A thermopressure-sensing flexible phototherapy patch and system for diabetic foot ulcers
By integrating pressure sensing, temperature sensing, and phototherapy output into a flexible phototherapy patch, the problems of excessive thickness, lack of flexibility, and overheating in existing devices have been solved, enabling continuous monitoring and phototherapy suitable for diabetic foot ulcers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTHERN UNIVERSITY OF SCIENCE AND TECHNOLOGY
- Filing Date
- 2026-03-18
- Publication Date
- 2026-06-30
AI Technical Summary
Existing wound management devices are thick, have light-emitting units that occupy the sensing area, have concentrated leads that result in inflexibility, lack temperature and pressure linkage, and pose a risk of local overheating, making them unsuitable for the continuous management of diabetic foot ulcers.
Pressure sensing, temperature sensing, and phototherapy output are integrated into the same flexible patch. The light-emitting layer is arranged through the light-transmitting area, and red light and near-infrared dual-band phototherapy are used. The phototherapy intensity is controlled by pressure and temperature signals, and the flexibility is improved by FPC interface and multi-layer wiring design at the bottom.
This invention achieves a compact structure, unobstructed sensing area, good flexibility, and temperature and pressure linkage control and overheat protection phototherapy patch, which is suitable for continuous monitoring and auxiliary phototherapy of diabetic foot ulcers.
Smart Images
Figure CN122297923A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of flexible electronics, skin-attached phototherapy technology, and physiological signal acquisition technology, specifically to a temperature and pressure sensing flexible phototherapy patch and system for diabetic foot ulcers. Background Technology
[0002] Diabetic foot ulcers are typical chronic, non-healing wounds. These wounds are often accompanied by continuous local pressure, repeated deformation, abnormal temperature, and microcirculatory disturbances. Therefore, it is necessary to simultaneously sense the stress state around the wound and deliver local phototherapy while the medicated dressing is in place.
[0003] Existing wound management devices typically have the following problems: First, the monitoring unit and the light-emitting unit are set separately, and the overall thickness is relatively large, making it difficult to adhere to curved areas such as the sole, edge, and toes of the foot for a long time. Secondly, when the light-emitting layer is directly placed on the surface, it tends to occupy the effective sensing area, which is not conducive to the synchronous acquisition of temperature and pressure information. Third, external leads are often concentrated from the side, causing the edge area to harden and affecting flexible adhesion; Fourth, it lacks an automatic protection mechanism based on local temperature feedback, which poses a risk of local overheating when emitting light continuously; Fifth, there is a lack of clear linkage between pressure monitoring and phototherapy output, making it difficult to adjust the phototherapy intensity according to the local biomechanical state.
[0004] Therefore, there is a need for a more compact flexible phototherapy patch and system with higher integration of light emission and sensing, and with the ability to monitor temperature and pressure and control safety, to adapt to the continuous management of diabetic foot ulcers. Summary of the Invention
[0005] (a) Purpose of the invention The purpose of this invention is to provide a temperature and pressure sensing flexible phototherapy patch and system for diabetic foot ulcers, so as to solve the problems of existing wound patches such as separation of sensing and light emission, concentration of leads, local overheating, and difficulty in adjusting the output according to the local pressure state.
[0006] (II) Technical Solution To achieve the above objectives, the present invention adopts the following technical solution: A temperature and pressure sensing flexible phototherapy patch system for diabetic foot ulcers includes a flexible phototherapy patch, a control module, and a power supply module.
[0007] The flexible phototherapy patch includes an adhesion layer, a pressure sensing layer, a light-emitting layer, a temperature sensing unit, a protective covering layer, and a flexible interface.
[0008] The pressure sensing layer is used to collect pressure signals from the attachment area and has a pressure sensing area and a light-transmitting area. The light-emitting layer is disposed within the light-transmitting area or corresponding to the light-transmitting area, so that the emitted red light and near-infrared light can pass through the protective layer to irradiate the corresponding area of the diabetic foot ulcer.
