SU1657144A1 - Intracavitary impedance plethysmography sensor - Google Patents

Abstract

The invention relates to medical technology, in particular to functional diagnostics. The purpose of the invention is to reduce the depth of the zone of maximum sensitivity of the sensor when measuring the impedances of symmetrical sections of the walls of the cavity organ. The sensor consists of a cylindrical case, along the perimeter of which, parallel to its axis, are located diametrically opposite to the forming current electrodes, and between them are placed symmetric pairs of potentiometric electrodes 2 or more

Description

This invention relates to the field of medical technology, in particular to functional diagnostics.

The aim of the invention is to reduce the depth of the zone of maximum sensitivity of the sensor while simultaneously measuring the impedances of the symmetrical sections of the walls of the cavity organ.

Fig. 1 shows diagrams of the intracavitary rheoplethysmographic sensor; FIG. 2 is a section A — A in FIG. one.

The sensor consists of a housing 1 in the form of a hollow cylinder on which current electrodes 2 and 3 are located. Potentiometric electrodes 4 and 5 are located symmetrically to potentiometric electrodes 6 and 7. Conductors (not shown) connect the electrodes to a reoplethysmograph. The distance between the centers of the current electrodes (along the shortest arc) is

G. I - l II -12

where d is the diameter of the base.

The distance between the potentiometric electrodes is chosen from the condition

, fi -I rcd

si - Ј-.

JО

which ensures that the potentiometric electrodes are located in the zone of uniform density of the measuring current.

The length of the electrode is chosen equal to the length of the test area.

The sensor works as follows. The sensor is located in an electrically conductive biological environment. The current electrodes 2 and 3 are connected by means of connecting drives located inside the cylindrical case 1 and are supplied with a measuring current, the value of which is constant in the range of possible changes in electrical conductivity between current electrodes 2 and 3. The measuring current flowing between current electrodes 2 and 3 creates a voltage drop between the pairs of potentiometric electrodes 4 and 5, 6 and 7. This voltage is used by calculating

(L

about ate

four

J

impedance between pairs of potentiometric electrodes 4 and 5, 6 and 7.

Current electrodes 2 and 3 are located in diametrically opposite guides of the cylindrical body 1. This ensures equal conditions for the flow of the measuring current in a biological object on both sides of the current electrodes (provided that these areas have equal electrical conductivity).

Claims (1)

Claims of the Invention The intracavitary reoplethysmographic sensor, which contains two current and two potentiometric electrodes placed between them, is mounted on a housing made in the form of a hollow cylinder, inside of which are located the conductors connecting the electrodes with reoplethistography, characterized in that In order to reduce the depth of the zone of maximum sensitivity while measuring the impedances of symmetric sections of the walls of the cavity organ, it is equipped with a second pair of potentiometric electrodes, all ectrodes They are made straight and reinforced along the cylinder forming lines, while the current electrodes are diametrically opposite the forming ones, and the two pairs of potentiometric electrodes are symmetrically forming the two half-cylinders. 3 5 t / to reoplethysmograph Aa Fig 1