Abdominal heating device

Abstract

This invention belongs to the field of hot compress technology, specifically an abdominal hot compress device, comprising a dressing chamber containing an air-activated dressing; the dressing chamber includes a top wall, a bottom wall, an inner side wall, and an outer side wall, the tops of the inner and outer side walls being connected to the top wall, and an air inlet cavity being provided between the inner and outer side walls, with multiple air vents on both the inner and outer side walls; the bottom wall is connected to the bottom of the inner side wall, and the bottom wall, inner side wall, and top wall form a heating chamber, in which the air-activated dressing is located; a liquid-absorbing layer is provided on the lower surface of the bottom wall, and a water-absorbing and expanding layer is connected to the edge of the liquid-absorbing layer, the water-absorbing and expanding layer being located at the bottom of the air inlet cavity; a sealing protective layer is provided on the outer surface of the outer side wall and the lower surface of the liquid-absorbing layer. This invention has a simple structure, is easy to use, and can prevent overheating during hot compress.

Description

Technical Field

[0001] This invention belongs to the field of heat therapy technology, and in particular to an abdominal heat therapy device. Background Technology

[0002] Applying heat to the abdomen can promote gastrointestinal motility, improve blood circulation in the abdomen, and relieve symptoms such as bloating and abdominal pain during menstruation in women. Currently, the most cost-effective and convenient heat therapy device is the heat pack, which is filled with heating materials such as iron powder and activated charcoal. To use it, simply tear off the sealing film and stick it to the area where heat is needed. However, the temperature of the heat pack cannot be adjusted during heat therapy, and it often becomes too hot, affecting the user experience.

[0003] Currently, there are many electric heating devices that can adjust the heating temperature, but their structures are relatively complex, their costs are high, and they are not as convenient to use as hand warmers. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an abdominal heat therapy device that is simple in structure and easy to use, and can prevent overheating during heat therapy.

[0005] To solve the above problems, the technical solution adopted by the present invention is: an abdominal hot compress device, including a dressing chamber, wherein an air-activated dressing is provided in the dressing chamber;

[0006] The dressing chamber includes a top wall, a bottom wall, an inner side wall, and an outer side wall. The top of the inner side wall and the outer side wall are connected to the top wall, and an air inlet is provided between the inner side wall and the outer side wall. Multiple air vents are provided on the inner side wall and the outer side wall.

[0007] The bottom wall is connected to the bottom of the inner side wall, and the bottom wall, inner side wall and top wall form a heating cavity, in which the air-activated dressing is located;

[0008] The lower surface of the bottom wall is provided with a liquid-absorbing layer, and the edge of the liquid-absorbing layer is connected with a water-absorbing and expanding layer, which is located at the bottom of the air inlet chamber.

[0009] The outer surface of the outer sidewall and the lower surface of the liquid-absorbing layer are both provided with a sealing protective layer.

[0010] Furthermore, a dehydration hole is provided on the outer wall at the bottom of the air intake cavity, and a one-way moisture-wicking layer is provided inside the dehydration hole;

[0011] The water-absorbing and expanding layer is a temperature-sensitive water-absorbing and expanding layer, with a water absorption and expansion temperature of 42-45℃ and a dehydration and shrinkage temperature of 35-38℃.

[0012] Furthermore, the method for preparing the temperature-sensitive water-absorbing and swelling layer is as follows:

[0013] S1. Preparation of temperature-sensitive microgel dispersion: N-isopropylacrylamide was polymerized via free radical polymerization to obtain an aqueous dispersion of poly-N-isopropylacrylamide microgel;

[0014] S2. Preparation of prepolymer mixture: Disperse nano-clay in deionized water under low temperature and shear force to form a homogeneous slurry. The low temperature is 0-10℃. Then add sodium acrylate, the temperature-sensitive microgel dispersion prepared in step S1 and crosslinking agent to the slurry and mix evenly to obtain the prepolymer mixture.

[0015] S3. In-situ polymerization: After deoxygenation treatment of the prepolymer mixture, an initiator is added, and a static polymerization reaction is carried out in an inert atmosphere at a temperature of 35°C to 45°C to form a composite hydrogel block.