[0009] The temperature sensing unit is located near the light-emitting layer and is used to monitor the temperature of the light-emitting area.
[0010] The control module is connected to the flexible phototherapy patch, receives pressure and temperature signals, and adjusts the driving parameters of the light-emitting layer according to the pressure signal; when the temperature signal exceeds a preset threshold, the control module reduces the light-emitting power or stops emitting light.
[0011] Preferably, the light-emitting layer includes red light-emitting units and near-infrared light-emitting units.
[0012] Preferably, the center wavelength of the red light emitting unit is about 630 nm, and the center wavelength of the near-infrared light emitting unit is about 850 nm.
[0013] Preferably, the light-emitting layer uses an SMD 2835 surface mount device.
[0014] Preferably, the single-point power density is 10–25 mW / cm².
[0015] Preferably, the control module uses PWM to adjust the light intensity and supports 2 to 4 independent drives.
[0016] Preferably, the flexible interface is an FPC interface.
[0017] Preferably, the patch panel adopts a bottom multi-layer routing structure to reduce redundant leads on the sides.
[0018] (III) Beneficial Effects Compared with the prior art, the present invention has the following beneficial effects: The pressure sensor, temperature sensor, and phototherapy output are integrated into the same flexible patch, resulting in a more compact structure. By setting a light-transmitting area in the pressure sensing layer and arranging a light-emitting layer at the corresponding position, the occupancy of the light-emitting unit in the sensing area is reduced; By arranging the temperature sensing unit near the light-emitting layer, local temperature rise can be sensed in real time and over-temperature protection can be implemented. By adjusting the phototherapy output through pressure signals, the patch can be made to have the ability to regulate in conjunction with the local biomechanical state. The bottom multi-layer wiring and FPC interface design improve the smoothness and comfort of the patch. By combining red light and near-infrared dual-band, the phototherapy needs of both superficial and deeper tissues are taken into account. Suitable for continuous monitoring and adjunctive phototherapy of diabetic foot ulcers. Attached Figure Description
[0019] Figure 1 A schematic diagram of a closed-loop application of a temperature and pressure sensing flexible phototherapy patch.
[0020] Figure 2 This is a schematic diagram of the sensing layer, light-emitting layer, and cross-sectional structure of a flexible phototherapy patch.
[0021] Figure 3 This diagram illustrates the parameters and driving configuration of the light-emitting layer device.
[0022] Figure 4 This is a comparison chart of emission spectra and radiative flux in dual-band, red-light single-band, and near-infrared single-band light.
[0023] Figure 5 A comparison chart of average irradiance and estimated dose under different luminescence modes.
[0024] Figure 6 This is a graph showing the transmission spectrum and transmittance curves of red light after passing through a simulated layer of pigskin tissue.
[0025] Figure 7 This is a thermal imaging sequence of a flexible phototherapy patch in its bare state.
[0026] Figure 8 Thermal imaging sequence of a flexible phototherapy patch covering a simulated layer of pig skin tissue.
[0027] Figure 9 Comparison of changes in the appearance of animal wounds.
[0028] Figure 10 This graph shows the changes in wound healing rate and wound area under different models or phototherapy modes. Detailed Implementation
[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments. However, the present invention is not limited to the following embodiments.
[0030] Example 1: Overall Structure This embodiment provides a temperature and pressure sensing flexible phototherapy patch system for diabetic foot ulcers, including a flexible phototherapy patch, a control module, and a power supply module.
[0031] The flexible phototherapy patch comprises an adhesive layer, a pressure-sensing layer, a light-emitting layer, a temperature-sensing unit, a protective covering layer, and a flexible interface. The patch can be applied to areas related to diabetic foot ulcers, such as the sole, edge, toes, and heel.
