperature value of the preheating temperature range and the maximum temperature value of the target temperature is less than 3°C; in this embodiment, the absolute value of the difference between the minimum temperature value of the preheating temperature range and the maximum temperature value of the target temperature is 1°C. For example, when the user sets the target temperature of the liquid supply to 37°C, at this time, the first-level temperature control unit 10 is used to control the temperature of the liquid in the liquid bag 17 within the range of 39-40°C, and then the second-level temperature control unit 20 is used to control the temperature of the liquid pumped into the liquid bag 27 within the range of 36.5-37.5°C. That is, the second-level temperature control unit 20 at this time is used to cool the liquid and make the liquid temperature within the target temperature range.

[0139] Note: The "and / or" mentioned in this article represents the two logical relationships of "and" and "or". For example, "A and / or B" can mean "A or B" or "A and B".

[0140] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A two-stage temperature control system for a CRRT device, characterized in that: It includes a primary temperature control unit, a secondary temperature control unit and a neutralization temperature control system; The primary temperature control unit includes a primary container, a primary temperature control actuator and a primary flow pump. The primary container is used to contain the liquid bag. The primary temperature control actuator is used to control the liquid temperature T1 in the liquid bag and make the liquid temperature T1 within the set preheating target temperature zone [T 11 ,T 12 ], the primary temperature control unit has a preheating temperature range [T 1a ,T 1b ], The primary flow pump is used to pump the preheated liquid into the secondary temperature control unit according to a set flow rate; The secondary temperature control unit includes a secondary container, a secondary temperature control actuator and a secondary flow pump. The secondary container is used to contain a liquid capsule, which is used to contain the pumped liquid. The secondary temperature control actuator is used to control the liquid temperature T2 in the liquid capsule and make the liquid temperature T2 within the set liquid supply target temperature zone [T 21 ,T 22 ], the secondary temperature control unit has a target temperature range [T 2a ,T 2b ], The secondary flow pump is used to pump the temperature-adjusted liquid out of the liquid capsule at a set flow rate; The neutralization temperature adjustment system comprises a neutralization container and a neutralization flow pump, wherein the neutralization container is used to accommodate a neutralization liquid bag, the temperature of the liquid stored in the neutralization liquid bag is lower than the maximum temperature value of the target temperature range, and the liquid inlet of the neutralization flow pump is connected to the neutralization liquid bag, and the liquid outlet is connected to the liquid capsule; The maximum temperature value of the preheating temperature range is within the target temperature range, and the minimum temperature value of the target temperature range is within the preheating temperature range; or, the maximum temperature value of the preheating temperature range is less than the minimum temperature value of the target temperature range; The secondary temperature regulating unit is used to heat the liquid and make the liquid temperature fall within the target temperature range; or, The minimum temperature value of the preheating temperature range is within the target temperature range, and the maximum temperature value of the target temperature range is within the preheating temperature range; or, the minimum temperature value of the preheating temperature range is greater than the maximum temperature value of the target temperature range; The secondary temperature regulating unit is used to cool the liquid and make the temperature of the liquid fall within a target temperature range.

2. The two-stage temperature control system of the CRRT equipment according to claim 1, characterized in that: The maximum temperature value of the preheating temperature range is within the target temperature range, and the minimum temperature value of the target temperature range is within the preheating temperature range; or, the minimum temperature value of the preheating temperature range is within the target temperature range, and the maximum temperature value of the target temperature range is within the preheating temperature range; The absolute value of the difference between the minimum temperature value of the target temperature range and the minimum temperature value of the preheating temperature is 2-3°C, and the absolute value of the difference between the maximum temperature value of the target temperature range and the maximum temperature value of the preheating temperature is 2-3°C.

3. The two-stage temperature control system of the CRRT equipment according to claim 1, characterized in that: The maximum temperature value of the preheating temperature range is less than the minimum temperature value of the target temperature range, and the absolute value of the difference between the maximum temperature value of the preheating temperature range and the minimum temperature value of the target temperature is less than 3°C; or, the minimum temperature value of the preheating temperature range is greater than the maximum temperature value of the target temperature range; An absolute value of a difference between a minimum temperature value of the preheating temperature range and a maximum temperature value of the target temperature is less than 3°C.

