CZ31541U1 - Smart footwear with a comprehensive system of monitoring data of its user - Google Patents

Description

Smart footwear with a comprehensive system of user data monitoring

Technical field

The technical solution concerns smart footwear with a comprehensive system of monitoring its user data. The complex solution of smart shoes is aimed at wide application in areas ranging from sports and training, or leisure activities such as children, or in the field of medicine and rehabilitation, up to special applications such as the area of protection of non-military and military population. Based on static and dynamic analysis it can determine the type, directionality, frequency and intensity of the pedal. This makes it possible, for example, to determine what type of foot pedal a particular user has (pronounced, supine or neutral) and then to choose the appropriate shoes. It is also possible to monitor the technical performance of certain specific movements and their reactions - for example, the kick-ball technique, where the forces produced by the interaction of the ball, the shoe and the foot of a footballer can be accurately evaluated. This can be very effective eg in teaching and checking technology in children and juniors. In the health sector, a smart shoe will be used to determine the step for rehabilitation or, for example, to analyze the prognosis of disease in multiple sclerosis patients.

BACKGROUND OF THE INVENTION

At present, the concept of intelligent footwear is beginning to develop, not only in professional and patent literature, but also in specific applications on the market. These are, for example, footwear for user walking monitoring with insert insoles equipped with pressure sensors, possibly also in combination with some other types of sensors, such as a gyroscope or accelerometer - see for example the solution according to Chinese patent application CN 104422947 or Chinese utility model CN 205126247. From the point of view of monitored parameters, however, this is a partial solution, not sufficiently comprehensive - for example, missing data on the temperature field in footwear, the connection with the route on which walking takes place, etc. their limited use in practice.

Also, the solution of the sensors themselves is not yet optimal in the known solutions and consists rather in the use of known physical principles of sensing the relevant quantities without sufficient respect for the specificities of integration of known sensors, respectively. their collecting electrodes into the interior of the shoe. One notable example of this problem is, for example, insufficient optimization of the sensors to sense the pressure inside the shoe.

Current sensors designed to measure pressure deformation use three basic measurement methods, which include mechanical measurement method, electrical measurement method and optical measurement method.

A) Mechanical sensors operate on a mechanical basis and gain is achieved by such elements as lever, thread, wedge, various gears and combinations thereof. Therefore, these sensors are not suitable for measuring steep deformation gradients and for dynamic measurements. Factors such as friction, loss stroke, weight, and inertia of the elements used also influence the accuracy of the measurement. These are the oldest methods used to design strain gauges. Also, these sensors are not able to measure over a wide range of deformation and their integration into footwear as surface sensors seems to be very problematic.

B) Pressure sensors working on electric basis are divided into piezoresistive and piezoelectric sensors, surface acoustic wave sensors, inductive, magnetic and capacitive sensors,

Piezoresistive sensors - resistance sensors. Changes in electrical resistance are due to geometric deformations or changes in crystallographic orientation. Deformation is most often caused by pressure or pull within the limits of Hook's law. The basic function of semiconductor strain gauges, like metal strain gauges, is to transform their dimensions in a determinable direction into a resistance change. For resistance strain gauges an important quantity known as deformation sensitivity K (GF - gauge factor) is known. These piezoresistive sensors - for example, metal foil strain gauges - are made of metal alloys with a coefficient near 2 and selected further with respect to the minimum temperature coefficient of resistance. The second method of production is sputtered metal strain gauges. These are produced by sputtering under vacuum, where a dielectric layer is first formed on

The support plate (eg silicon) and then the active layer. The same materials are used as for foil strain gauges (Cermet, Nichrom and others).