[0032] The pressure sensing layer is used to acquire local pressure distribution information. The light-emitting layer is positioned corresponding to the light-transmitting area in the pressure sensing layer, allowing the emitted light to pass through the protective layer and illuminate the affected area. A temperature sensing unit is located adjacent to the light-emitting layer to monitor the local temperature rise during continuous light emission.
[0033] The control module receives pressure and temperature signals and controls the output intensity, duty cycle, and operating time of the light-emitting layer. The power supply module provides power to the control module and the surface mount device.
[0034] Example 2: Pressure sensing layer and light-emitting layer structure In a preferred embodiment, the pressure sensing layer is a multi-layer flexible sensing structure, including a PI / Cu flexible substrate, an insulating layer, and upper and lower electrode patterned layers. The pressure sensing layer forms an array of pressure sensing regions, with light-transmitting areas reserved in the array.
[0035] The light-emitting layer is disposed within the light-transmitting area, or at a position corresponding to the light-transmitting area. This ensures that light is emitted outward while maintaining the effective layout of the pressure-sensing layer.
[0036] Figure 2 The structure shown indicates that the light-emitting layer and the sensing layer can be formed as an integral structure stacked on top of each other or partially embedded, which is suitable for flexible patches that can be bent and attached.
[0037] Example 3: Device Parameters and Drive Configuration according to Figure 3 As shown, in a preferred embodiment: The light-emitting device uses SMD 2835 standard surface-mount LEDs; The emission wavelength uses a combination of 630 nm red light and 850 nm near-infrared dual-band; Each device measures 2.8 mm × 3.5 mm and has a thickness of no more than 0.7 mm. The single-point power density is 10–25 mW / cm², which can be adjusted via PWM. The driving method supports 2 to 4 channel partition control; The power supply voltage is 5V DC; The flexible interface uses FPC, with an interface pitch of 1.0 mm or 1.27 mm; The circuit uses copper foil traces with a thickness of not less than 18 μm and a line width of not less than 150 μm, and supports an operating current of not less than 80 mA.
[0038] In a preferred embodiment, the light-emitting layer is embedded in the light-transmitting area of the sensing layer and extends through the top protective covering layer.
[0039] Example 4: Temperature and Pressure Linkage Control Method The control module uses PWM to adjust the duty cycle, output power, and irradiation duration of the light-emitting layer.
[0040] In a preferred embodiment, the pressure signal is used to reflect the local contact state and pressure level between the patch and the affected area. When a change in local pressure is detected, the control module can adjust the phototherapy output of the corresponding area to improve the output adaptability during the application state.
[0041] The temperature sensing unit is used to monitor the temperature of the light-emitting area in real time. When the temperature exceeds a preset threshold, the control module performs automatic over-temperature protection, including but not limited to reducing the drive current, reducing the PWM duty cycle, shortening the continuous illumination time, or stopping the corresponding channel from emitting light.
[0042] Example 5: Dual-band optical output data according to Figure 4 and Figure 5 As shown in an exemplary test: The total radiative flux in the dual-band mode is 155.572 mW; The total radiative flux of the red single-band mode is 89.733 mW; The total radiative flux of the near-infrared single-band mode is 105.545 mW.
[0043] Furthermore, the estimated average irradiance is: The dual-band mode has a power output of approximately 6.17 mW / cm². The near-infrared single-band mode has a power output of approximately 4.19 mW / cm². The red single-band mode is approximately 3.56 mW / cm².
[0044] The estimated dose increases approximately linearly with irradiation time. Based on... Figure 5 visible: Under 30 min irradiation conditions, the estimated dose in dual-band mode is approximately 11.1 J / cm², in near-infrared single-band mode it is approximately 7.6 J / cm², and in red light single-band mode it is approximately 6.4 J / cm².
[0045] In a preferred embodiment, when the target dose window is 3 to 7 J / cm², the dual-band mode can enter the effective dose range in a shorter irradiation time, which is suitable for continuous adhesive phototherapy.
