RU2584115C2 - Device for determining deformation and pain threshold of compression of side surface of foot - Google Patents

Abstract

FIELD: footwear industry.

SUBSTANCE: device can be used in shoe industry, particularly when determining deformation and pain threshold of compression side surface of foot. Said data are necessary for correct designing of shoe upper stock, selection of material, particularly for local zones of contact shoe top stocks with foot to prevent painful effect in said zones on tissue of side surface of foot. Device for measurement of compression force and deformation of foot in accordance with sensations of test subject involves measuring compression and deformation of tissues of foot, a processor, a monitor, a printer. Measuring unit consists of a step motor, screw-nut transmission and strain gage sensor actuated by remote control device, there is a magnetic plate for fixation and release of measurement unit installed on it by switching on and off power field.

EFFECT: measurement results are accurate measurements of forces of compression and deformation of side surfaces of foot, where person being tested senses allowable and critical level of tactile effects.

4 cl, 1 dwg

Description

Application area

The device is proposed to be used in the shoe industry, in particular when determining the deformation and pain threshold of compression of the lateral surface of the foot. These data are necessary for the correct design of the shoe upper blank, the selection of material, especially for the zones of local contact of the shoe upper with the foot, in order to exclude painful effects in these zones on the fabric of the lateral surface of the foot.

State of the art

A known design of a device for measuring deformation and compression forces of the plantar part of the foot that causes pain (the dissertation "Research and development of a method for calculating the stealth node for the prevention of longitudinal flatfoot", author Kupriyanov Anatoly Petrovich, 1999). Using this device, you can determine the degree of compression of the plantar part of the foot, with efforts corresponding to the threshold sensations of the patient, such as permissible, that is, the absence of unpleasant effects, and causing the onset of pain. Knowing these parameters allows you to more accurately design the top blank and make high-comfort shoes.

The device consists of a support plate with a series of holes on which the test foot is mounted. An indenter is inserted into the hole, at the end of which there is a hemispherical tip in contact with the plantar surface of the foot.

A pin is attached to the hemisphere from below, which passes through the hole of the base plate. A tared spring is attached to the lower end of the pin, resting on a movable platform. A measuring scale is attached to the latter, relative to which an arrow is shifted, indicating the compression force applied by the hemisphere to the plantar surface of the foot.

The full stroke of the device is fixed by an arrow located on a moving platform, moving relative to an independent measuring scale, which is not connected to the measuring device.

Reasons that do not allow deformation measurements to be carried out with the required accuracy and determine the allowable and critical level of compression force of the side surface of the foot:

- the prototype is not adapted to measure the vertical sections of the foot;

- the measurement accuracy is low due to the mechanical principle of the application of force and indenter movement inherent in the device;

- measurement errors are quite significant due to manual application of the measurement force;

- using the device you can only indirectly obtain the required data on the deformation of the plantar part of the foot.

The disadvantages of the device are:

- the implementation of the device in a vertical layout and inability to measure the lateral surface of the foot;

- the need to recalculate the total deformation of the device in the deformation of the surface of the foot;

- the device is in the hands of a person, which, due to the instability of the operator’s movements, will affect the measurement accuracy.

The required technical result:

- for the accuracy of measurement and the elimination of additional factors affecting the state of the measurement object (pillar), the latter should be in a stationary position, for the entire group of its measurements;

- the measuring unit should be able to quickly change position relative to the measured object and instantly be fixed in the selected position;

- for the chosen position of the foot, it is necessary to make the whole complex of actions on the lateral surface of measurements and deformations, compression forces at various levels of patient sensations, while observing the constant mutual position of the foot and the location of the measuring complex, the latter is carried out using a magnetic plate, which, due to the force field, holds the measuring complex in predetermined strictly positioned positions relative to the foot;

- to implement force and deformation of the lateral surface of the foot at various points, use a measuring complex consisting of a stepper motor that provides discreteness of rotation of the shaft connected to a rotational motion-converting screw-nut transmission connected to a strain gauge measuring the compression force;

- to control the movement of the compression force sensor, it is necessary to move it sequentially, which is electronically controlled by the step increment by the operator, which will increase the accuracy of the patient's response to the compression force of an acceptable and critical level applied to the foot.

