Distributed micro-channel heating film structure and multi-mode temperature control method

Abstract

The invention relates to the technical field of medical instruments, in particular to a distributed micro-channel heating film structure and a multi-mode temperature control method. The structure comprises an inlet connected with a blood source; the inlet is connected with one end of each of a plurality of parallel and annularly-surrounded micro-channel combinations; the micro-channel combination comprises a main channel and an auxiliary channel; the cache region is connected with the other ends of the micro-channel combinations; the cache region is respectively connected with the outlet and the return pipeline; the return pipeline is positioned in the middle of the plurality of parallel micro-channel combinations; a plurality of flexible double-sided heating films are arranged outside a pipe of each micro-channel combination and are in contact with the main channel, the auxiliary channel and the return pipeline; the temperature sensor set monitors the temperature of blood in the main flow channel and the temperature of blood in the buffer area in real time and transmits the temperatures to the processor set in real time. The application is improved in the aspects of accurate temperature control, blood protection, closed-loop safety, intelligent linkage, portability, reliability and the like.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and more specifically, to a distributed microchannel heating film structure and a multimodal temperature control method. Background Technology

[0002] In clinical treatment and emergency care, blood transfusion is a vital means of saving lives. However, administering hypothermic blood products can easily lead to adverse reactions such as hypothermia and shivering in patients; therefore, safe and effective warming of the blood is crucial.

[0003] Currently, most common blood transfusion warmers use contact heating plates or water bath heating, but these technologies still have significant shortcomings. First, temperature control accuracy and uniformity are insufficient. These devices typically rely on a single temperature sensor, which suffers from measurement lag and spatial limitations, making it difficult to reflect the overall temperature distribution of the blood in real time. This can easily lead to localized overheating causing hemolysis or overall insufficient heating. Second, traditional heating methods, due to uneven heat transfer, may create temperature gradients or hot spots, causing thermal damage to blood cells and affecting transfusion safety. Furthermore, existing systems lack closed-loop feedback; most can only control the temperature of the heating base, rather than directly monitoring the temperature of the blood output to the patient. Simultaneously, existing devices have limited functionality and low levels of intelligence, typically unable to link with data such as infusion pump flow rate and patient vital signs, making it difficult to achieve personalized, adaptive heating adjustments. Finally, there is a trade-off between portability and reliability. Devices suitable for out-of-hospital emergency scenarios often fall short in heating performance, battery life, and environmental adaptability, failing to meet the reliable blood transfusion needs under complex emergency conditions.

[0004] In summary, existing technologies have shortcomings in terms of precise temperature control, blood protection, closed-loop safety, intelligent linkage, and portability and reliability, and urgently need improvement.

[0005] In view of the above, this application is hereby submitted. Summary of the Invention

[0006] The purpose of this application is to provide a distributed microchannel heating film structure and a multimodal temperature control method to solve all or part of the technical problems in the background art.

[0007] To achieve the above objectives, this application adopts the following technical solution: In a first aspect, this application provides a distributed microchannel heating film structure, comprising: An inlet connected to a blood source; the inlet connects to one end of a combination of multiple parallel and annular microchannels; the microchannel combination includes a main channel and secondary channels; A buffer area connected to the other end of a combination of multiple microchannels; The buffer zone is connected to the outlet and the return pipeline respectively; a first valve is provided between the buffer zone and the outlet, and a second valve is provided between the buffer zone and the return pipeline; the return pipeline is located in the middle of a combination of multiple parallel microchannels. Each microchannel assembly has multiple flexible double-sided heating films installed outside the tube. These flexible double-sided heating films are in contact with the main channel, secondary channel, and return channel. The return channel simultaneously absorbs heat from the secondary channel and the flexible double-sided heating films, and stores the heat. The temperature sensor group monitors the temperature of blood in the main flow channel, the secondary flow channel, the return flow line, and the buffer area in real time, and transmits the temperature to the processor group in real time. The processor group controls the power of multiple flexible double-sided heating films based on the target temperature and the received real-time temperature; and if the temperature of the blood in the buffer area does not reach the target temperature within a set time, the first valve is closed and the opening of the second valve is controlled to guide the blood from the second valve into the return pipeline for heating and return to the buffer area, while controlling the power of the multiple flexible double-sided heating films; after the temperature of the blood in the buffer area reaches the target temperature, the first valve is opened and the blood flows out from the first valve.

