RU2844932C1 - Device for measuring strength of anterior abdominal wall tissues in experiment - Google Patents

Abstract

FIELD: medical science.

SUBSTANCE: invention refers to medicine, namely to devices for measuring strength of anterior abdominal wall tissues in experiment. Device comprises two clamps for fixing a segment of the anterior abdominal wall, a platform whereon two metal brackets for fixing the first clamp are mounted. Clamp for fixing a portion of the anterior abdominal wall consists of two transparent plates 200×10×15 mm with sharpened metal rods fixed in three rows by eight on each plate inner surface. On edges of each clamp on both sides of lower plate of clamp there is a metal pin with thread, protruding above surface of plate. Clamp is fixed to brackets by means of metal cable. Between two clamp plates there is a lug nut. Metal cable of the second clamp faces the opposite side and is fixed to one of the rings of the strain gauge. Second ring of the strain gauge is fixed to the brackets of the dynamic part of the force input device by means of a metal cable. Strain gauge is connected by a cable to the electronic unit of the dynamometer ACD/1R-50/1I-2. Force input device comprises a static part configured for fixation and movement in the platform four holes with diameter of 15 mm, located along the force input device motion vector, and a dynamic part configured to be driven by the rotation of the threaded inner pin by means of the handle of the device, to impart a free stroke with length of 150 mm.

EFFECT: achieving the possibility of measuring the maximum tensile load with provision of the tensile load along the axis of the fixed sample, ensuring high accuracy of measurements, fast installation and easy operation, as well as the ability to examine sections of the anterior abdominal wall of different topography and mesh implants used in herniology.

1 cl, 7 dwg, 4 ex

Description

The device for measuring the strength of the tissues of the anterior abdominal wall in an experiment relates to medicine, namely to experimental testing and measurement techniques in medicine, and can be used to study the breaking load of biological tissues, mesh implants and surgical plastics of the anterior abdominal wall.

From the prior art, the INSTRON ELECTROPULSE E3000 testing machine is known - an electrodynamic testing device designed for dynamic and static testing of a wide range of materials and components. It is designed for both dynamic and static testing of various materials and components. INSTRON ELECTROPULSE E3000 has high dynamic characteristics, the ability to operate at a frequency of more than 100 Hz, a dynamic load capacity of ±3000 N and a long-term static load capacity of ±2100 N. (URL: https://researchpark.spbu.ru/equipment-iasmk-rus/2472-iasmk-eq03-rus)

However, the INSTRON ELECTROPULSE E3000 electrodynamic testing device is a high-tech and expensive device, which limits its distribution for educational and research purposes.

A device for measuring the tension of the edges of the aponeurosis of a laparotomy wound is known (Patent RU 187472 U1 IPC A61B 5/00, A61B 17/00 published: 06.03.2019 Bulletin No. 7), which has two branches made of stainless steel 220 mm long, connected to each other using a hinge, one strip is fixed to the end of the working part of each branch and three pointed hooks are fixed to each stainless steel strip at a distance of 8 mm from each other by a welded joint for fixation to the aponeurosis. Adapters in the form of a cylindrical rod made of stainless steel are installed at the ends of the auxiliary part of the branches for mechanical connection with a strain gauge sensor operating on compression, which is connected to an electronic dynamometer for measuring the force applied to the branches when tightening the edges of the aponeurosis of the laparotomy wound. However, the design of this utility model is aimed at measuring the tension of tissues directly in the open wound during surgical intervention to determine the further course of the operation. Also known is a device for measuring the tensile strength of a postoperative scar in an experiment (Patent RU 105824 U1 IPC A61B 19/00 published: 27.06.2011 Bulletin No. 18), characterized in that it contains laboratory stands, clamps, a fragment of biological tissue with a formed postoperative scar, fastening slings, graduated containers for receiving water or another liquid of known density, a connecting tube for connecting the graduated container with a similar container with water or another liquid of known density.