4. The two-stage temperature control system of the CRRT equipment according to claim 1, characterized in that: The first-level temperature control unit also includes a first temperature sensor arranged at the liquid outlet of the first-level container or liquid bag and a second temperature sensor arranged on the first-level temperature control actuator; the first temperature sensor is used to measure the liquid temperature in the liquid bag, and the second temperature sensor is used to measure the temperature of the first-level temperature control actuator.

5. The two-stage temperature control system of the CRRT equipment according to claim 4, characterized in that: The primary temperature control unit further includes a primary temperature control unit, which receives the temperature data measured by the first temperature sensor and the second temperature sensor and controls the output power of the primary temperature control actuator. The principle is: Where: U1(t) is the output power of the first-stage temperature control actuator; kp1 is the first proportional coefficient; T I is the first integral time constant; T D is the first differential time constant; t is time; err1(t) is the PID feedback adjustment deviation of the primary temperature control unit, and: err1(t)=r1(t)―y1(t) Wherein: r1(t) is the temperature of the liquid in the liquid bag measured by the first temperature sensor; y1(t) is the temperature of the primary temperature control actuator measured by the second temperature sensor.

6. The two-stage temperature control system of the CRRT equipment according to claim 1, characterized in that: The secondary temperature control unit also includes a third temperature sensor arranged at the liquid outlet of the liquid sac and a fourth temperature sensor arranged on the secondary temperature control actuator; the third temperature sensor is used to measure the temperature of the liquid in the liquid sac, and the fourth temperature sensor is used to measure the temperature of the secondary temperature control actuator.

7. The two-stage temperature control system of the CRRT equipment according to claim 6, characterized in that: The secondary temperature control unit further includes a secondary temperature control unit, which receives the temperature data measured by the third temperature sensor and the fourth temperature sensor and controls the output power of the secondary temperature control actuator. The principle is: Where: U2(t) is the output power of the secondary temperature control actuator; kp2 is the second proportional coefficient; T′ I is the second integral time constant; T′ D is the second differential time constant; t is time; err2(t) is the PID feedback adjustment deviation of the secondary temperature control unit, and: err2(t)=r2(t)―y2(t) Wherein: r2(t) is the temperature of the liquid in the liquid capsule measured by the third temperature sensor; y2(t) is the temperature of the secondary temperature control actuator measured by the fourth temperature sensor.

8. The two-stage temperature control system for CRRT equipment according to claim 6, characterized in that: The secondary temperature control unit also includes a secondary temperature control control unit, which receives the temperature data measured by the third temperature sensor, and sets the heating temperature of the secondary temperature control actuator and keeps it stable according to the set target temperature and flow rate of liquid supply from the secondary temperature control unit to the rear end until the set target temperature and / or flow rate of liquid supply changes, and the secondary temperature control unit resets the heating temperature of the secondary temperature control actuator and keeps it stable.

9. The two-stage temperature control system of the CRRT equipment according to claim 1, characterized in that: The neutralization and temperature adjustment system further comprises a neutralization and temperature adjustment actuator, a fifth temperature sensor, a sixth temperature sensor and a neutralization and temperature adjustment control unit, wherein the fifth temperature sensor is used to measure the temperature of the liquid in the neutralization liquid bag, the sixth temperature sensor is used to measure the temperature of the neutralization and temperature adjustment actuator, and the neutralization and temperature adjustment control unit receives the temperature data measured by the fifth temperature sensor and the sixth temperature sensor, and controls the output power of the neutralization and temperature adjustment actuator so that the temperature of the liquid in the neutralization liquid bag is maintained within the set liquid supply target temperature zone [T 21 ,T 22 ]Inside.

10. A dialysis system, comprising a dialyzer, wherein the dialyzer is provided with a blood inlet, a blood outlet, a dialysate inlet and a waste liquid outlet, wherein the blood inlet is connected to an arterial line, the blood outlet is connected to a venous line, the dialysate inlet is connected to a dialysate supply system, and / or the arterial line and / or the venous line are provided with a replacement fluid inlet, and the replacement fluid inlet is connected to the replacement fluid supply system, characterized in that: The dialysate supply system is provided with a dialysate temperature control system, and / or the replacement fluid supply system is provided with a replacement fluid temperature control system, and both the dialysate temperature control system and the replacement fluid temperature control system adopt the secondary temperature control system of the CRRT equipment as described in any one of claims 1-9.