[0008] Secondly, this application provides a multimodal temperature control method, employing a distributed microchannel heating film structure, wherein the multimodal temperature control method includes: The power of multiple flexible double-sided heating films is controlled based on the target temperature and the received real-time temperature. If the temperature of the blood in the buffer zone does not reach the target temperature within the set time, the first valve is closed and the opening of the second valve is controlled to guide the blood from the second valve into the return pipeline for heating and back to the buffer zone; the power of multiple flexible double-sided heating films is controlled; Once the blood temperature in the buffer zone reaches the target temperature, the first valve is opened, and the blood flows out from the first valve.

[0009] Compared with the prior art, the beneficial effects of this application are as follows: First, by employing a combination design of multiple parallel and annularly distributed microchannels, the traditional single heating channel is expanded into a distributed heat exchange network with a huge surface area. This allows blood to contact the heating surface in an extremely thin laminar flow, thus achieving rapid and uniform heat transfer. This structure fundamentally eliminates red blood cell damage (hemolysis) and protein denaturation caused by localized overheating, ensuring the bioactivity of blood components. In particular, the application of a flexible double-sided heating film allows a single heating element to simultaneously transfer heat to adjacent main channels, secondary channels, and the central return channel, maximizing thermal energy utilization efficiency. The return channel, acting as a built-in "heat accumulator," not only recovers the waste heat from the secondary channels but also serves as a secondary heating source when needed. This gives the structure an instantaneous heating and heat buffering capacity that traditional equipment lacks when dealing with large-flow, low-temperature blood sources, resolving the contradiction between heating speed and blood protection.

[0010] Secondly, this patent establishes a multi-dimensional protection system regarding the accuracy, intelligence, and safety of temperature control. By integrating contact infrared temperature measurement, non-contact infrared calibration, and a distributed real-time temperature sensing module based on fiber optic gratings, a three-dimensional sensing network is constructed, encompassing point-to-line, tube wall-to-core, and indirect monitoring to direct measurement. This enables the processor to grasp the true and precise distribution of the blood temperature field within the flow channel, rather than just the single outlet temperature, providing an unprecedented data foundation for precise control. Furthermore, the main and secondary processor architecture, along with the active control of all patient-related safety valves, together form a rapid safety barrier, minimizing the risk of equipment failure.

[0011] Furthermore, by communicating with the infusion pump to obtain flow patterns and implementing preheating strategies, collaborative predictive control between devices was achieved, significantly improving response speed. By collecting the patient's core body temperature in real time and using this as dynamic feedback to adjust the target blood temperature and recommended infusion flow rate, the extracorporeal heating process was organically integrated with the stability of the patient's overall vital signs, enhancing the physiological rationality of medical intervention.

[0012] Finally, it ensures a constant body temperature during transfusion, effectively preventing iatrogenic hypothermia and its associated complications such as coagulation disorders, arrhythmias, and increased risk of infection. Its rapid, high-flow heating capability provides solid support for rapid blood transfusions in trauma emergency care and major surgeries. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 This is an overall structural diagram of a distributed microchannel heating film structure provided in an embodiment of this application; Figure 2 This is a cross-sectional view of the distributed microchannel heating film structure provided in the embodiments of this application; Figure 3 This is a schematic diagram of the structure of the return pipeline and buffer area provided in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of the flexible single-sided heating film and microchannel combination provided in the embodiments of this application; Figure 5 This is a schematic flowchart of the multimodal temperature control method provided in the embodiments of this application; Among them, 1-inlet, 2-main flow channel, 3-secondary flow channel, 4-buffer zone, 5-flexible double-sided heating film, 6-return pipeline, 7-outlet, 8-first valve, 9-second valve, 10-microchannel combination, 11-flexible single-sided heating film, 12-flow outlet. Detailed Implementation

[0015] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of this application, including various details to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0016] The present application will be further described in detail below with reference to the embodiments.

[0017] This application provides a distributed microchannel heating film structure. See also... Figures 1-4 The structure includes: Inlet 1 connects to the blood source. Specifically, inlet 1 connects to the blood source, such as a blood bag or infusion pump, via medical-grade sterile tubing. A filter and bubble detector can be installed at inlet 1 to ensure blood quality and safety.