[0016] S4. Post-treatment: The composite hydrogel block is shaped and then placed in an electrolyte solution for ion exchange treatment. Finally, it is dried at a temperature below 38°C to obtain a temperature-sensitive water-absorbing and swelling layer.

[0017] Further, step S1 includes: dissolving N-isopropylacrylamide, N,N'-methylenebisacrylamide and potassium persulfate in deionized water, reacting at 70℃-75℃ for 2-4 hours under a nitrogen atmosphere, and dialysis purification after the reaction to obtain a poly-N-isopropylacrylamide microgel aqueous dispersion with a solid content of 1% to 3%.

[0018] Furthermore, in step S2, the nano-clay is lithium saponite.

[0019] Further, in step S2, the weight parts of each component are as follows: 8-12 parts of sodium acrylate, 0.5-1.5 parts of thermosensitive microgel dispersion (based on solids), 1-2 parts of nano-clay, and 0.03-0.08 parts of N,N'-methylenebisacrylamide.

[0020] Furthermore, the absorbent layer is a non-woven fabric.

[0021] Furthermore, the air-activated dressing is an iron powder dressing.

[0022] Furthermore, the air-activated dressing is polypyrrole doped with p-toluenesulfonate.

[0023] Furthermore, the preparation method of the air-activated dressing is as follows: at 0℃ to 10℃, pyrrole is added dropwise to an aqueous reaction medium containing ferric p-toluenesulfonate and sodium p-toluenesulfonate for oxidative polymerization reaction, wherein the molar ratio of sodium p-toluenesulfonate to pyrrole is (0.8-1.2):1. After the reaction is completed, the product is separated, washed and dried to obtain a polypyrrole composite material; the polypyrrole composite material is mixed with carbon nanomaterials and adhesive to form a slurry, the slurry is coated on a substrate and dried.

[0024] The beneficial effects of this invention are: when using this invention, simply peel off the sealing protective layer, attach the absorbent layer to the abdomen of the human body, and keep the entire absorbent layer fixed. It is very convenient to use, and its small size makes it easy to carry and store.

[0025] After the sealing protective layer is removed, external air enters the heating chamber sequentially through the vents on the outer and inner walls. The air-activated dressing is activated by the air and begins to heat up, providing heat to the abdomen. When the heat application temperature is too high, the abdominal skin will sweat. The absorbent layer absorbs the sweat and transfers it to the water-absorbing and swelling layer at the edge. After absorbing the sweat, the water-absorbing and swelling layer expands in volume, filling the space in the air intake chamber and covering part of the vents on the inner and outer walls, thus slowing down the rate at which air enters the heating chamber and reducing the heating rate of the air-activated dressing, thereby lowering the temperature. Therefore, this invention also has the function of automatically controlling the heating rate of the air-activated dressing, effectively preventing overheating. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of Example 1;

[0027] Figure 2 This is a schematic diagram of Embodiment 2;

[0028] Reference numerals: 1—Air-activated dressing; 2—Top wall; 3—Bottom wall; 4—Inner wall; 5—Outer wall; 6—Air inlet chamber; 7—Absorbent layer; 8—Water-absorbing and expanding layer; 9—Sealing and protective layer; 10—One-way moisture-wicking layer; 11—Adhesive layer; 12—Hatch; 13—Positioning strap. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments. Example 1

[0030] The abdominal heat therapy device in this embodiment, such as Figure 1 As shown, it includes a dressing chamber, in which an air-activated dressing 1 is installed. The air-activated dressing 1 is a dressing that can react with air and release heat.

[0031] The dressing chamber includes a top wall 2, a bottom wall 3, an inner wall 4, and an outer wall 5. The tops of both the inner wall 4 and the outer wall 5 are connected to the top wall 2, and an air inlet 6 is provided between the inner wall 4 and the outer wall 5. Both the inner wall 4 and the outer wall 5 have multiple fine vent holes. The top wall 2 and the bottom wall 3 can be rectangular, circular, or other shapes. The inner wall 4 and the outer wall 5 are parallel to each other and perpendicular to the top wall 2 and the bottom wall 3. The top wall 2, the bottom wall 3, the inner wall 4, and the outer wall 5 can be made of thin plastic material.

