Non-metallic channel nucleation device for medical ice slurry preparation

Abstract

The application discloses a non-metal channel nucleation device for medical ice slurry preparation, which comprises a sealed pressure-bearing shell and a spiral channel pipe penetrating in the shell, the sealed pressure-bearing shell is provided with a cold medium inlet and a cold medium outlet, an external cold medium flows through a shell-side heat exchange cavity, physiological saline flows into the spiral channel pipe in a one-way mode through the inlet section, and the physiological saline and the cold medium exchange heat through a wall between the physiological saline and the cold medium, so that the physiological saline in the pipe is phase changed in situ to form a flowable ice slurry, and the ice slurry is directly output through a discharge outlet section, the physical isolation of the cold medium and the medical saline can be realized, and the cold medium pollution and metal ion precipitation can be avoided; the spiral channel structure utilizes fluid centrifugal effect to strip the nascent ice crystals from the pipe wall, and reduces the ice blockage risk; and the device is only connected with an external cold supply system through the cold medium inlet and the cold medium outlet, the structure is simple, and the integration requirement of various direct supply type medical ice slurry preparation systems can be met.

Description

Technical Field

[0001] This invention belongs to the field of medical device and multiphase flow thermal control technology, specifically relating to a direct-supply closed injectable medical ice slurry machine for local deep cryogenic cooling and protection of target organs in minimally invasive cardiac surgery, and its core component, a non-metallic channel nucleation device for the preparation of medical ice slurry. Background Technology

[0002] In cardiac surgery, rapid and uniform local deep hypothermia is required to protect the myocardium during cardiac arrest, thereby reducing myocardial metabolic rate, prolonging the safe ischemia period, and mitigating ischemia-reperfusion injury. With the increasing prevalence of minimally invasive procedures such as small-incision valve replacement under cardiopulmonary bypass and thoracoscopic-assisted coronary artery bypass grafting, the surgical space is extremely limited, placing higher demands on the fluidity, injectability, and aseptic safety of the cooling medium.

[0003] Currently, the routine clinical method for cooling involves manually scraping ice shavings and applying them topically before surgery. Nurses must use instruments to scrape ice shavings from ice blocks in an open environment and manually apply them to the surface of the heart. This procedure relies entirely on manual experience, and the scraped ice shavings have a wide range of particle sizes and sharp edges, which can easily scratch delicate myocardial tissue and make it difficult to fully adhere to the target organ surface, resulting in inconsistent cooling. Furthermore, the ice shavings are exposed to the atmosphere throughout the process, posing a high risk of microbial contamination. This method is also unsuitable for the precise injection requirements of minimally invasive surgery in confined spaces and is completely incompatible with modern cardiac surgery clinical requirements.

[0004] Medical ice slurry, possessing both the high fluidity of liquids and the high latent heat of phase change of solids, is widely recognized as an ideal medium for local cooling of target organs. However, existing ice slurry generation devices used clinically are mostly modified from industrial ice-making equipment, posing significant aseptic safety risks. Existing devices generally employ an open architecture, equipped with mechanical scraping structures or circulation systems with large intermediate ice storage tanks. The ice slurry is in direct contact with the external atmosphere throughout the scraping, storage, stirring, and pumping processes, making it highly susceptible to cross-contamination by microorganisms. Furthermore, the heat exchange pipes and scrapers are often made of metals such as copper, aluminum, and stainless steel. Under long-term fluid scouring and high-frequency shearing, there is a risk of metal ion release and toxicity injected into the body with the ice slurry, completely failing to meet the highest level of aseptic control standards for operating rooms.

[0005] Therefore, existing medical ice slurry generation devices cannot simultaneously meet the core clinical requirements of aseptic safety, minimally invasive compatibility, and stable operation. Thus, there is an urgent need to develop a direct-supply, closed, injectable medical ice slurry machine specifically for cardiac surgery. Summary of the Invention

[0006] To address the shortcomings of the prior art, this invention provides a non-metallic channel nucleation device for preparing medical ice slurry, comprising a sealed pressure-bearing shell and a spiral channel tube passing through the sealed pressure-bearing shell; the sealed pressure-bearing shell has a cooling medium inlet and a cooling medium outlet, and the inner wall of the sealed pressure-bearing shell and the outer wall of the spiral channel tube enclose a closed shell-side heat exchange cavity, which is used for the external cooling medium to flow into and out of the shell-side heat exchange cavity; the first end of the spiral channel tube is provided with a saline inlet section extending out of the sealed pressure-bearing shell, and the second end is provided with an ice slurry outlet section extending out of the sealed pressure-bearing shell; the spiral channel tube is made of medical non-metallic material.

