SU1421299A1 - Method of determining skin sensitivity when peripheral nerves are injured - Google Patents

Abstract

The invention relates to medicine, namely to clinical neurotraumatology, and can be used to objectively assess skin sensitivity in diagnosing the extent of damage to the peripheral nerves of the limbs. The purpose of the invention is to improve the accuracy of the method. For this, two pairs of electrodes are placed in the symmetric zones of the cutaneous innervation of the diagnosed nerve on healthy and sore limbs, the electrical activity of the skin in these zones is recorded in the frequency range of the irritating current 30-1600 Hz by measuring the established frequencies of the autogenerators and by the value of the difference of the mentioned frequencies t about the magnitude of skin sensitivity. about ((L

Description

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This invention relates to medicine, namely to neurotraumatology.

The aim of the invention is to improve the accuracy of the method.

The method is carried out as follows.

. Two pairs of electrodes (measuring and indifferent) are placed in the skin of healthy and sore extremities in the symmetric zones of skin innervation. Copper gilded cylinders with a base area of not more than 0.5 mm are used as measuring electrodes. Such an area of electrodes makes it possible to distinguish the degree of change in skin sensitivity by

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skin areas up to 1 mm. At the moment of combining the measuring electrodes with the symmetric zones of the innervation of the nerves under study, a simultaneous recording of the electrical activity of the skin in the form, measuring the electrical resistance in time, converted to frequency, is started. and frequency oscillators. The frequency range of the oscillator of 30–1600 Hz corresponds to the range of changes in the electric resistance of 1 com — 200 mehm. This operating frequency range corresponds to the natural operating frequency range of the electrical signals in axons. The mode of operation of each oscillator is chosen so that the amplitude of the current flowing through the electric resistance does not exceed 2.5 μA. This allows you to work on the area of the current-voltage characteristics of the skin below the pain thresholds. After the occurrence of the established frequency values of the auto-generators, their registration is completed. The frequency of the oscillators recorded pyoT using frequency meters. The quantization step at registration is 2.5 s, and the total registration time does not exceed 40 s. Chuvst skin vitality is determined by the value of the difference between the frequency of the oscillators according to the schedule of the empirical dependence of the difference between the average frequencies of the oscillators and the size of the skin sensitivity.

Example 1. Ill With ,, 6 years Wounded by glass of the middle third of the right

five

0 5

0 5 0 5,. 0 5

forearm with damage to the ulnar nerve.

Atrophy and paralysis of the brush. In the autonomous zone, the sensitivity is O points.

A study was conducted in the autonomous zone of the ulnar nerve. Two measuring electrodes with an area of 0.5 mm are placed at symmetrical points of the ulnar nerve on the palmar surfaces of the terminal phalanges of the little fingers on healthy and sore limbs. The indifferent electrodes are placed on the forearm x. Frequencies from autonomous zones are recorded simultaneously by two autogenerators when current is passed no higher than 2.5 µA, the frequency difference is determined, which is 760 Hz, and according to the empirical plot of the frequency difference of autogenerators, skin sensitivity is obtained, which is equal to O points.

The operation confirmed a complete anatomical break of the ulnar nerve, and an epineural suture of the ulnar nerve was applied in the middle third of the right forearm.

Example 2. Patient S., 42 years. Knife wound lower third of the right forearm. Imposed epineural suture of the median nerve.

Examined 9 years after the operation, in the autonomic zone of the mid-nerve, a sensitivity of 5 bp allo were revealed. A skin sensitivity test was conducted in the autonomous zone of the Mid-nerve. Two measuring electrodes with an area of 0.5 mm are placed in the symmetric points of the autonomous zones of the median nerve on the palmar surface of the terminal phalanx of the index finger of the healthy and sore limbs. The indifferent electrodes are placed on the forearm of these limbs. Frequencies from autonomous zones are recorded by two autogenerators at the same time, after which the difference in frequencies is determined, which is up to 20 Hz. The same difference is observed in healthy people normally. According to the graph of the empirical dependence of the frequency difference of the autogenerators, skin sensitivity is determined, which corresponds to 5 points, which confirms the good nerve conductivity.

The use of the invention improves the accuracy of diagnosis.

the extent of damage to the peripheral nerves of the limbs.

Claims (1)

Invention Formula The method of determining skin sensitivity when peripheral nerves are damaged by irritating the skin with alternating current and recording the body's response, characterized in that, in order to maintain the accuracy of the method, two pairs of electrodes are placed with an area of no more than 0.5 mm in the symmetric skin zones Noah innervations of the diagnosed nerves in healthy and diseased extremities irritate the skin with a current of 2-2.5 µA, record the electrical activity of the skin in these zones in the frequency range of an irritating current of 30-1600 Hz by measuring the established frequencies of autogenerators, in the feedback circuit of which The investigated skin areas are included, the difference of these frequencies is determined, and skin sensitivity is determined according to the empirical dependence of the frequency difference.