11. A two-stage temperature adjustment method for CRRT equipment, characterized in that: The device sets the target temperature zone [T 21 ,T 22 ] and the preheating target temperature zone [T 11 ,T 12 ]; The temperature adjustment process includes the following steps: Step S1: placing the liquid bag in a primary container; Step S2: The primary temperature control unit detects the temperature of the liquid in the liquid bag and makes a judgment based on the working state of the equipment: if the temperature control system of the equipment is in the liquid supply preparation state, or the temperature control system is in the liquid supply state but the temperature of the liquid in the liquid bag exceeds the preheating safety temperature limit, then the temperature is adjusted according to steps S21 to S24; if the temperature control system of the equipment is in the liquid supply state, and the temperature of the liquid in the liquid bag is within the preheating safety temperature limit, then step S3 is performed, and the temperature of the liquid retained in the liquid bag is adjusted according to steps S21 to S24 at the same time; Step S21: Use the primary temperature control actuator to control the temperature of the liquid in the fluid bag, and after setting the time interval, execute step S22; Step S22: Determine whether the temperature T1 of the liquid in the fluid bag is within the set preheating target temperature zone: If yes, execute step S24; if not, then: if the temperature T1 of the liquid in the fluid bag is less than the minimum temperature value T of the preheating target temperature zone, 11 , execute step S21; if the liquid temperature T1 in the liquid bag is greater than the maximum temperature value T of the preheating target temperature zone 12 , execute step S23; Step S23: turn off the primary temperature control actuator, set the time interval, and then execute step S22; Step S24: determine whether the difference between the temperature of the primary temperature control actuator and the temperature of the liquid in the liquid bag is within the steady-state temperature error range: if so, it indicates that the temperature of the liquid in the liquid bag has reached a stable state, and step S2 is executed; if not, step S21 is executed; Step S3: pumping the liquid in the fluid bag into the liquid bag in the secondary container according to the set flow rate; Step S4: The secondary temperature control unit detects the temperature of the liquid in the liquid capsule and makes a judgment based on the working state of the device: if the temperature control system of the device is in the liquid supply preparation state, or the temperature control system is in the liquid supply state but the temperature of the liquid in the liquid capsule exceeds the liquid supply safety temperature limit, then the temperature is adjusted according to steps S41 to S44; if the temperature control system of the device is in the liquid supply state, and the temperature of the liquid in the liquid capsule is within the liquid supply safety temperature limit, then step S5 is performed, and the temperature of the liquid retained in the liquid capsule is adjusted according to steps S41 to S44 at the same time; Step S41: Determine whether the temperature of the liquid in the liquid capsule is within the set liquid supply target temperature zone: If yes, execute step S44; if not, then: if the temperature T2 of the liquid in the liquid capsule is less than the minimum temperature value T of the liquid supply target temperature zone 21 The secondary temperature control actuator is a heating device, or the liquid temperature T2 in the liquid capsule is greater than the maximum temperature value T of the target temperature zone of the liquid supply. 22 If the secondary temperature control actuator is a cooling device, execute step S42; if the liquid temperature in the liquid capsule is greater than the maximum temperature value T of the target temperature zone of the liquid supply 22 , and the secondary temperature control actuator is a heating device, or the liquid temperature in the liquid capsule is lower than the minimum temperature value T of the target temperature zone of the liquid supply 21 If the secondary temperature control actuator is a cooling device, execute step S43; Step S42: using the secondary temperature control actuator to control the temperature of the liquid in the liquid capsule, after setting the time interval, executing step S41; Step S43: turn off the secondary temperature control actuator, set the time interval, and then execute step S41; Step S44: determine whether the difference between the temperature of the secondary temperature control actuator and the temperature of the liquid in the liquid capsule is within the steady-state temperature error range: if so, it indicates that the temperature of the liquid in the liquid capsule has reached a stable state, and step S4 is executed; if not, step S41 is executed; Step S5: Pumping the liquid out of the liquid bag according to the set flow rate.

12. The two-stage temperature control method for CRRT equipment according to claim 10, characterized in that: In step S43, after the secondary temperature control actuator is turned off, the neutralization flow pump is started to pump the liquid in the neutralization liquid bag into the liquid capsule.

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