CN106840890A - A kind of cornea three-dimensional whole field stress strain response measuring system and its measuring method - Google Patents
A kind of cornea three-dimensional whole field stress strain response measuring system and its measuring method Download PDFInfo
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- 210000004087 cornea Anatomy 0.000 title claims abstract description 147
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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
- G01N3/10—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces generated by pneumatic or hydraulic pressure
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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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- G01N2203/0001—Type of application of the stress
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- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
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- G01N2203/0069—Fatigue, creep, strain-stress relations or elastic constants
- G01N2203/0075—Strain-stress relations or elastic constants
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- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
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Abstract
The invention discloses a kind of cornea three-dimensional whole field stress strain response measuring system, including cornea physiological environment simulating chamber, the cornea physiological environment simulating chamber is used for immobilizing corneal and analog cornea is in intraocular physiological environment, cornea physiology simulating chamber is provided with water inlet pipe, water inlet pipe is provided with pressure sensor, the pressure sensor is connected with control computer, the control computer connects a pressure-regulating device, pressure-regulating device is connected with cornea physiology simulating chamber water inlet pipe, the control computer is also connected with two DVs, the DV is corresponding with cornea.The measuring system can simulate the physiological environment of human eyeball's cornea, and the stress and strain of the multiple points of cornea is directly measured in once testing, and accuracy is high, highly reliable.Invention additionally discloses a kind of cornea three-dimensional whole field stress strain response measuring method.
Description
Technical field
The present invention relates to cornea mechanical property fields of measurement, and in particular to a kind of cornea three-dimensional whole field stress strain response
Measuring system and its measuring method.
Background technology
Research on its biological mechanics is study hotspot in recent years, and the country is on its biological mechanical property at present
Measuring method be mainly uniaxial stretching method and using infrared sensor external plavini test method.Its biological mechanics
Performance measurement uses uniaxial stretching method earliest, and be cut into for cornea by (level, vertical, oblique) in different directions for uniaxial stretching method
Strip, being then fixed to cornea band carries out tension test on universal testing machine, draw cornea items mechanics parameter.It is specific to survey
Amount is to fix cornea band using cornea clamping device, and corneal applies certain drawing on the direction parallel to anterior corneal surface
Power, presses equivalent on the coronal-plane of cornea, the mechanical property on the simply cornea coronal-plane of reflection, and normal physiological condition
Under the main pressure that bears of cornea be intraocular pressure, wherein being that in the sagittal plane of cornea, cornea is by sagittal direction with direction
On mechanical property resist the effect of intraocular pressure, therefore uniaxial stretching method can not truly reflect biology of the cornea under physiological significance
Mechanical property.On the other hand, uniaxial stretching method can destroy cornea integrality, and applying mode is different from physiological status.
Used measurement cornea biomechanical property at present more and measure cornea top displacement using laser displacement sensor
External plavini measure.Specifically complete cornea is fixed on mechanical fastening system, using compression system corneal
Apply pressure, the change in displacement of laser displacement test system and test corneal vertex is recycled, so as to draw the mechanical property of the point
Parameter.The method measurement simply one pressure-dependent displacement of point of cornea so that can only calculate a strain for point and
Stress, then needs to be tested and changed laser displacement test system measurement point again to test other points.The method can not
The one-shot measurement cornea whole audience is strained, so as to the difference of cornea different piece strain can not be contrasted.
But two methods exist it is clearly disadvantageous, wherein, uniaxial stretching method measurement destroys the integrality of cornea, examination
Test error larger；The method of infrared sensor is then that can only measure a mechanical property for point in once testing, and such as to be measured
Multiple point then needs test of many times, so that experiment is cumbersome, and generates corresponding error.As cornea can not be accurately measured
Whole audience strain and stress, this is unfavorable for the sign to canthus biomechanical property,
The content of the invention
In order to solve the above-mentioned technical problem, the present invention discloses a kind of cornea three-dimensional whole field stress strain response measurement system
System, the measuring system can simulate the physiological environment of human eyeball's cornea, and the multiple points of cornea are directly measured in once testing
Stress and strain, accuracy is high, highly reliable, invention additionally discloses a kind of cornea three-dimensional whole field stress strain response measurement side
Method.
