Diameter-variable cornea biomechanical research system and use method

Abstract

The invention relates to the technical field of biomechanical research, and discloses a variable-diameter cornea biomechanical research system and a use method. The system comprises a pressure chamber, a rapid perfusion system, a precise pressurization system and a cornea full-field strain imaging system, and is composed of a mechanical sensor, a peristaltic pump, a pressure cavity, a reducing end cover, a cornea clamping ring and the like. The method comprises the following steps: S100, firstly, according to the size of a taken cornea sample, rotating an adjusting knob on a reducing end cover to enable the diameter of the adjusting knob to accord with the size of the cornea sample; and S200, the cornea and sclera area is placed between the variable-diameter end cover and the cornea clamping ring, and meanwhile, a sealing ring is placed on the periphery of the cornea and sclera. According to the invention, the adjustable reducing end cover is designed to meet different cornea requirements; the cornea clamping ring improves the fixing effect and adapts to the extreme environment; high-quality speckle patterns are obtained based on the projection speckle DIC technology, and the method is suitable for a high-temperature acid-base environment; advantage complementation is achieved through double-pump perfusion; and the BPT tube widens the experimental environment range. The invention further provides a using method of the system, and an efficient, accurate and high-adaptability solution is provided for cornea biomechanical research.

Description

Technical Field

[0001] This invention relates to the field of biomechanical research technology, specifically to a variable diameter corneal biomechanical research system and its usage. Background Technology

[0002] In in vitro biomechanical studies of corneal tumescence, the geometric dimensions of corneas vary significantly among different animals, and even within the same species, corneal geometry exhibits variability influenced by age, environment, and genetics. Currently, the common approach is to replace endcaps of different diameters to address the specific needs of different corneal tumescence tests, a process that is quite cumbersome. Furthermore, in corneal tumescence tests, most researchers use fixative adhesive to immobilize the cornea. This method, when applied at the corneal-scleral junction, can contaminate the cornea, affecting its mechanical properties, and with slow application of pressure, corneal detachment may occur, impacting the experiment. In addition, adhesive fixation cannot withstand extreme environments such as high temperatures and acid / alkali conditions, limiting comprehensive studies of corneal biomechanical properties. Currently, the most widely used experiments in in vitro corneal biomechanical property research involve uniaxial tests and corneal tumescence tests. Uniaxial tests have many limitations in obtaining the parameters needed for a corneal mechanical constitutive model, such as the loading state being non-physiological, damage to corneal collagen fibers during corneal strip sample preparation, and the measurement of mechanical properties only in a specific direction. Current methods for obtaining full-field corneal strain in corneal tumescence experiments often involve creating speckle patterns on the corneal surface using spray painting or graphite spraying. However, the moist surface of the cornea is not conducive to generating high-quality speckle patterns using these methods. During large deformations caused by corneal tumescence, the speckle pattern can slip, creating large cracks and gaps that affect the experimental results. Furthermore, the quality of the speckle pattern is heavily dependent on the experience of the experimenter in creating the pattern. In addition, current perfusion methods in corneal biomechanical research are limited and cannot simultaneously meet the requirements of rapid transport of corneal storage solution and precise pressurization. Moreover, the tubing connections cannot withstand high and low temperatures or corrosive environments, restricting the scope of in vitro corneal biomechanical tumescence experiments.

[0003] This invention discloses a variable-diameter corneal biomechanical research system and its usage method, which has the following beneficial effects:

[0004] 1. Adjustable diameter end cap to meet different corneal needs: An adjustable diameter end cap is designed. The diameter can be adjusted by rotating the diameter knob to meet the needs of different corneas for in vitro three-dimensional biomechanical performance research, making the operation more convenient and efficient.

[0005] 2. Corneal clamping ring improves fixation effectiveness and experimental adaptability: A corneal clamping ring was designed and developed to fix the corneal edge through clamping force, avoiding the contamination and detachment problems caused by glue fixation. The central part of the clamping ring is designed with multiple holes to ensure the flowability of the corneal storage solution; a sealing ring is added between the corneal clamping ring and the end cap to ensure airtightness. At the same time, this fixation method can withstand extreme environments such as high temperature and acid / alkali conditions, which is beneficial for comprehensive research on corneal biomechanical properties.

