RU2255645C2 - Flexible controllable tube usable with endoscope - Google Patents

Abstract

FIELD: medical engineering.

SUBSTANCE: device has identical, in series connected terminal articulating ring members having two symmetry planes with four cylindrical holes produced thereon in the symmetry planes for receiving control ropes. Mating ring members are 90° turned relative to each other about longitudinal tube axis. Two protrusions having prismatic grooves of triangular cross-section are produced in the first symmetry plane on one side of the ring member. Two symmetric grooves are produced in the second symmetry plane having prismatic teeth of triangular cross-section on the internal surface side of the member. Angle near tooth top is less than the angle near the groove apex. Tooth height is not less than groove depth. Angle between planes forming protrusion groove is greater than the angle between surfaces forming tooth and less than 90°.

EFFECT: high endoscope operation reliability; simplified production process.

6 dwg

Description

The invention relates to optical-mechanical engineering, in particular to devices that are used for examining and treating hollow organs and body cavities in medicine, for examining hard-to-reach hollow spaces with equipment, in endoscopes it is that part of the device, by changing the position of which the operator performs a complete inspection of the test cavity.

Known flexible guided tube for an endoscope (US Pat. UK No. 1447901 MKI A 61 B 1/00, priority date 05.02.70, publ. 1971), containing ring links with protrusions on one side and depressions on the other and control rods missing into the holes of the links, captured by an elastic protective sheath.

The disadvantage is the limited reliability of the tube with a decrease in its diameter, as a result of which, with the slightest off-axis force, the links come out of engagement and the flexible tube breaks.

Known flexible guided tube (US Pat. US No. 3998216 MKI A 61 1/06, priority date 05.10.76) containing an inner cylindrical flexible braid, to the outer side of which is adjacent a flexible skeleton made of a set of rings having a protrusion at one end, and on the second, a concentrating recess, and control cables passing inside the flexible tube in the lateral notches of the tape spring located inside the hollow cylindrical braid.

The disadvantage of this tube is its limited reliability, due to the fact that the fixation of the ring elements of the flexible skeleton is carried out on a flexible cylindrical wicker structure, which does not ensure the constancy of the installation of one element relative to another due to the fact that the control cables interact with the rings by braiding. When the tube is bent, the engagement of the spiky tooth of the notch ring and the failure of the cylinder is possible.

A flexible tubular design of endoscopes is known (USSR AS No. 1329603 MKI A 61 B 1/00, priority date 10/12/85), containing annular elements resting on one another, made in the form of hollow prismatic or cylindrical links, one of which has restrictive surfaces provided at least two protruding abutment teeth, and the other at least two horseshoe-shaped protrusions, the annular elements are arranged so that the abutment teeth of one element enter holes in the horseshoe-shaped protrusion of the other element.

The disadvantage of this controlled tube is the complexity (laboriousness) of manufacturing the ring elements with precisely mating surfaces of the abutment teeth and holes in the horseshoe-shaped protrusions.

A flexible controllable tube is known for an endoscope (AS USSR No. 1509031 MKI A 61 B 1/00, F 16 C 1/00, priority date 04/01/87), containing an elastic sheath, inside of which are located successively connected tubular links with passing inside control cables and hinge elements, each link being made with an end recess and a bore, a hinge element in the form of a cylindrical roller with end heads, while in the opposite bores of two adjacent links there is a cylindrical part of the hinge element, one of the end olovok located in recesses, the other is in contact with the inner surface of the tubular member.

The disadvantage of this tube is the limited functionality due to the lack of a panoramic view of the cavity under study. The tube can only bend in the x-x or y-y plane.

Known flexible guided tube (USSR AS No. 1480806 MKI A 61 B 1/00, priority date 05/23/89), containing hollow identical articulated elements having two longitudinal grooves for cables and four control cables, the elements have outer flats, parallel to the plane passing through the axis of symmetry of the grooves, from one of the ends the elements are bounded by a concave and convex cylindrical surfaces from the other, and the axis of symmetry of the concave, convex cylindrical surfaces and the longitudinal axis of the tube are mutually perpendicular rny and adjacent elements are deployed relative to one another by 90 ° around the longitudinal axis of the tube.

The disadvantage of this flexible steered tube is its limited reliability.

The closest in technical essence to the proposed and selected by the authors as a prototype is a flexible controlled tube (US Pat. RF No. 2068229 MKI A 61 V 1/00, priority date 10.06.93), containing an elastic shell, inside of which are connected series-connected links containing an annular element and two hinged elements symmetrically arranged around the circumference, made in the form of rollers, and in the next link, the axes of the hinged elements are rotated 90 ° in pairs with respect to the axes of the hinged elements of the previous link, tr control axes are located inside through holes having a toroidal shape, annular and corresponding hinge elements.

The disadvantages of this tube are:

- limited reliability due to the large number of elements used;

- low manufacturability, determined by the need for accurate manufacturing and fixing the relative position of the hinge elements with a surface curvature equal to the surface curvature of the ring elements.

The problem of increasing the reliability of the endoscope is solved due to the fact that the annular element has two planes of symmetry, which allows one to make a distal end based on the same type element, consisting of identical conjugated links, which simplifies the manufacturing technology of the distal part and its assembly by reducing the number of mating surfaces.

This is achieved by the fact that in a flexible controlled tube for an endoscope containing the same hinged ring elements with two planes of symmetry, on which four cylindrical holes for control cables are made, the axes of which are parallel to the axis of the ring, the conjugated ring elements are rotated 90 ° relative to each other around the longitudinal tube axis.

