Chronometre

Chronometre method, which determines the magnitude of chronaki, i.e. the least time during which an irritant to the double threshold of force will cause the excitation process.
In medical practice is most often defined by ironaxe muscles and motor nerves. Also studied ironaxe and sensitive sphere.
To measure chronaki use the special device - franksinatra consisting of a constant current source, series resistance and devices for dosing duration of current is fed to the object. Depending on the device accessories for dosing duration of current distinguish pendulum, condenser and electronic chronometry. Pendulum franksinatra very cumbersome and in the clinic of little use. In condensing franksinatra the duration of the current is regulated by a capacitor discharge and depends on its capacity. The irritation caused by this franksinatra, almost insensitive. In electronic franksinatra dosage duration of action of the current produced by the vacuum tube. In medicine used instruments giving gradation voltage from 1-2 V to 300 V, and duration of action - from 0.01 to 40 msec msec.
Chronometre is used to determine the degeneration of nerve injuries of different nerve centers. Research chronaki help establish shifts excitability under influence of various factors: work, heat, cold, pressure, etc.

Chronometre (from the Greek. chronos - time, axia - number, metreo " measure") - methods of measurement of chronaki for research excitability of living
fabrics taking into account not only the strength of the stimulus, but the time factor is the duration of the stimulus. Ironaxe - the least time during which a direct current power 2 times higher threshold may cause reactions.
The question about the meaning of time in determining the activities of the various systems, was designed N. That is, the Vedeno in the study lability. The experiences of a number of psychologists was the dependence of threshold effect as from the strength of the stimulus, and from the time of its validity. This dependence is expressed curve force - duration threshold stimulus (ABC on Fig. 1). This curve is most characteristic of anxiety tissue, but to build it it is necessary for each current to set a limit of duration. The branches wrapping (L. Lapicque) proposed to define the curve force - duration only two points - LeoBase and chronaki. LeoBase - threshold current at sufficient length, at which time factor is not playing a decisive role (HL=OM). LeoBase expressed in volts or Mas. To measure chronaki need to double reaso (FH=EC) and find the lowest duration twice the current (DE=OK Fig. 1). Chronaki expressed in milliseconds. Was able to show that the excitability of all living entities is characterized by a homogeneous hyperbolic curve force - duration. The difference lies only in the absolute values of realizy and chronaki. Were established General biological regularities of the evolution of chronaki in phylogenesis and ontogenesis. So, the transition from smooth slow-twitch muscles to quickly shrinking striated ironaxe shortened a thousand times. The large value of chronaki muscles of the embryo is shortened in early postnatal period and reaches the shortest values in adults.
French neurologist Bourguignon (G. Bourguignon) in 1915 he created clinical chronometrie. To determine chronaki were used for the discharge of capacitors of different capacity. In Fig. 2 Dana schematic diagram capacitor franksinatra, as in Fig. 3 and 4 General view of devices of different designs. The study of chronaki various muscles and nerves in healthy volunteers and patients revealed a number of regularities. In norm ironaxe muscle varies in the range of 0.04-1.0 m/sec. There is a certain ratio of chronaki muscles-antagonists; ironaxe flexor on the hands in 2-3 times shorter than the extensor, ironaxe distal muscles of the limbs longer than proximal.
The doctrine of chronaki put forth the concept of isochronism. Distribution of excitation from one tissue to another (for example, from the nerve to the muscle) due isochronism, ie, the ability of these tissues to develop arousal at the same speed. This is evidenced by the same or close chronaki nerve and muscle. Isochronism individual links reflex arc explains the passing of excitation by a complex reflex pathways. If for any reason ironaxe one link is markedly different from chronaki another, you heterochronies, preventing the transfer of excitation. The number of Soviet researchers have put forward idea about dynamic isochronism that is not pre-existent, and is created in the process of physiological activity.
The level of chronaki muscle is largely due to the condition of the nerve centers. Ironaxe muscles, preserving normal communication with the Central nervous system, called subordinate. Ironaxe muscle deprived of this connection is referred to as the constitutional and depends on the properties of the muscles themselves.
Damage innervating apparatus muscles, disorders of the peripheral of the neuron (for example, polio) entail a dramatic extension of motor chronaki. Chronometrie used in neurological, surgical, partially therapeutic clinics. Dermatology, ophthalmology, amatriciana clinics are interested in determining the touch chronaki. Skin is sensitive, visual, vestibular chronaki explore feels or reflex reaction.
Chronometre helps to put early diagnosis or clarify it, to justify the forecast, identify the effectiveness of therapeutic measures.
Chronometre is of great practical importance, expanding electric diagnostics (see).

Fig. 1. Curve force - duration threshold of the stimulus. The abscissa axis is the length (time) of action of the current - t; y-axis - the power (voltage) irritating galvanic current - V.
Fig. 2. Schematic diagram capacitor franksinatra: V - a current source; L - rheostat for voltage regulation; - a set of capacitors; F - electrodes; J and 3 - key for charging and discharging capacitors.
Fig. 3. General view of the condenser franksinatra.
Fig. 4. General view of electronic franksinatra.