[0018] Inlet 1 connects to one end of multiple parallel and ring-shaped microchannel assemblies 10 (this embodiment sets 4 microchannel assemblies 10, but the number is not limited); the microchannel assembly 10 includes a main channel 2 and a secondary channel 3. A buffer area 4 is connected to the other end of the multiple microchannel assemblies 10.

[0019] In this system, the main flow channel 2 handles basic circulation, while the secondary flow channel 3 is activated when a large flow rate is required. Optionally, if the blood flow rate (obtained via the infusion pump) is less than a set value (based on the maximum flow capacity of the main flow channel 2), the processor controls the switching mechanism of the diversion valve or the flow channel itself, ensuring that blood is delivered only through the main flow channel 2. In this case, the secondary flow channel 3 is closed, and blood is delivered only through the main flow channel 2. If the blood flow rate is greater than or equal to the set value, the processor opens all flow channels, and blood is delivered simultaneously through the main flow channel 2 and all secondary flow channels 3.

[0020] The buffer zone 4 is connected to the outlet 7 and the return pipe 6 respectively; a first valve 8 is provided between the buffer zone 4 and the outlet 7, and a second valve 9 is provided between the buffer zone 4 and the return pipe 6; the return pipe 6 is located in the middle of multiple parallel microchannel combinations 10.

[0021] Outlet 7 is connected to the patient's intravenous access. Buffer zone 4 is a chamber with a certain volume, its function being to mix blood from the parallel flow channels, making its temperature more uniform, and to serve as a temporary temperature monitoring and control node. This embodiment does not limit the specific structure of the first valve 8 and the second valve 9, only requiring that they can receive electrical signals (opening signal, opening / closing signal) from the processor group and respond accordingly. Return line 6 includes an inflow line entering from buffer zone 4 and an outflow line flowing into buffer zone 4. The shape of return line 6 is adapted to the internal space enclosed by multiple microchannel combinations 10, see [reference needed]. Figure 2 The reflux conduit 6 has an irregular shape, and its walls need to fit tightly against the walls of the flexible double-sided heating film 5 and the secondary flow channel 3 to simultaneously absorb heat from both the secondary flow channel 3 and the flexible double-sided heating film 5, and to store heat. The reflux conduit 6 includes an outlet 12 (located at the end of the outflow conduit). The outlet 12 is a valve structure that guides unidirectional blood flow, meaning it only allows... Figure 3 The flow direction shown prevents blood from flowing back into the return line 6 from the outlet 12, thus avoiding blood stagnation in the return line 6. This valve structure can be a duckbill valve or umbrella valve made of medical-grade silicone. When blood flows through the outflow line, the pressure of the infusion pump drives the valve structure to open towards the buffer zone 4, allowing blood to flow back from the return line 6 to the buffer zone 4. Optionally, during transfusion preparation, the return line 6 can be pre-filled with sterile saline or the patient's own blood, and a pre-filling fluid drain valve is installed at the lowest point of the return line 6. When the second valve 9 needs to be opened (i.e., when the return line 6 needs to be used), the pre-filling fluid drain valve is opened to drain the pre-filling fluid. After blood flows in, only blood should exist within the return line 6 and its entire structure. The pre-filling fluid needs to be completely drained before blood enters the return line 6. This draining of the pre-filling fluid can be done manually or by an external aspiration device.

[0022] Each microchannel assembly 10 has multiple flexible double-sided heating films 5 disposed outside the tube, and the flexible double-sided heating films 5 are in contact with the main channel 2, the secondary channel 3 and the return channel 6.

[0023] The flexible double-sided heating film 5 includes: a middle flexible insulating substrate (not shown), an upper heating layer (not shown) on top of the middle flexible insulating substrate, and a lower heating layer (not shown) below the middle flexible insulating substrate. The middle flexible insulating substrate is preferably a polyimide film or a high-temperature resistant silicone film, typically with a thickness between 25 micrometers and 100 micrometers, possessing excellent electrical insulation, flexibility, and long-term thermal stability. The upper heating layer is formed on top of the middle flexible insulating substrate using processes such as screen printing, etching, or vacuum deposition. The material of the upper heating layer can be conductive carbon paste, metal alloy foil, or a nano-metal wire network. Similarly, the lower heating layer is formed below the middle flexible insulating substrate in a symmetrical or asymmetrical pattern. The upper and lower heating layers are electrically connected by passing through micropores in the substrate or extending from the edge; they can be connected in parallel or series, or designed as independent circuits for regional control. Finally, a very thin protective insulating coating is usually applied to the outer surfaces of the upper and lower heating layers.

