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    [分享]Arizona眼睛模型 [复制链接]

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    只看楼主 倒序阅读 楼主  发表于: 2020-12-09
    简介 zMzf=~  
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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。 GdeR#%z  
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    模型 Po!JgcJ#\  
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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。 |ezO@  
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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. IA 9v1:>  
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    光源 h9w^7MbO  
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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。 &R FM d=  
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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。 \v P2B  
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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。 ID).*@(I"  
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    图2. 字母F光源的设定方法光 VBsFT2XiL  
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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 M|E2&ht  
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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。 \%?8jQ'tX  
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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。 -k[tFBl w  
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    图5. 视网膜重点采样规格设定
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    脚本 'UXj\vJ3E  
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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: Jn@Mbl  
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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。 Wh'_ slDH+  
    余下的脚本计算与屈光度有关的所有参数。 q~' K9  
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    分析 gQpD]p%k  
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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。 e<O;pM:  
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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 ~ut& U  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. wp]7Lx?F  
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    Dim entity As T_ENTITY \`Ph=lJO  
    Dim op As T_OPERATION j#nO6\&o  
    Dim mat As T_MODELMATERIAL hA1gkEM2o  
    Dim A As Double x+*L5$;h  
    Dim pupilDiam As Double "U5Ln2X{J  
    Dim eID As Long 0q>NE <L  
    Dim parID As Long K@j^gF/0B  
    Dim count As Integer z^a!C#IX  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double  fBWJ%W  
    Dim tlens As Double, nlens As Double RqN_vk\  
    Dim curv As Double, conic As Double |!xfIR>=F  
    Dim ok As Long H6PXx  
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    Sub Main e2-70UvW^  
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        '用户输入对话框 Gkodk[VuLs  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 k}f<'g<H  
            TextBox 220,21,40,21,.TextBox1 'default: 0 z7t'6Fy9'  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 [nN\{"~O  
            OKButton 40,91,90,21 5;K-,"UQ  
            CancelButton 190,91,90,21 BudWbZ5>Ep  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Ot2zhR )  
            TextBox 220,49,40,21,.TextBox2 'default: 4 ><#2O  
        End Dialog CNpe8M=/3  
        Dim dlg As UserDialog uku}Mr"p  
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        ok = Dialog (dlg)  ENYF0wW  
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        If ok=0 Then    'cancel button was pressed "3Xv%U9@  
            Print "Execution cancelled." :uIi ?  
            End 7$1fy0f[l  
        End If bU:}ZO^S  
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        'Assign accommodation and pupil diameter & use defaults if field left empty *b6I%MZn  
        If dlg.TextBox1 = "" Then dxkRk#mf:  
            A = 0           'Default accommodation q2S!m6!  
        Else 6HEqm>Yau  
            A = CDbl(dlg.TextBox1) u6iU[5  
        End If ?x5wS$^q<  
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        If dlg.TextBox2 = "" Then zldfRo\wl  
            pupilDiam = 4   'Default pupil diameter l}Q"Nb)  
        Else QX/X {h6  
            pupilDiam = CDbl(dlg.TextBox2) [w&#+h-q  
        End If cD'HQ3+  
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        Print " " ?u_gXz;A  
        Print "Accommodation = " & A & " Diopters" !^)wPmk  
        Print "Pupil Diameter = " & pupilDiam & " mm" tp6csS,  
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        ' Calculate new parameters with accommodation tT@w%Sz57N  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness [5? 4c'Ev  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens T}L^CU0  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens E-yT  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens E[|s>Xv~  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens YGq=8p7.R  
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        tlens = 3.767 + 0.04*A                  'Lens thickness 99l>CYXd  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction D00G1:Ft(T  
    ]^J+-c  
        'Adjust parameters to account for accommodation GI2eJK  
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        '************************************************************************* c;:">NR  
        'Aqueous thickness (Position of Lens) (O)\#%,@R  
        '************************************************************************* gk!E$NyE  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) v2 29H<  
        GetCustomElement eID, entity B ~fSMB6h  
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        parID = FindFullName( "Geometry.Arizona Eye" ) &8[ZN$Xe"  
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        ' Delete any shift(s) in z qP~WEcH`[  
        count = 0 1R0ffP]  
        While GetOperationCount(eID)>count w)+wj[6 E  
            GetOperation eID, count, op yfmp$GO:  
            If op.Type="ShiftZ" Then 403[oOj  
                DeleteOperation eID,count uh]"(h(>  
                count=count-1  f~w>v  
            End If BdN8 ^W  
            count=count+1 3lo;^KX !  
