From Big Medical Encyclopedia

STROBOSKOPIYA (Greek strobos spinning, random motion + skopeo to observe, investigate) — a method of a research of bystry movements (fluctuations, vibrations) of objects, in particular phonatory bands (laringostroboskopiya), based on so-called stroboscopic effect.

The principle C. is described in 1829 by the physicist of J. A. F. Plateau, to-ry established that if to light quickly fluctuating subject with flashes of light, frequency to-rykh matches the frequency of fluctuations of a subject, then the stroboscopic effect, i.e. illusory impression of an immovability of this subject is created. If the frequency of flashes does not match the frequency of fluctuations, then the fluctuating body at the time of the following flash will fall into other state. Thereof an impression about the slowed-down movement is made. At continuous oscillatory process this seeming well noticeable movement is right display of more bystry valid movement.

For the first time the stroboscopic effect in laryngology for the purpose of studying of a functional condition of a throat applied in 1878 Mr. Ertel (M. J. Oertel), and from domestic researchers — D. I. Koshlakov (1884). The possibility of use of S. in laryngology is connected with features of function of phonatory bands (voice folds, T.), to-rye at survey at the time of phonation (when inspected says a sound of E or I) seem motionless. Actually they, as well as any other sounding body, vibrate. However, sight can distinguish separate fluctuations if they are made no more than 16 times in 1 sec. The number of fluctuations of phonatory bands, even at the lowest bass notes, makes not less than 32 in 1 sec. therefore visual objects merge and an impression of their immovability is made. Using stroboscopic effect, it is possible to observe phonatory bands not only in a motionless state, but also fluctuating. So, the seeming slow fluctuations are observed at small discrepancy of frequency of flashes of light with a frequency of fluctuations of phonatory bands, bystry fluctuations — at bigger discrepancy of the specified parameters. If discrepancy is a miscellaneous for each of phonatory bands, then and the stroboscopic picture for each of them will be various: one of sheaves will seem fluctuating slowly, and the second — quickly.

Laringostroboskopiya is used for studying of nature of functional disturbances of a voice, preliminary differential diagnosis of high-quality and malignant new growths of phonatory bands, for assessment of results of treatment, definition of working capacity of persons, the profession to-rykh is connected with big speech and vocal loading, and studying of questions of physiology voices (see). The value of a method C. consists that with its help it is possible to reveal symptoms of pathology at early stages of a disease when other methods to find them do not work well.

For carrying out a laringostrobo-skopiya use special devices — stroboscopes (laringo-stroboscopes). Earlier applied mechanical laringostroboskopa (strobofona), in a crust, time is used by more advanced — electronic. In modern electronic stroboscopes the frequency of flashes of a flashlight neon valve by means of the laryngophone automatically adapts on height to the sound made inspected. Special adaptation of an electronic stroboscope — the multivibrator allows to create artificially asynchrony between the frequency of flashes of a neon lamp and frequency of fluctuations of phonatory bands at phonation.

Carrying out a laringostroboskopiya usually does not demand pre-treatment. Only at persons with the raised emetic reflex surface anesthesia of a mucous membrane of a throat is shown. By means of a frontal mirror the blinking light through a guttural mirror is directed to a throat and reveal existence or lack of fonatorny fluctuations of phonatory bands, their uniformity on the frequency and amplitude, character of shift of a mucous membrane on free edge of phonatory bands, etc. Normal at the same time are observed uniform on frequency and on amplitude of fluctuation of phonatory bands. They are opposite in the direction, are made preferential in the horizontal plane, cover all mass of phonatory bands. Emergence of a periodic irregularity of fluctuations is characteristic of functional frustration. At organic lesion (a tumor, tuberculosis) permanent limited disturbance of fluctuations of one phonatory band comes to light. At malignant tumors of a throat fonatorny fluctuations of phonatory bands on the party of defeat are absent, at high-quality — they are often asynchronous, weakened, have smaller amplitude.

Bibliography: Vasilenko Yu. S. Value of separate indicators of a dipole cycle of voice folds in the general assessment of a stroboscopic picture, Vestn. from-rinolar., No. 5, page 63, 1972; it, the La ringostroboskopichesky picture of functional diseases of a throat at persons of speech professions, Zhurn. ushn., nose. and throats, Bol., No. 3, page 39, 1974; Ibragimova S. I. and Bekbulatov G. T. Electronic stroboskopiya, M., 1970; Koshlakovd. I. Types of fluctuations of phonatory bands, Doctor, No. 38, page 648, 1884; Mareev V. I. and Papshits-k and y Yu. A. Stroboskopiya at hyperplastic and tumoral processes of a throat, Vestn. otorinolar., No. 5, page 71, 1972; Yakovleva I. Ya. About a stroboskopiya using mechanical and electronic stroboscopes, Zhurn. ushn., nose. and throats, Bol., No. 6, page 60, 1965; S with h p-h and of 1 E. Die Stroboskopie in der prak-tischen Laryngologie, Stuttgart, 1960; S e i d n e r W., Wendler J. u. Haifa e d 1 G. Mikrostroboskopie, Folia pho-niat. (Basel), Bd 24, S. 81, 1972; Wendler J. Die Bedeutung der Stimmstarke bei der stroboskopischen Untersuchung, ibid., Bd 19, S. 73, 1967.

Yu. S. Vasilenko.