(Greek endon inside + radio sounding; a synonym endoradiometry) — a method of a biotelemetric research of activity of digestive tract and other hollow bodies by means of endoradiosondes.
Development of a method E. became possible after creation of semiconductors, microminiature electronic circuits and small-size power supplies that led to creation of tiny endoradiosondes (intestinal sensors, radiopills, radiopills, telemetric capsules). In 1957 Ferrar (I. T. Farrar) in the USA designed a radiopill for tonometry in went. - kish. path. In 1958 Mr. of Ardenne (M. of Ardenne) in GDR the intestinal transmitter of own design applied to tonometry and acidities in went. - kish. path of the person. Later radiopills for E were created. at children. In the USSR works in the area E. are connected with names E. B. Babsky (t. 10, additional materials), A. M. Sorina and A.S. Belousov (1960).
AA. found application for hl. obr. in gastroenterology and obstetric and gynecologic practice. In gastroenterology of the indication to use E. with the diagnostic purpose the same, as at a usual zondirova-
of Fig. 1. Diagrammatic representation of radio-telemetric system: 1 — a radio ox
ny, let out by the radiopill which is in digestive tract; 2 — the accepting device; z — the analyzing device; 4 — the chart recorder.
scientific research institute of a stomach (see) and a duodenum (see. Duodenal sounding). Advantages E. lack of adverse effects on an organism, and also a possibility of long overseeing is the course of secretion and other processes in went. - kish. path almost under natural conditions. At the same time the analysis of kislotovydelitelny ability of a stomach can be carried out not only in digestive, but also in mezhpishchevari-telny the periods of its secretion.
A complex of the equipment for E. includes a tiny radio transmitter (radiopill), the accepting device, the radio receiver and registrar (fig. 1). The radiopill represents a microdimension-ny the transmitter (length of 11 — 13 mm, to dia. 8 mm) convenient for a proglatyvaniye and capable it is free to move on a digestive tract (fig. 2). Domestic about -
Fig. 2. Outward of radiopills (endoradiosondes) for a research of temperature (1), pressure (2) and hydrogen ion exponent — pH (5).
the myshlennost releases radiopills for definition of hydrogen ion exponent (pH), pressure and temperature in cavities of digestive organs. The measuring sensitivity of pH reaches 0,2. By means of dates -
Chick pressure register changes of hydrostatic pressure in l. - kish. a path in the range from About to 200 cm w.g. As the sensor of temperature use the ceramic condenser with a high temperature coefficient or the temperaturozavisimy transistor. The measuring sensitivity reaches ± 0,1 °. Also the radiopills perceiving at the same time pH and hydrostatic pressure are designed. Radiopills for definition of ion concentration of chlorine, level of ionizing radiation, partial tension of oxygen, existence in l are created. - kish. path of «free» blood. Perhaps also determination of speed of splitting of nutrients in went. - kish. path. For this purpose place substrate (protein, fat or carbohydrate) in the capsule, to-ry in process of splitting by its enzymes went. - kish. a path changes electric characteristics of the sensor. The signals transformed by the sensor cause the changes of frequency of electromagnetic oscillations of the related generator proportional to changes of the studied parameter that allows to receive rather exact quantitative expression of these or those physiological processes.
The source of electric food which is in a radiopill consists of the oxide mercury cells ensuring functioning of the generator throughout 40 — 100 hour. The so-called passive radiopills working from the external power supply which is out of a human body are developed. Similar radiopills differ from radiopills with the independent power supply in the smaller amount and unlimited term of continuous operation. By means of passive radiopills new data on features of secretory activity of a stomach at children of chest age are obtained. The signals radiated by a radiopill are perceived by the special antenna which is near inspected or directly on his body. Moving on went. - kish. to a path, the radiopill transfers information on the processes happening in its various departments. In this regard it is necessary to know exact location of a radiopill and speed of its movement. Keeping track of by movement of a radiopill is carried out by the principle of a radiopelengovaniye along with registration of the studied parameter. If necessary to investigate intra-gastralny pH in a pipe the radiopill is fixed on one end of a thin silk thread, and the free end of a thread is fixed on skin of a cheek an adhesive plaster so that the capsule kept in a stomach at distance of 50 — 55 cm from edge of teeth.
The research by means of radiopills is conducted on an empty stomach in the morning. Within an hour define a curve of intragastric acidity in the interdigestive period of secretion. Then after a trial breakfast dynamics of secretion is investigated. The general duration of a research makes apprx. 3 — 3Va hour. The radiopill with the thermal sensor allows to find acute local inflammatory processes in a small or large intestine.
Repeated use of radiopills demands their sterilization before the repeated use. As hot ways of sterilization of the capsule put a radiopill out of action, use only chemical ways of sterilization, immersing the capsule in 6% solution of hydrogen peroxide at f 18 — 20 ° for 30 — 180 min., or in 3% solution of formaldehyde for 30 min., or 0,1% solution «Dezok-son-1» for 20 min.
E. use also in obstetric and gynecologic practice. Out of pregnancy a method E. allows to determine both the intrauterine, and intra vulval pressure, and also temperature in a vagina. Fiziol. researches of sokratitelny function of a uterus allowed to obtain more exact information both on dynamics of patrimonial process, and on sokratitelny function of a myometrium in the intergeneric period. Registered at E. fluctuations of intrauterine pressure reflect rhythmic reductions and a condition of a tone of a uterus. The radiopill attached to sterile thread is placed in a back vault of the vagina. Thread 20 cm long is fixed on a front abdominal wall. Clearly the changes of pressure arising under the influence of breath, change of a pose, a natuzhivaniye, reduction of muscles of a pelvic bottom are registered. Researches of temperature in a vagina are conducted in various phases of a menstrual cycle (see).
In an experiment began to use E. for a research of dynamics of pressure in a bladder.
See also Biotelemetry, Sensors.
Bibliography: Babsky E. B., With about -
Rihn A. M. and Davydov S. N. Devices of endoradio sounding, Principle of design, Technology of use, M.,
1975, bibliogr.; Belousov A. S. and N. I. Endoradiozondirovaniye's Hawk in gastroenterologies, Kiev, 1972, bibliogr.; Fishzon-Ryss Yu. I. Modern methods of a research of gastric secretion, L., 1972; Gleason D.M. Lattimer J. To. A miniature radio transmitter which in incerted into bladder and which records voiding pressures, J. Urol. (Baltimore), v. 87, p. 507, 1962; Johansen H. Untersuchungen zur telemetrischen Ubertragung pansenphysiolo-gischer Kennwerte durch eine hochfrequen-zgespeiste Endoradiosonde, Arch. Tierernah-rung, Bd 21, S. 321, 1971. Yu. A. Fadeyev.