Foot sole detection insole for diabetic patient and preparation method of foot sole detection insole

Abstract

The invention relates to the technical field of medical instruments and intelligent wearable equipment, in particular to a foot sole detection insole for a diabetic patient, which comprises a contact layer, a sensing layer, a buffer layer and a bottom layer which are sequentially stacked, the pressure sensing yarn adopts a core sheath structure formed by interweaving and winding conductive fibers and elastic fibers, and pressure detection is realized through resistance change caused by plantar pressure. The insole is further integrated with a data collecting and processing module and a wireless transmission module, and pressure data can be sent to external equipment for analysis and early warning. The invention further discloses a corresponding preparation method. The preparation method comprises the steps of yarn spinning, fabric weaving, lamination compounding, module integration and the like. The insole has the advantages of being low in cost, good in durability, high in textile compatibility, comfortable to wear and the like, and is suitable for daily monitoring and health management of plantar pressure of diabetic patients.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices and smart wearable devices, in particular to a plantar detection insole for diabetic patients and a preparation method thereof. BACKGROUND

[0002] Diabetes is a common chronic metabolic disease, and its complications seriously threaten the quality of life of patients, among which foot complications are particularly prominent. Due to the influence of long-term high blood sugar, diabetic patients are prone to peripheral neuropathy and vascular disease, leading to reduced foot sensation, poor blood circulation, and insensitivity to abnormal foot pressure and damage, which can cause foot ulcers, infections, and even amputation and other serious consequences.

[0003] Abnormal distribution of foot pressure is an important inducement for the occurrence and development of diabetic foot complications. Under normal circumstances, the foot pressure of the human body is evenly distributed, which can effectively disperse the force generated during walking and standing. However, due to abnormal gait caused by neuropathy or foot deformity, diabetic patients often have high local foot pressure. Studies have shown that when the local foot pressure exceeds a certain threshold, the local tissue is in a state of ischemia and hypoxia for a long time, which can easily cause skin damage and further develop into ulcers.

[0004] Currently, the technologies for foot pressure detection mainly include capacitive, piezoelectric, optical, and resistive types. Capacitive sensors have high sensitivity, but are easily affected by environmental humidity, have complex structures and high costs; piezoelectric sensors have good dynamic response, but have low static pressure measurement accuracy and are brittle; optical sensors have high accuracy, but have complex structures, are easily contaminated, and are expensive, which is not conducive to daily wear. In resistive sensing technology, traditional coating or thin film sensors have poor durability, while resistive sensing technology based on conductive fibers has potential advantages in comfort, textile compatibility, and cost control, but its structural stability, anti-interference, and mass production consistency are still technical difficulties.

[0005] Therefore, it is of great significance for the health management of diabetic patients to develop an intelligent insole that is low in cost, durable, comfortable to wear, suitable for daily long-term use, and can accurately monitor the distribution of foot pressure. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides a plantar detection insole for diabetic patients and a preparation method thereof. The insole uses interlaced and twisted resistive pressure sensing yarn technology, has the advantages of low cost, strong durability, good textile compatibility, and comfortable wear, and can realize real-time and accurate monitoring and early warning of foot pressure.

[0007] To achieve the above purpose, the present application realizes the following technical solutions: In a first aspect, the present application provides a plantar detection insole for diabetic patients, comprising: a sensing layer formed by weaving of a pressure sensing yarn, the pressure sensing yarn adopting an interwoven and wound resistive pressure sensing structure formed by interwoven and wound of conductive fibers and elastic fibers; when pressure is applied to the plantar, the contact state between the conductive fibers changes, resulting in a change in the overall resistance value of the yarn; a data acquisition and processing module electrically connected with the sensing layer, for acquiring the resistance change signal of the pressure sensing yarn and converting the signal into digital pressure data; a data transmission module connected with the data acquisition and processing module, for sending the digital pressure data to an external device; The insole further comprises a contact layer, the sensing layer, a buffer layer and a bottom layer arranged in sequence.

[0008] Preferably, the conductive fibers are silver-plated polyester filaments; the elastic fibers are spandex filaments; the pressure sensing yarn further comprises cotton fibers wrapped outside the conductive fibers, forming a core-sheath composite structure with spandex as the core, silver-plated polyester filaments as the conductive sheath, and cotton fibers wrapped outside.

