A precision temperature-controlled dressing and its preparation method

Abstract

This invention provides a precision temperature-controlled dressing and its preparation method to solve the problem that existing wound dressings cannot precisely regulate temperature and maintain it within a favorable range for wound healing. The precision temperature-controlled dressing comprises, from top to bottom, a moisturizing layer, a precision temperature-controlled layer, a phase-change temperature-regulating layer, and a temperature monitoring area. The precision temperature-controlled layer has embedded cooling and heating channels for the flow of cooling and heating fluids, respectively. The threshold values ​​for initiating the flow of cooling and heating fluids in the precision temperature-controlled layer are 38°C and 33°C, respectively.

Description

Technical Field

[0001] This invention relates to the field of wound dressing technology, specifically to a precision temperature-controlled dressing and its preparation method. Background Technology

[0002] With the development of research on wound healing mechanisms and dressing technology, attention is now gradually being paid to the impact of local wound temperature on wound healing. Studies have shown that when the temperature is below 33°C, the activity of neutrophils, fibrinogen and human keratinocytes decreases, which leads to delayed healing. When the temperature is above 38°C, the local temperature spreads to the surrounding areas, stimulating inflammation and causing a burning sensation.

[0003] Patent CN117138092A discloses a method for preparing a temperature-controlled and moisturizing medical dressing loaded with biocompatible phase change microcapsules. It mentions that controlling the phase change temperature range within the body temperature range of 33-38℃ suitable for wound healing is crucial. According to its experimental results, it does control the phase change temperature within this temperature range. However, phase change is a continuous process that continuously releases or absorbs heat. For example, the peak values ​​during melting and solidification exceed this range. Therefore, it cannot completely achieve the effect of precise temperature control.

[0004] Patent CN109512579A discloses a multi-layer moisture-absorbing and breathable magnetic therapy and intelligent temperature-controlled dressing and its application method. It detects the wound temperature through a sensor, with a temperature detection range of 18-24℃ in autumn and winter and 22-28℃ in spring and summer. When the temperature is too low, the dressing is heated by heating coils and oxygen-generating elements. When the temperature is too high, the dressing usually needs to be replaced. It can be seen that its temperature control process is relatively crude, the heating process is not very controllable, and it cannot handle the situation of excessively high temperature, with limited temperature regulation. Summary of the Invention

[0005] This invention provides a precise temperature-controlled dressing and its preparation method, which solves the problem that existing wound dressings cannot precisely control the temperature and keep it within a favorable range for wound healing.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A precision temperature-controlled dressing and its preparation method are disclosed. The precision temperature-controlled dressing consists of a moisturizing layer, a precision temperature-controlled layer, a phase change temperature-regulating layer, and a temperature monitoring area, which are fixedly connected from top to bottom. The precision temperature-controlled layer has embedded cooling channels and heating channels for the flow of coolant and heating liquid, respectively. The threshold values ​​for initiating the flow of coolant and heating liquid in the precision temperature-controlled layer are 38°C and 33°C, respectively.

[0007] Furthermore, the method for preparing the moisturizing layer is as follows: S1: Add 5g sodium hyaluronate and 10g sodium alginate to 100mL of distilled water and stir until completely dissolved; S2: Measure the pH value of the solution and adjust the pH to the range of 6-7.5 using acid or alkaline solutions; S3: Slowly add 1-5% calcium chloride solution dropwise to the solution while stirring. When the solution begins to thicken and form a gel, stop adding calcium chloride solution and continue stirring for 10-15 minutes. Then slowly add 0.5-1% glutaraldehyde solution dropwise to the solution while stirring. After the addition is complete, continue stirring for 30-60 minutes. S4: Pour the stirred solution into the mold, place the mold in a vacuum drying oven at 40-50℃ and dry for 4-6 hours to obtain a moisturizing layer.

[0008] In step S3, the molar ratio of calcium chloride and sodium alginate is 1:2 or 1:3, and the amount of glutaraldehyde used is usually 0.5-2% of the weight of sodium hyaluronate.

[0009] Furthermore, the cooling channel and the heating channel are respectively connected to a cooling module and a heating module. The cooling module is composed of a cooling electronic valve and a cooling circulation pump, and the cooling circulation pump is connected to the cooling channel. The heating module is composed of a heating electronic valve and a heating circulation pump, and the heating circulation pump is connected to the heating channel.

