SU1303139A1 - Transducer of uterine contractions force - Google Patents

Abstract

The invention relates to melt technology and, more precisely, to a force transducer into an electrical signal, intended to measure the strength of uterine contractions during labor contractions. The purpose of the invention is to improve the accuracy of measurements of the strength of uterine contractions. The uterine contraction force transducer includes a housing 1, an elastic element 2, strain gauges 3, a plate 4 for fastening the pilot 5, made in the form of a fungus with a threaded channel in the lower part, trimming screws 6 and 7, hemispherical supports 8 and 9, a support ring 10. Under Actually, the si.ly on the pilot 5 is deformed by A.Aastina 4 .. on which the pilot is strengthened. Through the trimmer screw 7, the deformation is transferred to the elastic element 2. The strain gages 3 of type KF5111-400- pasted on the yiipyinui element. 16 is connected by a bridge circuit, it in the absence of si, which is the bridge of resistance, I find myself in a state of slight imbalance with a constant value of the output voltage. (Uo) on the diagonal of the bridge. The value of Uij is set adjusted by the screw 6 by the way of preloading the elastic element. The deformed elastic element under the action of force increases the imbalance of the resistance bridge due to the deformation of the resistance strain gages, and a voltage (U) is established on the bridge diagonal proportional to the force F acting on the pilot, the displacement in the installation plane does not deform it, since the trimmer screw forms a loosened link with an elastic element with the H1 rnr const, i1nen1 properties with an elastic element. Г S (Л со о со со со

Description

The invention relates to medical technology, namely to a force transducer into an electrical signal, and can be applied in the generic compartments to measure the strength of uterine contractions during labor contractions.

The aim of the invention is to improve the accuracy of measurements of the strength of uterine contractions.

FIG. 1 shows the proposed device, a general view; in fig. 2 - distribution of active forces.

The uterine contraction force transducer consists of a body 1, an elastic element 2 with glued strain gauges 3, a plate 4 for fastening pelota 5 on the axis of the transducer, a trimming screw 7. The elastic element is supported by four hemispherical supports 8 on the supporting plane on the bottom of the body and is connected by a trimming screw The conical end of which enters freely into the hole in the center of the plate of the elastic element, with the pilot through the threaded connection. The center of the elastic element is chosen as the intersection of the diagonals of the plate of the elastic element.

The pilot, made in the form of a fungus with a threaded channel in the lower part, is rigidly fixed on the mount plate of the pilot. The plate with one end is fixed on the supporting annular recess in the upper part of the inner wall of the housing, and the free end rests on the hemispherical supports 9, on the supporting annular recess 10. The rigidity of the mounting plate of the elastic element is 2-2.5 times less than the rigidity of the elastic element (3-10 N / m).

The Converter operates as follows.

Under the action of the force F on the pilot 5, the plate 4 is deformed, on which the pilot is fixed. Through the trimmer screw 7, the deformation is transferred to the elastic element 2. The tensoriser 3 of type KF5P1-400-A16 pasted on the elastic element are switched on but on the bridge circuit, and in the absence of force F the resistance bridge is in a state of slight imbalance with a constant value of the output voltage ( L / o) on the diagonal of the bridge. The voltage value (L o) is set by the trimmer screw 6 by pre-pressing the elastic element. The deformed elastic element under the force F increases the imbalance of the resistance bridge due to the deformation of the strain resistors, and a voltage (U) is established on the bridge diagonal, which is proportional to the force F acting on the pilot.

The accuracy of transducers designed for low pressure depends on the magnitude of the sliding friction force on the supports and the hysteresis of the stresses at the point of attachment of the elastic element. To reduce the friction and hysteric force, the elastic element is made in the form of a plate by stamping with four hemispherical supports installed at the corners. The sliding friction force on the supports is replaced by rolling friction force.

In order to deform the elastic element and at the same time not slide on the supports, the radius of the latter is selected as follows. When the deflection X of an elastic element is long / it moves relative to the fulcrum by the distance

4-vW - ()

then the smallest radius of the hemispherical supports is defined as

/ 6 (1-2 V

(2)

where / is the length of the elastic element;

6 - deflection of the elastic element at nominal force.

For constructive reasons, the radius is chosen from

.5 (l-2V -jr) (3)

and the height h Rn The elastic element has three degrees of freedom, and moving in the installation plane does not cause its deformation, since the trimmer screw forms a backlash link with swivel properties with an elastic element, for which the screw-shaped end of the screw enters the hole in the center of the elastic element, pressing it .

Claims (1)

Invention Formula Uterine contraction force transducer, comprising a housing, an elastic element with strain gauges, a pilot with a trimmer screw and a plate for fastening it, characterized in that, in order to improve the accuracy of measuring uterine contractions, the elastic element and the plate for fastening the pilot are freely hemisphericly mounted relative to the surface of the housing, wherein the elastic element is located under the pelota-mounting plate mounted in an annular recess made in the upper part of the housing. . ,,, „„ .j  V / / / / / x u / / / p F //. 2