RU2195171C2 - Apparatus for investigating distribution of individual's center of gravity - Google Patents

Abstract

FIELD: medical equipment. SUBSTANCE: apparatus has feet resting platforms with strain measuring sensor on each of them, unit for converting signals delivered by said sensors, said unit having ACP, data processing and visualizing unit and isolation transformer. Each platform has area of 290x80 mm. Apparatus is used for effectuating functional diagnosis of individual's state, in particular, for drawing conclusion on the state of individual's locomotor system on the basis of measured values. EFFECT: increased efficiency and provision for obtaining precise data. 3 dwg

Description

 The invention relates to medical equipment and allows with high accuracy to measure the distribution of the center of pressure of a person between the left and right legs, as well as the distribution of pressure between the heel and toe of both the left and right legs, which allows the use of this device in medicine for functional diagnosis of human condition, to monitor the course of the disease and patient rehabilitation processes.

 A known reference pressure meter (certificate of autonomy 1214087, A 61 V 5/10), comprising two supporting platforms, an indication unit, an adder connected in series with the platform outputs, a voltage to number of pulses converter, a pulse number divider and a control unit. The known device is used in solving problems of the rehabilitation of lost motor functions of the lower extremities, in the practice of prosthetics, during biomechanical studies.

 Significant disadvantages of this device is that it does not allow to determine the pressure of each leg between the heel and the toe and has low accuracy in determining the distribution of pressure between the left and right leg.

 A device is also known for studying the distribution of the center of gravity of a person according to the international application PCT WO 93/21825 (IPC A 61 B 5/103). The device contains two identical supporting platforms (11, 12) for the right and left legs. Support pads contain four sensors connected to an amplifier (18, 19), which converts the mechanical load of a person’s weight into an electrical signal. The output signals from the amplifiers are fed to a computing unit (processor 10), which is paired with a graphic display 13. The device is used as a monitor, an equilibrium indicator that graphically displays the movement of a person’s center of gravity.

 The known device has a number of significant structural and functional disadvantages that do not allow its effective use in wide medical practice. So, in particular, the geometric dimensions of the platforms exceed the dimensions of the patient’s foot, which makes it impossible to measure in the “legs together” position, and also the fact that this device only allows a qualitative assessment of the pressure distribution between the patient’s legs, graphically displaying the result on the screen.

 The present invention solves the problem of measuring the position of the center of pressure between the right and left legs of the patient, as well as between the heel and toe of each leg separately, conducting research in various positions of the patient’s legs, starting from the position of the legs together and ending with the position of the legs wider than the shoulders, and also "right foot forward," "right foot back." In addition, the objective of the present invention is to obtain measurement results in real time, which makes it possible to work in biological feedback mode and allows for rehabilitation procedures in the form of specialized computer simulator games with biological feedback.

 The solution of the problem is achieved as follows. In the device for studying the distribution of the center of gravity of a person, containing reference areas for the right and left legs with strain gauges, a signal conversion unit including an analog-to-digital converter and a data processing and visualization unit, according to the present invention, each support platform is provided with two strain gauges with dimensions of 290x80 mm. Support pads are made with the possibility of various options for their relative positioning.

 Each strain gauge sensor is connected by an output to the first input of the corresponding DC amplifier, the output of each of which is connected respectively to the first, second, third, and fourth inputs of the analog-to-digital converter, the output of which is connected to the first input of the interface of the strain gauge signal conversion unit. Moreover, its second input is connected to the first output of the power supply, the second output of which is connected to the fifth input of the analog-to-digital converter, the third and fourth outputs are connected to the corresponding second inputs of the DC amplifiers, and its multi-bit input is connected to the first output of the isolation transformer, the second, the third and fourth outputs of which are connected respectively to the first, second and third inputs of the data processing and visualization unit, connected by a bi-directional multi-bit bus to the interface.

 The technical result of the present invention consists in the possibility of measuring with high accuracy the distribution of the position of the patient’s center of pressure both between the left and right legs, and between the heel and toe of each leg separately, calculating, based on the results of these measurements, indicators characterizing the condition of the musculoskeletal system of a person and the preparation of syndromic conclusions.

The essence of the present invention is illustrated by the description of a patented device for studying the distribution of the center of gravity of a person and the drawings, which show:
figure 1 is a block diagram of a device;
figure 2 - block diagram of the calculator 17;
figure 3 is an enlarged block diagram of the algorithm of the device.