[0010] Furthermore, the coolant comprises: a 35% aqueous solution of polyethylene glycol with a molecular weight of 400-600 and a 30% ethanol aqueous solution by volume; the heating fluid comprises: paraffin oil or high-boiling-point silicone oil heated to 39-40°C.

[0011] Furthermore, the phase change temperature regulating layer contains several phase change microspheres, and the preparation method of the phase change microspheres is as follows: S11: To prepare the oil phase solution, add 1g of polylactic acid-glycolic acid copolymer to 5ml of dichloromethane, add 0.3g of lauric acid and 0.2g of myristic acid, and stir until homogeneous; S12: To prepare an aqueous solution, add 2g of polyvinyl alcohol to 100ml of deionized water and stir until completely dissolved. S13: Load the oil phase solution and the aqueous phase solution into two injection pumps respectively, connect the microfluidic chip to the injection pumps, control the flow rate of the oil phase at 5 μl / min and the flow rate of the aqueous phase at 50 μl / min, start the injection pumps, and the reaction yields a microsphere emulsion. S14: Stir the collected microsphere emulsion on a magnetic stirrer for 2-4 hours to allow the organic solvent to evaporate. Finally, wash the microspheres 3-5 times with deionized water and dry them in a vacuum drying oven at 40°C for 12-24 hours.

[0012] Furthermore, the preparation method of the phase change temperature-regulating layer is as follows: S15: Add 10g of carrageenan to 100ml of distilled water to form a gel solution, and heat to 80-90℃ to promote the complete dissolution of carrageenan; S16: Add the phase change microspheres to the above gel solution and stir for 15-30 min to complete the dispersion of the phase change microspheres; S17: Pour the above solution into the mold, cool the mold at room temperature, and dry it at 40-50℃ for 4-6 hours.

[0013] Furthermore, at least one temperature monitoring area is fixed below the phase change temperature regulating layer, and at least one temperature sensor is located in the temperature monitoring area. The temperature sensor is wrapped with an insulating skin and is connected to a signal converter via a wire. The signal output by the signal converter is transmitted to the memory, display, cooling electronic valve, cooling circulation pump, heating electronic valve, and heating circulation pump, respectively.

[0014] Furthermore, one of the precise temperature control modes of the aforementioned precise temperature control dressing is as follows: when the temperature detected by the temperature sensor is higher than the highest threshold or lower than the lowest threshold, the cooling circulation pump and heating circulation pump connected to the threshold will be automatically started to circulate the coolant and heating liquid stored in the cooling channel and heating channel to achieve precise temperature control.

[0015] Furthermore, the second precise temperature control mode of the aforementioned precise temperature-controlled dressing is as follows: When the temperature detected by the temperature sensor is higher than the maximum threshold, the cooling electronic valve and the cooling circulation pump will be activated sequentially. At this time, the cooling circulation pump will pump coolant into the cooling channel to quickly bring the temperature back below 38°C. When the detected temperature is lower than 36°C, the system will control the cooling electronic valve and the cooling circulation pump to shut down. When the temperature detected by the temperature sensor is lower than the minimum threshold, the heating electronic valve and the heating circulation pump will be activated sequentially. At this time, the heating circulation pump will pump heating liquid into the heating channel to quickly bring the temperature back above 33°C. When the detected temperature is higher than 35°C, the system will control the cooling electronic valve and the cooling circulation pump to shut down.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention addresses the problem of phase change materials exceeding a predetermined temperature range during phase change by adding a precise temperature control layer to the dressing. The temperature is consistently controlled within the predetermined temperature range through the control of the coolant, heating fluid, and an automatic temperature monitoring and control system. This invention has two control modes, which can realize both short-term and long-term control of lightweight equipment, thereby meeting the needs of various usage scenarios, such as field or clinical use. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a precision temperature-controlled dressing according to Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the precise temperature control layer in a precise temperature control dressing according to Embodiment 1 of the present invention; Figure 3 This is a photograph of phase change microspheres in a precision temperature-controlled dressing according to Embodiment 1 of the present invention; Figure 4 This is a flowchart illustrating a precise temperature-controlled dressing mode 1 according to Embodiment 1 of the present invention; Figure 5 This is a flowchart illustrating a second mode of precise temperature-controlled dressing according to Embodiment 1 of the present invention.