[0007] This invention employs a structure with a sealed pressure-bearing shell containing a spiral channel tube. Within the confined shell space, this effectively extends the effective length of the heat exchange channel, increasing the heat exchange contact area and contact time between the fluids inside and outside the tube. This facilitates the full absorption of shell-side cooling capacity by the saline solution inside the tube, enabling controlled phase change and improving ice slurry generation efficiency. Simultaneously, the pressure-bearing design of the shell can adapt to the circulation requirements of cooling media at different pressures. The closed shell-side heat exchange cavity formed by the sealed pressure-bearing shell and the outer wall of the spiral channel tube achieves complete physical isolation between the cooling medium and the medical saline solution inside the tube. This avoids mixing and contamination between the refrigerant and the medical fluid, and also prevents microorganisms and impurities from the external environment from entering the heat exchange cavity. When the saline solution in the tube precipitates primary micro-ice crystal nuclei in the near-wall region under the influence of the shell-side cooling, the near-wall shear stress generated by the aforementioned spiral flow channel can exert a continuous mechanical stripping force on the primary ice nuclei, achieving in-situ cutting of the newly formed ice crystals on the wall. The ice crystals are stripped and enter the mainstream region before they can firmly adhere to the tube wall, which avoids ice blockage caused by ice crystal accumulation on the wall surface and also prevents the coarsening of the ice crystals caused by continuous growth on the wall surface. This ensures that the generated ice slurry has good fluidity and is suitable for subsequent minimally invasive injections. This cutting action is generated entirely by the fluid's own flow characteristics, without any additional moving parts, avoiding the risks of metal contamination and component wear caused by mechanical scraping. Moreover, the spiral channel tube is made of medical non-metallic materials, which have low affinity for ice crystal adhesion at the interface. This, combined with the near-wall shearing and cutting action of the spiral flow channel, creates a dual synergy, further reducing the probability of ice crystals adhering to the wall. At the same time, the non-metallic material does not release metal ions or harmful substances under deep cryogenic conditions, fundamentally eliminating the risk of ice slurry contamination. This meets the highest level of sterility and safety requirements of the operating room, and the material can withstand high-temperature and high-pressure sterilization, making it suitable for clinical reuse or disposable replacement needs.

[0008] Preferably, the device further includes an anti-clogging detection sensing component integrated on the main body of the device; the anti-clogging detection sensing component includes a first temperature sensor and a first pressure sensor integrated in the inlet section of the spiral channel pipe, and a second temperature sensor and a second pressure sensor integrated in the outlet section of the spiral channel pipe. The first pressure sensor and the second pressure sensor are used to detect the fluid pressure at the inlet and outlet of the spiral channel pipe to obtain pressure drop parameters, and the first temperature sensor and the second temperature sensor are used to detect the fluid temperature at the inlet and outlet of the spiral channel pipe to obtain temperature difference parameters; the anti-clogging detection sensing component is also provided with an external communication interface for transmitting the pressure drop parameters and temperature difference parameters to external devices.

[0009] Temperature and pressure sensors are integrated at the inlet and outlet sections of the spiral channel tube, forming a multi-dimensional sensing capability covering thermodynamics and rheology. This capability is highly compatible with the inherent shearing and cutting characteristics of the spiral channel tube. The first and second temperature sensors collect the fluid temperature at the inlet and outlet of the tube, respectively. The temperature difference parameter obtained through calculation can directly reflect the degree of latent heat release of the ice slurry phase change in the tube, assisting external equipment in judging the stability of ice crystal formation. It can also serve as an indirect characterization indicator of supercooling, providing a basis for thermodynamic prediction of ice blockage risk. The first and second pressure sensors collect the fluid pressure at the inlet and outlet of the tube, respectively. The pressure drop parameter obtained through calculation can sensitively reflect the flow channel unobstructedness in the spiral channel tube. When the flow cross-sectional area decreases due to a small amount of ice crystal accumulation in the tube, the pressure drop will rise abnormally before the temperature, serving as a basis for judging the precursor of ice blockage. External equipment can verify the effectiveness of the near-wall shearing effect of the spiral flow channel by the changing trends of pressure drop and temperature difference parameters. That is, if the pressure drop remains within a stable fluctuation range and the temperature difference is within the reasonable phase change temperature range, it indicates that the shearing and cutting effect is normal and there is no risk of ice crystal accumulation.

