RU79239U1 - FINGER TREMOR REGISTRATION SYSTEM - Google Patents

Abstract

The finger tremor recording system contains an ultralight integrated accelerometer sensor (1) connected in series, made on the basis of sensitive surface capacitive elements, and incorporating a biaxial acceleration sensor, demodulators and output signal generating circuits, a computer (3) with specialized software, and analog digital converter (2). The work of the proposed system of registration of digital tremor is based on spectral analysis of the signal received from the accelerometer sensor (1), which fixes on the distal phalanges of the fingers of the subject. Registration of tremor is performed using a computer (3) with specialized software. Information is entered into the computer using an analog-to-digital converter (2). The amplitude-frequency characteristics of the tremor are estimated by spectrograms using specialized software. 1 silt

Description

The utility model can be used in medical technology for conducting objective early diagnosis of diseases, as well as for biomechanical studies, in assessing professional suitability, in sports, and in neurophysiological studies.

Tremor occurs as a result of involuntary muscle contraction. An increase in the amplitude and a change in the frequency and shape of the oscillations relative to the norm (the frequency and amplitude of the physiological tremor) are signs of a violation of the central and peripheral neural mechanisms of regulation of movements. The analysis of these parameters is important both for understanding the role of dysfunction of individual brain structures in the processes of motion control, and for the clinic in the aspects of early detection, more accurate diagnosis of motor disorders, selection and correction of optimal treatment methods associated with the selection of effective drug therapy.

Currently, systems and methods are widely used to detect tremor, designed to determine the high-amplitude tremor characteristic of Parkinson's disease and Essential tremor.

All measuring systems in biomechanics include sensors of biomechanical characteristics with amplifiers and converters, a communication channel and a recording device. The sensor is the first link in the measuring system. Sensors directly perceive changes in the measured indicator and are fixed either on the human body or outside it.

A sensor mounted on a person should have a minimum weight and dimensions, high mechanical strength, ease of attachment and at the same time should not hamper movements and create any discomfort.

Known tremometer (SU, copyright certificate, 1391622, class AB 5/11, 1988), containing the sensor of the test subject, an electronic unit and a recorder. The motion sensor of such a device consists of a light source, a screen and a photodiode mounted deep in the pointer. The disadvantage of this device is the low accuracy of the measurements and the lack of objectivity in registering tremors.

The closest in technical essence to this utility model is the “TREMOMETER” (RF patent No. 2102922 C1 IPC 6 A61B 5/11, 1998.01.27, prototype), containing the subject’s motion sensor, electronic unit and recorder. The test subject’s motion sensor is made in the form of a plate on which two absolute angular velocity sensors are mounted, made in the form of rotary vibration

gyroscopes. The plate is attached to the wrist of the subject using a watch strap or bracelet. The sensitivity axes of the absolute angular velocity sensors comprise an orthogonal trihedron.

The disadvantages of the known technical solutions, selected as a prototype, include:

- the impossibility of registering digital tremor due to the high mass of the angular velocity sensors;

- the impossibility of registering physiological tremor due to limited sensitivity;

- the impossibility of registering kinetic due to the peculiarities of gyroscopic sensors of angular velocities of tremor

The utility model is aimed at increasing the reliability of measurement results, the accuracy of determining parameters and increasing sensitivity for recording small-amplitude tremor, including physiological.

The technical result consists in the fact that the proposed system allows you to register and analyze the characteristics of all types of digital tremor, including physiological (in healthy people) and kinetic (in motion), and includes the technical characteristics necessary for these purposes.

This is achieved by the fact that in the registration system of the finger tremor containing the test sensor’s motion sensor in series, the electronic unit and the recorder, according to the utility model, for measuring the tremor, the test person’s motion sensor is made in the form of an integral accelerometer sensor based on surface sensitive capacitive elements such as, for example, ADXL series from Analog Devices, or similar from other manufacturers, and subsequent analysis is done using computer technology.

A feature of the proposed technical solution is that it proposes the use of a new generation of integrated accelerometric sensors based on surface, sensitive capacitive elements containing a biaxial acceleration sensor, demodulators, and output signal generating circuits. Registration of tremor is performed using computer equipment and specialized software. Information is entered into the computer using an analog-to-digital converter.

The work of the proposed registration system of digital tremor is based on spectral analysis of the signal received from the accelerometer sensor, which fixes on the distal phalanges of the fingers of the subject. Constructively

The accelerometer is an integrated circuit containing two sensing elements, demodulators and output signal generating circuits. The microcircuit allows measuring acceleration simultaneously in two planes (frontal - channel X and sagittal - channel Y). It has normalized levels of the output signal, noise, and conversion error. The miniature ultralight sensor practically does not have inertia, and, as a result, does not introduce distortions caused by the occurrence of additional forces of inertial mass movement, which allows even micro-vibrations of physiological finger tremor to be recorded.

The essence of the utility model is illustrated in the drawing, which shows a functional diagram (block diagram) of the measuring system.

The positions in the drawing indicate: integrated sensor-accelerometer - 1; analog-to-digital converter - 2 (ADC); computer - 3.

The signal from the accelerometer sensor 1, proportional to the acceleration, is input into the computer 3 by means of an analog-to-digital converter 2.

Tremorogram analysis is performed using the Power Graph program. The tremor amplitudes are estimated using the rms value calculated by the program based on the data obtained. The frequency characteristics of tremor are estimated using spectral analysis based on the Fourier transform. In addition, the software allows for temporary analysis of the signal, and various mathematical operations with it.

The obtained amplitude-frequency characteristics of the tremor are subjected to further statistical processing to identify differential diagnostic criteria.

This research method allows you to objectively capture the slightest finger vibrations simultaneously in two - planes - the frontal and sagittal in a wide frequency range, and allows you to record the amplitude-frequency characteristics of tremor not only with extrapyramidal pathology, but also with vegetative dysfunction, as well as in healthy people (physiological tremor).

The system allows you to register all three main types of tremor:

- rest tremor, when the patient sits in an armchair, his hands lie freely on the armrests;

- postural tremor, when arms are stretched out in front of you, fingers are slightly spread apart;

- kinetic tremor, when the assessment is carried out with a finger test.

The ability to register the last type of tremor is another distinguishing feature of the described technical solution.

Registration is carried out simultaneously in two planes - horizontal and vertical.

Distinctive features of the utility model:

- the sensor with the mother mass does not have inertia, and. as a result, it does not introduce distortions caused by the occurrence of additional forces of inertial mass movement, which allows measuring finger tremor;

- high sensitivity allows you to register even the tremor of a healthy person (physiological tremor);

- the sensor has normalized output levels and measurement error, which allows measuring tremor in SI units;

- the sensor is insensitive to the location relative to the horizon, this makes it possible to measure kinetic tremor (in motion).

Claims (1)

A finger tremor registration system, including a test subject’s motion sensor, an electronic unit and a registrar, characterized in that the test subject’s motion sensor is an ultralight, integrated accelerometer sensor based on sensitive surface capacitive elements and incorporating a biaxial acceleration sensor, demodulators and circuits for generating output signals, the electronic unit is an analog-to-digital converter, the recorder represents It is a computer with specialized software.