CN113267288A - Radial supporting force test experiment platform and method for thoracic aorta covered stent - Google Patents
Radial supporting force test experiment platform and method for thoracic aorta covered stent Download PDFInfo
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- CN113267288A CN113267288A CN202110634762.7A CN202110634762A CN113267288A CN 113267288 A CN113267288 A CN 113267288A CN 202110634762 A CN202110634762 A CN 202110634762A CN 113267288 A CN113267288 A CN 113267288A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
- G01L5/16—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes for measuring several components of force
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- G—PHYSICS
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/0202—Control of the test
- G01N2203/0212—Theories, calculations
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Abstract
The invention relates to a radial support force test experimental platform and a method for a covered stent of thoracic aorta, which comprises the following steps: the fixing component is used for adjusting and fixing the thoracic aorta covered stent to be measured and comprises a limiter, a secondary slide rail and a transverse slide rail; the test assembly is used for performing pressure holding on the thoracic aorta covered stent to be tested and measuring stress, and comprises a wire arranging wire, a lower wire fixing device, an upper wire fixing device, a vertical slide rail and a dynamometer; the constant-temperature water bath tank is used for simulating the real application environment of the thoracic aorta covered stent; the platform support and the back plate are used for assembling, connecting and fixing the components. Compared with the prior art, the invention improves the automation and the accuracy of the experimental platform on the premise of confirming the accuracy and credibility of the experimental result, can measure the radial supporting force of various thoracic aorta covered stents with different lengths, different thicknesses and the like, and can simulate the real and complex application condition.
Description
Technical Field
The invention relates to the technical field of biomedical textiles, in particular to a radial supporting force test experimental platform and method for a thoracic aorta covered stent.
Background
Thoracic Aortic Aneurysm (TAA) is a disease in which blood vessels are abnormally dilated to more than 15% of the diameter of a normal aorta, is a disease with low morbidity and high mortality and seriously harms human health, and the treatment method of the Thoracic Aortic Aneurysm mainly comprises drug treatment, traditional open surgery and endoluminal stent repair. The endoluminal stent repair is the most clinically applied operation at present, has the characteristics of quick recovery, small wound and few complications, and still can be accompanied with the occurrence of some complications, such as new lacerations, stent displacement, internal leakage, stent fracture and the like. The thoracic aorta covered stent comprises a stent ring and a covered membrane, the radial support performance of the stent refers to the capability of resisting deformation of the stent after radial pressure is applied to the stent, and the radial support performance of the covered stent is one of important factors influencing new lacerations.
The thoracic aorta covered stent is implanted into a human body by utilizing a delivery system, wherein the self-expanding stent is formed by contracting the covered stent in the delivery system, releasing the stent after the delivery system delivers to a specified lesion site, and the diameter of the stent is the preset stent size.
In summary, the thoracic aortic stent graft generates radial support forces within the delivery sheath and when implanted into the body vessel. The thoracic aortic stent graft needs to have suitably good radial support performance to ensure the operability of the above-mentioned operation, the quality of the operation, and the avoidance of postoperative complications. Therefore, it is necessary to perform experimental measurement and evaluation on the radial supporting force of the thoracic aorta stent graft through related experimental platforms.
At present, two methods of finite element simulation analysis and experimental device determination are mainly used for testing the radial supporting force of the thoracic aorta covered stent. The finite element simulation analysis is used for modeling the covered stent and endowing the covered stent with material properties, and the loading load is used for operation to obtain a mechanical analysis result, wherein the result has certain reference and can be used as a reference of an actual experiment, but the simulation is different from a real covered stent inevitably, and the environment and the stress condition of the covered stent are difficult to completely simulate.