[0010] Preferably, the anti-blocking detection sensing component further includes an AC conductivity meter integrated into the outlet section of the spiral channel pipe, used to detect the conductivity of the outlet ice slurry to assist in calculating the ice content parameter, which is transmitted to an external device through the external communication interface.

[0011] Medical ice slurry is a solid-liquid two-phase mixed medium, in which pure ice crystals are the electrically insulating phase and the remaining unfrozen saline solution is the ion-conducting phase. There is a definite physical mapping relationship between the overall macroscopic conductivity of the ice slurry, the conductivity of the liquid saline solution, and the volumetric ice content of the ice slurry. The overall conductivity decreases regularly with increasing ice content. This characteristic provides a theoretical basis for the electrical detection of ice content. The AC conductivity meter itself is existing technology. The innovation of this application lies in placing it at the outlet section of the spiral channel tube. During operation, an alternating excitation signal of a specific frequency is applied to the flowing ice slurry, and the overall impedance response of the ice slurry is collected to obtain the real-time conductivity value. Compared with the DC detection mode, AC excitation can avoid the interference of electrode surface polarization effect and double-layer capacitance on the detection signal in principle, and is suitable for ice slurry detection scenarios with high solid content and high shear flow field. The flow disturbance in the spiral channel tube makes the generated ice crystals uniformly dispersed in the liquid phase, avoiding the conductivity detection distortion caused by local ice crystal agglomeration and tube wall adhesion, ensuring the representativeness of the test sample, and enabling the measured conductivity value to truly reflect the average state of the entire tube of ice slurry.

[0012] Preferably, the first temperature sensor, the second temperature sensor, the first pressure sensor, the second pressure sensor, and the AC conductivity meter all adopt an embedded mounting structure, with the detection probe flush with the inner wall of the spiral channel tube.

[0013] In this technical solution, the embedded flush mounting structure does not disrupt the smooth continuity of the inner wall of the spiral channel tube. It will not interfere with the naturally formed near-wall shear stress field in the spiral flow channel, nor will it form a flow dead zone or eddy zone at the root of the probe. This fundamentally avoids the problem of ice crystal adhesion and accumulation caused by probe protrusion, ensures that the ice crystal shearing and peeling function of the spiral flow channel can be properly performed, and eliminates the additional ice blockage risk brought about by the sensor installation itself.

[0014] Preferably, the medical non-metallic material of the spiral channel tube is any one of medical-grade silicone, polytetrafluoroethylene, or medical polyurethane.

[0015] The aforementioned non-metallic materials have no cytotoxicity, sensitization, or hemolytic risk, and no small molecule additives, metal ions, or other harmful components are released under long-term rinsing with physiological saline. This fundamentally ensures the safety of medical ice syrup infusion and meets the stringent clinical requirements for direct injection into the body in minimally invasive cardiac surgery.

[0016] Preferably, the spiral channel tube and the sealed pressure-bearing shell adopt an integral plug-in modular installation structure, and the spiral channel tube can be moved out or inserted entirely from the sealed pressure-bearing shell.

[0017] The spiral channel tube, as the core functional component in constant contact with medical saline, can be completely removed from the shell and directly replaced with a pre-sterilized disposable sterile module. This eliminates the need for additional disassembly and cleaning of external components such as the shell and cooling medium interface, fundamentally avoiding the risk of cross-infection between patients undergoing different surgeries. The plug-in structure eliminates the need to disassemble the shell, disconnect the external cooling medium pipeline, or readjust the sensing components; medical staff or engineers can easily disassemble and replace the module manually. The one-piece molded structure avoids gaps caused by segmented splicing, preventing ice crystal blockage and ensuring the stability of the flow channel.