Piezoelectric sensors are mostly used for monitoring dynamic inputs. The sensors are anchored to the sample and the output voltage is generated when the sample is stressed. The piezoelectric effect is based on the elastic deformation and orientation of the electrical dipoles in the crystal structure. The basis is an unsymmetrical crystal structure in which the centers of electric charge do not coincide and thus form dipoles. Applying external mechanical force distorts the dipoles and creates a charge on the crystal surface (direct piezoelectric effect). On the other hand, the application of an electric field causes the dipole to deform, and the constant intensity of the mechanical stress (inverse piezoelectric effect) excels. The following materials are most commonly used in the manufacture of piezoelectric sensors: quartz, polyvinyl fluoride (PVFD) based polymers, sintered PZT ceramics (lead - zirconium - titanium), PLZT ceramics (lanthanum added) and give 2 to 8 times more stress than PZT ceramics. One of the essential characteristics of piezoelectric sensors is that they behave electrically as capacitors, mechanically as a rigid spring. Another feature of piezoelectric sensors is that the system has two natural resonant frequencies, one given by the frequency of the spring's own oscillations and the other by the electrical capacity of the converter. Examples of applications of piezoelectric sensors of deformation meters, forces, displacements or accelerometers whose inertia acts on the piezoelectric element. The disadvantage of these sensors is that they cannot be used to measure static forces. Finally, single crystal semiconductor strain gauges. The strain sensitivity coefficient depends on the type of conductivity. It has positive values for P type of semiconductor, negative values for N type of conductivity. Again, these sensors are not suitable for detecting stress or deformation in shoes, as they are fragile and functional only for small deformations.

Electrical deformation sensors also include surface acoustic wave sensors often referred to as SAW. The basic principle is the dependence of the mechanical resonance frequency of the elastic element on the deformation induced by external action. Sensors with surface acoustic waves make use of changes in the parameters of the waves propagating from the ridge structure of the transmitter to the receiver. Piezoelectric materials for substrates of SAW sensors are most commonly used as SiO ₂ quartz, GaAs, ZnO films, PZT ceramics, GaPO ₄ (Gallium Phosphate), it leads SAW waves even at temperatures exceeding 600 ° C. Inductive, magnetic and capacitive sensors are usually very large, heavy and are used only in very specialized applications, especially in engineering.

C) Optical deformation sensors. Another group is optical deformation sensors, which are divided into fiber waveguide sensors, photoelastic sensors and sensors using lattice and moiré methods. The mechanical deformation of the optical fiber results in a change in the light beam propagation conditions as the core-sheath geometry and also the refractive index change due to the effect of mechanical stress. It also depends on whether the deformation acts perpendicularly or along the fiber axis. Optical fiber sensors are suitable for applications at higher temperatures (up to 400 ° C) and also in situations where the sensor must not contain metal parts.

Lattice techniques: these sensors have reference marks on them, the distance of which is measured at rest and then under stress. The deformation is then calculated from the ratio of the change in length to the original length between the marks. The reference marks are arranged in a continuous grid pattern (rectangular, polar). Between individual points we can observe the gradient of mechanical stress. The grid is produced by: drawing or engraving, photographic printing, bonding the pre-prepared grid to the surface of the measured object, and / or etching.

Moiré method: two samples with grids are required to measure the deformation, one test and one reference. The "Moiré" scattering effect is a pattern of alternating dark and light streaks that arises when comparing the deformed and reference grids when they are stacked and one is either rotating or shifting.

Photoelastic Sensors: Some materials produce birefringence under mechanical stress. The speed of light then changes depending on the direction of propagation. The application of this phenomenon consists in illuminating the transparent model with polarized light. Materials used: various types of glasses, celluloid, gelatin, rubber, cellulose nitrates, vinyls, phenolic formaldehydes, polyester, epoxy, ethyl carbamate.

-2EN 31541 Ul

It is clear from the above-mentioned principles of optical sensors that they are not very useful in practice to monitor the pressure field inside the shoe.

The essence of the technical solution

Smart footwear with a comprehensive system of user data monitoring according to the present technical solution contributes to eliminating the above mentioned shortcomings of existing solutions of the overall concept of intelligent footwear and specific sensor solution for pressure sensing. The principle of the solution consists in that the complex monitoring system comprises a microprocessor-based control module to which pressure sensors and temperature sensors stored in the insole and / or the shoe upper are attached, as well as a gyroscope, accelerometer and GPS module stored in the bottom of the shoe. then in the heel cavity. Other system modules connected to the microprocessor control module are also stored here: communication modules, such as the LTE and WiFi module and the power supply., The collecting electrodes from the sensors consist of an electrically conductive thread embroidery in the insole and / or shoe upper.

The control module includes a memory part for temporarily storing the data and information obtained, a communication and transmission part for ensuring the connection of the smart footwear to the smart mobile phone or smart watch using wireless technology. It is also possible to connect the smart shoe to a computer to transfer information and charge the battery.