[0009] Preferably, in the sensing yarn of the heel area of the insole, the winding density of the silver-plated polyester filaments is higher than that of the arch area and the forefoot area, so as to adapt to the pressure distribution characteristics of different areas.

[0010] Preferably, the contact layer is a medical polyurethane film for isolating sweat; the buffer layer is an EVA foaming material for dispersing local pressure; and the bottom layer is a Coolmax breathable mesh for moisture removal and ventilation.

[0011] Preferably, the sensing layer is a partition array formed by weaving of the pressure sensing yarn, wherein the heel and metatarsal areas constitute a high-pressure area, and the sensing point array density is higher than that of the arch and forefoot low-pressure areas.

[0012] Preferably, the insole further comprises an encapsulation layer for encapsulating the sensing layer and internal circuit, and the encapsulation material is a polytetrafluoroethylene film with good temperature resistance and moisture permeability.

[0013] Preferably, the data acquisition and processing module comprises a MEMS sensor and a microcontroller, and the data transmission module is a Bluetooth module.

[0014] In a second aspect, the present application provides a preparation method of the above-mentioned plantar detection insole, comprising the following steps: S1. preparing a pressure sensing yarn: spirally winding silver-plated polyester filaments on a core yarn of spandex filaments to form a core-sheath structure, and then wrapping cotton fibers outside the core-sheath structure and twisting to form a composite yarn; S2. Weaving sensing fabric: using weaving equipment, the composite yarn is woven into a fabric with a partition dot matrix structure as a sensing layer of the insole; S3. Laminating composite: laminating the contact layer, the sensing layer, the buffer layer and the bottom layer in sequence, and molding by hot pressing or bonding process; S4. Integrated electronic module: electrically connecting the data acquisition and processing module, the data transmission module and the sensing layer, and packaging and fixing.

[0015] Preferably, in step S1, ring spinning or doubling machine is used for spinning, and the winding density of silver-plated polyester filament is controlled to be 8-15 turns / cm, and the twisting twist is controlled to be 15-20 twists / inch.

[0016] Preferably, in step S2, a rapier loom is used for weaving, and the weft density is controlled to be 30-40 needles / inch, and the tension of spandex yarn and conductive fiber is controlled.

[0017] Working principle: When the foot bottom exerts pressure on the insole, the pressure sensing yarn in the sensing layer deforms, the contact area and contact resistance between the conductive fibers (silver-plated polyester filaments) change, resulting in a change in the overall resistance value of the yarn. The resistance change signal is collected by the MEMS sensor and converted into an electrical signal, which is digitized after being processed by the microcontroller, and then transmitted wirelessly to external devices such as mobile phones and computers through the Bluetooth module. The application program on the device side can visually display the pressure data and issue a warning according to the preset abnormal pressure threshold, reminding the user or doctor to intervene in time.

[0018] The application provides a foot bottom detection insole for diabetic patients and a preparation method thereof. The insole has the following beneficial effects: The insole is made of silver-plated polyester filaments, spandex, cotton and other conventional textile materials, and combined with mature textile processes. The cost of single and double insole materials and processes can be controlled at a low level, and the insole is suitable for large-scale promotion.

[0019] The sensing yarn with the core-sheath structure is combined closely, and can withstand more than 100,000 times of stepping cycles, has low resistance drift rate and excellent sweat resistance, and meets the long-term daily use requirements.

[0020] The insole is soft, breathable and has low bending stiffness, and meets the ergonomic and wearing comfort requirements.

[0021] The sensing mechanism based on resistance change is mature and reliable, and the partition array design and signal processing algorithm can realize real-time and accurate monitoring of foot bottom pressure distribution and abnormal warning. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1A structure diagram of the insole for detecting the present application; Figure 2 A yarn structure diagram of the sensing layer of the present application.

[0023] Wherein, 1, conductive fiber; 2, elastic fiber; 3, cotton fiber cladding layer; 4, contact layer; 5, sensing layer; 6, buffer layer; 7, bottom layer. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. EMBODIMENT

[0025] As shown in the drawings, Figures 1-2 The present application provides a plantar detection insole for diabetic patients, which comprises, from bottom to top, a contact layer 4, a sensing layer 5, a buffer layer 6 and a bottom layer 7.