[0018] Preferably, the sealed pressure-bearing shell is provided with a medical non-metallic support bracket, which is adapted and snapped into the outer wall of the spiral channel tube. The two are pre-assembled into an integrated nucleation module that can be moved out or placed into the sealed pressure-bearing shell synchronously with the spiral channel tube.

[0019] The support bracket and the spiral microchannel tube are pre-assembled into an inseparable integrated core-promoting module through adapter snap-fit. It can be moved out or placed into a sealed pressure-bearing shell at the same time during the insertion and removal operation, avoiding problems such as loosening and deformation of the spiral tube, pitch change, and displacement of embedded sensors during the insertion and removal process.

[0020] Other beneficial effects of this application will be further explained in the specific embodiments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall principle and structure of the direct-supply closed injectable medical ice slurry machine of the present invention;

[0022] Figure 2 This is a three-dimensional structural diagram of the non-metallic channel nucleation device of the present invention;

[0023] Figure 3 This is a front view of the non-metallic channel nucleation device of the present invention.

[0024] Figure 4 yes Figure 3 AA sectional view.

[0025] In the picture:

[0026] 1. Condenser; 2. Throttling device; 3. Compressor; 4. Evaporator; 5. Room temperature alcohol tank; 6. Three-way solenoid directional valve; 7. Circulation pump; 8. Ice-making heat exchanger; 9. Pre-cooling heat exchanger; 10. Peristaltic pump; 11. Physiological saline; 12. Ice slurry storage tank; 13. External piping; 14. Vacuum pump; 16. Shell; 17. Spiral tube; 18. Support. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be fully and thoroughly described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are intended to enable those skilled in the art to fully implement the technical solutions, and are not intended to limit the scope of protection of this invention.

[0029] This implementation method combines Figure 1 This paper details the hardware and topology of a medical ice slurry machine that meets the clinical needs of minimally invasive cardiac surgery. The system is divided into three highly decoupled closed-loop circuits in physical space and control field: a refrigeration cycle system, an alcohol delivery system, and an ice-making system.

[0030] The refrigeration cycle system includes a variable frequency compressor, a condenser, a dryer filter, an electronic expansion valve, and a cold-side flow channel of an alcohol-refrigerant evaporator, all connected in a closed loop via high-pressure refrigerant copper piping. The variable frequency compressor is a low-thermal-inertia, high-frequency-response DC variable frequency scroll compressor, and the working fluid can be medical-grade, non-toxic, and environmentally friendly mixed refrigerant R404A. The high-pressure gaseous refrigerant discharged from the variable frequency compressor releases heat and liquefies in the condenser. After being dehydrated and filtered by the dryer filter, it undergoes precise high-frequency throttling and pressure reduction via the electronic expansion valve, and then enters the cold side of the alcohol-refrigerant evaporator. In this embodiment, the evaporator can be a compact stainless steel plate heat exchanger with high heat exchange efficiency, or a finned heat exchanger. The refrigerant undergoes vigorous boiling and phase change in the evaporator, absorbing heat, and finally returns to the suction end of the variable frequency compressor, providing the initial basic cold source for the entire system.

[0031] The alcohol delivery system serves as a thermal buffer layer between the refrigeration and ice-making ends, and the low freezing point refrigerant circulating inside it has a volume concentration of... The system uses medical-grade anhydrous ethanol. The standard liquid freezing point of this system is -114℃, and it maintains a stable single-phase liquid state throughout all operating temperature ranges (-30℃ to 30℃). The system includes a variable frequency alcohol circulation pump, a high-precision alcohol flow meter, and the hot-side flow channel of the alcohol-refrigerant evaporator, all connected in a closed loop via stainless steel low-temperature insulated piping. An alcohol storage tank is connected to the alcohol delivery system via two three-way solenoid valves, and the storage tank is connected in parallel with the hot-side flow channel of the alcohol-refrigerant evaporator. The variable frequency alcohol circulation pump facilitates forced convection heat exchange between the hot-side flow channel of the alcohol-refrigerant evaporator and the high latent heat of phase change refrigerant undergoing phase change evaporation on the cold side. The cooling capacity is then steadily accumulated in the alcohol of the delivery system and provides cooling for the ice-making system.