[0006] 3. Obtaining High-Quality Speckle Patterns Using DIC Based on Projected Speckle Technology: A method for obtaining corneal full-field strain using DIC based on projected speckle technology is proposed. This method can directly generate electronic speckles on the corneal surface using a speckle projector, without the need for corneal surface pretreatment. It is simple to operate, less dependent on experience, and conducive to generating high-quality speckle patterns. Furthermore, it can conduct corneal tumescence tests under high temperature and acid / alkali conditions without considering the influence of the speckle-generating material.

[0007] 4. Dual-pump irrigation achieves complementary advantages: Employing a dual-pump irrigation method, the peristaltic pump rapidly transports corneal storage fluid to the corneal hydraulic chamber while providing initial pressure; the syringe pump precisely delivers the fluid, providing a highly accurate loading method. Furthermore, it enables cyclic loading and unloading, allowing for in vitro cyclic expansion and fatigue testing of the cornea.

[0008] 5. BPT tubing expands the experimental environment: The tubing connection of this invention uses BPT tubing, which can withstand high and low temperatures and corrosion, and can be used to conduct in vitro corneal biomechanical expansion tests under high and low temperature and corrosive environments. Summary of the Invention

[0009] To overcome the problems existing in current corneal biomechanics research, such as poor adaptability to differences in corneal size between different animals and within the same species, inadequate corneal fixation methods, significant limitations in mechanical performance research experiments, single perfusion methods, and inability of tubing to adapt to special environments, this invention proposes a variable-diameter corneal biomechanics research system and its usage method.

[0010] This invention discloses a variable-diameter corneal biomechanical research system, comprising: a pressure chamber 22, a rapid perfusion system, a precise pressurization system, and a corneal full-field strain imaging system; the components include: a mechanical sensor 1, a peristaltic pump 2, a hydraulic chamber 3, a three-way tube 4, a variable-diameter end cap 5, a sealing ring 6, a corneal clamping ring 7, a sealing ring 8, an injection pump 9, a valve 10, a beaker 11, a BPT tube 12, a binocular DIC 13, a valve 14, a valve 15, a valve 16, a speckle projector 17, a computer 18, a beaker 19, a three-way tube 20, a three-way tube 21, and a pressure chamber 22.

[0011] Preferably, in this embodiment, the pressure chamber 22 consists of a hydraulic chamber 3, a tee pipe 4, a reducing end cap 5, a sealing ring 6, a corneal clamping ring 7, a sealing ring 8, and a tee pipe 20. The assembly process of the pressure chamber 22 is as follows: First, the reducing end cap 5 is placed at the top, followed by a 2mm thick sealing ring 6 underneath, as the corneal thickness is generally between 1-4mm. Next, the corneal clamping ring 7 is installed under the sealing ring 6 to fix and hold the cornea, and finally, a sealing ring 8 is added. The reducing end cap 5, sealing ring 6, corneal clamping ring 7, and sealing ring 8 have four through holes evenly distributed along the circumference, and the hydraulic chamber 3 has four corresponding threaded holes. The hydraulic chamber 3, reducing end cap 5, sealing ring 6, corneal clamping ring 7, and sealing ring 8 are connected by bolts to achieve corneal fastening and sealing. Two pipe threads are opened at both ends of the bottom of the hydraulic chamber 3 for connection and installation with the tee pipe 4 and tee pipe 20. Pipe sealant is applied during connection to ensure a tight seal.

[0012] Preferably, in this embodiment, the rapid perfusion system comprises a mechanical sensor 1, a peristaltic pump 2, a pressure chamber 22, valves 14 and 16, a BPT tube 12, a computer 18, and a beaker 19. The assembly process of the rapid perfusion system is as follows: A BPT tube 12 extends from the inlet of the peristaltic pump 2 and is placed into the beaker 19. The outlet of the peristaltic pump 2 is connected to valve 14 via the BPT tube. Valve 14 is connected to a T-junction 4 of the pressure chamber 22, and the other port of the T-junction 4 is connected to the pressure sensor 1. One port of the T-junction 20 of the pressure chamber 22 is connected to valve 16, and the other end of valve 16 is connected to the beaker 19 via the BPT tube 12. The mechanical sensor 1 and the peristaltic pump 2 are connected to the computer via cables, and the computer 18 controls the peristaltic pump and collects mechanical signals.