The disadvantages of the device for measuring the tensile strength of a postoperative scar in an experiment are the duration of the experiment due to the complexity of assembling and operating the invention, as well as insufficient measurement accuracy for validating the results.

When developing the proposed device, the goal was to create a device for measuring the strength of the tissues of the anterior abdominal wall in an experiment that generates the necessary breaking load, meets modern requirements for recording and measuring the results of the study, and also has low costs for the creation of the device and its operation.

The result of the implementation of the set goal is a device for measuring the strength of the tissues of the anterior abdominal wall in an experiment, which includes a platform on which are placed: a mechanical force-introducing device that acts on clamps for fixing the studied area of the anterior abdominal wall and a tensiometric sensor connected by a cable to the electronic unit of the dynamometer ACD/1P-50/1I-2 recording the results.

The device for measuring the strength of the tissues of the anterior abdominal wall in the experiment includes a platform, metal brackets, two clamps for fixing a section of the anterior abdominal wall, a force-introducing device, a tensiometric sensor with an electronic dynamometer unit (Fig. 1).

A platform made of white polymethyl methacrylate, rectangular, measuring 800*250*15 mm, on which two metal brackets are installed for fixing the first clamp. The clamp for fixing a section of the anterior abdominal wall consists of two transparent plates measuring 200*10*15 mm, with eight pointed metal rods fixed in three rows on the inner surface of each plate. A metal pin with a thread of 5 mm in diameter and protruding above the surface of the plate by 25 mm is installed along the edges of each clamp on both sides of the lower plate of the clamp. The clamp is fixed to the brackets by means of a metal cable of 2 mm in diameter and 50 mm long. Two through holes of 6 mm in diameter are formed in the upper plate of the clamp, necessary for alignment with the metal pins of the lower plate of the clamp. For tight fixation of the cadaver material, a petal nut with an internal thread diameter of 5 mm is provided between the two plates of the clamp (Fig. 2).

The metal cable of the second clamp is turned in the opposite direction and fixed to one of the rings of the tensiometric sensor. The second ring of the tensiometric sensor is fixed to the brackets of the movable part of the force-introducing device by means of a metal cable 2 mm in diameter.

The strain gauge is connected by a cable to the electronic unit of the dynamometer АЦД/1Р-50/1И-2, located on the platform below the gauge in a niche for the dynamometer measuring 176*85*10 mm (Fig. 3). The force-input device consists of static and dynamic parts. The static part is fixed in the platform holes, and the dynamic part is set in motion by rotating the threaded internal pin using the device handle, thereby giving a free stroke of 150 mm.

The static part of the force-introducing device can, if necessary, move in four holes of the device platform with a diameter of 15 mm, located along the vector of movement of the force-introducing device. The movement of the static part of the force-introducing device is necessary to create tension, depends on each specific experiment and is determined by the properties of the cadaver material (Fig. 4).

Symmetrically located at the corners of the platform at a distance of 2 cm from each edge of the platform are 4 silicone suction cups with a diameter of 3 cm, providing fixation and cushioning.

To implement the proposed device for measuring the strength of the tissues of the anterior abdominal wall in the experiment, a section of the anterior abdominal wall is fixed in the clamp plates of the device. The presence of sharpened metal rods on the inner surface of the clamps ensures strong, immobile fixation of the cadaver material.

After fixing the cadaver material, pre-tensioning is performed by rearranging the static part of the force-introducing device; this is necessary to remove the sagging of the fixing cables and cadaver material between the clamps. The dynamometer is turned on and the threaded stud is set in motion by rotating its handle clockwise until the cadaver material breaks. The parameters from the dynamometer are recorded in the table.

The proposed device is illustrated by the following examples.

Example No. 1. Measuring the rupture force of an intact aponeurosis. The cadaveric complex of the anterior abdominal wall of the epigastric region with a white line length of 12 cm is fixed between clamps and pre-tensioned with the static part of the force-introducing device. Then the dynamometer is turned on. The threaded pin is set in motion by rotating its handle clockwise. The rupture force was 256 N (Fig. 5).