[0032] The ice-making system is a completely closed, unidirectional, single-flow, sterile physical channel for generating clinically injectable medical ice slurry. The system includes a medical sterile saline supply bag, a medical variable frequency peristaltic pump, an internal flow channel of a pre-cooling heat exchanger, an internal flow channel of a non-metallic channel nucleation device, and a cardiac surgery injection needle connected at the end, all sequentially connected via medical-grade wear-resistant tubing. The saline is pushed in at one end by the peristaltic pump, flows unidirectionally forward within the pipe, and undergoes a controlled phase change in situ. At the other end, it is directly converted into ice slurry and output to the surgical target organ. The entire ice-making process involves no fluid backflow or repeated circulation, and there are no intermediate ice storage containers or openings to the atmosphere, thus completely cutting off the channels for external bacterial invasion. The pre-cooling heat exchanger uses a sleeve-type non-metallic pipeline structure, with a regulated, relatively mild alcohol flow introduced into the outer jacket to rapidly cool the initial room temperature (20-25°C) saline to the critical temperature range of convective non-freezing (2-4°C).

[0033] This implementation method combines Figure 2 This paper details the internal microscopic anti-icing structure design of a non-metallic channel nucleation device. The device includes a cryogenic resin outer jacket and a single long spiral channel tube fixed inside the jacket by a seal. Deep cryogenic anhydrous ethanol from the alcohol circuit flows in through the lower inlet and out through the upper outlet of the outer jacket; pre-cooled sterile saline flows in unidirectionally through the upper inlet of the spiral channel tube, forming a completely counter-current heat exchange structure within the device.

[0034] The spiral channel tubes are all made of medical-grade high-purity polytetrafluoroethylene (PTFE) or silicone material with extremely low solid surface energy, with the solid surface energy strictly controlled at 18~22 mN / m. When pre-cooled saline flows in the tube channel and is rapidly cooled below its equilibrium freezing point by deep-temperature ethanol on the outside, the liquid enters a highly metastable supercooled liquid state due to the lack of natural crystal nuclei.

[0035] This invention introduces macroscopic fluid dynamics shear through a unique helical coil configuration. For example... Figure 2 As shown, the fluid moving through the spiral pipe generates a strong forced centrifugal force due to the continuous change in its direction of motion. This causes the mainstream fluid with a higher velocity at the center of the pipe to be violently pushed towards the outer wall, and after reaching the outer wall, it folds back towards the inner side along both sides of the pipe wall. This generates a pair of strongly convective transverse secondary vortices, Dean vortices, with opposite directions and symmetrical distribution on the cross-section of the coiled pipe. In this embodiment of the invention, the inner diameter of the spiral channel pipe can be selected as d=6.4mm, the central rotation diameter of the spiral coil is 300mm, and the total length of the pipe is 8.0m. Due to the extremely high contact angle of the pipe wall interface, the adhesion of the primary crystal nuclei is extremely weak. When microscopic crystal nuclei bud on the channel wall, they are instantly cut and peeled off layer by layer without damage by the high-frequency strong radial shear force, and then ejected into the mainstream area at the center of the pipe. The detached microcrystalline nuclei are suspended in the central region, uniformly absorbing the latent heat of phase change from the surrounding supercooled water. Completely surrounded by the liquid phase, they develop into micron-sized, spherical, uniform ice crystal particles with a diameter between 30 and 60 μm. This effectively prevents pipe blockage caused by frost and ice buildup on the pipe wall. The continuous high-shear turbulence breaks the thermodynamic conditions of large ice crystals spontaneously consuming small ice crystals during traditional static storage, ensuring the low-viscosity flow characteristics of the medical ice slurry at the output end. Before the start of minimally invasive cardiac surgery, a standard sterile bag... Medical saline solution is hung on a stent, and its output tubing is inserted into the roller slot of a variable frequency peristaltic pump. The end of the tubing is connected to the inlet of a non-metallic channel nucleation device through a sterile Luer connector. The outlet of the nucleation device is connected to an injectable catheter for cardiac surgery through a sterile extension tube.