[0032] The bottom wall 3 is connected to the bottom of the inner wall 4, and the bottom wall 3, inner wall 4 and top wall 2 form a heating chamber, in which the air-activated dressing 1 is located. Outside air can enter the heating chamber in sequence through the vent holes of the outer wall 5, the air inlet chamber 6 and the vent holes of the inner wall 4, thereby reacting with the air-activated dressing 1 and causing the air-activated dressing 1 to release heat.

[0033] A liquid-absorbing layer 7 is provided on the lower surface of the bottom wall 3, and a water-absorbing and expanding layer 8 is connected to the edge of the liquid-absorbing layer 7. The water-absorbing and expanding layer 8 is located at the bottom of the air inlet chamber 6. The liquid-absorbing layer 7 is made of a material that easily absorbs sweat, which can prevent sweat from affecting the comfort of heat therapy. It is also used to transfer sweat to the water-absorbing and expanding layer 8. The liquid-absorbing layer 7 can be made of medical non-woven fabric. When it does not absorb water, the water-absorbing and expanding layer 8 has a small volume and will not block or cover the vents of the inner wall 4 and the outer wall 5. After absorbing sweat, it expands and increases in volume, which can cover the vents of the inner wall 4 and the outer wall 5. The coverage area is determined by the amount of water absorbed. When the amount of water absorbed is high enough, all the vents can be sealed.

[0034] A sealing protective layer 9 is provided on the outer surface of the outer wall 5 and the lower surface of the liquid-absorbing layer 7. The sealing protective layer 9 serves to seal and protect, preventing external air from entering the heating chamber when not in use, and also preventing external impurities from contaminating the liquid-absorbing layer 7.

[0035] When using the abdominal heat therapy device of the present invention, the sealing protective layer 9 is torn off, the liquid-absorbing layer 7 is to be attached to the abdominal skin, and the dressing chamber is fixed. Outside air enters the heating chamber through the air vents of the outer wall 5, the air inlet chamber 6 and the air vents of the inner wall 4 in sequence, and reacts with the air-activated dressing 1, so that the air-activated dressing 1 releases heat and the heat is transferred to the abdomen to achieve heat therapy on the abdomen.

[0036] When the heat application temperature is suitable, the amount of sweat produced on the abdomen is minimal, and the small amount of sweat is difficult to effectively transfer to the water-absorbing and swelling layer 8, so the volume of the water-absorbing and swelling layer 8 remains almost unchanged. When the heat application temperature is too high, the abdominal skin will sweat rapidly. After the sweat is absorbed by the absorbent layer 7, it is transferred to the water-absorbing and swelling layer 8. After absorbing the sweat, the volume of the water-absorbing and swelling layer 8 will increase rapidly, filling the space of the air inlet cavity 6 and sealing some or all of the air vents on the inner wall 4 and the outer wall 5. The speed at which outside air enters the heating cavity is slowed down, or it can no longer enter the heating cavity. The reaction rate of the air-activated dressing 1 is reduced, the heat release rate is reduced, and thus the heat application temperature is lowered.

[0037] When the body is at a comfortable heat application temperature, it typically doesn't sweat rapidly. Rapid sweating not only causes discomfort and makes one more susceptible to catching a chill afterward, but also indicates that the heat application temperature exceeds the comfortable range, meaning it's overheated. Therefore, this invention employs an automatic sweat-triggered overheat protection mechanism, eliminating the need for various sensors and maintaining a simple, compact, and cost-effective heat application device.

[0038] In order to keep the heat treatment temperature within a suitable range, that is, to slow down the reaction rate of the air-activated dressing 1 to cool it down when the temperature is too high, and to speed up the reaction rate of the air-activated dressing 1 to heat it up when the temperature is too low, the present invention provides a dehydration hole on the outer wall 5 at the bottom of the air inlet 6. A one-way moisture-wicking layer 10 is provided in the dehydration hole. The one-way moisture-wicking layer 10 is used to transport the sweat in the air inlet 6 to the outside of the outer wall 5 and evaporate it. Specifically, existing quick-drying materials such as CoolMax fabric can be used.

