Patch for phototherapy, preparation method thereof and medical instrument

Abstract

The patch comprises a substrate layer and a light shielding layer, the substrate layer comprises a working surface and a decorative surface, and the light shielding layer is arranged on the side of the decorative surface and contains reflective powder and PDMS. Through detection, the light shielding layer has flexibility, is suitable for a flexible patch, and meets the wearing requirements. When the patch is used in a medical instrument for implementing phototherapy, light can be effectively prevented from leaking from the periphery of the patch after the patch is powered on and emits light, and light pollution to a treatment environment is reduced.

Description

Technical Field

[0001] The present invention relates to a device for physical treatment of diseases, and in particular to a device for emitting light waves for treating organs that are in the process of aging. Background Art

[0002] Safe and non-invasive phototherapy, including photodynamic therapy (PDT) and photobiomodulation (PBM), is gaining increasing attention. Taking chronic wound care as an example, PDT and PBM are becoming effective methods to fight microbial infection and promote wound healing, respectively. Blue light is widely used in photodynamic therapy due to its safe, efficient, and broad-spectrum antimicrobial properties, and can effectively kill a variety of bacteria. In addition, PBM uses red or near-infrared (NIR) light to stimulate the dissociation of NO from complex IV (CIV, cytochrome c oxidase), a key rate-limiting enzyme of the electron transport chain (ETC), resulting in changes in oxidative stress in mitochondria. This process enhances oxidative phosphorylation (OXPHOS) and accelerates the mitochondrial respiratory chain (MRC) of cells under stress, thereby improving mitochondrial function and wound healing. For decades, various phototherapy methods have been used in hospital settings and have shown beneficial effects. However, the equipment currently used to implement phototherapy is not only bulky and relies on professional operators, but also has problems such as high treatment costs, inconvenient treatment processes for users, and inability to adapt to various shapes of wounds during treatment, all of which have burdened phototherapy equipment. These limitations hinder their widespread use in homes.

[0003] Flexible wearable body-shaped electronic devices have been increasingly developed in various fields such as energy harvesting and storage, health sensing and monitoring. These electronic devices are flexible, stretchable and soft, and can be seamlessly and covertly integrated into the human body to perform various required functions. Despite this, the development of flexible LED devices still faces many obstacles. For example, the manufacture of micro-LEDs on flexible substrates limits their flexibility and stretchability. Another example: flexible quantum dot light-emitting diodes (QD-LEDs) have a short service life, and due to the small particle size of QD materials, they are prone to leakage, posing a biosafety hazard. Flexible photoluminescent diodes are potential materials, but high-brightness and high-efficiency photoluminescent diodes usually contain heavy metals and are not suitable for use in the medical field. Therefore, existing flexible LED devices mainly rely on traditional LED chips, but after they are powered on, light leakage appears around the wearable device (such as a skin patch), which will pose a hidden danger to the safe use of the device and cause light pollution. Summary of the invention

[0004] One object of the present invention is to provide a light emitting device that facilitates the implementation of light therapy and improves safety.

[0005] Another object of the present invention is to provide a light-emitting patch having a light-shielding layer to prevent light from leaking from the edge of the patch after being powered on, thereby improving the safety of the device.

[0006] Another object of the present invention is to provide a method for preparing a light-shielding layer for a patch, so as to obtain a patch without light lines, reduce light pollution, and improve the environment of phototherapy.

[0007] Another object of the present invention is to provide a light-emitting patch for use in the preparation of phototherapy medical devices.

[0008] A patch comprises a base layer and a light shielding layer. The base layer comprises a working surface and a decorative surface. The light shielding layer is arranged on the decorative surface side and contains reflective powder and polydimethylsiloxane (PDMS).

[0009] The reflective powder of the present invention contains strontium aluminate europium doped powder Al 14 O 25 Sr4, CAS number: 76125-60-12, for example: 3M high refractive and high brightness reflective powder, the applicable particle size is: 300 mesh ~ 1000 mesh, 1000 mesh is preferred, the dosage is such as: 5% ~ 30%, especially: 10% ~ 25%, specifically, such as: 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24% or 25%.

[0010] Another patch includes a light shielding layer disposed on the base layer of the patch. The light shielding layer contains 20 wt% of reflective powder and 80 wt% of polydimethylsiloxane, and has a thickness such as but not limited to 0.3±0.01 mm.

[0011] The method for preparing the light-shielding layer of the present invention is as follows:

[0012] PDMS prepolymer (e.g. 10 ml) is mixed with curing agent (e.g. 1 ml), and after stirring evenly, reflective powder (e.g. particle size 300-1000 mesh, 5wt%-30wt%) is added to obtain a semi-fluid colloid, and an adjustable scraper coater (e.g. Leiqi KTQ-Ⅱ) is used to scrape the semi-fluid colloid on the decorative surface of the substrate layer to form a thickness of 0.3±0.01 mm, and heat-cured (e.g. LICHEN LC-DB-XAB device, heating at 80°C for 2h) to obtain a light-shielding layer on the substrate layer.