[0018] Among them, 10 is the moisturizing layer, 20 is the precision temperature control layer, 21 is the cooling channel, 22 is the heating channel, 23 is the cooling module, 24 is the heating module, 30 is the phase change temperature regulation layer, and 40 is the temperature monitoring area. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Example

[0020] like Figure 1 As shown, the precision temperature control dressing consists of four layers stacked and fixed from top to bottom: a moisturizing layer 10, a precision temperature control layer 20, a phase change temperature regulating layer 30, and a temperature monitoring zone 40.

[0021] The moisturizing layer 10 can be prepared using existing technologies, such as the moisturizing layers in patents CN117138092A and CN109512579A, which are suitable for this embodiment. Furthermore, this embodiment also provides a method for preparing the moisturizing layer 10: S1: Add 5g sodium hyaluronate and 10g sodium alginate to 100mL of distilled water and stir until completely dissolved; S2: Measure the pH value of the solution and adjust the pH to the range of 6-7.5 using acid or alkaline solutions; S3: Slowly add 1-5% calcium chloride solution dropwise to the solution while stirring. When the solution begins to thicken and form a gel, stop adding calcium chloride solution and continue stirring for 10-15 minutes. Then slowly add 0.5-1% glutaraldehyde solution dropwise to the solution while stirring. After the addition is complete, continue stirring for 30-60 minutes. S4: Pour the stirred solution into the mold, place the mold in a vacuum drying oven at 40-50℃ and dry for 4-6 hours to obtain a moisturizing layer.

[0022] In step S3, the molar ratio of calcium chloride and sodium alginate is 1:2 or 1:3, and the amount of glutaraldehyde used is usually 0.5-2% of the weight of sodium hyaluronate.

[0023] The biggest difference from existing technologies is that this embodiment adds a precision temperature control layer 20, such as... Figure 2 As shown, the precision temperature control layer 20 has two independent channels embedded within it: a cooling channel 21 and a heating channel 22. Coolant flows through the cooling channel 21, while heating fluid flows through the heating channel 22. Cooling module 23 and heating module 24 are respectively connected to the cooling channel 21 and heating channel 22. The cooling module 23 consists of a cooling electronic valve and a cooling circulation pump, which is connected to the cooling channel 21. The heating module 24 consists of a heating electronic valve and a heating circulation pump, which is connected to the heating channel 22. The cooling circulation pump is used to deliver and circulate the coolant, and the heating circulation pump is used to deliver and circulate the heating fluid. There are two flow methods for the coolant and heating fluid: one is pre-filling the channels, and the other is pumping them in from an external storage container. The first mode is only suitable for short-term temperature control, while the second mode can be used for long-term regulation.

[0024] The coolant used in the above process can be selected from the following: a 35% aqueous solution of polyethylene glycol with a molecular weight of 400-600, and a 30% ethanol aqueous solution by volume. The heating fluid can be selected from the following: paraffin oil or high-boiling-point silicone oil (silicone oil with a boiling point above 200℃) heated to 39-40℃.

[0025] Below the precision temperature control layer 20, a phase change temperature regulating layer 30 is fixed (the fixing method is not described in detail here; it applies to all methods used for fixing multi-layer dressings). The phase change temperature regulating layer 30 contains several phase change microspheres, which are prepared by the following method: S11: To prepare the oil phase solution, add 1g of polylactic acid-glycolic acid copolymer to 5ml of dichloromethane, add 0.3g of lauric acid and 0.2g of myristic acid, and stir until homogeneous; S12: To prepare an aqueous solution, add 2g of polyvinyl alcohol to 100ml of deionized water and stir until completely dissolved. S13: Load the oil phase solution and the aqueous phase solution into two injection pumps respectively, connect the microfluidic chip to the injection pumps, control the flow rate of the oil phase at 5 μl / min and the flow rate of the aqueous phase at 50 μl / min, start the injection pumps, and the reaction yields a microsphere emulsion. S14: Stir the collected microsphere emulsion on a magnetic stirrer for 2-4 hours to allow the organic solvent to evaporate. Finally, wash the microspheres 3-5 times with deionized water and dry them in a vacuum drying oven at 40°C for 12-24 hours.

[0026] The phase change microspheres prepared by the above method are as follows: Figure 3 As shown.