[0024] The flexible insulating substrate in the middle ensures electrical isolation between the upper and lower heating layers, preventing short circuits. Its flexibility also allows the entire heating film to perfectly conform to the cylindrical or irregularly shaped microchannel wall, achieving a close contact with low thermal resistance. The double-sided heating mechanism allows a single heating film element to transfer heat in two directions simultaneously. In this application, simultaneous heating of the main flow channel 2 (or secondary flow channel 3) and the return flow channel 6 is achieved, greatly improving space utilization and heat transfer efficiency, resulting in a more compact overall structure.

[0025] Optional, see Figure 2 The main flow channel 2 is a cylindrical pipe, and the secondary flow channel 3 is a crescent-shaped pipe. The upper heating layer of the flexible double-sided heating film 5 adheres to the main flow channel 2, a portion of the lower heating layer adheres to the two adjacent secondary flow channels 3, and another portion of the lower heating layer adheres to the return flow channel 6. The main flow channel 2 is designed as a cylindrical pipe with a smooth inner wall to ensure smooth blood flow, low resistance, and minimal turbulence and hemolysis. The secondary flow channel 3 is designed as a pipe with a crescent-shaped cross-section, and its curved surface can fit against the outer wall of the cylindrical main flow channel 2. This layout saves space and allows multiple "cylinder-crescent" combinations to be arranged tightly in a ring, optimizing heat transfer efficiency. The upper heating layer is flatly attached to and fixed to the outer surface of the main flow channel 2; due to its flexibility, the lower heating layer can simultaneously extend and adhere to the outer walls of the two secondary flow channels 3 adjacent to the main flow channel 2 (i.e., covering the curved surfaces of the two crescent-shaped pipes), and a portion of the lower heating layer also adheres to the outer wall of the centrally located return flow channel 6.

[0026] Optionally, the structure also includes multiple flexible single-sided heating films 11 that adhere to the main flow channel 2 to heat the blood within the main flow channel 2. This is suitable for situations where the blood flow is small and only the main flow channel 2 is used to transport blood, thus preventing the secondary flow channel 3 and the return flow line 6 from being "dry-burned".

[0027] This embodiment achieves axial zone heating of the pipeline by setting multiple spaced flexible single-sided / double-sided heating films, which improves the heating rate and facilitates uniform temperature control and targeted area control.

[0028] The structure also includes a temperature sensor array (not shown). The temperature sensor array monitors the temperature of the blood in the main flow channel 2, the secondary flow channel 3, the return flow channel 6, and the buffer area 4 in real time, and transmits the temperature data to the processor array in real time.

[0029] Optionally, the temperature sensor group includes: a contact infrared temperature measurement module for real-time monitoring of blood temperature at the inlet and outlet 7 of the microfluidic assembly 10; a non-contact infrared temperature measurement module for real-time monitoring of blood temperature at the outlet 7 of the microfluidic assembly 10 and the buffer area 4 as a redundancy check; and a distributed temperature sensing module based on fiber optic grating for real-time monitoring of the temperature inside the microfluidic assembly 10 tube.

[0030] In this embodiment, the temperature sensor group adopts a multimodal, redundant design to ensure comprehensive and reliable monitoring. The contact infrared temperature measurement module is installed on the outer wall of the microfluidic assembly 10 at the inlet and outlet 7. Its probe is tightly coupled to the wall through a highly thermally conductive material, indirectly and rapidly reflecting the instantaneous temperature of the blood inside the tube by non-invasively measuring the wall temperature. The non-contact infrared temperature measurement module is installed near the outlet 7 of the microfluidic assembly 10. Its infrared sensor lens is aimed at the outflowing blood column or a specially designed transparent observation window to directly measure the surface radiation temperature of the blood. This measurement result serves as a redundant verification and comparison reference for the contact infrared temperature measurement data. When the difference between the two exceeds a reasonable range, a calibration alarm is triggered. The fiber Bragg grating-based distributed temperature sensing module embeds a thin-diameter optical fiber (approximately 0.2 mm in diameter) etched with multiple fiber Bragg grating sensors into the interior of the microfluidic tube wall (between the inner and outer walls) using a special process, or inserts it into a micro probe that contacts the blood before placing it within the flow channel. Each fiber grating corresponds to a measurement point, which can monitor the precise temperature distribution of blood along the flow direction inside the flow channel in real time, providing the most direct, realistic, and spatially high-resolution temperature field information.