[0013] Preferably, in this embodiment, the precise pressurization system comprises a mechanical sensor 1, a pressure chamber 22, a syringe pump 9, a valve 10, a beaker 11, a valve 15, a computer 18, and a three-way connector 21. The assembly process of the precise pressurization system is as follows: The interface of the syringe pump 9 is connected to the three-way connector 21. One interface of the three-way connector 21 is connected to the valve 10, and the other end of the valve 10 is connected to the beaker 11 via a BPT tube 12. The last port of the three-way connector 21 is connected to the valve 15. The other interface of the valve 15 is connected to the last interface of the three-way connector 21. The computer 18 is connected to the syringe pump 9 via a data transmission line to control the syringe pump 9. Simultaneously, the computer 18 collects pressure data transmitted from the mechanical sensor 1.

[0014] Preferably, in this embodiment, the corneal full-field strain imaging system comprises a binocular DIC 13, a speckle projector 17, and a computer 18. The computer 18 acquires, stores, and processes binocular DIC images, while the speckle projector 17 is responsible for forming digital speckles on the corneal surface.

[0015] This invention also provides a method of using a variable diameter corneal biomechanical research system, which includes the following steps:

[0016] S100. First, based on the size of the corneal sample taken out, rotate the adjustment knob on the variable diameter end cap 5 to make its diameter match the size of the corneal sample.

[0017] S200. Place the corneal and scleral region between the variable diameter end cap 5 and the corneal clamping ring 7, while placing the sealing ring 6 around the corneal and scleral region.

[0018] S300, the cornea and sealing ring 6 are fastened together by bolts to ensure corneal fixation and device sealing.

[0019] S400. Load the cornea by pouring corneal storage solution into beaker 19. First, perform rapid perfusion to fill pressure chamber 22 with corneal storage solution. During rapid perfusion, valves 15 and 16 need to be opened first, then the mechanical sensor 1 is activated to collect the liquid pressure signal, and finally the peristaltic pump 2 is activated to rapidly fill pressure chamber 22 with corneal storage solution until the pressure reaches 18.5 mmHg, which is taken as the initial pressure value.

[0020] S500. Turn on the speckle projector 17 to generate electronic speckle on the already raised corneal surface. Turn on the binocular DIC 13, check the speckle formation quality on the computer 18, and adjust the speckle projector so that the speckle grid size and density meet the requirements for capturing the full-field strain of the cornea.

[0021] S600, open valve 10, and the computer 18 controls the syringe pump 9 to quickly draw corneal storage fluid from beaker 11, filling the syringe pump 9 and tubing with corneal storage fluid. Close valve 10, and open valve 15 to push the syringe pump 9 guide rod at a loading rate of 2 mm / min to slowly increase pressure.

[0022] The S700 and binocular DIC13 acquire corneal displacement signals in real time during the precise corneal compression process. These signals are then processed using professional DIC software to obtain the full-field strain field during the corneal expansion test.

[0023] S800. During unloading, close valves 15 and 14, and open valves 16 and 10. Start peristaltic pump 2 in reverse to draw all the corneal storage fluid in pressure chamber 22 into beaker 19. At the same time, start syringe pump 9 to push all the fluid in syringe pump 9 into beaker 11, completing the unloading process. Attached Figure Description

[0024] Figure 1 This is a three-dimensional diagram of a variable-diameter corneal biomechanical research system according to the present invention;

[0025] Figure 2This is a three-dimensional exploded view of the pressure chamber 22 of a variable diameter corneal biomechanical research system according to the present invention;

[0026] Figure 3 This is a schematic diagram of the components of a variable diameter corneal biomechanical research system according to the present invention;