[0039] The water-absorbing and swelling layer 8 is a temperature-sensitive water-absorbing and swelling layer. Its water absorption and swelling temperature is 42-45℃, and its dehydration and shrinkage temperature is 35-38℃. The water absorption performance of the temperature-sensitive water-absorbing and swelling layer is affected by temperature. When the heat application temperature is below 42-45℃, the water absorption capacity of the layer is poor, and the expansion rate is slow. When the heat application temperature reaches 42-45℃, the water absorption capacity of the layer increases rapidly, becoming strong. At this temperature, if the skin produces a large amount of sweat, the layer can quickly absorb water and expand, slowing down the reaction rate of the air-activated dressing 1 and lowering the heat application temperature. When the heat application temperature is above 35-38℃, the dehydration rate of the layer is slow. When the temperature drops to 35-38℃, the dehydration rate increases rapidly. After dehydration, the layer shrinks, reducing its volume. This increases the speed at which air enters the heating chamber, enhancing the reaction of the air-activated dressing 1 and raising the heat application temperature. As can be seen, by using a temperature-sensitive absorbent expansion layer, the heat therapy temperature can be controlled between the dehydration shrinkage temperature and the water absorption expansion temperature, a temperature range that allows the human body to be in a relatively comfortable state. The water released from the temperature-sensitive absorbent expansion layer reaches the outside of the outer wall 5 through the one-way moisture-wicking layer 10 and evaporates and is discharged.

[0040] The raw materials for preparing the above-mentioned temperature-sensitive water-absorbing and swelling layer include:

[0041] Sodium acrylate, used to form a superabsorbent network, 10 parts by weight, industrial grade, purity ≥98%;

[0042] N-Isopropylacrylamide, used to synthesize thermosensitive microgels, 2-4 parts by weight, purity ≥98%;

[0043] N,N'-methylenebisacrylamide, used as a crosslinking agent, 0.05-0.1 parts by weight, chemically pure;

[0044] Potassium persulfate, used as a thermal initiator, 0.1-0.2 parts by weight, chemically pure;

[0045] Lithium saponite, as a nano-clay, reinforcing agent and rheology modifier, 1-2 parts by weight, nanoscale sheets;

[0046] Deionized water, 200-300 parts by weight;

[0047] Nitrogen, used as an inert protective gas, is of industrial grade.

[0048] The preparation method is as follows:

[0049] S1. Preparation of temperature-sensitive microgel dispersion: N-isopropylacrylamide is polymerized via free radical polymerization to obtain an aqueous dispersion of poly(N-isopropylacrylamide) microgel. Specifically, N-isopropylacrylamide, N,N'-methylenebisacrylamide, and potassium persulfate are dissolved in deionized water and reacted at 70℃-75℃ for 2-4 hours under a nitrogen atmosphere to form a milky white dispersion. After the reaction, the dispersion is cooled to room temperature and dialyzed in deionized water for 3 days using a dialysis bag (molecular weight cutoff 8000-14000), changing the water 3 times a day to remove unreacted monomers and initiator fragments, obtaining an aqueous dispersion of poly(N-isopropylacrylamide) microgel with a solid content of 1% to 3%.

[0050] S2. Preparation of prepolymerized mixture: Disperse nano-clay in deionized water under the action of low temperature (0-10℃) and shear force (obtained by high-speed stirring at a rate of 2000r / min) to prevent nano-clay agglomeration and form a uniform slurry. The nano-clay can be lithium saponite.

[0051] Subsequently, sodium acrylate, the thermosensitive microgel dispersion prepared in step S1, and the crosslinking agent were added to the slurry. The mixture was stirred in an ice-water bath for 1 hour to ensure uniform mixing, resulting in a prepolymerized mixture. The weight proportions of each component were as follows: sodium acrylate 8-12 parts, thermosensitive microgel dispersion 0.5-1.5 parts (solids), nanoclay 1-2 parts, and N,N'-methylenebisacrylamide 0.03-0.08 parts.

[0052] S3. In-situ polymerization: After continuously purging nitrogen gas into the prepolymer mixture for 30 minutes to remove oxygen, add potassium persulfate as an initiator, stir and mix, and carry out static polymerization reaction for 4-6 hours under an inert atmosphere and at a temperature of 35°C to 45°C. The solution will gradually gel and eventually form a monolithic, elastic, and transparent composite hydrogel block.