[0046] Example 6: Basis for setting red and near-infrared parameters according to Figure 3 The preset parameters and experimental design shown are, in a preferred embodiment: 630 nm red light is mainly used for irradiation of superficial tissues, with a schematic penetration depth of about 2 to 3 mm and a recommended power density of 5 to 10 mW / cm². 850 nm near-infrared light is mainly used for irradiation of deeper tissues, with a schematic penetration depth of about 5 to 8 mm and a recommended power density of 10 to 25 mW / cm².
[0047] Based on this, the present invention uses a combination of 630 nm red light and 850 nm near-infrared dual-band to take into account the phototherapy output needs of both superficial and deeper tissues.
[0048] Example 7: Transmission Experiment of Simulated Layer of Pig Skin Tissue according to Figure 6 As shown, in one embodiment, pig skin with thicknesses of 1 mm, 3 mm, and 5 mm was used to simulate human skin tissue, and the transmission spectrum and transmittance under single-band red light irradiation were tested.
[0049] The experimental results show that: As the thickness of the pigskin increases, the intensity of the transmission peak near approximately 650 nm gradually decreases; However, even with 5 mm of pigskin, the red light peak can still be clearly detected; A measurable transmission window still exists in the 600–700 nm band.
[0050] The above results indicate that red light still has detectable transmittance in a tissue simulation layer of a certain thickness, and can provide effective irradiation for the superficial tissues surrounding diabetic foot ulcers.
[0051] Example 8: Thermal Safety Test according to Figure 7 As shown, under test conditions without a simulated layer of pigskin tissue, the thermal imaging sequence showed that the highest temperature during patch operation was approximately 31.5–31.7 °C, and the lowest ambient background temperature was approximately 21.4–22.0 °C.
[0052] according to Figure 8 As shown, after covering the simulated layer of pig skin tissue, the thermal imaging sequence showed that the highest temperature on the upper surface was approximately 36.8–37.2 °C.
[0053] The above results show that, under the test conditions shown, the surface temperature rise of the patch of the present invention under tissue coverage is still within a relatively mild range, which is beneficial for achieving further over-temperature protection and safety control through temperature feedback.
[0054] Example 9: Changes in the appearance of animal wounds according to Figure 9As shown, the appearance of the wounds in the different treatment groups exhibited varying degrees of wound shrinkage, periepithelialization, and localized color changes over time. The wound photographs in the figures can serve as examples of long-term continuous observation of the patch system of this invention in animal wound models.
[0055] In a preferred embodiment, the wound area is statistically analyzed by image boundary delineation to obtain the results of wound area changes at different time points.
[0056] Example 10: Changes in animal healing rate and wound area according to Figure 10 As shown, there are significant differences in the healing process between normal rabbits and diabetic rabbits. The wounds of normal rabbits heal faster overall than those of diabetic rabbits, indicating that the establishment of a diabetic chronic wound model is highly discriminative.
[0057] In multimodal comparisons, the red single-band, near-infrared single-band, and dual-band intervention groups all showed a faster wound healing trend compared to the blank control group. The graphic results indicate: In the normal rabbit model, the overall healing rate under different phototherapy modes was higher than that in the blank control group; In a diabetic rabbit model, near-infrared single-band and dual-band interventions showed a better recovery trend in the middle and late stages. The curve showing the change in wound area corresponds to the trend of the healing rate.
[0058] Therefore, the temperature and pressure sensing flexible phototherapy patch system proposed in this invention has the potential for application in continuous monitoring and adjuvant phototherapy of diabetic foot ulcers.
[0059] VI. Further Description of the Invention This invention focuses on protecting an attachable flexible device and system structure, the core of which is: 1. Integrate the pressure sensing layer, light-emitting layer, and temperature sensing unit into the same flexible patch; 2. The light-emitting layer and the sensing layer are conformally integrated through the light-transmitting area; Third, the light emission control is achieved through the combined use of pressure and temperature signals; IV. Improved flexibility and wearability through FPC interface and multi-layer bottom wiring; Fifth, the dual-band design takes into account both shallow and deeper tissue irradiation.