The present invention is achieved through the following technical solutions：
A kind of cornea three-dimensional whole field stress strain response measuring system, including cornea physiological environment simulating chamber, the angle
Film physiological environment simulating chamber is used for immobilizing corneal and analog cornea in intraocular physiological environment, cornea physiology simulating chamber be provided with into
Water pipe, water inlet pipe is provided with pressure sensor, and the pressure sensor is connected with control computer, and the control computer connects one
Pressure-regulating device, pressure-regulating device is connected with cornea physiology simulating chamber water inlet pipe, and the control computer is also connected with two numbers
Code video camera, the DV is corresponding with cornea.
The cornea physiological environment simulating chamber includes lid and hydraulic pressure chamber bottom, the hydraulic pressure chamber, liquid on hydraulic pressure chamber, hydraulic pressure chamber
Lid and hydraulic pressure chamber bottom are cylindrical in shape in pressure chamber, and water inlet pipe is fixed on the wall of hydraulic pressure chamber side, lid and hydraulic pressure chamber on the hydraulic pressure chamber
Bottom is separately fixed at the top and bottom of hydraulic pressure chamber by bolt, and the hydraulic pressure chamber side wall top surface is provided with annular groove one,
The side wall bottom surface covered on the hydraulic pressure chamber is provided with annular groove two corresponding with annular groove one, recessed in annular groove one and annular
One rubber ring of clamping in groove two, rubber ring inside sidewalls are provided with an annular groove three, clamping one in the annular groove three
Individual cornea grip block, the hydraulic pressure chamber side wall bottom surface is provided with annular groove four, and the side wall top surface of the hydraulic pressure chamber bottom is provided with
Annular groove five corresponding with annular groove four, one diffuser plate one of clamping in annular groove four and annular groove five.
The hydraulic pressure chamber upper cover top surface is fixed with a colourless transparent glass lid, the hydraulic pressure chamber bottom below diffuser plate one
A diffuser plate two is also fixed on inwall, optical fiber source is additionally provided with the hydraulic pressure chamber bottom below diffuser plate two.
The cornea grip block center is provided with fixing hole of the base diameter more than top diameter, fixing hole side wall and angle
Film form fit.
Outlet pipe is additionally provided with the wall of the hydraulic pressure chamber side.
The pressure-regulating device includes stepper motor and the liquid storage bottle being connected with water inlet pipe, and the liquid storage bottle passes through one
Connecting line through fixed pulley is connected with stepper motor, and stepper motor is controlled by control computer, and the fixed pulley is fixed on one
On support.
The inner chamber of the hydraulic pressure chamber is full of simulated body fluid, and simulated body fluid is provided with liquid storage bottle, and the simulated body fluid is made a living
Reason salt solution or balanced salt solution.
A kind of cornea three-dimensional whole field stress strain response measuring method, it is characterised in that comprise the following steps：
1) in the isolated cornea surface spraying graphite powder handled well, it is then fitted on the fixing hole of cornea grip block；
2) cornea grip block is fastened in the annular groove three of rubber ring, rubber ring is fixed on annular groove one and ring
In connected in star two, then optical fiber source is accessed in hydraulic pressure chamber bottom, close outlet pipe；
3) water inlet pipe is opened, to saline injection or balanced salt solution in cornea physiological environment simulating chamber, and by two
DV is separately positioned on cornea physiological environment simulating chamber top both sides, and two DV alignment corneas；
4) using controlling computer control pressure adjusting means to adjust the pressure suffered by anterior corneal surface, two numbers are recycled to take the photograph
Camera gathers cornea image, and control computer goes to calculate the 3D displacements of anterior corneal surface, the 3D displacements that recycling is obtained using DIC softwares
Calculate three-dimensional whole field strain and the three-dimensional whole field stress on cornea.
