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    [分享]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2020-12-09
    简介 ;[R{oW Nw  
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    人眼光学模型可用来设计眼科用设备,光学系统注定了要与人眼一起使用。本文演示了这样一个模型:Arizona眼睛模型,在Jim Schwiegerling教授的书中有详细描述:《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源,并包括一个基于想要的屈光度来调整模型的内嵌脚本。 ^%@(> :)0  
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    模型 C_rlbl;T  
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    模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 :EJ+#  
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    Table 1. AZ眼睛模型的定义
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    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. U;<07 aMj  
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    光源 P3jDx{F  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 Z 7rVM   
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 &> tmzlww  
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 '#mv-/<t*  
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    图2. 字母F光源的设定方法光 2 1.;lj  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 6}ct{Q  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 :8cp]v dW  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 ~:~-AXaMT  
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    图5. 视网膜重点采样规格设定
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    脚本  u;R<  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: |dcRDOTe  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 .Az' THD}  
    余下的脚本计算与屈光度有关的所有参数。 V +j58Wuf  
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    分析 :Lu=t3#  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 [+<lm 5t  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 T<1* R>el  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. :!H]gC 4  
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    Dim entity As T_ENTITY Gxx:<`[ON  
    Dim op As T_OPERATION YTP6m9hA+  
    Dim mat As T_MODELMATERIAL vDl6TKXcu  
    Dim A As Double Rg@W0Bc)  
    Dim pupilDiam As Double Nr 5h%<` I  
    Dim eID As Long Sxo9y0K8-  
    Dim parID As Long 7~(|q2ib  
    Dim count As Integer <d!_.f}v  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double &!7{2E\7C  
    Dim tlens As Double, nlens As Double !jZXh1g%  
    Dim curv As Double, conic As Double F} d>pK9fn  
    Dim ok As Long aF2vw{wT}  
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    Sub Main CJ0{>?  
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        '用户输入对话框 N0TEVDsk  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 &+]x  
            TextBox 220,21,40,21,.TextBox1 'default: 0 NbG`v@yH  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Z#w@ /!"}T  
            OKButton 40,91,90,21 ,FWC|uM"  
            CancelButton 190,91,90,21  {oQ.y  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 *UM=EQaYk  
            TextBox 220,49,40,21,.TextBox2 'default: 4 3zi(|B[,?  
        End Dialog Y)="of  
        Dim dlg As UserDialog DPIIE2X  
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        ok = Dialog (dlg) ~m4{GzB  
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        If ok=0 Then    'cancel button was pressed qRy<W  
            Print "Execution cancelled." m^hi}Am1  
            End =^  
        End If ,|RS]I>X  
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        'Assign accommodation and pupil diameter & use defaults if field left empty [wKnJu  
        If dlg.TextBox1 = "" Then NJ" d`  
            A = 0           'Default accommodation |j3fS[.$  
        Else !@2L g  
            A = CDbl(dlg.TextBox1) v(PwE B]  
        End If L#)F00/`  
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        If dlg.TextBox2 = "" Then @nIoYT='  
            pupilDiam = 4   'Default pupil diameter Ci{,e%  
        Else \jlem<&  
            pupilDiam = CDbl(dlg.TextBox2) 9k5$rK`  
        End If EtVRnI@  
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        Print " " %=C49(/K_  
        Print "Accommodation = " & A & " Diopters" DK-V3}`q}  
        Print "Pupil Diameter = " & pupilDiam & " mm" Ih_2")d  
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        ' Calculate new parameters with accommodation p%MH**A  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness zT _  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens E RnuM  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens (- ]A1WQ?  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens P'wn$WE[n\  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens btb$C  
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        tlens = 3.767 + 0.04*A                  'Lens thickness <K6:"  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^o;f~6#17  
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        'Adjust parameters to account for accommodation AHa%?wb  
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        '************************************************************************* 3}U {~l!K  
        'Aqueous thickness (Position of Lens) >b6!*Lrhs  
        '************************************************************************* Ab| t E5%  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) RXo!K iQO  
        GetCustomElement eID, entity 6 GL.bS  
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        parID = FindFullName( "Geometry.Arizona Eye" ) hT c VMc  
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        ' Delete any shift(s) in z rUg<(/c  
        count = 0 /Mac:;W`  
        While GetOperationCount(eID)>count >%x N?%  
            GetOperation eID, count, op G {wIY"~4  
            If op.Type="ShiftZ" Then -o\o{?t,  
                DeleteOperation eID,count CJn{tP  
                count=count-1 c,wYXnJ_t  
            End If :K-05$K  
            count=count+1 ihv=y\Jt  
        Wend rGNYu\\  
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        'Set new shift in !&8nwOG  
        op.Type = "ShiftZ" m {dXN=  
        op.val1 = taq Ib8*rL0p<L  
        op.parent = parID A>C&`A=-  
        AddOperation eID, op 2hD(zUSy  
        Print "Set aqueous humor thickness = " & taq-0.55 2N)siH  
    )sONfn  
        '************************************************************************* :>y?B!=  
        'Radius and conic constant of anterior lens SVJL|S 3k  
        '************************************************************************* ^`BiA'gPPC  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) @y"/hh_?  