[0031] The processor controls the power of multiple flexible double-sided heating films 5 based on the target temperature and the received real-time temperature to ensure that the output blood temperature reaches the target temperature. If the blood temperature in the buffer zone 4 does not reach the target temperature within a set time, the first valve 8 is closed and the opening of the second valve 9 is controlled to guide the blood from the second valve 9 into the return pipe 6 for heating and back to the buffer zone 4. At the same time, the power of the multiple flexible double-sided heating films 5 is controlled. After the blood temperature in the buffer zone 4 reaches the target temperature, the first valve 8 is opened and the blood flows out from the first valve 8.

[0032] The processor group includes a main processor and a secondary processor. If either processor detects that the blood temperature exceeds the limit, it will immediately cut off the power and issue an audible and visual alarm.

[0033] Optionally, the distributed microfluidic heating membrane structure is a disposable consumable, completely avoiding cross-contamination and ensuring consistent performance with each use. The distributed microfluidic heating membrane structure integrates a high-energy-density battery module, supporting continuous operation for several hours. The outer shell features a waterproof and shockproof design, suitable for mobile emergency scenarios such as ambulances, helicopters, and field hospitals.

[0034] This application also provides a multimodal temperature control method using a distributed microfluidic heating film structure, suitable for scenarios involving blood transfusions to patients. See also Figure 5 The method includes: S110: Control the power of multiple flexible double-sided heating films according to the target temperature and the received real-time temperature.

[0035] Based on the preset target temperature (e.g., 37°C) and the real-time blood temperatures in the main flow channel, secondary flow channel, and buffer zone received from the temperature sensor group, the power applied to multiple flexible double-sided heating films and flexible single-sided heating films is dynamically calculated and adjusted using a proportional-integral-derivative control algorithm or other algorithms to control the blood temperature in the buffer zone to reach the target temperature.

[0036] Optionally, if the blood flow is less than the set value, blood will be delivered only through the main channel. In this case, the processor group only controls the power of the flexible single-sided heating film. If the flexible single-sided heating film cannot reach the target temperature even when turned on to the maximum power, the flexible double-sided heating film will be turned on and its power will be adjusted from small to large.

[0037] If the blood flow rate is greater than or equal to the set value, the blood is delivered through the main flow channel and the secondary flow channel. At this time, the processor group simultaneously controls the power of the flexible double-sided heating film and the flexible single-sided heating film.

[0038] S120. If the temperature of the blood in the buffer zone does not reach the target temperature within the set time, close the first valve and control the opening of the second valve to guide the blood from the second valve into the return pipeline for heating and return to the buffer zone; control the power of multiple flexible double-sided heating films.

[0039] If the temperature of the blood in the buffer reaches the target temperature within a set time, the current power of the heating membrane, the open state of the first valve, and the closed state of the second valve are maintained.

[0040] S130. After the temperature of the blood in the buffer zone reaches the target temperature, the first valve is opened and the blood flows out from the first valve.

[0041] In practice, it was found that, considering that blood cannot be heated too much, otherwise uneven temperature or even hemolysis may occur, the blood temperature needs to be raised in a certain "slow" manner. If the patient needs a large flow transfusion (both the main flow channel and the secondary flow channel are transfused at the same time), the blood needs to stay in the distributed microfluidic heating membrane structure for a period of time before it can be supplied to the patient.