The present invention compared with prior art, has the following advantages and advantages：
A kind of cornea three-dimensional whole field stress strain response measuring system of the present invention and its measuring method, by setting cornea
Physiological environment simulating chamber simulates interior environment of the cornea in eyeball, lifting measurement reliability, sets digital code video camera and pre-
Speckle point is put, using controlling computer to adjust cornea pressure, the deformation analysis further according to cornea is calculated, and can directly be existed
The stress and strain of the multiple points of cornea is measured in once testing, it is thus possible to more preferable measurement cornea biomechanical property.
Brief description of the drawings
Accompanying drawing described herein is used for providing further understanding the embodiment of the present invention, constitutes of the application
Point, do not constitute the restriction to the embodiment of the present invention.In the accompanying drawings：
Fig. 1 is schematic structural view of the invention；
Fig. 2 is cornea physiological environment simulating chamber generalized section of the present invention；
Fig. 3 is cornea physiological environment simulating chamber of the present invention longitudinal direction explosive view；
Fig. 4 is cornea grip block sectional view of the present invention；
Fig. 5 is the cornea grip block schematic diagram that the present invention is provided with cornea；
Fig. 6 is the cornea grip block sectional view that the present invention is provided with cornea；
Fig. 7 is corneal spherical coordinate system schematic diagram of the present invention；
Fig. 8 is the deformation process figure put on cornea of the present invention；
Fig. 9 is that tensor of the present invention strains explanatory diagram；
Figure 10 is stress explanatory diagram suffered by cornea of the present invention；
Figure 11 is present invention ellipse stress explanatory diagram；
Figure 12 is free body balance equation explanatory diagram of the present invention；
Mark and corresponding parts title in accompanying drawing：
1- cornea physiological environment simulating chambers, 11- hydraulic pressure chambers, 111- annular grooves one, 112- annular grooves four, 12- hydraulic pressure
Covered on room, 121- annular grooves two, 13- hydraulic pressure chamber bottoms, 131- annular grooves five, 14- bolts, 15- rubber rings, 151- annulars
Groove three, 16- cornea grip blocks, 161- fixing holes, 17- diffuser plates one, 18- colourless transparent glass lids, 19- diffuser plates two, 2-
Cornea, 3- water inlet pipes, 4- pressure sensors, 5- control computers, 6- pressure-regulating devices, 61- stepper motors, 62- liquid storage bottles,
63- connecting lines, 64- supports, 7- DVs, 8- optical fiber sources, 9- outlet pipes.
Specific embodiment
To make the object, technical solutions and advantages of the present invention become more apparent, with reference to embodiment and accompanying drawing, to this
Invention is described in further detail, and exemplary embodiment of the invention and its explanation are only used for explaining the present invention, do not make
It is limitation of the invention.
Embodiment
As shown in figs. 1 to 6, a kind of cornea three-dimensional whole field stress strain response measuring system of the invention, including cornea is given birth to
Reason environmental chamber 1, the cornea physiological environment simulating chamber 1 is used for immobilizing corneal 2 and analog cornea 2 is in intraocular physiologic ring
Border, cornea physiology simulating chamber 1 is provided with water inlet pipe 3, and water inlet pipe 3 is provided with pressure sensor 4, the pressure sensor 4 and control
Computer 5 is connected, and the control computer 5 connects a pressure-regulating device 6, and pressure-regulating device 6 enters with cornea physiology simulating chamber 1
Water pipe 3 is connected, and the control computer 5 is also connected with two DVs 7, and the DV 7 is corresponding with cornea 2.