[0036] In practical use, this embodiment divides the system into a refrigeration cycle system, an alcohol-cooled buffer circuit, and a saline ice-making circuit, i.e., an ice slurry generation system, and integrates a waste liquid recovery and pressure balancing unit.

[0037] 1) Construction of the initial cold source for the refrigeration cycle system

[0038] The compressor 3, air-cooled condenser 1, throttling device 2, and evaporator 4 are connected in a closed loop through a high-pressure refrigerant pipeline to form a heat pump circuit. The evaporator 4 undergoes a phase change and absorbs heat, with its cold-side flow channel serving as the cold side to provide the basic cooling capacity to the outside of the entire system; the hot-side flow channel has a reserved interface for connection to a subsequent cooling buffer circuit.

[0039] 2) Construction of the alcohol cooling buffer circuit

[0040] Medical-grade anhydrous ethanol with a volume concentration ≥99.5% was selected as the cooling buffer medium. The hot side flow channel of evaporator 4, circulation pump 7, ice-making heat exchanger 8 (i.e., the jacket shell side of the non-metallic channel nucleation device), and the shell side of cold heat exchanger 9 were connected in series through stainless steel low-temperature resistant insulated pipelines to form a single closed loop.

[0041] Simultaneously, a room-temperature alcohol tank 5 is installed, with both ends connected to the aforementioned circuit via a three-way solenoid valve 6, allowing the room-temperature alcohol tank 5 to be arranged in parallel with the evaporator 4. Under normal conditions, the three-way solenoid valve 6 cuts off the branch of the room-temperature alcohol tank 5, and the low-temperature alcohol circulates only after being cooled by the evaporator 4; when needed, the three-way solenoid valve 6 can switch to conduct the branch of the room-temperature alcohol.

[0042] 3) Construction of the ice-making circuit for the ice slurry generation system

[0043] Take sterile medical saline solution and suspend it on the support. Insert the medical-grade abrasion-resistant elastic tubing from the supply bag outlet into the roller slot of the peristaltic pump, so that the tubing forms a squeezed section inside the peristaltic pump; the outlet of the peristaltic pump is connected to the tube-side inlet of the precooling heat exchanger through a sterile pipeline, and the tube-side outlet of the precooling heat exchanger is then connected to the 17 spiral tubes inside the ice-making heat exchanger, i.e., the non-metallic channel tube-side inlet.

[0044] The ice-making heat exchanger 8 includes a low-temperature resistant shell 16 forming a jacketed shell side and a spiral tube 17 passing through it. The spiral tube is made of any one of medical-grade silicone, polytetrafluoroethylene or polyurethane, spirally wound, with an inner diameter of 3.2 to 9.6 mm, a wall thickness of 0.5 to 1.0 mm, a spiral rotation center diameter of 100 to 300 mm, and an effective heat exchange total length of 1.5 to 9.0 m for a single tube. The ice-making heat exchanger adopts a plug-in modular installation structure and is sealed to the shell by quick-release clamps.

[0045] The spiral tube outlet is divided into two paths. The main path is connected to a special injection needle for minimally invasive cardiac surgery via an external pipe, which leads directly to the surgical target organ. The side path, which is close to the outlet of the ice heat exchanger, is connected to an ice slurry storage tank, which is used to hold excess ice slurry that is not immediately injected during the operation.

[0046] Therefore, a unidirectional flow channel for medical saline is constructed between the saline solution, the pump, and the external piping / tank, and is completely closed to the outside world. A vacuum pump is placed nearby next to the external piping. This vacuum pump is configured to draw out dissolved saline wastewater from the patient's body via the external piping during surgery, and to regulate and balance the internal pressure of the patient's abdominal or thoracic cavity through negative pressure, preventing fluid accumulation after perfusion.

[0047] This embodiment further provides a method for using the non-metallic channel nucleation device for preparing medical ice slurry. The sealed pressure-bearing shell of the non-metallic channel nucleation device for preparing medical ice slurry can be made of thick-walled stainless steel, with the outer wall covered with a silicone rubber foam insulation layer; the shell has a cooling medium inlet and a cooling medium outlet, both of which are connected to the shell-side heat exchange cavity; a quick-connect clamp interface is provided at the end of the shell for sealing connection with the internal module.