Part of the comprehensive solution is a mobile application that ensures communication via a mobile phone with smart shoes. The control unit also ensures the initial evaluation of all the information thus obtained by means of a set of algorithms and the first comprehensible visualization display to the user. The application allows you to pass this information on to the server part, such as the cloud, and then to the web part.

From the web and presentation part, which is able to further analyze and visualize the complex analysis of walking, running, football kicking or pedaling using a 3D model of human anatomy so that it is clear to professional consultants or the user himself and obvious how to make the movement activities more effective, how to improve the technical performance used by the muscles, and how to avoid movements that cause painful musculoskeletal syndromes such as enthesopathy and the like.

The individual pressure sensors mounted on the insole and / or the upper of the shoe are made up of compact units for two-point resistance measurement by inserting a pressure stimulus. Each of these units having a thickness of 0.3 to 0.8 mm is formed by a pair of opposing collecting electrodes and a nanocomposite layer interposed therebetween. The nanocomposite layer contains in the elastic polyurethane matrix a fixed structure of randomly entangled carbon nanotubes, which is the product of vacuum filtration of an aqueous dispersion of carbon nanotubes through a filter membrane made of polyurethane nanofibres.

To increase the detection capability, the carbon nanotubes of the nanocomposite layer can advantageously be on their surface Ag clusters which are products of chemical functionalization.

In order to optimize the sensitivity to the embedded pressure stimulus, the nanocomposite pressure sensor layer may further comprise elastomeric spherical nanospaces that are the products of a microemulsion polymerization technique.

The collecting electrodes of the pressure sensors consist of a carbon fiber fabric.

The pressure sensors of the present invention utilize a network of randomly entangled carbon nanotubes (CNTs) integrated with a polymer nanocomposite. It then changes its electrical conductivity during deformation and this principle allows to detect and quantify the inserted pressure stimulus. Nanocomposite material is sensitive, reversible and deformable in many cycles and is able to measure even in areas of higher deformation ranges. On the opposite sides, the sensor is then provided with collecting electrodes based on carbon fiber cloth saturated with polyurethane. This design provides a surface sensor very compact and durable. It is designed and designed, both in terms of the arrangement of the individual members and the particular material composition, precisely for the pressure range and character of the foot when integrated into human footwear.

The main advantage of the smart shoe according to the present technical solution is that thanks to the overall analysis of data related to the movement of the human body it can technically - better than the current solution - evaluate the correctness of physical activity. The pressure sensors used consist of composite collecting electrodes with a composite highly elastic functional piezoresistive core. The core is made of an elastomeric matrix containing carbon nanotubes, further doped with silver clusters, and the intrinsic sensitivity to the inserted pressure stimulus is further increased by the addition of elastomeric spherical nanospaces (spacers). The sensor is sensitive and reversible, and resistant to load in many cycles. The big advantage of this solution is that besides the pressure sensors, the footwear itself is equipped with a complex solution of connected segments, which are interconnected and transmit information to the control circuit (microprocessor) and subsequently wireless software application, which is installed in the mobile phone.

Clarification of drawings

Fig. 1 - overall arrangement of sensors and modules in an example smart shoe solution, fig. 2 - detail of pressure sensor solution, fig. 3 - scheme of evaluation of the kick by instep, fig. 4 - Example of walking curve, Fig. 5 - visualization of the results of the tread recording.

Examples of technical solutions

Example 1

The comprehensive smart footwear user monitoring system in the exemplary embodiment (see footwear schematic diagram in Fig. 1) comprises a microprocessor control module 4 to which the pin sensors 5 and the eploe sensors 6 stored in the insole I are connected. It further includes a gyroscope 7, accelerometer 8, a GPS module 9, a communication module 10, such as an LTE and WiFi module, and a power accumulator T1, embedded in the heel 3a of the bottom portion 3 of the shoe. The collecting electrodes from the sensors 5, 6 consist of an embroidery of an electrically conductive thread in the material of the insole 1 and / or the upper 2 of the shoe.

The comprehensive monitoring system is further complemented by an interface for wiring the smart shoe to an external computer to transmit information and charge the battery 11.

The individual pressure sensors 5 mounted on the insole 1 and / or the upper 2 of the shoe consist of compact units for two-point measurement of the change in resistance by inserting a pressure stimulus (see Fig. 2). Each of these units having a thickness of 0.3 to 0.8 mm is formed by a pair of opposing collecting electrodes 5a and a nanocomposite layer 5b interposed therebetween. The composition of the individual layers of the pressure sensor is shown in Fig. 2a), the overall arrangement of the sensor is shown in diagram 2b) and visualization 2c).