The existing experimental device for testing the radial supporting force of the thoracic aorta covered stent mainly adopts a plane compression method, a V-shaped groove compression method and an iris crimp testing method. The equipment required by the plane compression method and the V-shaped groove compression method is too simple, and the supporting performance of the bracket can only be reflected by the side surface. Wherein, to V type groove compression method, because of the contact angle of the support of different external diameters and V type groove is different with the degree of depth of embedding V type groove, consequently can't carry out the comparative test to the support performance of different external diameters supports. The plane compression method can realize comparative test on the support performance of the supports with different outer diameters, but cannot reflect the difference of the compression resistance at the circumferential position. In addition, the structure of the test equipment of the iris crimp test method is complex, the self-friction between the fan-shaped blocks and the friction between the bracket and the fan-shaped blocks have certain influence on the test result, and the test requirement even for the bracket with weaker support performance can not be met. Therefore, a radial supporting force test experimental platform of the thoracic aorta covered stent, which can accurately reflect the supporting performance of the thoracic aorta covered stent, can realize comparative test on the supporting performance of stents with different outer diameters and can be closer to the practical application environment of the thoracic aorta covered stent, is urgently needed.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide the radial support force test experiment platform and the method for the covered stent of the thoracic aorta, which improve the automation and the accuracy of the experiment platform on the premise of confirming that the test result is accurate and credible, can measure the radial support force of various covered stents of the thoracic aorta with different lengths, different thicknesses and the like, and can simulate real and complex application conditions.
The purpose of the invention can be realized by the following technical scheme: the utility model provides a radial holding power test experiment platform of thoracic aorta tectorial membrane support, includes:
the fixing component is used for adjusting and fixing the thoracic aorta covered stent to be measured and comprises a limiter, a secondary slide rail and a transverse slide rail;
the test assembly is used for performing pressure gripping on the thoracic aorta covered stent to be tested and performing displacement and stress measurement and comprises a wire arranging wire, a lower wire fixing device, an upper wire fixing device, a vertical slide rail and a dynamometer;
the constant-temperature water bath tank is used for simulating the real application environment of the thoracic aorta covered stent;
the platform support and the back plate are used for assembling, connecting and fixing the components.
The limiter is connected with the upper sliding block of one or two sliding rails to realize horizontal movement and fixation. The slide rail is preferably an electric slide rail with a controllable stepping motor for controlling the movement.
Preferably, the stopper is arranged on the secondary slide rail in a sliding manner through the secondary slide block, the secondary slide rail is arranged on the transverse slide rail in a sliding manner through the transverse slide block, the transverse slide rail is fixed on the back plate, and the back plate is fixed on the platform support.
The limiting stopper is directly or indirectly fixed with a connecting plate, when the sliding block on the sliding rail connected with the limiting stopper is fixed, the left end part and the right end part of the limiting stopper are relatively static, and the integral horizontal movement and the fixation of the limiting stopper can be controlled by one sliding rail.
Further preferably, the transverse sliding block is connected with a connecting plate, a second-stage sliding rail is fixed on the connecting plate, and the second-stage sliding rail is connected with two oppositely-arranged limiters through the second-stage sliding block.
The limiting stopper is directly or indirectly fixed with a connecting plate, when the sliding block on the sliding rail connected with the limiting stopper is fixed, the left end part and the right end part of the limiting stopper are relatively static, and the integral horizontal movement and the fixation of the limiting stopper can be controlled by one sliding rail.
Still further preferably, the stopper comprises a stopper ring and a stopper through hole, the stopper rings of the two stoppers are oppositely arranged, and the stopper through hole is communicated with the stopper ring. The limiting ring can control the whole horizontal movement and fixation of the covered stent of the thoracic aorta to be tested, the limiting ring is made of materials with smooth outer surfaces, and the outer surfaces are smooth as far as possible so as to reduce the friction between the limiting ring and the covered stent to be tested. The limiting stopper through hole can enable liquid in the constant-temperature water bath tank to freely enter and exit the aorta covered stent to be detected so as to avoid the influence of hydraulic pressure difference.
Preferably, the covered stent for thoracic aorta to be tested is just sleeved on the limit ring, and the limit ring is provided with scale marks.
Preferably, the two ends of the wire arranging wire are fixed by the lower wire fixing device and the upper wire fixing device, and the wire arranging wire is pressed and held around the thoracic aorta covered stent to be measured.
Further preferably, the lower thread fixing device is fixed on the platform support through a fixed end of the lower thread fixing device, and the upper thread fixing device is connected with a force measuring end of the dynamometer. Preferably, the dynamometer is a tension dynamometer, and the dynamometer is a high-precision electronic dynamometer capable of reflecting stress and displacement.
Preferably, the dynamometer is arranged on a vertical sliding rail in a sliding mode through a vertical sliding block, and the vertical sliding rail is fixed on the platform support.