[0048] The spiral channel tube is made of medical-grade polytetrafluoroethylene (PTFE) and manufactured using an extrusion-winding integrated molding process. The support bracket is made of the same PTFE material as the spiral channel tube and is designed as an annular hollow structure adapted to the outer diameter of the spiral tube. The bracket and the spiral channel tube are pre-assembled into an inseparable integrated core-promoting module by interference fit. The spiral tube is fixed by a 15mm spiral pitch to ensure heat exchange uniformity.

[0049] The first temperature sensor is a PT1000 platinum resistance thermometer, and the first pressure sensor is a piezoresistive sensor, both embedded in the inlet section of the spiral tube. The second temperature sensor and the second pressure sensor are embedded in the outlet section of the spiral tube. All sensor probes are flush with the inner wall of the spiral tube, without any protrusions or depressions. The AC conductivity meter adopts a four-electrode structure with an excitation frequency of 25kHz and is embedded in the outlet section of the spiral tube, with the probe flush with the inner wall. All sensors are connected to an IP68-level medical waterproof connector at the end of the shell via internal shielded cables as an external communication interface for transmitting raw data on pressure drop, temperature difference, and conductivity to external devices.

[0050] The integrated core-promoting module is sealed to the closed pressure-bearing shell through quick-release clamps at the ends. No tools are required for disassembly or assembly; the module can be moved out or inserted into the shell as a whole. During installation, operators manually loosen the quick-release clamps at the shell ends, insert the pre-installed support bracket of the integrated spiral channel tube module axially into the closed pressure-bearing shell, align the positioning pins, and then tighten the clamps to ensure a leak-free seal.

[0051] Connect the inlet connector of the spiral tube to the outlet of the upstream pre-cooled saline pipeline, and connect the Luer connector of the outlet section to the pipeline of the downstream minimally invasive injection needle. Connect the inlet and outlet of the cooling medium to the anhydrous ethanol pipeline of the external cooling system via medical pressure-resistant tubing. Insert the external IP68 communication connector into the corresponding interface of the operating room monitoring system to confirm that the monitoring system can normally read the four types of raw parameters: inlet temperature, outlet temperature, inlet and outlet pressure drop, and outlet conductivity. Turn on the external cooling system and introduce room temperature anhydrous ethanol into the shell-side heat exchange chamber. Confirm that there are no leaks in the pipeline, no drift in the sensor signal, and the pressure drop is stable in the range of 1~2 kPa, thus determining that the device is in normal condition.

[0052] During the operation, the external cooling system stabilizes the temperature of the anhydrous ethanol supplied to the shell side at -10°C, and the cooling capacity in the shell-side heat exchange chamber is transferred to the tube side through the PTFE spiral tube wall. An external peristaltic pump pumps sterile saline into the spiral tube at a rated flow rate of 1.2 L / min: the fluid generates a natural centrifugal effect as it flows within the spiral channel, forming a stable radial shear stress field in the near-wall region of the tube; after exchanging heat with the shell-side cooling capacity, the saline cools to a supercooled state, and primary microscopic ice crystal nuclei precipitate in the near-wall region; the near-wall shear stress applies a continuous mechanical peeling force to the primary ice crystals, peeling them off from the low surface energy PTFE tube wall, allowing them to develop uniformly in the mainstream region, forming a fluid ice slurry without coarse agglomeration.