 A device for studying the distribution of a person’s center of gravity contains (Fig. 1) a support pad for the left foot 1, a support pad for the right foot 2, a signal transducer 3, a data processing and visualization unit 4, and an isolation transformer 5.

 Support pads 1 and 2 are two identical platforms measuring 290x80x30 mm each and contain two strain gauge sensors (see AFIN design documentation 941.349.006). The platform for the left foot 1 contains sensors 6 and 7, the platform for the right foot - sensors 8 and 9. Strain gauges 6-9 are used to convert the weighted efforts of a person into an electrical signal and can be made in the form of strain gauges glued to a metal spring in the form of a fixed on both sides of the beam (see, for example, copyright certificate 1457896).

 Each strain gauge sensor 6–9 is connected with its output to the first input of the corresponding DC amplifier - 10, 11, 12, 13. DC amplifiers 10–13 are designed to amplify and normalize the electrical parameters of the signal of load cells 6–9 and are made according to the known scheme (see V.L.Shilo, Linear Integrated Circuits in Radioelectronic Equipment (Moscow: Sovetskoe Radio, 1979, p. 162, Fig. 4-10a).

 The strain gauge signal conversion unit 3 is designed to convert an analog electrical signal into a digital code and transmit it via a standard interface to a calculator 17 and contains, for example, a 12-bit analog-to-digital converter (ADC) 14, an interface 15, and a power supply 16. The ADC 14 is made on the MAX 185 chip according to the well-known scheme (see MAXIM 1990 New Releases Data Book, p. 1-129, Fig. 1).

 The first, second, third and fourth inputs of the ADC 14 are the inputs of the signal conversion unit 3 and are connected to the output of the corresponding DC amplifier 10, 11, 12, 13. The output of the ADC 14 is connected to the first input of the interface 15, which is connected to the unit by its bi-directional multi-bit bus data processing and visualization 4.

 Interface 15 is designed to form a standard protocol for transmitting data to calculator 17 and can be performed according to the well-known scheme (see M. Guk. PC interfaces, reference book. St. Petersburg: Peter, p. 11, Fig. 2.6). The second input of the interface 15 is connected to the first output of the power supply 16.

 The power supply 16 provides stabilized voltages necessary for the operation of the device, and is made in the form of a voltage regulator on microcircuits (see A.G. Alekseenko. Use of precision analog ICs. M: Soviet Radio, 1980, p. 154, table 6.5 , scheme 3).

 The second output of the power supply 16 is connected to the fifth input of the ADC 14, the third output is to the second inputs of the DC amplifiers 10 and 11 of the reference platform 1 of the left foot, the fourth output is to the second inputs of the DC amplifiers 12 and 13 of the reference platform 2 of the right foot. The input of the power supply 16 is the fifth input of the electric signal conversion unit 3 and is connected to the first output of the isolation transformer 5.

 The isolation transformer 5 provides galvanic isolation of the operator and the patient from the mains supply, which is necessary to meet the requirements of electrical safety. The isolation transformer is made according to the well-known scheme (see E.I. Karetnikov, T.A. Rachina, A.I. Ermakov. Power transformers and filter chokes for electronic equipment. M: Soviet Radio, 1973, chap. III, p. 83-104).

 The second, third, fourth outputs of the isolation transformer 5 are respectively the first, second, and third inputs of the data processing and visualization unit 4.

 The data processing and visualization unit 4 provides: receiving data from the signal conversion unit of the load cells 3 and processing them according to a predetermined program, which allows displaying the received information on the screen of the video monitor 18, calculating stability indicators and receiving the results in the form of a printout on the printing device 19. The processing unit and the data visualization comprises a calculator 17, a bi-directional multi-bit bus connected to the interface 15, a video monitor 18 and a printing device 19. A video monitor 18 and a printing device 19 It is connected to the calculator 17, a bidirectional multibit bus. The first, second and third inputs of block 4 are connected respectively to the input of the calculator 17, the printing device 19 and the video monitor 18.