[0042] Because blood transfusions are urgent, ensuring both blood temperature and flow rate is crucial. Therefore, this application includes a "set time," such as 10 seconds, which can be adjusted according to the patient's condition. If the blood in the buffer zone does not reach the target temperature after 10 seconds, it is transferred to the return line for heating. When transfusing blood simultaneously in the main and secondary channels, multiple flexible double-sided heating films operate. The return line absorbs heat from both the secondary channel and the flexible double-sided heating films, storing the heat until its temperature is equal to or slightly higher than the blood temperature in the secondary channel. Transferring blood to the return line increases the heating area and blood capacity without requiring additional heating films. Meanwhile, the processor group continues to control the power of the multiple flexible double-sided and flexible single-sided heating films in real time to ensure that the blood temperature in the buffer zone does not exceed the target temperature.

[0043] Optionally, if the blood temperature in the buffer zone does not reach the target temperature within a set time, the first valve is closed; based on the blood temperature in the buffer zone, the target temperature, the current blood flow rate, and the real-time power of the flexible double-sided heating film, combined with a pre-calibrated rule engine, the target opening degree of the second valve is determined; after the guided blood enters the return pipeline from the second valve for heating and returns to the buffer zone, the power of multiple flexible double-sided heating films is controlled according to the closed-loop temperature control algorithm to control the blood temperature in the buffer zone to reach the target temperature.

[0044] In one specific implementation, if the blood temperature in the buffer zone fails to reach the target temperature within a set time period, the first valve is closed, and the system immediately and seamlessly enters the feedforward decision-making stage based on a rule engine. This stage is used to intelligently and quickly determine the optimal opening degree of the second valve, avoiding adjustment lag or system oscillation caused by improper setting of the second valve opening degree. In specific implementation, after closing the first valve, the processor group collects the current temperature of the buffer zone, the preset target temperature, the current blood flow rate measured by a high-precision flow sensor, and the total real-time output power of the flexible double-sided / single-sided heating film during all operations. These parameters collectively define the current heat load and heating status of the system. Subsequently, these parameters are used as inputs and fed into a multivariate rule engine that has undergone rigorous experimental calibration and training before the structure leaves the factory. This rule engine is essentially an embedded, simplified multivariate nonlinear relation. The specific form of the relation can be an explicit form combining polynomials and basic functions, or an implicit form combining functions and differential equations; this embodiment does not limit this. For example, Z=a0+a1×X+a2×Y+a3×X×Y+a4×X 2 ×Y×Z+a5×X 2 ×Y 2 ×Z 2 +a6×W; Where Z is the target opening, a0~a6 are pre-calibrated parameters, X is the current temperature, Y is the target temperature, Z is the current blood flow, and W is the total real-time output power.

[0045] The multivariate rule engine calculates and outputs the target opening degree of the second valve (in percentage format) in real time based on the input parameters.

[0046] In another implementation, the target opening can be calculated based on the principle of energy conservation. First, the total thermal power required to heat the current flow of blood from its actual temperature to the target temperature is estimated. Then, the thermal power already provided by the heating film is subtracted to obtain the additional thermal power that needs to be supplemented by the reflux heating system. Next, considering the current heat storage temperature of the reflux line (typically higher than the buffer temperature), the optimal circulating blood flow rate through the reflux line required to provide this additional thermal power is calculated using a built-in mapping relationship (which can also be calibrated). Finally, this optimal circulating blood flow rate is converted into the corresponding target opening of the second valve. The specific formula for calculating the thermal power is not limited in this application.

[0047] Before the target opening command is output, to ensure safety and stability, the opening value must undergo strict upper and lower limit constraints to prevent insufficient heating due to an insufficient opening or drastic pressure fluctuations due to an excessive opening. Finally, the constrained target opening command is sent to the servo actuator of the second valve (usually a proportional control valve) to quickly open it to the target opening.