[0013] In order to improve the adhesion between the light-shielding layer and the base layer material and prevent peeling, before the prepared semi-fluid colloid is scraped and coated on the decorative surface, the present invention also uses a plasma surface processor to act on the surface of the decorative surface. The working parameters used are as follows: the gas type is oxygen (O2), argon (Ar) or a mixed gas, the gas flow rate is 10-100sccm, the power is 20-200W, the processing time is 10-120 seconds, the pressure is 10-200mTorr, the temperature is room temperature, and the frequency is usually 13.56MHz.

[0014] After testing, the light-shielding layer has ideal mechanical strength, a tensile strength of approximately 3MPa, and is flexible with an elongation at break of approximately 300%, making it suitable for flexible patches and meeting wearable requirements.

[0015] The patch of the invention is used in medical devices for implementing phototherapy, which can effectively prevent light from leaking from the edge of the patch after it is powered on, thereby reducing light pollution in the treatment environment.

[0016] The patch of the present invention also includes an LED light-emitting layer, a control circuit layer and a packaging layer, all of which are arranged on the working surface side of the base layer. The LED light-emitting layer is arranged between the control circuit layer and the packaging layer to act on the surface of the tissue (such as skin). After photoelectric stimulation, phototherapy is performed on the local tissue. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of an embodiment of a patch for phototherapy according to the present invention;

[0018] Figure 2 is a schematic diagram of another embodiment of a patch for phototherapy according to the present invention;

[0019] Figure 3 It is a bright field photograph after the patch is powered on; wherein A is a package patch without a light-shielding layer, and B is a package patch with a light-shielding layer of the present invention. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is described in detail below. The embodiments of the present invention are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

[0021] The various test methods used in the following examples of the present invention are specifically described as follows:

[0022] 1) Mechanical properties testing

[0023] A tensile testing machine is used to test the tensile properties of the light-shielding layer. The PDMS sample is clamped between the two fixtures of the testing machine and tension is gradually applied until the sample breaks. By measuring the stress-strain relationship of the sample, its tensile strength and elongation at break can be calculated. The test standard adopts ASTM D412 (tensile test standard for rubber materials). The result parameters include tensile strength (stress at break) and elongation at break (ratio of elongation at break to original length).

[0024] 2) Light shielding performance test

[0025] Before and after using the light shielding layer to encapsulate the back of the LED chip, detect the optical power density of the light leaking from the back of the chip and calculate its reduction ratio. The specific steps are as follows:

[0026] Place the patch on the table with the back facing up, light up the red LED chip, and use an optical power meter (PM100D, Thorlabs, USA) to detect the light intensity of the back leakage. Then light up the blue light and repeat the operation to detect the light intensity of the leakage. Perform the same test after encapsulating the light shielding layer on the back, and calculate the percentage of light intensity reduction before and after encapsulation.

[0027] Example 1 Preparation of light-shielding layer

[0028] 10ml of liquid component (SYLGARD 184A, Dow, USA) is mixed with 1ml of curing agent (SYLGARD 184B, Dow, USA). After stirring evenly, add 5%-30% by mass of 3M reflective powder (300 mesh-1000 mesh) to obtain a semi-fluid colloid (i.e., the initial material). Use a plasma surface processor to treat the back of the patch to facilitate the attachment of the reflective coating, and then use an adjustable scraper coater (Lei Qi KTQ-Ⅱ) to scrape the premixed initial material with a working parameter of 0.3mm thickness to obtain a light-shielding coating with a thickness of 0.3±0.01mm. Then, place it on a heating platform (LICHEN LC-DB-XAB), set the temperature to 80℃ and heat and cure for 2h to obtain a patch with a light-shielding layer on the decorative side of the base layer.

[0029] Example 2 Performance Test

[0030] In order to meet the ideal reflective effect, thickness and mechanical strength of the reflective layer (see Table 1 below for details), 20 wt% of 1000 mesh 3M reflective powder was finally selected and mixed with PDMS prepolymer to obtain a reflective layer prepolymer solution.

[0031] Table 1

[0032]

[0033] Example 4 Patch for phototherapy

[0034] The patch with a light-shielding layer prepared in Example 1 is used, and an LED light-emitting layer, a control circuit layer and a packaging layer are arranged on the working surface of the base layer, and the LED light-emitting layer is arranged between the control circuit layer and the packaging layer, to prepare a medical device for implementing phototherapy. Figure 1 FIG. 1 is a schematic diagram of an embodiment of a patch for phototherapy according to the present invention, Figure 1 As shown, the patch 10 includes a base layer 100, which includes a working surface 110 and a decorative surface 120. The light shielding layer 200 is arranged on one side of the decorative surface 120, and the LED light emitting layer 400, the control circuit layer 300 and the packaging layer 500 are all arranged on one side of the working surface 110. The LED light emitting layer 400 is arranged between the control circuit layer 300 and the packaging layer 500, and the control circuit layer 300 receives signals to control the light intensity, time and light cycle of the LED light emitting layer 400.