The essence of the invention lies in the fact that using the proposed device it is possible to create new information support, to obtain more accurate results when determining the deformation and pain threshold of compression of the lateral surface of the foot, which allows you to design health-saving shoes of high comfort.

The structure of the feet of each person is individual, so it is very difficult to reproduce on the surface of the pads the inner form of the shoe, which ensures the comfort of the wearer. The use of this device will allow you to determine the allowable pressure corresponding to the individual shape of the foot, for further design and manufacture of shoes.

The device has the following distinctive features.

1. The measuring unit of the device consists of a stepper motor, a screw-nut transmission and a strain gauge, actuated by a remote control device through a central control unit including a processor, monitor, printer, while the operator controls it by pressing the buttons of the remote control device.

2. There is a magnetic plate, consisting of a number of controlled electromagnets, on which the measuring unit is mounted, for fixing and releasing the measuring unit on the magnetic plate, a central control unit is used, which transmits the corresponding commands to the controlled electromagnets of the magnetic plate received from the remote control device sent by the operator .

3. The central control unit simultaneously receives a signal of the compression force from the strain gauge when pressing the foot tissues and an impulsive signal from the remote control device, in accordance with which the deformation of the foot tissues due to the horizontal displacement of the strain gauge from the screw-nut and stepper motor transmission, the compression force signal and pulse signals are converted into a digital code sent to a computer.

4. Screw-nut transmission nut is made in the form of a square, the lower side of which, when moving, slides along the surface of the platform of the measuring unit, which provides reciprocating movements of the load cell itself and connected to the nut, the nut is made of non-magnetic material, such as bronze, plastic .

5. The coordinated operation of the measuring unit and the central control unit allows to obtain the results of measuring the compression force and deformation of the foot according to the test person’s response for each measured point on the side surface of the foot and to display the measurement data on a monitor and printer.

The content of the invention

A device for measuring the deformation of the foot consists of:

- a measuring unit, including a strain gauge, transmission screw - nut, stepper motor:

- a strain gauge that registers the applied compression force, with which the deformation of the side surface of the foot is performed;

- a stepper motor for moving the strain gauge connected to the screw-nut transmission, which, in turn, is coaxially connected to the stepper motor;

- transmission screw - nut, which converts the rotational movement of the stepper motor into a translational strain gauge;

- pairs of platforms for feet;

- a remote control device, through which a command is transmitted through the central control unit for the movement of the measuring unit (stepper motor - screw - nut - strain gauge);

- a central control unit including a processor, a monitor, a printer connected to a load cell and a stepper motor, measurement results are output to the central control unit.

The operation of the device is as follows. On the pair of platforms for feet fixed on a magnetic plate, the test subject becomes. A pair of foot platforms is static with respect to the magnetic plate. The measuring unit is mounted on the platform of the measuring unit, which interacts with the magnetic plate using a force field that fixes the position of the measuring unit on the magnetic plate at the time of measurement.

The movement of the measuring unit is controlled by a remote control device through the central control unit. The strain gauge located on the measuring unit is brought to the test foot by the operator with the power field of the magnetic plate turned off, then the measuring unit is fixed by turning on the magnetic field of the magnetic plate in the position of the primary contact of the load cell with the side surface of the foot. Using a remote control device through the Central control unit, a signal is supplied to the stepper motor, which is part of the measuring unit, which processes the pulses received to it at the angles of rotation of the output shaft. At the same time, the strain gauge receives power from the central control unit, which puts the strain gauge in measurement mode. The rotation angles of the output shaft of the stepper motor are converted by means of a screw-nut transmission into the translational movement of the strain gauge, which results in compression of the tissue of the lateral surface of the foot, which is recorded as the compression force of the strain gauge. The movement of the strain gauge when squeezing the surface of the foot leads to deformation of the portion of the foot, which is determined by the number of pulses transmitted to the stepper motor, counted into a discrete movement of the strain gauge. The obtained measurement data is sent to the central control unit, which transmits them to the monitor and then to the printer.