[0027] Figure 4 This is a schematic diagram illustrating the steps of using the variable diameter corneal biomechanical research system of the present invention; Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] This invention discloses a variable-diameter corneal biomechanical research system, comprising: a pressure chamber, a rapid perfusion system, a precise pressurization system, and a corneal full-field strain imaging system; the components include: a mechanical sensor 1, a peristaltic pump 2, a hydraulic chamber 3, a three-way tube 4, a variable-diameter end cap 5, a sealing ring 6, a corneal clamping ring 7, a sealing ring 8, an injection pump 9, a valve 10, a beaker 11, a BPT tube 12, a binocular DIC 13, a valve 14, a valve 15, a valve 16, a speckle projector 17, a computer 18, a beaker 19, a three-way tube 20, a three-way tube 21, and a pressure chamber 22.

[0030] Preferably, in this embodiment, the pressure chamber 22 consists of a hydraulic chamber 3, a tee pipe 4, a reducing end cap 5, a sealing ring 6, a corneal clamping ring 7, a sealing ring 8, and a tee pipe 20. The assembly process of the pressure chamber 22 is as follows: First, the reducing end cap 5 is placed at the top, followed by a 2mm thick sealing ring 6 underneath, as the corneal thickness is generally between 1-4mm. Next, the corneal clamping ring 7 is installed under the sealing ring 6 to fix and hold the cornea, and finally, a sealing ring 8 is added. The reducing end cap 5, sealing ring 6, corneal clamping ring 7, and sealing ring 8 have four through holes evenly distributed along the circumference, and the hydraulic chamber 3 has four corresponding threaded holes. The hydraulic chamber 3, reducing end cap 5, sealing ring 6, corneal clamping ring 7, and sealing ring 8 are connected by bolts to achieve corneal fastening and sealing. Two pipe threads are opened at both ends of the bottom of the hydraulic chamber 3 for connection and installation with the tee pipe 4 and tee pipe 20. Pipe sealant is applied during connection to ensure a tight seal.

[0031] Preferably, in this embodiment, the rapid perfusion system comprises a mechanical sensor 1, a peristaltic pump 2, a pressure chamber 22, valves 14 and 16, a BPT tube 12, a computer 18, and a beaker 19. The assembly process of the rapid perfusion system is as follows: A BPT tube 12 extends from the inlet of the peristaltic pump 2 and is placed into the beaker 19. The outlet of the peristaltic pump 2 is connected to valve 14 via the BPT tube. Valve 14 is connected to a T-junction 4 of the pressure chamber 22, and the other port of the T-junction 4 is connected to the pressure sensor 1. One port of the T-junction 20 of the pressure chamber 22 is connected to valve 16, and the other end of valve 16 is connected to the beaker 19 via the BPT tube 12. The mechanical sensor 1 and the peristaltic pump 2 are connected to the computer via cables, and the computer 18 controls the peristaltic pump and collects mechanical signals.

[0032] Preferably, in this embodiment, the precise pressurization system comprises a mechanical sensor 1, a pressure chamber 22, a syringe pump 9, a valve 10, a beaker 11, a valve 15, a computer 18, and a three-way connector 21. The assembly process of the precise pressurization system is as follows: The interface of the syringe pump 9 is connected to the three-way connector 21. One interface of the three-way connector 21 is connected to the valve 10, and the other end of the valve 10 is connected to the beaker 11 via a BPT tube 12. The last port of the three-way connector 21 is connected to the valve 15. The other interface of the valve 15 is connected to the last interface of the three-way connector 21. The computer 18 is connected to the syringe pump 9 via a data transmission line to control the syringe pump 9. Simultaneously, the computer 18 collects pressure data transmitted from the mechanical sensor 1.

[0033] Preferably, in this embodiment, the corneal full-field strain imaging system comprises a binocular DIC 13, a speckle projector 17, and a computer 18. The computer 18 acquires, stores, and processes binocular DIC images, while the speckle projector 17 is responsible for forming digital speckles on the corneal surface.

[0034] This invention also provides a method of using a variable diameter corneal biomechanical research system, which includes the following steps:

[0035] S100. First, based on the size of the corneal sample taken out, rotate the adjustment knob on the variable diameter end cap 5 to make its diameter match the size of the corneal sample.