[0027] The method for preparing the phase change temperature regulating layer 30 is as follows: S15: Add 10g of carrageenan to 100ml of distilled water to form a gel solution, and heat to 80-90℃ to promote the complete dissolution of carrageenan; S16: Add the phase change microspheres to the above gel solution and stir for 15-30 min to complete the dispersion of the phase change microspheres; S17: Pour the above solution into the mold, cool the mold at room temperature, and dry it at 40-50℃ for 4-6 hours.

[0028] The phase change temperature-regulating layer 30 prepared by the above method and dosage has a melting point of 36.2℃, a peak point of 41.9℃, and a melting enthalpy of 45.1 J / g; a freezing point of 33.4℃, a peak point of 25.5℃, and a freezing enthalpy of 47.1 J / g. It can be seen that its melting and freezing points are both between 33-38℃, but the peak points exceed these ranges, thus requiring adjustment through the precise temperature control layer 20.

[0029] At least one temperature monitoring area is fixed below the phase change temperature regulating layer 30. At least one temperature sensor is located in the temperature monitoring area. The temperature sensor is covered with an insulating skin and is connected to a signal converter via a wire. The signal output of the signal converter is transmitted to control components such as memory, display and cooling circulation pump.

[0030] Figure 4 and Figure 5 Two precise control methods were demonstrated respectively: Mode 1: The signal output from the temperature sensor is transmitted to a signal converter via wires. The signal output from the signal converter is stored in a memory and also transmitted to a display via Bluetooth. Simultaneously, when the detected temperature exceeds the highest threshold (38℃) or falls below the lowest threshold (33℃), the connected cooling and heating circulation pumps are automatically activated, respectively. This method achieves secondary temperature control. For example, if the temperature exceeds the 33-38℃ range during the melting or solidification of the phase change temperature-regulating layer, the precision temperature-regulating layer is activated. During this process, the circulation pump only circulates the coolant or heating fluid, which is pre-filled in the precision temperature-regulating layer. However, this method is only suitable for short-term use. As time progresses, thermal equilibrium will gradually be reached. Once thermal equilibrium is reached, the coolant or heating fluid needs to be replaced, or a new dressing needs to be applied.

[0031] Mode 2: Mode 2 is the recommended mode. The coolant and heating fluid are externally located and placed in an insulated container. When the temperature detected by the temperature sensor exceeds the maximum threshold, the cooling electronic valve and cooling circulation pump are activated sequentially. The cooling circulation pump then pumps coolant into cooling channel 21, rapidly lowering the temperature to below 38°C. When the detected temperature is below 36°C, the system controls (the system that controls the electronic valve and circulation pump via a signal converter is existing technology and will not be described further) to close the cooling electronic valve and cooling circulation pump. When the temperature detected by the temperature sensor is below the minimum threshold, the heating electronic valve and heating circulation pump are activated sequentially. The heating circulation pump then pumps heating fluid into heating channel 22, rapidly raising the temperature to above 33°C. When the detected temperature is above 35°C, the system controls the cooling electronic valve and cooling circulation pump to close.

[0032] It should be understood that although this specification describes the embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A precision temperature-controlled dressing and its preparation method, characterized in that, The precision temperature control dressing consists of a moisturizing layer, a precision temperature control layer, a phase change temperature regulation layer, and a temperature monitoring area, which are fixedly connected from top to bottom. The precision temperature control layer has embedded cooling channels and heating channels for the flow of coolant and heating fluid, respectively. The threshold values ​​for initiating the flow of coolant and heating fluid in the precision temperature control layer are 38°C and 33°C, respectively.

2. The precision temperature-controlled dressing and its preparation method according to claim 1, characterized in that, The method for preparing the moisturizing layer is as follows: S1: Add 5g sodium hyaluronate and 10g sodium alginate to 100mL of distilled water and stir until completely dissolved; S2: Measure the pH value of the solution and adjust the pH to the range of 6-7.5 using acid or alkaline solutions; S3: Slowly add 1-5% calcium chloride solution dropwise to the solution while stirring. When the solution begins to thicken and form a gel, stop adding calcium chloride solution and continue stirring for 10-15 minutes. Then slowly add 0.5-1% glutaraldehyde solution dropwise to the solution while stirring. After the addition is complete, continue stirring for 30-60 minutes. S4: Pour the stirred solution into a mold, place the mold in a vacuum drying oven at 40-50℃ and dry for 4-6 hours to obtain a moisturizing layer; In step S3, the molar ratio of calcium chloride and sodium alginate is 1:2 or 1:3, and the amount of glutaraldehyde used is usually 0.5-2% of the weight of sodium hyaluronate.