        Wend yJ!OsD  
    )v[XmJ>H~o  
        'Set new shift in :P3{Nxa  
        op.Type = "ShiftZ" 2O eshkE  
        op.val1 = taq WtEI] WO  
        op.parent = parID &&[zT/]P  
        AddOperation eID, op #SKfE  
        Print "Set aqueous humor thickness = " & taq-0.55 !Y ( apVQ  
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        '************************************************************************* ^_v[QV  
        'Radius and conic constant of anterior lens q[7CPE0n  
        '************************************************************************* y n SBVb!)  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) yL0f1nS  
        GetConic eID, entity, curv, conic 5L8&/EN9-  
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        SetConic eID, entity, 1/Rant, CCant k`Nyi )AGe  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !; IJ   
    ,V,f2W 4  
        '************************************************************************* 3KSpB;HX  
        'Radius and conic constant of posterior lens R (G2qi  
        '************************************************************************* |,b2b2v ?  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) z~,mRgc$B  
        GetConic eID, entity, curv, conic ZWO)tVw9G  
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        SetConic eID, entity, 1/Rpost, CCpost Yu'a<5f  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 4'',6KJ@  
    e}c&LDgU  
        '************************************************************************* dL-i)F  
        'Lens thickness (Position of posterior lens surface) NUCiY\td  
        '************************************************************************* ._?V%/  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) F|>05>8  
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        ' Delete any z-shift(s) (89Ji'dc  
        count = 0 ;f:gX`"\  
        While GetOperationCount(eID)>count `H\)e%]  
            GetOperation eID, count, op &iNwvA%9D  
            If op.Type="ShiftZ" Then >!L&>OOx  
                DeleteOperation eID,count CK0l9#g  
                count=count-1 Us,)]W.S  
            End If `\bT'~P  
            count=count+1 \q "N/$5{f  
        Wend RT^v:paNT2  
    `5q ;ssu  
        'Set new z-shift {T=52h=e  
        op.Type = "ShiftZ" OR:[J5M)  
        op.val1 = tlens v?%LQKO  
        op.parent = parID 3GF2eS$$P  
        AddOperation eID, op /`[!_4i  
        Print "Set lens thickness = " & tlens _%~$'Hy  
    D8%AV; -Y  
        '************************************************************************* 03k?:D+5  
        'Lens index of refraction %d1draL  
        '************************************************************************* MPIlSMe  
        eID = FindMaterial( "Lens" ) i^)WPP>4Aw  
        GetModelMaterial eID, mat KB!5u9  
    lwT9~Hyp  
        mat.Nd = nlens =>|C~@C?  
        SetModelMaterial eID, mat ]5' d&f  
        Print "Set lens index of refraction = " & nlens x&Cp> +i  
    N2ied^* 0  
        '************************************************************************* d,0 }VaY=D  
        'Pupil diameter <P_ea/5:|  
        '************************************************************************* x({H{'9?  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) WA6!+Gy  
    #]E(N~  
        'Adjust pupil diameter (trimming volume inner hole) ";x+1R.d  
    v .=/Y(J  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" JBC$Ku  
    -)jax  
        ' Adjust pupil location to just in front of the lens ff e1lw%  
        parID = FindFullName( "Geometry.Arizona Eye" ) l>6@:nq|R  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) #Yuvbb[  
        count = 0 D)Q)NI  
        While GetOperationCount(eID)>count H={&3poBz  
            GetOperation eID, count, op "5Uh< X  
            If op.Type="ShiftZ" Then ^e Gue  
                DeleteOperation eID,count ;@3FF  
                count=count-1  En6H%^d2  
            End If t *G/]  
            count=count+1 80pid[F  
        Wend t<j^q`;@v  
        op.Type = "ShiftZ" ;sPoUn s'  
        op.val1 = taq-0.01 -|S]oJy  
        op.parent = parID LD>\#q8a*  
        AddOperation eID, op ;eL9{eF  
    *\uM.m0$  
        Print "Set pupil diameter = " & pupilDiam ememce,Np  
    jS.g]k  
        'Update AZ Eye subassembly Description b:J(b?  
        eID = FindFullName( "Geometry.Arizona Eye" ) "TcW4U9  
        GetEntity eID, entity ORN6vX(1  
        entity.Description = "Accommodation = " & A & "D" $((6=39s  
        SetEntity eID, entity Oakb'  
    O#a6+W"U  
        Update D${={x  
        Print "DONE!" o|BP$P8V  
         3+Qxg+<  
    End Sub k S# CEU7  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: laKuOx}  
    E Y<8B3y  
    Accommodation = 4 Diopters ~EzaC?fQ  
    Pupil Diameter = 4 mm FR[ B v  
    Set aqueous humor thickness = 2.81 h}`!(K^;3  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 |RkcDrB~  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 S~Z|PLtF  
    Set lens thickness = 3.927 4mjgt<`  
    Set lens index of refraction = 1.42672 /u%h8!"R  
    Set pupil diameter = 4 }[+!$#  
    DONE! I` K$E/ns  
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    *l+OlQI0+  
    QQ:2987619807 B+d<F[ |  
     
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