[0060] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.
Claims
1. A temperature- and pressure-sensing flexible phototherapy patch system for diabetic foot ulcers, characterized in that, Includes flexible phototherapy patch, control module and power supply module; The flexible phototherapy patch includes an adhesive layer, a pressure sensing layer, a light-emitting layer, a temperature sensing unit, a protective covering layer, and a flexible interface. The pressure sensing layer is used to collect pressure signals from the patch attachment area, and is provided with a pressure sensing area and a light-transmitting area. The light-emitting layer is disposed within the light-transmitting area or corresponding to the light-transmitting area, so that the emitted light can pass through the covering protective layer and irradiate the skin area corresponding to the diabetic foot ulcer. The temperature sensing unit is located near the light-emitting layer and is used to collect temperature signals from the light-emitting area. The control module is electrically connected to the flexible phototherapy patch and is used to receive pressure signals and temperature signals. It adjusts the driving parameters of the light-emitting layer according to the pressure signal and reduces the light-emitting power or stops emitting light when the temperature signal exceeds a preset threshold.
2. The temperature and pressure sensing flexible phototherapy patch system for diabetic foot ulcers according to claim 1, characterized in that, The pressure sensing layer is a multi-layer flexible sensing structure, including a flexible substrate, an insulating layer, and upper and lower electrode pattern layers.
3. The temperature and pressure sensing flexible phototherapy patch system for diabetic foot ulcers according to claim 1, characterized in that, The light-emitting layer includes red light-emitting units and near-infrared light-emitting units.
4. The temperature and pressure sensing flexible phototherapy patch system for diabetic foot ulcers according to claim 3, characterized in that, The center wavelength of the red light emitting unit is 620–660 nm, and the center wavelength of the near-infrared light emitting unit is 830–870 nm.
5. The temperature and pressure sensing flexible phototherapy patch system for diabetic foot ulcers according to claim 1, characterized in that, The light-emitting layer uses a surface-mount light-emitting device, preferably an SMD 2835 package.
6. The temperature and pressure sensing flexible phototherapy patch system for diabetic foot ulcers according to claim 5, characterized in that, The patch-type light-emitting device has a size of 2.8 mm × 3.5 mm and a thickness of no more than 0.7 mm.
7. The temperature and pressure sensing flexible phototherapy patch system for diabetic foot ulcers according to claim 1, characterized in that, The control module uses PWM to adjust the light intensity and supports 2 to 4 independent drive channels.
8. The temperature and pressure sensing flexible phototherapy patch system for diabetic foot ulcers according to claim 1, characterized in that, The flexible interface is an FPC interface.
9. The temperature and pressure sensing flexible phototherapy patch system for diabetic foot ulcers according to claim 8, characterized in that, The cable spacing of the FPC interface is 1.0 mm or 1.27 mm.
10. The temperature and pressure sensing flexible phototherapy patch system for diabetic foot ulcers according to claim 1, characterized in that, The flexible phototherapy patch adopts a bottom multi-layer wiring structure to reduce redundant side leads and improve adhesion flexibility; The traces are made of copper foil with a thickness of not less than 18 μm and a width of not less than 150 μm. The single-point power density of the light-emitting layer is 10-25 mW / cm²; pressure sensing layer, light-emitting layer, temperature sensing unit, covering protective layer and flexible interface; The pressure sensing layer is provided with a pressure sensing area and a light-transmitting area; The light-emitting layer is disposed within the light-transmitting area or is disposed corresponding to the light-transmitting area; The temperature sensing unit is located adjacent to the light-emitting layer; The protective covering is a sweat-wicking membrane or a breathable protective membrane with a light-transmitting area; The adhesive layer is one of a medical pressure-sensitive adhesive layer, a silicone gel layer, or a hydrocolloid layer.