The cornea physiological environment simulating chamber 1 includes lid 12 and hydraulic pressure chamber bottom 13, the liquid on hydraulic pressure chamber 11, hydraulic pressure chamber
Lid 12 and hydraulic pressure chamber bottom 13 are cylindrical in shape in pressure chamber 11, hydraulic pressure chamber, and water inlet pipe 3 is fixed on the side wall of hydraulic pressure chamber 11, the liquid
Lid 12 and hydraulic pressure chamber bottom 13 are separately fixed at the top and bottom of hydraulic pressure chamber 11, the hydraulic pressure chamber 11 by bolt 14 in pressure chamber
Side wall top surface is provided with annular groove 1, and the side wall bottom surface of lid 12 is provided with corresponding with annular groove 1 on the hydraulic pressure chamber
Annular groove 2 121, one rubber ring 15 of clamping in annular groove 1 and annular groove 2 121, the side wall of rubber ring 15
Inner side is provided with an annular groove 3 151, one cornea grip block 16 of clamping, the hydraulic pressure chamber in the annular groove 3 151
11 sides wall bottom surface are provided with annular groove 4 112, and the side wall top surface of the hydraulic pressure chamber bottom 13 is provided with and annular groove 4 112 pairs
The annular groove 5 131 answered, one diffuser plate 1 of clamping in annular groove 4 112 and annular groove 5 131.
The top surface of lid 12 is fixed with a colourless transparent glass lid 18, the hydraulic pressure below diffuser plate 1 on the hydraulic pressure chamber
A diffuser plate 2 19 is also fixed on the inwall of room bottom 13, optical fiber is additionally provided with the hydraulic pressure chamber bottom 13 below diffuser plate 2 19
Light source 8.
The center of cornea grip block 16 is provided with fixing hole 161 of the base diameter more than top diameter, the fixing hole 161
Side wall and the form fit of cornea 2.
Outlet pipe 9 is additionally provided with the side wall of the hydraulic pressure chamber 11.
The pressure-regulating device 6 includes stepper motor 61 and the liquid storage bottle 62 being connected with water inlet pipe 3, the liquid storage bottle 62
It is connected with stepper motor 61 by a connecting line 63 through fixed pulley, stepper motor 61 is controlled by control computer 5, described fixed
Pulley is fixed on a support 64.
The inner chamber of the hydraulic pressure chamber 11 is full of simulated body fluid, and simulated body fluid, the simulated body fluid are provided with liquid storage bottle 62
It is physiological saline or balanced salt solution.
A kind of cornea three-dimensional whole field stress strain response measuring method, it is characterised in that comprise the following steps：
1) in the surface spraying graphite powder of isolated cornea 2 handled well, it is then fitted into the fixing hole 161 of cornea grip block 16
On；
2) cornea grip block 16 is fastened in the annular groove 3 151 of rubber ring 15, rubber ring 15 is fixed on annular
In groove 1 and annular groove 2 121, then optical fiber source 8 is accessed in hydraulic pressure chamber bottom 13, close outlet pipe 9；
3) water inlet pipe 3 is opened, to saline injection or balanced salt solution in cornea physiological environment simulating chamber 1, and by two
Individual DV 7 is separately positioned on the top both sides of cornea physiological environment simulating chamber 1, and two alignment corneas of DV 7
2；
4) using controlling 5 control pressure adjusting means of computer 6 to adjust the pressure suffered by the surface of cornea 2, two numbers are recycled
The code collection image of cornea 2 of video camera 7, control computer 5 is gone to calculate the 3D displacements on the surface of cornea 2 using DIC softwares, and recycling is obtained
3D displacements calculate on cornea 2 three-dimensional whole field strain and three-dimensional whole field stress.