Example No. 2. Measuring the rupture force of a sutured laparotomy wound with single interrupted sutures after a midline laparotomy. The cadaveric cadaveric complex of the anterior abdominal wall of the mesogastric region is dissected along the white line and sutured with single interrupted sutures using Capron USP 1 thread with a pitch of 8 mm. The complex is fixed between clamps and pretensioned with the static part of the force-introducing device. Then the dynamometer is turned on. The threaded pin is set in motion by rotating its handle clockwise until the suture ruptures. The rupture force was 24.4 N.

Example No. 3. Measuring the rupture force of the plication of the diastasis of the rectus abdominis muscles with single interrupted sutures using Prolen 2/0 thread.

The cadaveric complex of the anterior abdominal wall of the mesogastric region is sutured with single interrupted sutures using Prolen 2/0 thread with a pitch of 8 mm. The complex is fixed between clamps and pre-tensioned with the static part of the force-introducing device. Then the dynamometer is turned on. The threaded pin is set in motion by rotating its handle clockwise until the sutures are cut. The rupture force was 25.4 N (Fig. 6).

Example No. 4. Measurement of the rupture force of plication of the diastasis of the rectus abdominis muscles with a continuous V-loc 2/0 thread.

The cadaveric cadaveric complex of the anterior abdominal wall of the mesogastric region is sutured with a continuous V-loc 2/0 thread with a pitch of 7 mm. The complex is fixed between clamps and pre-tensioned with the static part of the force-introducing device. Then the dynamometer is turned on. The threaded pin is set in motion by rotating its handle clockwise until the sutures are cut. The rupture force was 32.4 N (Fig. 7). The device for measuring the strength of the anterior abdominal wall tissues in the experiment allows measuring the rupture force of cadaveric tissues from different topographic areas of the anterior abdominal wall. The device can be used both on an intact aponeurosis and after suturing tissues after laparotomy, plastic surgery of the anterior abdominal wall with local tissues or a mesh implant, as well as after methods of correcting diastasis of the rectus abdominis muscles.

Thus, the device for measuring the strength of stitched fabrics in the experiment has the following advantages:

1. the ability to measure the maximum breaking load;

2. the breaking load is applied along the axis of the fixed sample;

3. high measurement accuracy;

4. speed of installation;

5. ease of operation;

6. has low costs for the creation of the device and its operation;

7. the ability to examine areas of the anterior abdominal wall with different topography;

8. the opportunity to study mesh implants used in herniology.

Claims (1)

A device for measuring the strength of the anterior abdominal wall tissues in an experiment, comprising two clamps for fixing a section of the anterior abdominal wall, a platform on which two metal brackets are mounted for fixing the first clamp; wherein the clamp for fixing a section of the anterior abdominal wall consists of two transparent plates measuring 200×10×15 mm with pointed metal rods fixed in three rows of eight on the inner surface of each plate, a metal threaded pin protruding above the surface of the plate is mounted along the edges of each clamp on both sides of the lower plate of the clamp, the clamp is fixed to the brackets by means of a metal cable, a petal nut is located between the two plates of the clamp; the metal cable of the second clamp faces the opposite side and is fixed to one of the rings of the tensiometric sensor; the second ring of the tensiometric sensor is fixed to the brackets of the dynamic part of the force-introducing device by means of a metal cable; the tensiometric sensor is connected by a cable to the electronic unit of the dynamometer ACD/1R-50/1I-2; wherein the force-introducing device comprises a static part, made with the possibility of fixation and movement in four holes of the platform with a diameter of 15 mm, located along the vector of movement of the force-introducing device, and a dynamic part, made with the possibility of setting in motion by rotation of a threaded internal stud using the handle of the device, to give a free stroke of 150 mm in length.