[0053] S4. Post-processing: The composite hydrogel block is shaped, specifically by cutting with a mold or directly slicing to the required size.

[0054] The gel was then subjected to ion exchange treatment in an electrolyte solution, using a 0.5 mol / L sodium chloride solution, for 24 hours. During this process, sodium ions partially replaced hydrogen ions in the gel network, significantly improving the gel's mechanical strength, stability under repeated swelling and shrinkage, and making its swelling behavior more controllable.

[0055] Finally, the material is dried at a temperature below 38°C (preferably 35°C) to obtain a temperature-sensitive water-absorbing and swelling layer.

[0056] The low critical solution temperature (LCST) of traditional poly(N-isopropylacrylamide) gel is approximately 32°C. Below this temperature, the poly(N-isopropylacrylamide) gel hydrophilically swells. In this invention, the sodium acrylate superabsorbent network polymerized in situ in step S3 forms an interpenetrating network with the poly(N-isopropylacrylamide). When the temperature rises to 42-45°C, the strong hydrophilic groups (carboxylate ions) of sodium acrylate overcome the hydrophobic shrinkage tendency of N-isopropylacrylamide, forcing the gel to reabsorb water and swell. When the temperature drops back to 35-38°C, the hydrophobic shrinkage of N-isopropylacrylamide becomes dominant, leading to overall gel dehydration and shrinkage. The nanosheet lithium saponite forms physical cross-linking points in the gel, which not only improves the mechanical strength of the gel and avoids damage caused by repeated swelling and shrinkage, but also slows down the rate of water absorption and desorption, making the temperature-sensitive response more stable and preventing "uncontrolled swelling and shrinkage" during sudden temperature changes.

[0057] In step S3, the polymerization temperature is set to 35-45℃, which precisely covers the phase transition range of the gel. This promotes the formation of a more uniform interpenetrating network between sodium acrylate and N-isopropylacrylamide microgel, preventing premature hydrophobic aggregation of N-isopropylacrylamide due to excessively high polymerization temperature, and ensuring the consistency of the temperature-sensitive properties of the final product.

[0058] In step S4, the gel is soaked in a 0.5 mol / L NaCl solution. Sodium ions replace the free hydrogen ions in the gel network, neutralizing some of the carboxyl groups and precisely adjusting the balance between hydrophilicity and hydrophobicity. This makes the temperature thresholds for expansion and contraction more precise and improves the cycling stability (the expansion / contraction ratio decreases by ≤8% after 50 cycles).

[0059] The nanosheet lithium saponite forms physical cross-linking points in the gel, which not only improves the mechanical strength of the gel and avoids damage caused by repeated swelling and shrinkage, but also slows down the rate of water absorption and desorption, making the temperature-sensitive response more stable and preventing "uncontrolled expansion and contraction" when the temperature changes suddenly.

[0060] In this embodiment, the air-activated dressing 1 is an iron powder dressing, which can be made using existing commonly used formulas.

[0061] In this embodiment of the abdominal heat therapy device, an adhesive layer 11 can be provided in the absorbent layer 7, and the sealing protective layer 9 is a release film. When in use, the entire abdominal heat therapy device is adhered to the abdomen through the adhesive layer 11; after heat therapy, the abdominal heat therapy device is torn off and discarded.

[0062] The abdominal heat therapy device in this embodiment is a disposable product, suitable for home, outings and other scenarios, and is convenient to carry and use. Example 2

[0063] The abdominal heat therapy device in this embodiment, such as Figure 2 As shown, based on Example 1, the structure of the dressing chamber is changed. At the same time, the air-activated dressing 1 uses polypyrrole doped with p-toluenesulfonate. This air-activated dressing 1 can be regenerated and reused.

[0064] Specifically, the raw materials for preparing air-activated dressing 1 include:

[0065] Pyrrole, as the main monomer for polymerization, was purified by distillation (≥99%) and stored refrigerated and protected from light.

[0066] Ferric p-toluenesulfonate serves as both an oxidant and a dopant source.

[0067] Sodium p-toluenesulfonate, as an additional dopant and reaction medium;

[0068] Deionized water and ethanol are mixed as solvents, with a volume ratio of 4:1.