After measuring the compression force by the central control unit, the fixing of the measuring unit on the magnetic plate is disabled and the operator moves the measuring device to a new measuring point on the side surface of the foot. The selected position is again fixed by the force field and the next test is carried out.

After testing and obtaining data transmitted to a computer and processed by software, diagrams of critical (pain) and allowable sensations of the patient are built on the monitor at various points on the side surface of the foot.

The objective of the invention is to establish at what deformation of the lateral surface of the foot in all its sections along the perimeter and, accordingly, at what compression force the borders of the allowable and critical (painful) levels of sensation arise at the nose.

This information will be used by designers to develop the upper of the shoe, which, when grasping the foot, does not cause pain in the toe, both in a standing position and when walking. The design of the upper of the shoe should take into account the boundaries of permissible deformations and the compression of the side surface of the foot caused by them.

The essential features of the invention is the composition of structural elements:

- push type strain gauge;

- transmission screw - nut, converting rotational motion into translational;

- a stepper motor, allowing discrete reciprocating movement of the strain gauge by means of a screw-nut transmission;

- the platform of the measuring unit, on which the measuring unit is mounted (stepper motor - pair screw - nut - strain gauge);

- a pair of platforms for the feet, on which the measured foot and foot of the other leg are mounted, which maintains the balance of the person;

- a magnetic plate, on which, when the power field is turned off, the platform of the measuring unit can move when moving to a new measuring point of the foot, while the magnetic plate can instantly fix the selected position of the measuring unit;

- a remote control device that allows you to transmit pulses through the Central control unit to a stepper motor to rotate the shaft at a discrete angle. The remote control device reports a signal to fix and open the platform of the measuring device with a magnetic plate;

- the central control unit receives a signal from the strain gauge, which, together with information about the angle of rotation and, accordingly, the linear displacement of the strain gauge processed by the software, transmits to the printer of the central control unit to build a diagram of the foot compression force - deformation of the foot.

A distinctive feature of the invention from the prototype is the use of an electronic type strain gauge of increased accuracy instead of a spring dynamometer with a large measurement error. The use of a stepper motor, which together with the screw-nut transmission accurately reports discrete movement to the load cell instead of manual feed in the prototype. The use of a magnetic plate, which fixes the position of the platform of the measuring unit and itself relative to the foot instead of holding the dynamometer in the hands of the prototype. The transmission of strain and force measurements in the proposed device is carried out electronically, whereas in the prototype, by reading the position of the arrows relative to the scale.

List of figures

The figure shows a diagram of a device for determining the deformation and pain threshold of compression of the surface of the foot, where:

1 - magnetic plate;

2 - transmission screw - nut;

3 - strain gauge;

4 - stepper motor;

5 - a pair of platforms for the feet;

6 - platform measuring unit;

7 - remote control device;

8 - central control unit (processor - monitor - printer)

The implementation of the invention

Static Description

The implementation of the invention is as follows. On the magnetic plate 1 is a measuring unit, which is mounted on the platform of the measuring unit 6, which is able to move relative to the magnetic plate 1 and be fixed on it. The measuring unit includes a stepper motor 4 connected by a coupling to a screw-nut-2 transmission screw. To increase the stability of the screw's coaxial position relative to the screw-nut-2 transmission nut, a bearing is mounted on the measuring unit platform. At the end of the transmission nut screw - nut 2 is attached to the load cell 3 having a cylindrical shape. The measuring unit is fixed on the platform 6, and the stepper motor 4 is fixedly mounted on it, and the screw-nut transmission nut 2 contacts its surface with the side surface of the plate and has the ability to slide on it, which allows the nut to reciprocate when the screw rotates. The stepper motor 4 is connected to the screw-nut 2 transmission by means of a coupling that communicates rotational motion from the shaft of the stepper motor 4 to the screw-nut 2 transmission. A strain gauge 3 is attached to the screw-nut 2 transmission nut, which is designed to measure the compression force of the foot and simultaneously create deformation of the lateral surface of the foot, and the magnitude of the deformation of the foot is determined by the number of pulses from the remote control device 7 and, accordingly, the discrete angles of rotation of the shaft of the stepper motor 4 and the transfer from Ocean transmission screw - nut 2. In the magnetic plate 1 is fixed to a pair of foot platforms 5 on the upper planes are established patient's foot. Paired platforms are designed to maintain the balance of the human body and, if necessary, to measure on it the compressive forces and deformations of the lateral surface of both feet. To measure the inner side surface of the feet, they need to be placed in the appropriate positions.