The nanocomposite layer 5b contains in the elastic polyurethane matrix a fixed structure of randomly entangled carbon nanotubes, which is a product of vacuum filtration of an aqueous dispersion of carbon nanotubes through a filter membrane of polyurethane nanofibres.

The collecting electrodes 5a are formed by a carbon fiber fabric.

The control module with microprocessor 4 controls the operation of the individual sensors and modules. It provides communication with individual sensors, which are necessary for obtaining information from the performed activity (walking, running, pedaling, etc.) and wireless transmission of all data and information from these sensors further via communication modules 10 (LTE and WiFi).

Part of the comprehensive solution is a mobile application that ensures communication via a mobile phone with smart shoes. The control unit also ensures the initial evaluation of all the information thus obtained by means of a set of algorithms and the first intelligible visualization display by the user. The application allows you to pass this information on to the server part, such as the cloud, and then to the web part.

From web and presentation part, which is able to further process information about complex analysis of walking, running or pedaling of user's bike (see eg curve representing walking record recorded as relative change of electric resistance over time from one pressure sensor integrated into smart shoe in fig. 4) and visualize using a 3D model of human anatomy (see eg visualization of the results collected in the activity using the smart shoe application installed in the mobile phone in Fig. 5) so that it is clear for example to the consultants or the user physical activities such as using muscles, and how to avoid movements that cause painful syndromes of the musculoskeletal system, such as entesopathy, etc.

Example 2

A complex system of monitoring data of the user of smart shoes is solved similarly as in example 1. The pressure sensors 5 are in this case also located in the upper 2 of the shoe, namely football boots (see Fig. 3) and serves to evaluate the kicking technique of young football players. Example 3

A comprehensive system of monitoring data of the user of smart shoes is solved similarly as in example 1 or 2.

The carbon nanotubes of the nanocomposite layer 5b of the pressure sensors 5, however, contain here Ag clusters, which are products of chemical functionalization, to increase the detection capability on their surface.

The nanocomposite layer 5b further comprises spherical nanofibers, which are the products of the microemulsion polymerization technique, to optimize the sensitivity to the inserted pressure stimulus.

Claims (4)

Clever footwear equipped with a comprehensive system of monitoring user data, in particular up-to-date biomedical data and data characterizing the user's physical activity, characterized in that the complex monitoring system comprises monitoring components stored in the insole (1) and / or upper (2) of the footwear, which are pressure sensors (5) and temperature sensors (6), and components stored in the shoe bottom (3), in particular in the shoe hollow cavity (3a), which are the monitoring components - gyroscope (7), accelerometer (8) and GPS a module (9) together with communication modules (10) such as an LTE and WiFi module and a power supply battery (11), the individual components of the complex monitoring system mentioned above being connected to a microprocessor control module (4) in the bottom part (3) shoes, whereby the connection of sensors (5, 6) is solved by collecting electrodes formed by embroidery of electrically conductive thread in the insole material (1) and / or a shoe upper (2). Smart shoe according to claim 1, characterized in that the pressure sensors (5) mounted in the insole (1) and / or the upper (2) of the shoe consist of compact units for two-point measurement of resistance change by inserting a pressure stimulus, 0.3 to 0.8 mm thick is formed by a pair of opposing electrodes (5a) formed by a carbon fiber fabric and a nanocomposite layer (5b) disposed therebetween, the nanocomposite layer (5b) comprising a fixed polyurethane matrix fixed therein the structure of randomly entangled carbon nanotubes, which is the product of vacuum filtration of an aqueous dispersion of carbon nanotubes through a polyurethane nanofiber filter membrane. Smart shoe according to claim 2, characterized in that the carbon nanotubes of the nanocomposite layer (5b) comprise Ag clusters, which are products of chemical functionalization, on their surface, and / or that the nanocomposite layer (5b) contains Furthermore, to optimize the sensitivity to an inserted pressure stimulus, the elastomeric spherical nanospaces are products of the microemulsion polymerization technique. Smart shoe according to claim 1, characterized in that the complex monitoring system is further supplemented by an interface for wiring the smart shoe to an external computer for transmitting information and for recharging the battery (11).