1st, to calculate the method that three-dimensional whole field on cornea strains using the 3D displacements for obtaining specific as follows：
In Fig. 7, a is the front view of cornea, and b is the top view of cornea, and c is that the spheric coordinate system of definition goes to describe the position of point
Put, the situation for describing cornea, we regard not deformed cornea as suitable sphere and introduce spheric coordinate systemHereThe meridian direction from the summit of cornea, θ is circumferencial direction, R be sphere radially.We
Deformation explanatory diagram is provided simultaneously, as shown in figure 8, that test measurement is rectangular mesh motion vector u under cartesian coordinate system
Component uX、uY、uZ.In order to calculate the strain in circumference and meridian direction, we create the circumference and meridian of not deformed cornea
The Grid in both direction on line direction and the u of mesh point is calculated by DIC softwaresX、uY、uZDisplacement.Thus may be used
To have obtained the displacement component under spheric coordinate system
Conversion from rectangular coordinate system bottom offset component to spheric coordinate system displacement component：
Lagrangian tensor strain seeks method under spheric coordinate system：
If object is that initial state takes up space certain region B in undeformed state, the position of any point p is by curve in object
Coordinate XK(K=1,2,3) is described, or is described by the position vector p of origin of coordinates O to p.After deformation, occupied region B's originally
Particle set enters another region b in space, and p points move to p '.State after deformation is final state, and the position of point is by another curve
Coordinate xk(k=1,2,3) is described, or by origin of coordinates O to position vector p ' descriptions.
The method for expressing of infinitesimal before deformation：
We define rectangular coordinate system first, and origin of coordinates o elects the center of circle of cornea as, such as Fig. 9, and now we define p points
It is a bit on pre-altered cornea, its origin coordinates is spheric coordinate system and is defined as initial state, the deformation represented by it
Preceding infinitesimal is：
DS=GKdXK
(here it is that, using mute target representation, K takes 1,2,3.And X1,X2,X3In representing spheric coordinate system respectivelyG1,G2, G3This is represented respectively puts this coordinate system lower edgeBase vector, and)
The value of wherein base vector is：|G1|=1 | G2|=R
Then we define：
dS2=GKLdXKdXL
Wherein：GKL=GK·GL(K and L take 1,2,3 respectively)
The method for expressing of infinitesimal after deformation：
P points after same definition deformation are p point displacements u in p ' and deformation process.Now we do not know that p ' is specific
Do not know the base vector under this coordinate system is specially how many under what coordinate system yet, it is assumed that it base vector be g1,
g2,g3, then defining the infinitesimal after deformation is：
ds2=gKLdxKdxL(K and L are respectively 1,2,3.And we only know)
In deformation process, x is definedK=xK(X1,X2,X3), and xKIt is XKContinuous function (XKAnd xKRespectively initial state
With the coordinate of final state), then
So：ds2-dS2=gKLdxKdxL-GKLdXKdXL (2-2)
By ds2Conversion：
Then (2-2) formula abbreviation is obtained：
Definition：
Lagrangian tensor is strained：
It is understood that the value of Lagrangian tensor strain is relevant with selected base vector size, but on sphere, with
The difference of selection, the size of base vector can also change therewith, so being contrasted for convenience and being easy to unified standard
Compare, then allow what needs were askedDirection starting infinitesimal be：dS2=dX2(wherein dS2For initial infinitesimal existsHave on direction
The infinitesimal of basis vectors).Similarly dS3=dX3(such dS3Infinitesimal with basis vectors on the θ directions for representing).
In order thatInitial infinitesimal on direction reaches and reached as shown in above formula unified standard, has done as follows to formula
Simplify：
(formula (2-4) is for asking starting point to existOn direction have basis vectors (| G2The Suzanne Lenglen day of |=1)
Measure the formula of the components of strain)
(formula (2-5) be for ask starting point on θ directions have basis vectors (| G3The Suzanne Lenglen day of |=1)
Measure the formula of the components of strain)
So now drawThere are the unified standard infinitesimal Lagrange tensor components of strain to be respectively on direction：
We seek C belowKL：(there is unified standard on θ directions)
The E with unified starting infinitesimal is sought below33：
Wherein e3It is the unit vector on θ directions, andThen above formula can change a kind of expression way：
To be brought into (2-8) specificObtain final Eθθ：
Thus obtained θ has the Lagrangian tensor components of strain E of unified starting infinitesimal along directionθθ。
Similarly can be in the hope of with unified starting infinitesimal
To be brought into (2-10) specificObtain final
Thus edge has been obtainedThere are the Lagrangian tensor components of strain of unified starting infinitesimal on direction
DefinitionWithAnd will be specificWithBand
Enter to obtain final λθWith
λθWithRepresent be circumferential and meridian direction on deformation after length.