[0036] S200. Place the corneal and scleral region between the variable diameter end cap 5 and the corneal clamping ring 7, while placing the sealing ring 6 around the corneal and scleral region.

[0037] S300, the reducing end cap 5, cornea, sealing ring 6, cornea clamping ring 7, sealing ring 8, and hydraulic chamber 3 are fastened with bolts to ensure cornea fixation and equipment sealing.

[0038] S400. Load the cornea by pouring corneal storage solution into beaker 19. First, perform rapid perfusion to fill pressure chamber 22 with corneal storage solution. During rapid perfusion, valves 15 and 16 need to be opened first, then the mechanical sensor 1 is activated to collect the liquid pressure signal, and finally the peristaltic pump 2 is activated to rapidly fill pressure chamber 22 with corneal storage solution until the pressure reaches 18.5 mmHg, which is taken as the initial pressure value.

[0039] S500. Turn on the speckle projector 17 to generate electronic speckle on the already raised corneal surface. Turn on the binocular DIC 13, check the speckle formation quality on the computer 18, and adjust the speckle projector so that the speckle grid size and density meet the requirements for capturing the full-field strain of the cornea.

[0040] S600, open valve 10, and the computer 18 controls the syringe pump 9 to quickly draw corneal storage fluid from beaker 11, filling the syringe pump 9 and tubing with corneal storage fluid. Close valve 10, and open valve 15 to push the syringe pump 9 guide rod at a loading rate of 2 mm / min to slowly increase pressure.

[0041] The S700 and binocular DIC13 acquire corneal displacement signals in real time during the precise corneal compression process. These signals are then processed using professional DIC software to obtain the full-field strain field during the corneal expansion test.

[0042] S800. During unloading, close valves 15 and 14, and open valves 16 and 10. Start peristaltic pump 2 in reverse to draw all the corneal storage fluid in pressure chamber 22 into beaker 19. At the same time, start syringe pump 9 to push all the fluid in syringe pump 9 into beaker 11, completing the unloading process.

[0043] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. This invention discloses a variable-diameter corneal biomechanical research system, comprising: Pressure chamber 22, rapid irrigation system, precise pressurization system and corneal full-field strain imaging system; components include: mechanical sensor 1, peristaltic pump 2, pressure chamber 3, water inlet tee 4, reducing end cap 5, sealing ring 6, corneal clamping ring 7, sealing ring 8, syringe pump 9, valve 10, beaker 11, BPT tube 12, binocular DIC 13, valve 14, valve 15, valve 16, speckle projector 17, computer 18, beaker 19, water outlet tee 20, tee 21, pressure chamber 22.

2. The variable diameter corneal biomechanical research system according to claim 1, characterized in that, The pressure chamber 22 consists of a hydraulic chamber 3, a tee pipe 4, a reducing end cap 5, a sealing ring 6, a corneal clamping ring 7, a sealing ring 8, and a tee pipe 20. The assembly process of the pressure chamber 22 is as follows: First, the reducing end cap 5 is placed at the top, and then a sealing ring 6 with a thickness of 2mm is placed underneath. This is because the thickness of the cornea is generally between 1-4mm. Next, the corneal clamping ring 7 is installed under the sealing ring 6 to fix and clamp the cornea. Finally, a sealing ring 8 is added. The reducing end cap 5, the sealing ring 6, the corneal clamping ring 7, and the sealing ring 8 have four through holes evenly distributed along the circumference. The hydraulic chamber 3 has four corresponding threaded holes. The hydraulic chamber 3, the reducing end cap 5, the sealing ring 6, the corneal clamping ring 7, and the sealing ring 8 are connected by bolts to achieve corneal fastening, clamping, and sealing. Two pipe threads are opened at both ends of the bottom of the hydraulic chamber 3 for connection and installation with the tee pipe 4 and the tee pipe 20. When connecting, pipe sealant is applied to ensure sealing.