3. The precision temperature-controlled dressing and its preparation method according to claim 1, characterized in that, The cooling channel and heating channel are respectively connected to a cooling module and a heating module. The cooling module is composed of a cooling electronic valve and a cooling circulation pump, and the cooling circulation pump is connected to the cooling channel. The heating module is composed of a heating electronic valve and a heating circulation pump, and the heating circulation pump is connected to the heating channel.

4. The precision temperature-controlled dressing and its preparation method according to claim 1, characterized in that, The coolant comprises: a 35% aqueous solution of polyethylene glycol with a molecular weight of 400-600 and a 30% ethanol aqueous solution by volume; the heating fluid comprises: paraffin oil or high-boiling-point silicone oil heated to 39-40°C.

5. The precision temperature-controlled dressing and its preparation method according to claim 1, characterized in that, The phase change temperature regulating layer contains several phase change microspheres, and the preparation method of the phase change microspheres is as follows: S11: To prepare the oil phase solution, add 1g of polylactic acid-glycolic acid copolymer to 5ml of dichloromethane, add 0.3g of lauric acid and 0.2g of myristic acid, and stir until homogeneous; S12: To prepare an aqueous solution, add 2g of polyvinyl alcohol to 100ml of deionized water and stir until completely dissolved. S13: Load the oil phase solution and the aqueous phase solution into two injection pumps respectively, connect the microfluidic chip to the injection pumps, control the flow rate of the oil phase at 5 μl / min and the flow rate of the aqueous phase at 50 μl / min, start the injection pumps, and the reaction yields a microsphere emulsion. S14: Stir the collected microsphere emulsion on a magnetic stirrer for 2-4 hours to allow the organic solvent to evaporate. Finally, wash the microspheres 3-5 times with deionized water and dry them in a vacuum drying oven at 40°C for 12-24 hours.

6. The precision temperature-controlled dressing and its preparation method according to claim 5, characterized in that, The method for preparing the phase change temperature regulating layer is as follows: S15: Add 10g of carrageenan to 100ml of distilled water to form a gel solution, and heat to 80-90℃ to promote the complete dissolution of carrageenan; S16: Add the phase change microspheres to the above gel solution and stir for 15-30 min to complete the dispersion of the phase change microspheres; S17: Pour the above solution into the mold, cool the mold at room temperature, and dry it at 40-50℃ for 4-6 hours.

7. The precision temperature-controlled dressing and its preparation method according to claim 3, characterized in that, At least one temperature monitoring area is fixed below the phase change temperature regulating layer. There is at least one temperature sensor in the temperature monitoring area. The temperature sensor is wrapped with an insulating skin and is connected to a signal converter through a wire. The signal output by the signal converter is transmitted to the memory, display, cooling electronic valve, cooling circulation pump, heating electronic valve, and heating circulation pump, respectively.

8. The precision temperature-controlled dressing and its preparation method according to claim 7, characterized in that, One of the precise temperature control modes of the aforementioned precise temperature control dressing is as follows: when the temperature detected by the temperature sensor is higher than the highest threshold or lower than the lowest threshold, the cooling circulation pump and heating circulation pump connected to the threshold will be automatically started to circulate the coolant and heating liquid stored in the cooling channel and heating channel to achieve precise temperature control.

9. The precision temperature-controlled dressing and its preparation method according to claim 7, characterized in that, The second precise temperature control mode of the aforementioned temperature-controlled dressing is as follows: When the temperature detected by the temperature sensor is higher than the maximum threshold, the cooling electronic valve and the cooling circulation pump will be activated sequentially. At this time, the cooling circulation pump will pump coolant into the cooling channel to quickly bring the temperature back down to below 38°C. When the detected temperature is below 36°C, the system will control the cooling electronic valve and the cooling circulation pump to shut down. When the temperature detected by the temperature sensor is lower than the minimum threshold, the heating electronic valve and the heating circulation pump will be activated sequentially. At this time, the heating circulation pump will pump heating liquid into the heating channel to quickly bring the temperature back up to above 33°C. When the detected temperature is above 35°C, the system will control the cooling electronic valve and the cooling circulation pump to shut down.

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