[0069] The preparation method is as follows: pyrrole is added dropwise to an aqueous reaction medium containing ferric p-toluenesulfonate and sodium p-toluenesulfonate at 0℃ to 10℃ to carry out an oxidative polymerization reaction. The reactants are stirred. The aqueous reaction medium is a mixed solvent of deionized water and ethanol. The molar ratio of ferric p-toluenesulfonate, sodium p-toluenesulfonate and pyrrole is (0.3-0.4):(0.8-1.2):1. The dropping rate of pyrrole is 0.2-0.4 mL / s. After the dropping is completed, the reaction is continued for 12-24 hours under ice-water bath conditions at 0-5℃.

[0070] After the reaction, the product was separated, washed, and dried to obtain the polypyrrole composite material. Specifically, the product was filtered using a Buchner funnel to obtain a black precipitate. The precipitate was washed with a large amount of deionized water until the filtrate was colorless to remove sodium ions, unreacted ferrous ions, ferric ions, etc. It was then washed twice with anhydrous ethanol to remove oligomers and residual water. The filter cake was placed in a vacuum drying oven and dried at 50-60°C for 24-48 hours to obtain a dry, black powdery polypyrrole composite material.

[0071] A slurry is prepared by mixing polypyrrole composite material with carbon nanomaterials and an adhesive. The adhesive can be an aqueous polyurethane dispersion. The weight ratio of polypyrrole composite material to carbon nanomaterials and adhesive is 70:15:15. After mixing, the mixture is ground to obtain a uniform slurry. The slurry is coated onto a substrate and dried to obtain a flexible polypyrrole membrane with a porous structure, which is the air-activated dressing 1.

[0072] The air-activated dressing 1 prepared in this embodiment exhibits polypyrrole molecular chains capable of undergoing an oxidation reaction with oxygen. The conjugated double bonds in the polypyrrole molecules lose electrons, completing the oxidation doping process. The reaction releases a mild amount of heat, with the temperature ranging from 32°C to 45°C. The reaction rate can be adjusted by controlling the oxygen supply rate, thereby controlling the temperature. The addition of carbon nanomaterials enhances the material's conductivity and porosity, accelerates oxygen diffusion, and makes the heat release rate more uniform.

[0073] The polypyrrole doped with p-toluenesulfonate is a regenerable and reusable air-activated dressing 1. In order to facilitate the handling of the air-activated dressing 1, this embodiment has a repeatedly openable and closable door 12 on the top wall 2. After the door 12 is opened, the air-activated dressing 1 in the heating chamber can be taken out and regenerated, or the regenerated air-activated dressing 1 can be put into the heating chamber.

[0074] To facilitate fixing the dressing chamber to the abdomen, it can be glued or a positioning strap 13 can be provided on the outer wall 5. When in use, the positioning strap 13 can be tied around the waist.

[0075] This embodiment is suitable for centralized use in medical institutions. After use, multiple air-activated dressings 1 can be collected and regenerated, realizing the reuse of air-activated dressings 1. The regeneration process of air-activated dressing 1 in this embodiment is as follows:

[0076] Configure an electrolytic cell, and fill the electrolytic cell with an electrolyte, which can be physiological saline.

[0077] The electrolytic cell is equipped with a working electrode and a counter electrode. The working electrode is used to connect the air-activated dressing 1, and the counter electrode can be a carbon rod.

[0078] Configure a potentiostat that can output a stable and controllable negative voltage, such as -0.5V to -0.8V. The WE interface of the potentiostat is connected to the working electrode, and the CE interface is connected to the counter electrode.

[0079] Connect the used air-excited dressing 1 to the working electrode and immerse it in the electrolyte. Start the potentiostat and run it for 20-40 minutes. Remove the air-excited dressing 1, rinse it with water, vacuum dry it, and then put it into the heating chamber.

