IR Tarkhanov found that any irritation caused to a person through
1-10 sec. latent period is at first slight and slow, and then all
accelerating deflection of the mirror galvanometer, often transcending
scale. This deviation sometimes lasts for several minutes on end
the stimulus. Gradually, the mirror galvanometer returns to its original position
.
It was also noted that the electrical phenomena in the human skin
dramatically enhanced with imaginary imagination feeling when
abstract mental activity, excitation of the nervous system, fatigue.
By Tarkhanov, cause vibrations RAG is to enhance nerve activity
person that is accompanied by increased secretion of sweat and is manifested in
occurrence of galvanic current on the skin surface. The role of the secretion of sweat glands in the genesis of
RAG in a large number of works. Also recorded that
galvanic skin response is not recorded in the areas of the body, anatomically
not have sweat glands (red border of lips, etc.)
study the potentials of the skin in the clinic showed the dependence of the potentials from the skin
state of the autonomic nervous system and the possibility of judgments
electrical parameters of skin on a number of different features of course
pathological processes.
In 1962, U.S. patented system for signaling a loss of
alert the operator. It is based on the change in electrical resistance
skin surface of the palm. This resistance increases sharply (three times) at
high body temperature, sleep, or while intoxicated.
A similar device is used in France to determine the extent
sobriety of drivers of cars. The electrodes are mounted in the steering wheel, and when
intoxicated driver to start the engine impossible.
Interesting recordings were obtained at the time of awakening astronauts - the fall
skin resistance coincides with opening his eyes.
impedance of skin varies during the meal. Depending on the time of the day
skin conductivity increases by noon and reaches a maximum and then to
evening falls. On the diurnal rhythm superimposed physiological effects.
resistance increases with age, regardless of gender.
Some researchers have unsuccessfully applied for the analysis of skin potentials
pregnancy tests for the diagnosis and prognosis of cancer.
RAG can be used for the selection of people performing certain tasks, and
to monitor the condition of the operator before the work of high difficulty. There
patterns manifested in the form of statistical similarity among different
people in similar circumstances in solving similar problems.
However, virtually all studies indicated that a significant dependence
physiological norms on the individual patient can be reliably
diagnose only pronounced changes in conditions such as shock,
hypoxia, etc. Established that the resistance of the skin varies from 10
ohms to 2 megohms. Thus, pacing the face and back of the hand is in the range of 10 to 20 Com,
leather thigh - 2 megohms, palms and soles - from 200 ohms to 2 megohms.
Therefore, the greatest diagnostic value are not absolute values
resistance, physiological norms which vary considerably for different
individuals, and analysis of galvanic skin response, or that the same thing
, the relative change of the electrical resistance depending on
imposed mode.
In accordance with the procedure proposed FY Verkhovsky and modernized
OV Zhbankova [1], the specialists of the Moscow State Technical University
. Bauman was developed hardware and software package «Visual
SGR» [2], which allows you to objectively determine the psychophysical state
rights based on the relative change of the electrical resistance.
According genesis of the theory of galvanic skin response
secretory activity of sweat glands is closely related to the activity of the human nervous system. Activating
psychomotor causes profuse sweating, and skin resistance
falls. For the reverse flow of sweat is absorbed, and skin resistance
growing. And the first state of the CNS called the concentration, and the second -
relaxation.
analysis of the dynamics of the electrical resistance is attractive for research
also a practical side. This is:
· No effect of constant resistance element "electrode-skin" in
measuring chain. System "electrode-skin" is a comprehensive
resistance and significantly affect the results of finite dimensions. To
reduction is necessary to use special electrodes and wetting
contact surface of the electrode with the skin with conductive solution. In measuring the relative change in resistance
this constant value is subtracted and
not affect the results, so no need to use special
measurement tools.
· not critical to the constant measurement error due to technical
performance measurement tools. These requirements significantly reduce the cost of
technical means used to measure the ECS.
· lack of influence of external factors on the testimony of measurement, such as
ambient temperature, the interference from household electrical appliances, etc.
All permanent interference by measuring samovychitayutsya.
· Low requirements for personnel participating in the measurement process. No
necessary skills for finding biologically active points.
Electrodes can be applied on any part of the patient's skin.
isolating the absolute values of pacing and taking a normal physiological growth
resistance in the phase of relaxation and reduction of resistance in the phase of the concentration,
possible to build an objective picture of the psychophysical state of a person.
In system «Visual SGR» testing is performed according to standard program
«Relaxation - concentration. After applying the electrodes on two different fingers
one hand (usually right) and turn on the instasment is undergoing a period of establishing
transition and stabilization of the exponential (1 min). Followed by
relaxation times (5 min) and concentration (3 min) with the installation for the test
on achieving the maximum state of relaxation or mobilization
respectively. The tests recorded three values EX:
· at the end of the first minute, after transients (R1);
· at the end of the fourth minute, following a phase of relaxation (R2);
· at the end of nine minutes at the conclusion of the phase concentration (R3).
After completion of the test, a graph that reflects the quality
aspect of the process, as well as a quantitative assessment - a normalized index
psychophysical state (IPFS), which is important to note, in conventional units, ie
does not depend on the absolute values of resistance of the patient.
Thus, the study of a reversible process, "Relaxation - Activate»
takes the practical application of skin-galvanic reflex
a new stage of development. Various physiological norms of the absolute values of the electrical resistance
are no longer a barrier to study the level of
activity of the sympathetic nervous system and evaluation neuropsychical voltage
rights.
Useful links:
[ 1] Zhbankov OV, Tolstoy, EV - Control technology psychophysical state
students and administration.
Http://lib.sportedu.com/press/tpfk/1997N8/p40-43.htm
[2] electrocutaneous resistance as an indicator of psycho-physical state of
rights. www.skgr.narod.com