3. The variable diameter corneal biomechanical research system according to claim 1, characterized in that, The rapid perfusion system consists of a mechanical sensor 1, a peristaltic pump 2, a pressure chamber 22, valves 14 and 16, a BPT tube 12, a computer 18, and a beaker 19. The assembly process of the rapid perfusion system is as follows: A BPT tube 12 extends from the inlet of the peristaltic pump 2 and is placed into the beaker 19. The outlet of the peristaltic pump 2 is connected to valve 14 through the BPT tube. Valve 14 is connected to the T-connector 4 of the pressure chamber 22. The other port of the T-connector 4 is connected to the pressure sensor 1. One port of the T-connector 20 of the pressure chamber 22 is connected to valve 16. Then, the other end of valve 16 is connected to beaker 19 through the BPT tube 12. The mechanical sensor 1 and the peristaltic pump 2 are connected to the computer through cables. The computer 18 controls the peristaltic pump and collects mechanical signals.

4. The variable diameter corneal biomechanical research system according to claim 1, characterized in that, The precision pressurization system consists of a mechanical sensor 1, a pressure chamber 22, a syringe pump 9, a valve 10, a beaker 11, a valve 15, a computer 18, and a three-way pipe 21. The assembly process of the precision pressurization system is as follows: the interface of the syringe pump 9 is connected to the three-way pipe 21, one interface of the three-way pipe 21 is connected to the valve 10, the other end of the valve 10 is connected to the beaker 11 through a BPT pipe 12, the last port of the three-way pipe 21 is connected to the valve 15, and the other interface of the valve 15 is connected to the last interface of the three-way pipe 20. The computer 18 is connected to the syringe pump 9 through a data transmission line to control the syringe pump 9, and at the same time, the computer 18 collects the pressure data transmitted from the mechanical sensor 1.

5. The variable diameter corneal biomechanical research system according to claim 1, characterized in that, The corneal full-field strain imaging system consists of a binocular DIC 13, a speckle projector 17, and a computer 18. The computer 18 acquires, stores, and processes binocular DIC images, while the speckle projector 17 is responsible for the formation of digital speckles on the corneal surface.

6. The present invention also provides a method of using a variable diameter corneal biomechanical research system, comprising the following steps: S100. First, according to the size of the corneal sample taken out, rotate the adjustment knob on the variable diameter end cap 5 to make its diameter match the size of the corneal sample. S200. Place the corneal and scleral region between the variable diameter end cap 5 and the corneal clamping ring 7, and at the same time place the sealing ring 6 around the corneal and scleral region. S300, the cornea and sealing ring 6 are fastened together by bolts to ensure corneal fixation and device sealing; S400. Load the cornea by pouring corneal storage solution into beaker 19. First, perform rapid perfusion to fill pressure chamber 22 with corneal storage solution. During rapid perfusion, valves 15 and 16 need to be opened first, then mechanical sensor 1 is opened to collect liquid pressure signal, and finally peristaltic pump 2 is opened to rapidly fill pressure chamber 22 with corneal storage solution until the pressure reaches 18.5 mmHg, which is taken as the initial pressure value. S500. Turn on the speckle projector 17 to generate electronic speckle on the raised corneal surface. Turn on the binocular DIC 13, check the speckle formation quality on the computer 18, and adjust the speckle projector so that the speckle grid size and density meet the requirements for capturing the full-field strain of the cornea. S600, open valve 10, and computer 18 controls the syringe pump 9 to quickly draw corneal storage fluid from beaker 11, so that the inside of syringe pump 9 and tubing are filled with corneal storage fluid. Close valve 10, open valve 15 to push the guide rod of syringe pump 9 at a loading rate of 2mm / min, and slowly pressurize. The S700 and binocular DIC13 acquire corneal displacement signals in real time during the precise corneal compression process. The signals are then processed using professional DIC software to obtain the full-field strain field during the corneal expansion test. S800. During unloading, close valves 15 and 14, open valves 16 and 10, and start peristaltic pump 2 in reverse to draw all the corneal storage fluid in pressure chamber 22 into beaker 19. At the same time, start syringe pump 9 to push all the fluid in syringe pump 9 into beaker 11 to complete unloading.

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