2nd, the method that three-dimensional whole field stress on cornea is calculated using the 3D displacements for obtaining is specific as follows：
As shown in Figure 10, during expansion test, the profile of cornea will not keep spherical.In order to calculate meridian and side
Upward stressAnd σθθ, it is oval Gyro Shell body that we simulate the cornea after deformation, and it is thin that its shape meets oval revolution
A part for housing, we ignore the stress of anterior corneal surface while assuming that the components of stress are along corneal thickness in such thin layer
It is uniform constant.Thus, in the presence of we can calculate pressure p internally, cornea is circumferential and meridian direction on should
Power can be calculated by following formula.
The cornea after deformation is regarded as spheroid shape housing that an oval shell is formed around 360 degree of rotations of Y-axis, wherein ellipse
The data such as first, second radius of curvature of any are presented in Fig. 11 explanation on spherical shell.Wherein first curvature radius R1Generation
Radius of curvature KK on table K point meridian directions1, second curvature radius R2Representative is done vertically by the normal of a point K on meridian
In meridianal plane, it is second curvature radius in the radius of curvature that K is pointed out that it intersects the curve for obtaining with median surface, is equal to |
KK2|.The oval major semiaxis a and semi-minor axis b formed after deformation can be measured in process of the test, while measuring any on cornea
A little to Y-axis apart from x.What is surveyed in calculating process is first and second radius of curvature in face in ellipsoid shell, actual in examination
The process of testing measure be anterior corneal surface point the first and second radius of curvature, but due to cornea thickness relative to corneal radii very
It is small, so as to neglect the influence for taking the first second curvature radius on hull outside face and producing.
Such as Figure 12, the first and second radius of curvature of any point on the cornea after deformation are sought below：
The infinitesimal balance equation and free body balance equation of Gyro Shell be：
Two equations of above formula can obtain stress：
Wherein t is the thickness of cornea at the point deformation.
In order to calculate each components of stress of point in circumference and meridian both direction, our corneas from after deformation
The size of the major semiaxis a and semi-minor axis b of ellipse under the pressure is walked is obtained in coordinate system under each pressure step.In order to calculate
The thickness t of cornea after deformationpSize in pressure p, we use the thickness t under 15mmHg pressure15It is standard reference, together
When cornea meet Incoercibility hypothesis.Cornea is divided into 8 regions by us in experiment, and the point of same position with phase
Same thickness.Thickness when so we measure eight positions of cornea under 15mmHg pressure.It is ginseng by eight thickness of position
Examine, the thickness of optional position cornea at various pressures can be calculated, formula is as follows：
Above-described specific embodiment, has been carried out further to the purpose of the present invention, technical scheme and beneficial effect
Describe in detail, should be understood that and the foregoing is only specific embodiment of the invention, be not intended to limit the present invention
Protection domain, all any modification, equivalent substitution and improvements within the spirit and principles in the present invention, done etc. all should include
Within protection scope of the present invention.
Claims (8)
1. a kind of cornea three-dimensional whole field stress strain response measuring system, it is characterised in that including the simulation of cornea physiological environment
Room, the cornea physiological environment simulating chamber is used for immobilizing corneal and analog cornea is in intraocular physiological environment, cornea physiology mould
Intend room and be provided with water inlet pipe, water inlet pipe is provided with pressure sensor, and the pressure sensor is connected with control computer, the control electricity
Brain connects a pressure-regulating device, and pressure-regulating device is connected with cornea physiology simulating chamber water inlet pipe, and the control computer is also
Two DVs of connection, the DV is corresponding with cornea.