Preferably, the wire arrangement line comprises a row of wires with equal length and smooth surfaces, and the wires are not in contact with each other. The silk thread is firm and smooth-surfaced filament material, and the surface of the silk thread in the silk thread arrangement is as smooth as possible.
The constant-temperature water bath box is transparent and has a temperature regulation and control function, and the thoracic aorta covered stent to be measured is completely immersed in water in the constant-temperature water bath box. The platform bracket is fixed with the constant temperature water bath box. Preferably, the platform support is built from an aluminium alloy profile.
A radial supporting force test experiment method for a thoracic aorta covered stent uses the test experiment platform, and specifically comprises the following steps:
winding the thoracic aorta covered stent to be tested by using a wire arranging line, fixing the thoracic aorta covered stent to be tested by using an adjusting limiter, controlling a transverse sliding rail to adjust the thoracic aorta covered stent to be tested to a proper position, removing the axial constraint of the limiter on the thoracic aorta covered stent to be tested, and recording the length of the thoracic aorta covered stent to be tested before crimping;
after the thermostatic water bath tank is filled with water and preheated, controlling the dynamometer to pull the silk discharge threads to press and hold the thoracic aorta covered stent to a required degree, recording the reading of the dynamometer, discharging part of water from the thermostatic water bath tank, and reading the axial growth of the thoracic aorta covered stent;
repeating the above operations to sequentially measure the stress and axial growth of each stent ring of the thoracic aorta covered stent after being pressed and held;
removing the measured thoracic aorta covered stent, closing the power supply of the experiment platform, and ending the experiment operation;
the number of the matched sets of the experimental platform is utilizedAccording to a processing formula:
and obtaining an experimental result.
In the processing formula, D is the radius of the stent, L is the length of the stent, Delta D is the radius change of the thoracic aorta covered stent to be measured, Delta L is the axial elongation of the thoracic aorta covered stent to be measured, and the axial length changes before and after the thoracic aorta covered stent to be measured is pressed and held under each stent ring are added to obtain Sigma Delta L and FMeasuringThe average value of the readings of the dynamometer of the covered stent of the thoracic aorta to be tested under each stent ring is obtained.
The experimental platform is used for simulating and testing the radial supporting force of the thoracic aorta covered stent in a conveyer sheath and when the thoracic aorta covered stent is implanted into a blood vessel of a human body. Adjusting the limiting stopper and a slide rail for controlling the integral horizontal movement of the covered stent, and mounting the covered stent to be tested on the limiting stopper and positioning the covered stent to be tested at a proper position, namely, the silk arranging wire can be just pressed and held on a stent ring of the stent to be tested; adjusting and fixing the upper thread fixing device to control the thread arranging wire to be reasonably wound on the covered stent to be tested; according to different measured conditions, the constant-temperature water bath box is selectively opened and adjusted to be at a proper test temperature; adjusting a slide rail for controlling the tension dynamometer to vertically move to enable the dynamometer to drive the wire arrangement line to operate, straightening the wire arrangement line, further performing required press-holding on the covered stent to a certain degree, and reading the reading of the dynamometer; adjusting a slide rail for controlling the whole horizontal movement of the covered stent to enable the covered stent to be measured to horizontally move to the next appropriate position; and repeating the previous operation to measure the corresponding radial supporting force on all the stent rings of the covered stent to be measured, and calculating by combining a related formula to obtain the radial pressing and holding performance of the covered stent under the corresponding condition. The invention improves the automation and the accuracy of the experimental platform on the premise of confirming the accuracy and credibility of the experimental result, can measure the radial supporting force of various thoracic aorta covered stents with different lengths, different thicknesses and the like, and can simulate the real and complex application condition.