[0026] The contact layer 4 is a medical polyurethane film with a thickness of 0.8 mm and a friction coefficient of about 0.7, which can effectively isolate sweat and transmit pressure to the sensing layer.

[0027] The sensing layer 5 is knitted by pressure sensing yarns. As shown in the drawings, Figure 2 The pressure sensing yarn adopts a core-sheath structure: 40D spandex yarn is used as the core yarn (elastic fiber 2), and 70D silver-plated polyester yarn (conductive fiber 1) is spirally wound on the spandex core yarn at a density of 8-15 turns per centimeter to form a conductive sheath layer; then 30 combed cotton fibers are evenly wrapped outside the conductive sheath layer to form a cotton fiber cladding layer 3, and are twisted to form a composite yarn with a diameter of 0.3-0.5 mm. The silver-plated layer of the silver-plated polyester yarn has a thickness of 5-10 μm, and the conductivity is 5×10 4 S / m, and the silver release amount meets the EN1811 standard.

[0028] The sensing layer 5 is knitted into a fabric by a rapier loom, and the knitting organization is 1+1 rib weft-knitted plain weave, with a weft density controlled at 30-40 needles per inch. In the high-pressure areas such as the heel and metatarsal, a 12×12 dot matrix layout is adopted with a dot spacing of 2 mm; in the low-pressure areas such as the arch, an 8×8 dot matrix layout is adopted with a dot spacing of 3 mm.

[0029] The buffer layer 6 is an EVA foaming material with a thickness of 3 mm, and its attenuation rate under a pressure of 700 kPa is about 85%, which can effectively disperse local impact pressure.

[0030] The bottom layer 7 is a Coolmax breathable mesh fabric with a permeability of about 200 mm / s, which is conducive to sweat discharge.

[0031] The insole further integrates a data acquisition and processing module (including a MEMS sensor and an Arduino microcontroller) and a Bluetooth data transmission module. The module is connected to the sensing layer through a flexible circuit and is integrally packaged with a polytetrafluoroethylene film, with a packaging thickness of 0.05-0.1 mm. Embodiment

[0032] The present application provides a preparation method of a plantar detection insole for diabetic patients, comprising the following steps: S1 preparation of pressure sensing yarn: 40D high-elasticity spandex yarn is selected as the core yarn, 70D silver-plated polyester yarn is selected as the conductive sheath material, and 30 combed cottons are selected as the outer covering material. On a ring spinning machine, the spandex yarn is stably fed through a tension controller at a tension of 8-10 cN; the silver-plated polyester yarn is spirally wound on the spandex core yarn at a set density (12-15 turns / cm in the heel area, 8 turns / cm in the arch area, and 10 turns / cm in the forefoot area); then the cotton fibers are evenly covered according to the blending ratio (20%-30% spandex and 70%-80% cotton) and are twisted to form a composite sensing yarn, with the twist degree controlled at 15-20 twists per inch. The yarn diameter is controlled at 0.3-0.5 mm, and the resistance deviation of the same batch is less than 8%.

[0033] S2 weaving of sensing fabric: The composite yarn is placed on a rapier loom for weaving, with 1+1 rib weave and a weft density of 30-40 needles per inch, the spandex yarn tension of 5-8 cN, the conductive fiber tension of 3-5 cN, and the loom speed of 200-300 revolutions per minute. After weaving, post-processing is performed: ultrasonic cleaning with deionized water for 30 minutes, followed by heat setting at 130°C for 10 minutes to control the shrinkage rate to be less than 3%; then 0.1% nano-silver solution is immersed and dried, so that the antibacterial rate of the fabric against Staphylococcus aureus is greater than 99%.

[0034] S3 insole compounding and forming: The polyurethane film (contact layer), sensing fabric (sensing layer), EVA foam pad (cushion layer), and Coolmax mesh fabric (bottom layer) are stacked in sequence, with a total thickness of about 4.8 mm, and are sent to a hot press for compounding and forming under suitable temperature and pressure.