[0048] Then, the blood begins to flow through the heat-storing return pipeline for secondary heating and returns to the buffer zone, entering a fine-tuning stage based on a closed-loop control algorithm. The goal of this stage is to achieve high-precision, overshoot-free steady-state control of the buffer zone temperature, ensuring it smoothly and quickly reaches and maintains the target value. In this stage, the blood temperature in the buffer zone, measured by a non-contact infrared thermometer, is used as the controlled variable, and the total power applied to all flexible double-sided and single-sided heating films is used as the primary control variable. An incremental digital PID control algorithm is employed as the core regulator, with the processor executing the control loop at fixed millisecond intervals. Within each control cycle, the algorithm calculates the error between the current temperature and the target temperature, and based on the combined results of proportional, integral, and derivative calculations, determines the required adjustment to the heating power, generating a new power setpoint and allocating it to each heating film for execution. To improve control quality and meet the specific physiological requirements of blood heating, this basic PID algorithm integrates several enhancement strategies. These include setpoint filtering, which applies a smooth ramp to the target temperature to avoid shocks to the control system caused by abrupt changes in the setpoint, thereby achieving gentle heating; introducing anti-integral saturation logic, which pauses the accumulation of integral terms when power cannot be increased further due to reaching physical limits, preventing large overshoot during recovery; and using blood flow as a feedforward signal, which increases the thermal power proportionally in advance when an increase in flow is detected, in order to actively offset the cooling effect caused by the increase in flow, significantly improving the system's response speed against disturbances.

[0049] Optionally, a fine-tuning stage based on a closed-loop control algorithm continuously scans the temperature of the buffer zone and each key heating area. If the temperature at any point exceeds the absolute safety threshold, hardware-level protection will be immediately triggered, cutting off all heating power and resetting the valve status to ensure the patient's safety.

[0050] This embodiment, through three stages of adjustment (S110, S120 and S130), can achieve extremely precise and gentle control of the final output temperature while ensuring heating speed and blood flow, perfectly resolving the clinical contradiction between high-flow blood transfusion and gentle heating.

[0051] Optionally, the processor group obtains the mode of the infusion pump through the communication device. If the infusion pump is in high-power mode, the flexible double-sided heating film is preheated to improve the blood heating efficiency. If the infusion pump is in standby mode or the blood flow in the microchannel assembly is less than the set value, the heating function of the flexible double-sided heating film is turned off to avoid dry burning and save power.

[0052] The processor unit collects the patient's body temperature in real time via a temperature probe; it then adjusts the target blood temperature and flow rate based on this temperature. For example, if a patient is admitted due to severe trauma and blood loss, and their core body temperature (measured via an esophageal or bladder probe) is 34.5°C (mild hypothermia), and they require rapid blood transfusion and fluid replacement, the target temperature is set to 36°C to avoid "rewarming shock" caused by excessively rapid rewarming. The temperature is then gradually increased to 37°C. Simultaneously, the target flow rate is also set to a small value and gradually increased to a larger value.

[0053] In summary, the above embodiments have the following technical effects: 1. Extreme Precision: Through multi-sensor fusion and corresponding control algorithms, the output temperature control accuracy is improved from the industry standard of ±2℃ to ±0.5℃.

[0054] 2. Ultra-high safety: Enables full-process monitoring and protection from the device end to the blood end and then to the patient end, minimizing the risks of hemolysis and burns.

[0055] 3. High level of intelligence: Breaking down equipment silos, it links with the infusion system and patient monitoring system to achieve data-driven intelligent infusion management.

[0056] 4. Wide range of applications: It can be integrated into the operating rooms and ICUs of large hospitals, or used as a standalone device for field rescue, meeting the needs of multiple scenarios.

[0057] 5. Reduced overall costs: The disposable consumable design eliminates the cumbersome cleaning and disinfection process, reducing the hospital's labor costs and infection control risks.

[0058] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this application can be achieved, and this is not limited herein.

[0059] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A distributed microchannel heating film structure, characterized in that, include: The entrance that connects to the blood source; The inlet is connected to one end of a combination of multiple parallel and annular microchannels; the microchannel combination includes a main channel and a secondary channel; A buffer area connected to the other end of a combination of multiple microchannels; The buffer zone is connected to the outlet and the return pipeline respectively; a first valve is provided between the buffer zone and the outlet, and a second valve is provided between the buffer zone and the return pipeline; the return pipeline is located in the middle of a combination of multiple parallel microchannels. Each microchannel assembly has multiple flexible double-sided heating films installed outside the tube. These flexible double-sided heating films are in contact with the main channel, secondary channel, and return channel. The return channel simultaneously absorbs heat from the secondary channel and the flexible double-sided heating films, and stores the heat. The temperature sensor group monitors the temperature of blood in the main flow channel, the secondary flow channel, the return flow line, and the buffer area in real time, and transmits the temperature to the processor group in real time. The processor group controls the power of multiple flexible double-sided heating films based on the target temperature and the received real-time temperature; and if the temperature of the blood in the buffer area does not reach the target temperature within a set time, the first valve is closed and the opening of the second valve is controlled to guide the blood from the second valve into the return pipeline for heating and return to the buffer area, while controlling the power of the multiple flexible double-sided heating films; after the temperature of the blood in the buffer area reaches the target temperature, the first valve is opened and the blood flows out from the first valve.