[0053] The first temperature sensor measured a stable inlet saline temperature of 20℃, and the second temperature sensor measured a stable outlet ice slurry temperature of -1.5℃. The temperature difference reflects normal release of latent heat of phase change. The first pressure sensor measured an inlet pressure of 12 kPa, and the second pressure sensor measured an outlet pressure of 7 kPa. The pressure drop was stable at 5 kPa, indicating that the flow channel was unobstructed and the spiral shearing action effectively inhibited ice crystal accumulation. The AC conductivity meter measured the outlet ice slurry conductivity to be 60% of that of pure 20℃ physiological saline. Based on this raw data, the monitoring system calculated that the ice content of the ice slurry was approximately 30%, which meets the requirements for clinical injection. If a localized ice crystal agglomeration occurs, causing a sudden increase in pressure drop to 15 kPa and a decrease in conductivity to 40% of that of pure saline, the monitoring system will issue an early warning. The external cooling system or peristaltic pump will adjust its operating parameters, and the pressure drop will fall back to the 5 kPa range, indicating that the shearing action of the spiral flow channel has dispersed the agglomerated ice crystals and the flow channel has been restored to unobstructed flow. The qualified ice slurry is continuously delivered to the minimally invasive injection needle through the outlet pipeline, and the surgeon directly injects it into the surface of the target organ to achieve local deep cryogenic protection. There is no intermediate ice storage link throughout the process, and the ice slurry is not subject to secondary contamination.

[0054] After the operation, the cooling output of the external cooling system was first turned off, and the saline solution was pumped at a flow rate of 0.5L / min for 30 seconds to melt the residual ice crystals inside the tube using the residual heat in the shell side. Then, all pipeline connections were disconnected, the external communication connector was unplugged, the quick-release clamps were loosened by hand, and the integrated spiral channel tube module was pulled out of the shell as a whole.

[0055] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A non-metallic channel-based nucleation device for preparing medical ice slurry, characterized in that, It includes a sealed pressure-bearing shell and a spiral channel pipe passing through the inside of the sealed pressure-bearing shell; The sealed pressure shell is provided with a cooling medium inlet and a cooling medium outlet. The inner wall of the sealed pressure shell and the outer wall of the spiral channel tube form a closed shell-side heat exchange cavity. The heat exchange cavity is used for the external cooling medium to flow into the shell-side heat exchange cavity and flow out. The spiral channel tube has a saline inlet section extending out of the sealed pressure-bearing shell at its first end and an ice slurry outlet section extending out of the sealed pressure-bearing shell at its second end; the spiral channel tube is made of medical non-metallic materials.

2. The non-metallic channel nucleation device according to claim 1, characterized in that, It also includes an anti-blocking detection sensing component integrated on the device body; The anti-clogging detection sensing component includes a first temperature sensor and a first pressure sensor integrated in the inlet section of the spiral channel pipe, and a second temperature sensor and a second pressure sensor integrated in the outlet section of the spiral channel pipe. The first pressure sensor and the second pressure sensor are used to detect the fluid pressure at the inlet and outlet sections of the spiral channel pipe to obtain pressure drop parameters, and the first temperature sensor and the second temperature sensor are used to detect the fluid temperature at the inlet and outlet sections of the spiral channel pipe to obtain temperature difference parameters. The anti-clogging detection sensing component is also provided with an external communication interface for transmitting the pressure drop parameters and temperature difference parameters to external devices.

3. The non-metallic channel nucleation device according to claim 2, characterized in that, The anti-blocking detection sensing component also includes an AC conductivity meter integrated into the outlet section of the spiral channel pipe, used to detect the conductivity of the outlet ice slurry to assist in calculating the ice content parameter, which is transmitted to an external device through the external communication interface.

4. The non-metallic channel nucleation device according to claim 3, characterized in that, The first temperature sensor, the second temperature sensor, the first pressure sensor, the second pressure sensor, and the AC conductivity meter all adopt an embedded mounting structure, with the detection probe flush with the inner wall of the spiral channel tube.

5. The non-metallic channel nucleation device according to claim 1, characterized in that, The medical non-metallic material of the spiral channel tube is made of any one of medical-grade silicone, polytetrafluoroethylene, or medical polyurethane.

6. The non-metallic channel nucleation device according to claim 1, characterized in that, The spiral channel tube and the sealed pressure-bearing shell adopt an integral plug-in modular installation structure. The spiral channel tube can be moved out or inserted into the sealed pressure-bearing shell as a whole. The spiral channel tube is a continuously spiraling integral molded structure.

7. The non-metallic channel nucleation device according to claim 1, characterized in that, The sealed pressure-bearing shell is equipped with a medical non-metallic support bracket, which is adapted and snapped into the outer wall of the spiral channel tube. The two are pre-assembled into an integrated nucleation module that can be moved out or placed into the sealed pressure-bearing shell synchronously with the spiral channel tube.

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