Distinctive features of the proposed flexible tube are:

- on one side of the annular element in the first plane of symmetry there are two protrusions with prismatic grooves and a triangular section from the side of the inner surface of the annular element;

- on the other side of the element in the second plane of symmetry two symmetrical grooves are made with a prismatic tooth of triangular section from the side of the inner surface of the element;

- the angle at the top of the tooth is less than the angle at the top of the groove;

- the height of the tooth is not less than the depth of the groove;

- the angle between the faces forming the groove of the protrusion is greater than the angle between the faces forming the tooth, and less than 90 °;

- the implementation of articulated annular elements with two planes of symmetry, which allows on the basis of one typical element to perform the distal part of the endoscope, consisting of paired identical links -

which allows you to expand the functionality, reduce residual torque, simplify the manufacturing technology of ring elements and the assembly of the distal part, as well as increase the reliability of the endoscope as a whole.

The essence of the invention is illustrated by drawings, in which Fig. 1 shows a flexible controlled tube, in Fig. 2 is a horizontal projection of an annular element, in Fig. 3 is a frontal projection of an annular element, in Figs. 4, 5 are respectively horizontal and frontal projections of an annular element in the second plane of symmetry, Fig.6 is a perspective view of the annular element.

The element with prismatic teeth of the horizontal projection (figure 4) is included in the grooves formed by the protrusions in the horizontal projection (figure 2) of the next element. The prismatic teeth of the frontal projection (figure 2) are included in the grooves formed by the protrusions of the frontal projection (figure 4) of the subsequent link. Thus, a sequential conjugation of these protrusions and grooves is formed when the annular elements are connected in series.

Flexible controlled tube for the endoscope (Fig. 1) contains identical series-connected hinged ring elements 1 with four through holes 2 (Figs. 2, 4), the axes of which are evenly spaced parallel to the axis of the tube (XX), the conjugated ring elements are rotated 90 ° relative to each other around the axis of the tube, the control cables 3 are fixed in the ring 4 at the distal end, passed through the internal holes 2 of the ring elements 1 and ring 5 at the other end of the tube, the ends of Bowden braids 6 are fixed in the ring 5. The control cables 3 pass through these webs to the rods of the control mechanism (this mechanism is not shown in FIG. 1. Its technical implementation may be similar to the control mechanism according to AS USSR No. 871786, etc.). To protect the links from the environment, they can be placed, if necessary, inside the elastic shell 7.

The annular element 1 has two planes of symmetry (FIGS. 2, 3 and FIGS. 4, 5, respectively), which allows, on the basis of one typical element, to perform the distal part of the endoscope, consisting of paired identical links rotated 90 ° relative to each other. In the annular element 1 there are four through holes 2, the axes of which are parallel to the axis of the tube XX. The holes 2 are located symmetrically around a circle with a diameter L parallel to the axis of the tube X-X (see figure 2, 4).

To eliminate residual torque when bending the tube on the mating surfaces of the ring:

- in the first plane of symmetry made two protrusions with prismatic grooves of a triangular section from the side of the inner surface of the annular element 1;

- in the second plane of symmetry two symmetrical grooves are made with a prismatic tooth of triangular section from the side of the inner surface of the element 1; allowing to exclude (or reduce) slippage of the data of the mating (contacted) surfaces relative to each other.

Moreover, the angle at the top of the tooth is less than the angle at the top of the groove, and the height of the tooth is not less than the depth of the groove. The angle between the faces forming the groove of the protrusion is greater than the angle between the faces forming the tooth, and less than 90 °.

Thus, the rotation angle of two adjacent links in the same plane, α:

where α _max - max angle of deviation of the axis of the endoscope lens from the initial position in one plane;

n is the number of links.

To increase the durability of the control cables 3 by reducing the friction force and more smooth bending of the tube in the annular element 1 (Fig.3), the holes 2 on the opposite side of the tooth and groove are toroidal in shape.

In the initial state, all control cables 3 are evenly stretched. In this case, the axis of symmetry of the ring elements 1 are parallel to the axis XX of the tube.

Flexible guided tube for the endoscope (figure 1) works as follows.

Using the control mechanism, one of the control cables 3 (for example, 3.1 (Fig. 1)) is moved by Δ. This movement will cause the displacement of the odd ring elements 1, which ensures bending of the tube in the direction of tension of the cable 3.1. To bend the tube in the opposite direction, move the cable 3.2 of this pair. Similarly, when moving a pair of control cables 3.3, 3.4, the tube bends in a plane perpendicular to the bending plane when moving the cables 3.1, 3.2.

Combining the movements of the control cables 3, a panoramic overview of the cavity under study is performed without rotation of all the elements of the distal end around the axis.

Thus, as a result of the application of the proposed flexible controlled tube:

- increases the reliability of the endoscope with a flexible controlled tube of the proposed design due to the fact that the annular element has two planes of symmetry, which allows on the basis of one typical element to perform the distal part of the endoscope, consisting of paired identical links rotated 90 ° relative to each other;

- simplifies the manufacturing technology of the annular elements of the tube and their assembly;

- expanding functionality by providing a panoramic view of the investigated cavity without rotation of all elements of the distal end around the axis;

- eliminates residual torque.

Claims (1)

A flexible controlled tube containing the same, sequentially connected hinged ring elements with two planes of symmetry, on which four cylindrical holes for control cables are made in the planes of symmetry, the conjugated ring elements are rotated relative to each other by 90 ° about the longitudinal axis of the tube, characterized in that on one side of the annular element in the first plane of symmetry there are two protrusions with prismatic grooves of a triangular section on the side of the inner surface of the rings of the element, on the other side of the element in the second plane of symmetry two symmetrical grooves are made with a prismatic tooth of triangular section on the side of the inner surface of the element, the angle at the top of the tooth is less than the angle at the top of the groove, and the height of the tooth is not less than the depth of the groove, while the angle between the faces, forming a groove of the protrusion, more than the angle between the faces that form the tooth, and less than 90 °.

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