2. The distributed microchannel heating film structure according to claim 1, characterized in that, Flexible double-sided heating films include: The intermediate flexible insulating substrate, the upper heating layer located on the intermediate flexible insulating substrate, and the lower heating layer located below the intermediate flexible insulating substrate.

3. The distributed microchannel heating film structure according to claim 2, characterized in that, The main flow channel is a cylindrical pipe, the secondary flow channel is a crescent-shaped pipe, the upper heating layer of the flexible double-sided heating film is attached to the main flow channel, a part of the lower heating layer is attached to the two adjacent secondary flow channels, and the other part of the lower heating layer is attached to the return flow channel. If the blood flow is less than the set value, blood will be delivered only through the main channel; If the blood flow rate is greater than or equal to the set value, blood is delivered through the main flow channel and the secondary flow channel.

4. The distributed microchannel heating film structure according to claim 3, characterized in that, The shape of the return pipeline is adapted to the internal space formed by the combination of multiple microchannels; The reflux line includes an outlet, which is a valve structure that guides blood to flow in one direction.

5. The distributed microchannel heating film structure according to claim 4, characterized in that, It also includes multiple flexible single-sided heating films that adhere to the main channel to heat the blood within it.

6. The distributed microchannel heating film structure according to claim 5, characterized in that, The temperature sensor group includes: A contact infrared temperature measurement module monitors the temperature of blood at the inlet and outlet of the microfluidic combination in real time. A non-contact infrared temperature measurement module monitors the temperature of blood at the outlet of the microfluidic combination and in the buffer area in real time as a redundancy check. A distributed temperature sensing module based on fiber Bragg gratings is used to monitor the temperature inside the microchannel combined tube in real time.

7. The distributed microchannel heating film structure according to any one of claims 1-6, characterized in that, The processor group includes a main processor and a secondary processor.

8. A multimodal temperature control method, characterized in that, Employing the distributed microchannel heating film structure according to any one of claims 1-7, the multimodal temperature control method includes: The power of multiple flexible double-sided heating films is controlled based on the target temperature and the received real-time temperature. If the temperature of the blood in the buffer zone does not reach the target temperature within the set time, the first valve is closed and the opening of the second valve is controlled to guide the blood from the second valve into the return pipeline for heating and back to the buffer zone; the power of multiple flexible double-sided heating films is controlled; Once the blood temperature in the buffer zone reaches the target temperature, the first valve is opened, and the blood flows out from the first valve.

9. The multimodal temperature control method according to claim 8, characterized in that, If the blood temperature in the buffer zone does not reach the target temperature within the set time, the first valve is closed and the opening of the second valve is controlled to guide the blood from the second valve into the return pipeline for heating and back to the buffer zone, controlling the power of multiple flexible double-sided heating films; including: If the temperature of the blood in the buffer zone does not reach the target temperature within the set time, the first valve will be closed. Based on the temperature of the blood in the buffer zone, the target temperature, the current blood flow, and the real-time power of the flexible double-sided heating film, combined with a pre-calibrated rule engine, the target opening degree of the second valve is determined. After the blood is guided from the second valve into the return pipeline for heating and then returned to the buffer zone, the power of multiple flexible double-sided heating films is controlled according to the closed-loop temperature control algorithm to control the temperature of the blood in the buffer zone to reach the target temperature.

10. The multimodal temperature control method according to claim 8 or 9, characterized in that, The method further includes: The mode of the infusion pump is obtained through the communication device. If the infusion pump is in high-power mode, the flexible double-sided heating film is preheated in advance; if the infusion pump is in standby mode or the blood flow in the microchannel assembly is less than the set value, the heating function of the flexible double-sided heating film is turned off. The patient's body temperature is collected in real time using a temperature probe; the target temperature and target flow rate of the blood are adjusted based on the body temperature.

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