SU929058A1 - Apparatus for determining limb tremor - Google Patents

Description

I

The invention relates to medical technology, namely, devices for biomechanical research and can be used in functional diagnostics.

A device for detecting tremor of limbs is known, comprising a motion sensor, a control trigger, a clock pulse generator, a digital recorder 1.

A disadvantage of this device is the inability to measure the movement of an object in two directions, horizontal and vertical.

Closest to the present invention is a device for determining tremor of limbs, which contains a circular screen with variable density of darkening, a pointer with a photodiode at the end, and an amplifier,

A disadvantage of the known device is the low accuracy of the control of the amplitude of movements, since with equal amplitude of movements the amplitude

The oscillation of the photodiode signal depends on the magnitude of the angle o between the radius of the screen, passing through the point of direction of the pointer, and the direction of motion. For small oscillations of the pointer, the amplitude of oscillations of the photodiode signal is proportional to the magnitude of A cosoi, where A is the amplitude of oscillations of the limb. If the direction of the pointer coincides with. center of the screen, frequency

10 oscillations of the photodiode signal will also differ from the frequency of oscillation of the limb.

The purpose of the invention is to improve the accuracy of determining the amplitude of movement

15 limbs.

Claims (2)

The goal is achieved by the fact that a device for tremor of extremities, containing a screen with variable density of darkening, fc20 with an amplifier and a pointer, it is equipped with a point light source mounted on the end of the pointer, a lens mounted between the point source 392 light source and the screen, a collective lens located on the optical axis of the lens on the other side of the screen, and the photodiode is mounted at the focus of the collecting lens, while the screen is made with a blackout density varying along its diagonal. Fig. 1 shows schematically a device for tremor of limbs; in FIG. 2, a front view of the screen. The device contains a pointer 1, a screen 2 with a variable blackout density varying along its diagonal photodiode 3 with an amplifier t, a point source 5 of light fixed at the end of the pointer. In addition, the device is equipped with a lens 6 mounted between the source 5 of light and the screen 2, and a collecting lens 7 mounted on the optical axis of the lens 6 on the other side of the screen. While the photodiode 3 is installed in the focus of the lens 7j and the pointer is hinged on a fixed support 8. The sensor works as follows. The end of pointer 1 is attached at the end of the subject, for example, with a rubber ring. The subject takes a position in which the limb is stretched and points the tip of pointer 1 at the lens. The image 9 of the light source 5 is projected by the lens 6 onto the screen 2, and the flow of light passing through the screen is focused by the lens 7 on the photodiode 3, causing the photocurrent to appear and at the input of the amplifier 4. During the experiment, the subject closes his eyes and continues to hold the limb in a predetermined position. When a tremor occurs, the end of the pointer 1 with the photodiode 3 oscillates in horizontal or vertical directions, which causes the image 9 of the syta source to move.5 to the screen 2. Because in both cases The direction of movement of the image 9 crosses the direction (1.0 decrease of the density of the darkening of the screen 2, with equal amplitudes of the oscillation of the limb both in and in the horizontal direction of changing the amount of light a, passing from the source 5 through the screen 2, and, consequently, the current of the photodiode 3 in the same way (Fig. 2). In addition, the hinge pinning of the pointer 1 on the support 8 does not require an additional force from the person under test. to reveal the nature of the involuntary movements of the limb. Thus, in the proposed device, the screen darkens in the direction of its diagonal, resulting in involuntary oscillatory movements of the limb in both the vertical and horizontal directions, the angle between ION movement of the light spot and a diagonal screen remains constant, equal to SO, and changes in the light amplitude of the photodiode is independent from the average position of the light spot on the screen. This provides an increase in the accuracy of determining the amplitude of movement of the limb. An apparatus for detecting tremor of extremities, comprising a screen with variable density of darkening, a photodiode with an amplifier and a pointer, characterized in that, in order to improve the accuracy of determining the amplitude of movement of an extremity, it is provided with a point source of light fixed at the end of the pointer, with a lens mounted between a point source of light and a screen, a collective lens located along the optical axis of the lens on the other side of the screen, and a photodiode is installed in the focus of the collective lens, while the screen n is formed with the density of blackening, varying in its diagonal. Sources of information taken into account in the examination 1. USSR author's certificate number, cl. A 61 B 5/10, 1976. 2. USSR author's certificate number 556559, cl. A 61 B 5/10, 1976. rr FIG. I