Compared with the prior art, the invention has the following advantages:
1. according to the invention, through the matching design of the position limiter, the secondary slide rail and the transverse slide rail in the horizontal direction, the thoracic aorta covered stent to be measured can be adjusted and fixed, through the matching design of the silk arranging wire, the lower wire fixing device, the upper wire fixing device, the vertical slide rail and the dynamometer in the vertical direction, the pressing, displacement and stress measurement can be carried out on the thoracic aorta covered stent to be measured, the real application environment of the thoracic aorta covered stent to be measured is simulated through the constant temperature water bath box, on the premise of confirming that the test result is accurate, the automation and the accuracy degree of the experimental platform are improved, the radial support force measurement of various thoracic aorta covered stents with different lengths, different thicknesses and the like can be carried out, and the real and complex application conditions can be simulated;
2. according to the invention, through the matching design of the secondary slide rail and the transverse slide rail, the stoppers can move relatively to realize the mounting and the dismounting of the thoracic aorta covered stent to be tested, and can move integrally to realize the testing of different stent rings on the thoracic aorta covered stent to be tested;
3. the thoracic aorta covered stent to be tested is crimped through the wire arrangement lines with smooth surfaces, so that the real compression condition of the thoracic aorta covered stent in practical application can be effectively simulated, and the influence of factors such as friction on experimental results is eliminated;
4. the constant-temperature water bath tank can simulate the real temperature and liquid environment of the thoracic aorta covered stent applied to the human body, so as to improve the accuracy of the experimental result;
5. the limiting device fixes the thoracic aorta covered stent to be tested through the limiting ring with the smooth outer surface, and is provided with the through hole which can enable liquid in the constant-temperature water bath tank to freely enter and exit the thoracic aorta covered stent to be tested, so that the influences of the limiting device on the fixation of the stent and the liquid in the constant-temperature water bath tank on the stent can be reduced, and the reliability of an experimental result is improved;
6. the invention can be used for the comparative test of the support performance of the stent with different outer diameters, can reflect the difference of the pressure resistance capacity of the circumferential position, can directly reflect the support performance of the stent, has simple equipment structure, small friction and accurate experimental result, and can simulate the real application environment of the thoracic aorta covered stent to be tested.
Drawings
FIG. 1 is a schematic view of the overall structure of the present invention;
FIG. 2 is an exploded view of the present invention;
FIG. 3 is a schematic view of the position adjustment and fixation part of the covered stent for thoracic aorta according to the present invention;
FIG. 4 is a schematic view of a portion of a crimping embodiment of the present invention;
FIG. 5 is a schematic illustration of the winding of a flat yarn according to the present invention;
FIG. 6 is a schematic view of the manner in which the filaments of the present invention are wound in a laid-up yarn;
FIG. 7 is a schematic view of the radial supporting force of the stent graft of the present invention;
FIG. 8 is a schematic view of a stent graft of the present invention under compression;
in the figure: 1-a stopper, 101-a limiting ring, 102-a stopper through hole, 2-a second-stage sliding rail, 3-a transverse sliding rail, 4-a row of silk threads, 5-a lower thread fixer, 6-an upper thread fixer, 7-a vertical sliding rail, 8-a dynamometer, 801-a force measuring end, 9-a constant temperature water bath box, 10-a platform support, 11-a back plate, 12-a second-stage slide block, 13-a transverse slide block, 14-a connecting plate, 15-a lower thread fixer fixing end, 16-a vertical slide block, 100-a thoracic aorta tectorial membrane support, 110-a support ring and 120-a row of silk thread winding parts.
Detailed Description
The invention is described in detail below with reference to the figures and specific embodiments. The following examples are carried out on the premise of the technical scheme of the invention, and detailed embodiments and specific operation processes are given, but the scope of the invention is not limited to the following examples.
Example 1
The utility model provides a radial holding power test experiment platform of thoracic aorta tectorial membrane support, includes stopper 1, second grade slide rail 2, horizontal slide rail 3, arranges silk line 4, solidus ware 5 down, goes up solidus ware 6, vertical slide rail 7, dynamometer 8, constant temperature water bath 9, platform support 10 and backplate 11.
As shown in fig. 2, the back plate 11 is fixed to the platform holder 10, and the platform holder 10 is placed in the constant temperature water bath tank 9 to form a basic frame of the present embodiment, on which the following components are mounted.
As shown in fig. 1, the present embodiment employs an electric vertical slide rail 7 driven by a stepping motor, and an electric horizontal slide rail 3 (other suitable slide rails may also be employed). The electric transverse slide rail 3 is horizontally fixed on the back plate 11.
As shown in fig. 3, in the present embodiment, the secondary slide rail 2 adopts a set (two) of manually adjustable and fixable dovetail slide rails (one slide rail at one end may be adopted, and a stopper 1 is directly fixed at the other end, or other suitable slide rails may be adopted), and the secondary slide rail 2 is fixed with the transverse slide block 13 on the transverse slide rail 3 through the connecting plate 14, so that the set of secondary slide rails 2 can horizontally move to a desired position along with the transverse slide block 13 under the control of the transverse slide rail 3. The second-stage slide block 12 on the second-stage slide rail 2 is fixed with a group of (two) limiters 1.