[0035] Figure 2 is a schematic diagram of another embodiment of the patch for phototherapy of the present invention, combined with Figure 1 ,like Figure 2 As shown, the patch 10 also includes a controller 20, and the control circuit layer 500 is connected to the controller 20 (for example, electrically connected or wirelessly connected), receives the signal sent by the control, and realizes remote (contactless) control of the luminous intensity, time and luminous cycle of the LED light-emitting layer 400.

[0036] In this embodiment, a thermoplastic polyurethane (TPU) substrate was used as the initial substrate, and holes were opened to connect the bottom layer and the top layer. The typical dimensions of the TPU substrate were 4 cm × 4 cm and 2 cm × 2 cm, and the thickness of the TPU pattern was set to 20 μm. The packaged rLED chip (wavelength = 630 nm; REFOND, China) and bLED chip (wavelength = 470 nm; REFOND, China) were manually placed on the contact pads together with the temperature sensor (M117Z, Mysentech) separately, and then coated with high-density conductive silver paste (Shanghai Mifang Technology, China) and reflowed at 90 ° C with a melting interval of 3 minutes. PDMS was then applied to the surface-mounted LED using a dip coating process (mixing ratio of prepolymer and curing agent was 10:1; SYLGARD 184, Dow, USA) and cured in an oven at 70 ° C overnight. Finally, PDMS mixed with reflective coating was applied to the back of the substrate to prevent light from leaking from the back.

[0037] The optical power density of the r&bLED patch was measured with an optical power meter (PM100D, Thorlabs, USA), and the mechanical durability of the r&bLED patch was repeatedly tested by load pressure in a folded state (Mifang Technology Co., Ltd., Shanghai, China). The heat generation of the r&bLED patch was measured with an infrared thermal imager (E54, FLIR, Shanghai, China).

[0038] The control module consists of a rigid FR4 printed circuit board (PCB), surface mount electronic components, a battery, and a package. The double-layer custom PCB was designed using JLCEDA (Professional Edition) and manufactured by an ISO 9001:2015 certified supplier (JLCPCB.com). The device uses a 0.4 mm thick FR4 PCB with solder mask and electroless nickel immersion gold (ENIG) treatment on the exposed pads. The electronic components including the ESPSoC and peripherals are attached to the PCB using lead-free solder paste (AZ50 solder paste, Anrecson). The ESPSoC is programmed using a custom embedded firmware developed in Arduino IDE 2.3.2.

[0039] The device housing was made using a DLP light-curing 3D printer (Anycubic Photon D2) and designed using SolidWorks 2019 (Education Edition). The .stl file was sliced ​​using Anycubic Slicer, then 3D printed and post-processed using various photosensitive resins (Wash and Cure 2.0, Anycubic).

[0040] The printed circuit board and lithium battery were assembled in the device housing and then encapsulated using PDMS (prepolymer and curing agent mixed in a ratio of 10:1; SYLGARD 184, Dow, USA). Subsequently, the assembly was cured in an oven at 70 °C to form a soft and smooth protective layer.

[0041] The patch prepared by the present invention is tied and fixed to the leg. After the patch is energized, Figure 3 As shown in FIG. 1 , the patch without the light shielding layer 200 has a strong light sensation and is highly irritating to the naked eye (FIG. A). As shown in FIG. B, after the patch with the light shielding layer of the present invention is powered on, no obvious light sensation is seen in the field of vision.

Claims

1. A patch, characterized in that The invention comprises a base layer and a light shielding layer. The base layer comprises a working surface and a decorative surface. The light shielding layer is arranged on the decorative surface side and contains reflective powder and PDMS.

2. The patch according to claim 1, characterized in that It also includes an LED light-emitting layer, a control circuit layer and a packaging layer, wherein the LED light-emitting layer is arranged between the control circuit layer and the packaging layer.

3. The patch according to claim 1, characterized in that The reflective powder contains strontium aluminate europium doped powder Al 14 O 25 Sr4.

4. The patch according to claim 1, characterized in that The reflective powder has a particle size of 300 to 1000 meshes.

5. The patch according to claim 1, characterized in that The light-shielding layer contains 20 wt % of reflective powder and 80 wt % of polydimethylsiloxane.

6. A method for preparing the patch according to claim 1, characterized in that The steps include: The PDMS prepolymer and the curing agent are mixed, and after stirring evenly, reflective powder is added to obtain a semi-fluid colloid. The semi-fluid colloid is applied on the decorative surface of the base layer using an adjustable scraper coater to form a thickness of 0.3±0.01mm, and heated and cured to obtain a light-shielding layer on the base layer.

7. The method according to claim 6, characterized in that The curing was heated at 80°C for 2 hours.

8. The method according to claim 6, characterized in that Before the scraping, a plasma surface processor is used to act on the surface of the decorative surface to improve the bonding force between the light shielding layer and the base layer.

9. A medical device, characterized in that Comprising the patch according to claim 1.

10. The medical device according to claim 9, characterized in that It also includes a controller connected to the control circuit of the patch.

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