2. a kind of cornea three-dimensional whole field stress strain response measuring system according to claim 1, it is characterised in that institute
State cornea physiological environment simulating chamber including hydraulic pressure chamber, on hydraulic pressure chamber lid and hydraulic pressure chamber bottom, on the hydraulic pressure chamber, hydraulic pressure chamber lid and
Hydraulic pressure chamber bottom is cylindrical in shape, and water inlet pipe is fixed on the wall of hydraulic pressure chamber side, and lid and hydraulic pressure chamber bottom pass through spiral shell on the hydraulic pressure chamber
Bolt is separately fixed at the top and bottom of hydraulic pressure chamber, and the hydraulic pressure chamber side wall top surface is provided with annular groove one, the hydraulic pressure chamber
The side wall bottom surface of upper lid is provided with annular groove two corresponding with annular groove one, the clamping in annular groove one and annular groove two
One rubber ring, rubber ring inside sidewalls are provided with an annular groove three, one cornea clamping of clamping in the annular groove three
Plate, the hydraulic pressure chamber side wall bottom surface is provided with annular groove four, and the side wall top surface of the hydraulic pressure chamber bottom is provided with and annular groove
Four corresponding annular grooves five, one diffuser plate one of clamping in annular groove four and annular groove five.
3. a kind of cornea three-dimensional whole field stress strain response measuring system according to claim 2, it is characterised in that institute
State hydraulic pressure chamber upper cover top surface and be fixed with a colourless transparent glass lid, it is also solid on the hydraulic pressure chamber bottom inwall below diffuser plate one
A fixed diffuser plate two, optical fiber source is additionally provided with the hydraulic pressure chamber bottom below diffuser plate two.
4. a kind of cornea three-dimensional whole field stress strain response measuring system according to claim 2, it is characterised in that institute
State cornea grip block center and be provided with fixing hole of the base diameter more than top diameter, fixing hole side wall and cornea shape
Match somebody with somebody.
5. a kind of cornea three-dimensional whole field stress strain response measuring system according to claim 2, it is characterised in that institute
State and be additionally provided with outlet pipe on the wall of hydraulic pressure chamber side.
6. a kind of cornea three-dimensional whole field stress strain response measuring system according to any one of Claims 1 to 5, its
It is characterised by, the pressure-regulating device includes stepper motor and the liquid storage bottle being connected with water inlet pipe, the liquid storage bottle passes through one
Root is connected through the connecting line of fixed pulley with stepper motor, and stepper motor is controlled by control computer, and the fixed pulley is fixed on one
On individual support.
7. a kind of cornea three-dimensional whole field stress strain response measuring system according to claim 6, it is characterised in that institute
The inner chamber of hydraulic pressure chamber is stated full of simulated body fluid, simulated body fluid is provided with liquid storage bottle, the simulated body fluid is physiological saline or flat
Weighing apparatus salting liquid.
8. the survey of a kind of cornea three-dimensional whole field stress strain response measuring system as any one of claim 1~7
Amount method, it is characterised in that comprise the following steps：
1) in the isolated cornea surface spraying graphite powder handled well, it is then fitted on the fixing hole of cornea grip block；
2) cornea grip block is fastened in the annular groove three of rubber ring, rubber ring is fixed on annular groove one and annular is recessed
In groove two, then optical fiber source is accessed in hydraulic pressure chamber bottom, close outlet pipe；
3) water inlet pipe is opened, to saline injection or balanced salt solution in cornea physiological environment simulating chamber, and by two numbers
Video camera is separately positioned on cornea physiological environment simulating chamber top both sides, and two DV alignment corneas；
4) using controlling computer control pressure adjusting means to adjust the pressure suffered by anterior corneal surface, two DVs are recycled
Collection cornea image, control computer is gone to calculate the 3D displacements of anterior corneal surface using DIC softwares, and the 3D displacements that recycling is obtained are calculated
Draw three-dimensional whole field strain and the three-dimensional whole field stress on cornea.
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| CN106840890B (en) | 2019-04-23 |
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