[0035] S4 integration and packaging of electronic module: The MEMS sensor, microcontroller, and Bluetooth module are welded on a flexible circuit board, and the conductive end points of the sensing fabric are connected through silver paste or conductive glue. After testing that the circuit functions normally, the whole is packaged with a polytetrafluoroethylene film to ensure the sealing property and moisture permeability.

[0036] S5 Function test: The finished insole is subjected to pressure-resistance linearity test, cycle durability test, sweat soaking test and wearing comfort evaluation to ensure that its performance meets the design index.

[0037] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A foot testing insole for diabetic patients, characterized in that, include: The sensing layer (5) is woven from pressure sensing yarn. The pressure sensing yarn adopts an interwoven and wound resistive pressure sensing structure, which is made of conductive fibers (1) and elastic fibers (2). When pressure is applied to the sole of the foot, the contact state between the conductive fibers (1) changes, causing the overall resistance value of the yarn to change. The data acquisition and processing module is electrically connected to the sensing layer and is used to acquire the resistance change signal of the pressure sensing yarn and convert the signal into digital pressure data. A data transmission module, connected to the data acquisition and processing module, is used to send the digital pressure data to an external device; The insole also includes a contact layer (4), a cushioning layer (6), and a bottom layer (7) stacked in sequence.

2. The insole for foot testing in diabetic patients according to claim 1, characterized in that, The conductive fiber (1) is silver-plated polyester filament; the elastic fiber (2) is spandex filament; the pressure sensing yarn also includes cotton fibers covering the outer layer of the conductive fiber (1), forming a core-sheath composite structure with spandex as the core, silver-plated polyester filament as the conductive sheath, and cotton fibers covering the outer layer.

3. The insole for foot testing in diabetic patients according to claim 1, characterized in that, In the pressure-sensing yarn of the insole in the heel area, the winding density of silver-plated polyester yarn is higher than that in the arch area and the forefoot area.

4. The insole for foot testing in diabetic patients according to claim 1, characterized in that, The contact layer (4) is a medical polyurethane film, the buffer layer (6) is an EVA foam material, and the bottom layer (7) is a breathable mesh fabric.

5. The insole for foot testing in diabetic patients according to claim 1, characterized in that, The sensing layer (5) is a partitioned array woven from the pressure sensing yarn, wherein the heel and metatarsal regions constitute a high-pressure zone, and the density of the sensing dot matrix is ​​higher than that of the low-pressure zone of the arch and forefoot.

6. The insole for foot testing in diabetic patients according to claim 1, characterized in that, The insole also includes an encapsulation layer for encapsulating the sensing layer and internal circuitry, and the encapsulation material is a polytetrafluoroethylene film.

7. The insole for foot testing in diabetic patients according to claim 1, characterized in that, The data acquisition and processing module includes a MEMS sensor and a microcontroller, and the data transmission module is a Bluetooth module.

8. A method for preparing a foot testing insole for diabetic patients according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Preparation of pressure sensing yarn: Using spandex yarn as core yarn, silver-plated polyester yarn is spirally wound on the core yarn to form a core sheath structure. Then, cotton fibers are wrapped around the outer layer of the core sheath structure and twisted to form a composite yarn. S2. Weaving the sensing fabric: Using a weaving device, the composite yarn is woven into a fabric with a partitioned dot matrix structure as the sensing layer of the insole; S3. Lamination and composite: The contact layer (4), sensing layer (5), buffer layer (6) and bottom layer (7) are laminated in sequence and composited by hot pressing or adhesive process; S4. Integrated electronic module: The data acquisition and processing module and the data transmission module are electrically connected to the sensing layer (5) and then encapsulated and fixed.

9. The method for preparing a foot testing insole for diabetic patients according to claim 8, characterized in that, In step S1, ring spinning or doubling spinning is used to control the winding density of the silver-plated polyester yarn to be 8-15 turns / cm and the twist to be 15-20 twists / inch.

10. A method for preparing a foot testing insole for diabetic patients according to claim 8, characterized in that, In step S2, a rapier loom is used for weaving, with the weft density controlled at 30-40 needles / inch, and the tension between the spandex yarn and the conductive fiber is controlled.

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