The limiting rings 101 and the limiting through holes 102 are arranged on the limiting device 1, as shown in fig. 1 and 3, the size of the limiting device 1 ensures that the thoracic aorta covered stent 100 to be tested, which is arranged between a group of the limiting rings 101 during testing, can be completely immersed below the highest water level of the constant temperature water bath tank 9, and the limiting through holes 102 on the limiting device 1 can enable water to flow into the thoracic aorta covered stent 100 to be tested, so that the influence of water pressure is eliminated.
As shown in fig. 1, an electric vertical slide rail 7 is vertically fixed on the upper side of the platform support 10, and the dynamometer 8 is fixed on a vertical slide block 16 of the vertical slide rail 7 and can vertically move along the vertical slide rail 7 within a certain range along with the vertical slide block 16.
As shown in fig. 4 and fig. 1, an upper thread fixing device 6 is fixedly connected to a force measuring end 801 of a force measuring meter 8, a lower thread fixing device 5 is arranged right below the force measuring meter, and a lower thread fixing device fixing end 15 is fixed on a platform support 10. The upper thread fixing device 6 and the lower thread fixing device 5 are arranged between the thread arranging line 4, the thread arranging line 4 is composed of a proper number of threads, two ends of each thread are respectively connected with the upper thread fixing device 6 and the lower thread fixing device 5, the threads are arranged in a row, and the row surface coincides with the vertical tangent plane of the front side or the rear side (the rear side in the exemplary embodiment) of the thoracic aorta covered stent 100 to be measured. The distance between the threads in the thread row 4 should be small but should not touch each other.
The device of the embodiment operates as follows:
as shown in figures 1, 5 and 3, the vertical slide rails 7 are adjusted first to allow the wire arrangement 4 to be loosened so as to form a winding manner as shown in figure 6 when the thoracic aorta covered stent 100 to be tested is installed. The thoracic aorta covered stent 100 to be tested is wound according to the winding mode shown in fig. 6, at this time, the wire arranging wire 4 is not too tight, and the diameter length of the formed wire arranging wire winding part 120 is slightly larger than the outer diameter length of the thoracic aorta covered stent 100 to be tested. And adjusting the secondary slide rail 2 to enable two ends of the thoracic aorta covered stent 100 to be tested to be sleeved on the limiting ring 101 of the limiting device 1, and enabling the limiting device 1 to be in contact with two end faces of the thoracic aorta covered stent 100 to be tested so as to drive the thoracic aorta covered stent 100 to be tested to move horizontally. The two-stage slider 12 is fixed. Adjusting the transverse slide rail 3 to enable the target stent ring 110 to be measured to coincide with the winding part 120 of the traverse thread, releasing the fixation of the second-stage slide block 12, adjusting the second-stage slide block 12 to enable the limiting device 1 not to contact with the two end surfaces of the thoracic aorta covered stent 100 to be measured, namely releasing the axial restraint of the limiting device 1 on the thoracic aorta covered stent to be measured so as not to influence the experimental result, aligning the two end surfaces of the thoracic aorta covered stent 100 to be measured with a certain scale mark on the limiting ring 101, and recording the scale mark reading aligned at the two ends at the moment. According to the requirement, the constant temperature water bath box 9 is not used or the constant temperature water bath box 9 is filled with water and preheated to the required temperature. The present invention is exemplified by using a constant temperature water bath tank 9.
The vertical slide rail 7 is adjusted to straighten the wire array 4 just, and the dynamometer 8 displays the stress just 0 at the moment. The displacement measurement of the load cell 8 is reset. And calculating the required pull-up distance according to the outer diameter of the thoracic aorta covered stent 100 to be measured and the target compression size. And adjusting the vertical slide rail 7 again to enable the displacement measured value to reach the target pull-up distance. The reading is recorded for the load cell 8. And (3) discharging water to the constant-temperature water bath tank 9, stopping discharging water when the water level is lower than the scale marks on the limiting ring 101, quickly recording the scale mark readings aligned at the two ends of the thoracic aorta covered stent 100 to be tested so as to avoid temperature influence, and obtaining the axial length change quantity before and after the target stent ring 110 is pressed and held down in the operation by subtracting the scale mark readings before and after the pressing and holding is carried out.