In operating condition, the measuring unit is launched by the remote control device 7 through the Central control unit 8, including a processor, monitor, printer. The signal from the remote control device 7 is supplied by pressing its buttons. The central control unit 8 is functionally connected to the magnetic plate 1, the stepper motor 4, the load cell 3, which receives power and transmits information to the central control unit 8. The central control unit 8 captures and displays the measurement result through the software on the monitor.

Dynamics Description

The test subject stands on a pair of platforms for foot 5. The operator selects the starting measurement point on the side surface of the test foot. The measuring unit is brought to this measuring point so that the strain gauge 3 touches the measuring point on the foot. The operator fixes the selected position of the measuring unit by turning on the force field of the magnetic plate 1, fixing the platform of the measuring unit 6 on it. Next, the operator from the remote control device 7 sends through the central control unit 8 pulse signals to the stepper motor 4, which drives a pair of screw-nut 2. The nut, resting on the side of the plane on the platform, rotates the screw in a linear motion, sliding along the surface of the platform measuring unit 6. The load cell 3, previously brought to a selected point on the side surface of the foot, moves forward, compressing the tissue of the side surface of the foot. The strain gauge 3 receives the compressive forces and transmits the information to the central control unit 8. The operator sends pulses by means of the remote control device 7 through the central control unit 8 to rotate the stepper motor 4, which, through the screw-nut transmission 2, drives the strain gauge 3. The magnitude of the movement of the load cell and accordingly, the compression force is controlled by the sensations of the subject. Simultaneously with the deformation of the foot tissue, an increase in the compression force of these tissues occurs. The subject, evaluating the force of compression of the foot by the load sensor 3 by sensations, informs the operator when an acceptable and critical (pain) level of sensations is achieved. The measurement data - the compression and deformation forces of the foot with acceptable and critical (pain) sensations of the test person, are transmitted by the appropriate signal from the operator to the central control unit 8, for further graphing. At the end of the measurement, the operator using the remote control device 7 through the central control unit 8 supplies pulses to the stepper motor 4 for the return movement of the screw-nut 2, strain gauge 3 transmission and then turns off the magnetic field of the magnetic plate 1. The platform of the measuring unit 6 freed from fixing is moved by the operator to a new measuring point.

All received data is transmitted to the central control unit 8 and graphs are built on the monitor:

- a graph of changes in compression forces that cause acceptable sensations on the measured points of application of the load;

- a graph of the changes in the compression force, causing critical sensations at the measured points of application of the load;

- a graph of changes in tissue deformations of the lateral surface of the foot, causing acceptable sensations at the measurement points;

- a graph of changes in tissue deformations of the lateral surface of the foot, causing critical sensations at the measurement points.

On the basis of the obtained data, a blank for the upper shoe of superior comfort is constructed in the contact areas of the blank for the upper with the side surfaces of the foot.

Claims (4)

1. A device for measuring the compression force and deformation of the foot in accordance with the sensations of the test subject, having a meter for compressing and deforming the tissues of the foot, a processor, a monitor, a printer, characterized in that the measuring unit consists of a stepper motor, a screw-nut transmission and a strain gauge driven in action by a remote control device, there is a magnetic plate for fixing and releasing the measuring unit mounted on it by turning the power field on and off. 2. The device according to claim 1, characterized in that the central control unit receives simultaneously a compression force signal from the load cell when the foot tissue is pressed and a pulse signal from the remote control device, in accordance with which the foot tissue is deformed due to the horizontal displacement of the load cell from the screw transmission - nut and stepper motor. 3. The device according to claim 1, characterized in that the screw-nut transmission nut is made in the form of a square, the lower side of which, when moving, slides along the surface of the platform without rotation. 4. The device according to claim 1, characterized in that the coordinated operation of the measuring unit and the central control unit allows you to obtain the results of measuring the compression force and deformation of the foot by the reaction of the test person.

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