 The calculator 17 provides data processing and calculation of indicators of patient stability. The calculator 17 can be made in the form of a system unit of a personal computer consisting of serial purchased units, for example, type CPU-Intel P-II 333 MHz Cache / MB Asustec P2B / RAM - SDRAM 64 MB PC-100 / video - S3 savage 3D 8 MB AER / FDD -1.44 MB 3.5 '/ CD-ROM 32x Matsushita CR586 / HDD - slagate 8.6 MB / case - midi-tower ATX / keyboard BTC Turbo-PS / 2 (see figure 2). The computer 17 consists of a housing 20 (midi-tower ATX brand), in which a power supply unit 21 (model AL 230W) is integrated, and a keyboard 30 (type BTC Turbo-PS / 2). The motherboard 22 (Asustec P2B brand) strengthened inside the case 20 contains a processor 23 (type Intel Pentium-II 333 MHz), memory 24 (type SDRAM 64 MB), a hard disk 25 (type Seagate 8.6 GB), and input controllers -Output: RS-232 controller 26 (type i8250), keyboard controller 27, video card 28 (brand S3 savage 3D 8 MB) and printer controller 29 (type Centronix). The work of the calculator 17 is carried out according to a special program developed by the applicant for this device.

 An enlarged block diagram of the algorithm of the device is shown in figure 3, and a full description of the software product is described in the technical documentation of the applicant AFIN 941-349.006.

 The video monitor 18 is used to visualize the indicators of stability and is made, for example, in the form of a monitor 17 "View Sonic 17 PS" 16 ".

 The printing device 19 is designed to obtain results on paper and can be made in the form of an inkjet printer HP DeskJet 685.

 A device for studying the distribution of the center of gravity of a person works as follows.

 The patient is installed on the supporting platforms of the left 1 and right 2 legs according to the examination program (various options for the location of the platform 1 and 2 are possible: "legs together", "legs shoulder width apart", "right foot forward", "right foot back", "most comfortable position of the legs ", etc.), while the signal about the distribution of body weight from the sensors 6 and 7, 8 and 9 is fed to the first inputs of the DC amplifiers 10-13, amplified to the levels necessary for the operation of the ADC 14, and at its first, second, third and fourth inputs, it is converted to a serial digit The code that arrives at the first input of the interface 15, which generates a signal block of the corresponding standard for transmission to the calculator 17.

 The power supply 16 converts the mains voltage of 220 V into stabilized voltages necessary for the operation of the device. From the first, second, third and fourth inputs of the power supply, stabilized voltage is supplied to the platforms of the left 1 and right 2 legs, the ADC (input 5) and the interface (input 2). From the output of the interface 15, a digital signal code on the data bus enters the data bus of the calculator 17, where the data is processed according to the specified examination program (see figure 3) and the calculation of the indicators of the patient’s pressure center, which are transmitted to the video monitor 18 via the corresponding data buses, allowing you to visually control the examination process, and a printing device 19, issuing the calculation results in the form of a printout to the medical history.

 The isolation transformer 5 provides its outputs 1-4 with a power supply 16, a computer 17, a video monitor 18 and a printing device 19 with a voltage of 220 V, which is galvanically isolated from the mains voltage, which ensures compliance with the electrical safety requirements of the device according to GOST R 50267.0-92.

 Examination of the patient is carried out according to various tests: "open eyes", "closed eyes" ("Romberg test"), "with biological feedback", i.e. when the patient, looking at the screen of the video monitor, tries to keep the center of pressure in a certain position, etc.

 According to the results of recording the survey data in the calculator 17, the indicators of the position of the center of pressure and stability parameters are calculated (more than 10 indicators), the disease is diagnosed.

 In the regime of rehabilitation simulators, the patient is asked to combine the track ("bunny") of the center of mass displacement with the point moving along the screen of the video monitor according to the specified program ("direct", "forward - backward", "ellipse", "random distribution mode", etc. .). At the end of work in the mode of rehabilitation simulators, the patient’s performance indicators and the assessment of the assignment (the number of points scored, the time of the assignment, the assessment by the indicators of the group and an individual assessment) are issued.

Claims (1)

 A device for studying the distribution of the center of gravity of a person, containing reference pads for the right and left legs with strain gauge sensors, a unit for converting their signals, including an analog-to-digital converter and a data processing and visualization unit, characterized in that each support platform is equipped with two strain gauge sensors with dimensions of 290x80 mm, the support pads are made with the possibility of various options for their relative positioning, each strain gauge is connected to the first input by the output the corresponding DC amplifier, the output of each of which is connected respectively to the first, second, third and fourth inputs of the analog-to-digital converter, the output of which is connected to the first input of the interface of the signal conversion unit of the strain gauge sensors, while its second input is connected to the first output of the power supply, the second output of which is connected to the fifth input of the analog-to-digital converter, the third and fourth outputs - with the corresponding second inputs of the DC amplifiers, and its many one-way input - with the first output of the isolation transformer, the second, third and fourth outputs of which are connected respectively to the first, second and third inputs of the data processing and visualization unit, connected by a bi-directional multi-bit bus to the interface.

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