[0080] By applying a negative voltage, oxidized polypyrrole can be reduced to a lower oxidation state, allowing the polypyrrole molecular chains to gain electrons and regain their ability to excite and release heat in air, thus achieving regeneration.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An abdominal heat therapy device, comprising a dressing chamber, wherein an air-activated dressing (1) is disposed within the dressing chamber; characterized in that: The dressing chamber includes a top wall (2), a bottom wall (3), an inner wall (4) and an outer wall (5). The tops of the inner wall (4) and the outer wall (5) are connected to the top wall (2), and an air inlet chamber (6) is provided between the inner wall (4) and the outer wall (5). Multiple air vents are provided on the inner wall (4) and the outer wall (5). The bottom wall (3) is connected to the bottom of the inner wall (4), and the bottom wall (3), the inner wall (4) and the top wall (2) form a heating cavity, in which the air-activated dressing (1) is located; The lower surface of the bottom wall (3) is provided with a liquid-absorbing layer (7), and the edge of the liquid-absorbing layer (7) is connected with a water-absorbing expansion layer (8), which is located at the bottom of the air inlet chamber (6). The outer surface of the outer wall (5) and the lower surface of the liquid-absorbing layer (7) are both provided with a sealing protective layer (9); The outer side wall (5) at the bottom of the air intake cavity (6) is provided with a dehydration hole, and a one-way moisture-wicking layer (10) is provided inside the dehydration hole. The water-absorbing and swelling layer (8) is a temperature-sensitive water-absorbing and swelling layer. The water-absorbing and swelling temperature of the temperature-sensitive water-absorbing and swelling layer is 42-45℃, and the dehydration and shrinkage temperature is 35-38℃. The method for preparing the temperature-sensitive water-absorbing and swelling layer is as follows: S1. Preparation of temperature-sensitive microgel dispersion: N-isopropylacrylamide was polymerized via free radical polymerization to obtain an aqueous dispersion of poly-N-isopropylacrylamide microgel; S2. Preparation of prepolymer mixture: Disperse nano-clay in deionized water under low temperature and shear force to form a homogeneous slurry. The low temperature is 0-10℃. Then add sodium acrylate, the temperature-sensitive microgel dispersion prepared in step S1 and crosslinking agent to the slurry and mix evenly to obtain the prepolymer mixture. S3. In-situ polymerization: After deoxygenation treatment of the prepolymer mixture, an initiator is added, and a static polymerization reaction is carried out in an inert atmosphere at a temperature of 35°C to 45°C to form a composite hydrogel block. S4. Post-processing: The composite hydrogel block is shaped and then placed in an electrolyte solution for ion exchange treatment. Finally, it is dried at a temperature below 38°C to obtain the temperature-sensitive water-absorbing and swelling layer.

2. The abdominal heat therapy device as described in claim 1, characterized in that: Step S1 includes: dissolving N-isopropylacrylamide, N,N'-methylenebisacrylamide and potassium persulfate in deionized water, reacting at 70℃-75℃ for 2-4 hours under a nitrogen atmosphere, and dialysis purification after the reaction to obtain a poly-N-isopropylacrylamide microgel aqueous dispersion with a solid content of 1% to 3%.

3. The abdominal heat therapy device as described in claim 1, characterized in that: In step S2, the nano-clay is lithium saponite.

4. The abdominal heat therapy device as described in claim 1, characterized in that: In step S2, the weight parts of each component are as follows: 8-12 parts of sodium acrylate, 0.5-1.5 parts of thermosensitive microgel dispersion (based on solids), 1-2 parts of nano-clay, and 0.03-0.08 parts of N,N'-methylenebisacrylamide.

5. The abdominal heat therapy device as described in claim 1, characterized in that: The absorbent layer (7) is a non-woven fabric.

6. The abdominal heat therapy device as described in claim 1, characterized in that: The air-activated dressing (1) is an iron powder dressing.

7. The abdominal heat therapy device as described in claim 1, characterized in that: The air-activated dressing (1) is polypyrrole doped with p-toluenesulfonate.

8. The abdominal heat therapy device as described in claim 7, characterized in that: The preparation method of air-activated dressing (1) is as follows: at 0℃ to 10℃, pyrrole is added dropwise to an aqueous reaction medium containing iron p-toluenesulfonate and sodium p-toluenesulfonate for oxidative polymerization reaction, wherein the molar ratio of sodium p-toluenesulfonate to pyrrole is (0.8-1.2):

1. After the reaction is completed, the product is separated, washed and dried to obtain polypyrrole composite material; the polypyrrole composite material is mixed with carbon nanomaterials and adhesive to make a slurry, the slurry is coated on the substrate and dried.

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