And adjusting the vertical slide rail 7 to loosen the wire arranging wire 4, adjusting the transverse slide rail 3 again to make the wire arranging wire winding part 120 coincide with the next target support ring 110, injecting water into the constant-temperature water bath tank 9 until the water level completely submerges the thoracic aorta covered stent 100 to be tested and preheating the stent to the required temperature, and repeating the operation again to record the reading of the dynamometer 8 under the stent ring.
After the experiment operation is finished, the constant temperature water bath tank 9 is closed and water is emptied, the vertical slide rail 7 is controlled to loosen the wire arranging line 4, the fixation of the second-stage slide rail 2 is released, and the measured thoracic aorta covered stent 100 is taken down.
Experimental results processing formula:
wherein D is the radius of the stent, L is the length of the stent, Δ D is the change amount of the radius of the thoracic aorta covered stent 100 to be tested, and Δ L is the axial elongation of the thoracic aorta covered stent 100 to be tested, and the change amounts of the axial length of the thoracic aorta covered stent 100 to be tested before and after being crimped under each stent ring 110 are added to obtain Σ Δ L.
FMeasuringIs the average value of the experimental readings of the thoracic aorta covered stent 100 to be tested under each stent ring 110, FDiameter of a pipeThe radial supporting force test value of the thoracic aorta covered stent 100 to be tested is shown.
The derivation of this equation is as follows:
as shown in FIGS. 7 and 8, which are cross-sectional views of a stent graft in accordance with the present invention as it contracts radially, the stent graft 100 approximates a circle during the transformation. In the figure, F is the tension on the contraction support frame wire arranging line 4 in the experiment table, FPThe radial force per unit area is shown, and theta is an included angle between a connecting line of a contact point of the thin line and the support and a circle center.
The following equation is derived from the geometric relationship, where p is the pressure acting on a unit area of the stent graft 100 wall and R is its radius:
Fdθ＝p×Δs＝p×R×dθ×dl (2)
F＝p×R×dl (3)
when pressure acts on the thin-wall cylindrical pipe structure, annular tension F is generated in the pipe wallroundThe calculation formula is as follows, whereinD is the initial diameter of the stent, L is the initial length of the stent:
for convenience, it is usually expressed in terms of tension per unit length:
in the formula, FroundIs hoop tension. The supporting counter force of the node can be obtained by finite element analysis, but the annular tension F of the pipe wall can not be obtained from the analysis resultround. And (4) by using a thin-wall circular tube model for reference, establishing a model for calculating the radial supporting force of the bracket according to the finite element analysis result.
Assuming that the radial force of the tube wall acting on the ith node of the stent is F, the force diagram is shown in FIG. 8, and can be obtained as follows:
Fout＝∑fi (6)
in the formula, FoutIs the sum of the radial forces applied by the vessel wall to the entire stent.
Under the action of the tube wall, the stent generates a radial force resisting deformation, and the calculation formula is as follows:
Fin＝pπ(D-ΔD)(L+ΣΔL) (7)
in the formula, FinA resultant radial force against deformation generated for the stent; l is the initial length of the stent; Σ Δ L is the sum of the axial length change amount before and after the stent 100 grips each stent ring 110; d is the initial diameter of the stent, Delta D is the diameter compression of the stent, and the radial support counter force on the ith node of the stent is set as fi，freThe total of the radial support reaction force of the support node is as follows:
Fout，Fre，Finthe following relationships exist:
Fout＝Fin
Fre＝Fout
the radial support force of the stent obtained by the formulas (1) to (8) is:
in the above formula, F is the direct data F obtained by the experiment of the inventionMeasuringNamely:
the embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.
Claims (10)
1. The utility model provides a radial holding power test experiment platform of thoracic aorta tectorial membrane support which characterized in that includes:
the fixing component is used for adjusting and fixing the thoracic aorta covered stent to be measured and comprises a limiter (1), a secondary slide rail (2) and a transverse slide rail (3);
the test assembly is used for pressing and holding the thoracic aorta covered stent to be tested and measuring the stress, and comprises a wire arranging wire (4), a lower wire fixing device (5), an upper wire fixing device (6), a vertical slide rail (7) and a dynamometer (8);
a constant temperature water bath tank (9) used for simulating the real application environment of the thoracic aorta covered stent;
a platform bracket (10) and a back plate (11) for assembling, connecting and fixing the components.