        GetConic eID, entity, curv, conic Z4&,KrV  
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        SetConic eID, entity, 1/Rant, CCant [ 2WJ];FJ  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant NU]+ {7  
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        '************************************************************************* [9hslk  
        'Radius and conic constant of posterior lens D90.z"N\i9  
        '************************************************************************* 1KHFzx,  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) /b|V=j}W  
        GetConic eID, entity, curv, conic G}|!Jdr  
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        SetConic eID, entity, 1/Rpost, CCpost x6h';W_ 8  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost SC Qr/Q  
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        '************************************************************************* ZmXO3,sf)  
        'Lens thickness (Position of posterior lens surface) t\GoUeH]  
        '************************************************************************* RWX?B  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) x/<eY<Vgm?  
    vO?\u`vY  
        ' Delete any z-shift(s) 4Go$OQ`  
        count = 0 -za+Wa`vH  
        While GetOperationCount(eID)>count g-4m.;  
            GetOperation eID, count, op .eNeq C  
            If op.Type="ShiftZ" Then :kQ%Mj>  
                DeleteOperation eID,count |.ZYY(}  
                count=count-1 ?o>JX.Nl&7  
            End If fRt`]o:Om  
            count=count+1 Xur{nk~?  
        Wend 6d# 7  
    j\LJ{?;jC  
        'Set new z-shift b +4x2{  
        op.Type = "ShiftZ" rDD,eNjG  
        op.val1 = tlens [iO*t, 3@h  
        op.parent = parID qV7F=1k]  
        AddOperation eID, op 4qYT  
        Print "Set lens thickness = " & tlens 8:9/RL\"x  
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        '************************************************************************* K6z)&<  
        'Lens index of refraction ;YfKG8(0  
        '************************************************************************* ,E._A(Z  
        eID = FindMaterial( "Lens" ) "p"M9P'  
        GetModelMaterial eID, mat \nzaF4+$  
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        mat.Nd = nlens MEI.wJZ  
        SetModelMaterial eID, mat ;^"#3_7T]  
        Print "Set lens index of refraction = " & nlens KAFx^JLo  
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        '************************************************************************* ]di^H>,xU  
        'Pupil diameter o-}q|tD$<  
        '************************************************************************* ; *ZiH%q,  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) =>0 G  
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        'Adjust pupil diameter (trimming volume inner hole) ,q".d =6  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" yu.N>[=  
    Y CBcyE}p  
        ' Adjust pupil location to just in front of the lens 8q"C=t7  
        parID = FindFullName( "Geometry.Arizona Eye" ) -#y^$$i0  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) #;lB5) oe  
        count = 0 [ U`})  
        While GetOperationCount(eID)>count Y+ Qm.  
            GetOperation eID, count, op -qDM(zR  
            If op.Type="ShiftZ" Then !iHJ!  
                DeleteOperation eID,count ;,2;J3,pA  
                count=count-1 0] u=GD%  
            End If U#mrbW  
            count=count+1 .B?J@,  
        Wend *?`<Ea  
        op.Type = "ShiftZ" JA]qAr  
        op.val1 = taq-0.01 r.vezsH  
        op.parent = parID FWb`F&  
        AddOperation eID, op 5;:964Et  
    a{y"vVQOF  
        Print "Set pupil diameter = " & pupilDiam Be4n\c.  
    $%Kyz\;7/  
        'Update AZ Eye subassembly Description W*!u_]K>  
        eID = FindFullName( "Geometry.Arizona Eye" ) 1=^edQ+   
        GetEntity eID, entity &f"kWOe$X  
        entity.Description = "Accommodation = " & A & "D" h4,S /n  
        SetEntity eID, entity 7.!`c-8 u  
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        Update 9`| ^cL*6  
        Print "DONE!" 8)m  
         rl0|)j  
    End Sub ;#+Se,)  
    :OC(93d)0  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: IS [&V&.n  
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    Accommodation = 4 Diopters PpWn+''M  
    Pupil Diameter = 4 mm +}Q@{@5w  
    Set aqueous humor thickness = 2.81 vbMt}bM(GD  
    Set anterior lens radius = 10.4 and conic constant = -2.375869  cq,8^o&  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 e< E]8GAF  
    Set lens thickness = 3.927 sR*.i?lN  
    Set lens index of refraction = 1.42672 G8hq;W4@]/  
    Set pupil diameter = 4 +H `FC  
    DONE! =(\xe| Q  
    /q\{OsrX  
    _ rIFwT1]  
    QQ:2987619807 #$*l#j"#A  
     
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