2. The thoracic aorta tectorial membrane stent radial supporting force test experimental platform as claimed in claim 1, wherein the stopper (1) is slidably disposed on the secondary slide rail (2) through a secondary slide block (12), the secondary slide rail (2) is slidably disposed on the transverse slide rail (3) through a transverse slide block (13), the transverse slide rail (3) is fixed on the back plate (11), and the back plate (11) is fixed on the platform stent (10).
3. The radial supporting force test experiment platform for the thoracic aorta covered stent according to claim 2, wherein the transverse sliding block (13) is connected with a connecting plate (14), a secondary sliding rail (2) is fixed on the connecting plate (14), and the secondary sliding rail (2) is connected with two stoppers (1) which are arranged oppositely through a secondary sliding block (12).
4. The radial supporting force test experimental platform for the thoracic aorta covered stent according to claim 3, wherein the stopper (1) comprises a stopper ring (101) and a stopper through hole (102), the stopper rings (101) of the two stoppers (1) are arranged oppositely, and the stopper through hole (102) is communicated with the stopper rings (101).
5. The radial supporting force test experimental platform for the thoracic aorta covered stent according to claim 4, wherein the thoracic aorta covered stent to be tested is just sleeved on the limiting ring (101), and the limiting ring (101) is provided with scale marks.
6. The radial supporting force test experimental platform for the covered stent of thoracic aorta according to claim 1, wherein the wire arranging wires (4) are fixed at two ends by the lower wire fixing device (5) and the upper wire fixing device (6) and are pressed and held around the covered stent of thoracic aorta to be tested.
7. The radial supporting force test experimental platform for the aorta thoraci-covered stent as claimed in claim 6, wherein the lower thread fixing device (5) is fixed on the platform stent (10) through a lower thread fixing device fixing end (15), and the upper thread fixing device (6) is connected with a force measuring end (801) of the force measuring unit (8).
8. The thoracic aorta covered stent radial supporting force test experimental platform as claimed in claim 1, wherein the dynamometer (8) is slidably arranged on a vertical sliding rail (7) through a vertical sliding block (16), and the vertical sliding rail (7) is fixed on the platform stent (10).
9. The experimental platform for testing radial supporting force of the covered stent of thoracic aorta according to claim 1, wherein the wire row (4) comprises a row of wires with equal length and smooth surface, and the wires are not in contact with each other.
10. A radial supporting force test experiment method for a covered stent of thoracic aorta is characterized in that the test experiment platform of any one of claims 1 to 9 is used, and the method specifically comprises the following steps:
winding a thoracic aorta covered stent to be tested by using a silk arranging wire (4), fixing the thoracic aorta covered stent to be tested by using an adjusting limiter (1), controlling a transverse sliding rail (3) to adjust the thoracic aorta covered stent to be tested to a proper position, removing the axial restraint of the limiter (1) on the thoracic aorta covered stent to be tested, and recording the length of the thoracic aorta covered stent to be tested before being pressed and held;
after the constant-temperature water bath tank (9) is filled with water and preheated, the dynamometer (8) is controlled to pull the stringing thread (4) to press and hold the thoracic aorta covered stent to a required degree, the reading of the dynamometer (8) is recorded, part of water is discharged from the constant-temperature water bath tank (9), and the axial growth amount of the thoracic aorta covered stent is read;
repeating the above operations to sequentially measure the stress and axial growth of each stent ring of the thoracic aorta covered stent after being pressed and held;
the data processing formula matched with the experimental platform is utilized:
obtaining an experimental result, wherein D is the radius of the stent, L is the length of the stent, delta D is the radius change quantity of the thoracic aorta covered stent to be detected, and delta L is the axial direction of the thoracic aorta covered stent to be detectedElongation, adding the axial length change before and after the pressing and holding of the covered thoracic aorta stent under each stent ring to obtain sigma delta L, FMeasuringThe average value of the readings of the dynamometer (8) of the covered stent of the thoracic aorta to be tested under each stent ring is obtained.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117030093B (en) * | 2023-08-23 | 2024-01-26 | 杭州糖吉医疗科技有限公司 | Gastric inversion support radial force measuring system for simulated press grasping machine |
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