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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 donw(_=  
    v{x{=M]  
    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。 >n5:1.g  
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    模型 $.St ej1  
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    模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 -5G)?J/*  
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    Table 1. AZ眼睛模型的定义
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    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 2h30\/xkU  
    z +2V4s=  
    光源 w[Gh+L30=5  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 rPzQ8<  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 /x@RNdKv  
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 dpZ;l 9  
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    图2. 字母F光源的设定方法光 7J$b$P0}  
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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 jLg@FDb~  
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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。 92W&x'  
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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。 )bOBQbj  
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    图5. 视网膜重点采样规格设定
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    脚本 "+"{+k5t  
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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: ~IVd vm7  
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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。 iSK+GQ~  
    余下的脚本计算与屈光度有关的所有参数。 I lR\  #  
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    分析 rk2xKm^w  
    wl=61 Mb  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 HYr}wG  
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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 D bX{#4lx  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. I 1d0iU  
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    Dim entity As T_ENTITY k?nQ?B W  
    Dim op As T_OPERATION JF9yVE-  
    Dim mat As T_MODELMATERIAL j '%4{n  
    Dim A As Double C=Fzu&N}  
    Dim pupilDiam As Double #4LFG\s  
    Dim eID As Long G>qZxy`c  
    Dim parID As Long $V>98M>j  
    Dim count As Integer RNVbcd  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double /{2*WI;  
    Dim tlens As Double, nlens As Double ge3sU5iZ  
    Dim curv As Double, conic As Double \h<BDk*  
    Dim ok As Long 5@Bu99`  
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    Sub Main ?VU(Pq*`  
    "ceed)(:  
        '用户输入对话框 MWk:sBCqr  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 vY|^/[x#B  
            TextBox 220,21,40,21,.TextBox1 'default: 0 ~`;rNnOT3  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 X8eJ4%  
            OKButton 40,91,90,21 Z[!d*O%R_  
            CancelButton 190,91,90,21 _#e&t"@GS  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 vh!v MB}}  
            TextBox 220,49,40,21,.TextBox2 'default: 4 6Z?j AXGSq  
        End Dialog K[\'"HyQ,X  
        Dim dlg As UserDialog :m=m}3/:  
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        ok = Dialog (dlg) 57{oh")  
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        If ok=0 Then    'cancel button was pressed G}@#u9  
            Print "Execution cancelled." %m5Q"4O  
            End gQSNU_o Z  
        End If !%<^K.wG  
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        'Assign accommodation and pupil diameter & use defaults if field left empty y]..= z_ql  
        If dlg.TextBox1 = "" Then h<l1]h+x  
            A = 0           'Default accommodation ER2GjZa\z  
        Else p_*M:P1Ma4  
            A = CDbl(dlg.TextBox1) ! ueN|8'  
        End If g o5]<4`r  
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        If dlg.TextBox2 = "" Then ^_I} x)i*@  
            pupilDiam = 4   'Default pupil diameter $h9='0Wi0'  
        Else wCs3:@UH  
            pupilDiam = CDbl(dlg.TextBox2) j;yf8Nf  
        End If e)nimq {6  
    ){s*n=KIO  
        Print " " M x5`yT7  
        Print "Accommodation = " & A & " Diopters" ;P&y,:<m:  
        Print "Pupil Diameter = " & pupilDiam & " mm" _,Fny_u=;  
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        ' Calculate new parameters with accommodation HWns.[  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Q0?\]2eet9  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens "Y`3DxXz  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens rn@`yTw^  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens :_<_[Y]1  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens r#PMy$7L  
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        tlens = 3.767 + 0.04*A                  'Lens thickness r90+,aLM#?  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Bsf7mcXz7z  
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        'Adjust parameters to account for accommodation DVZdClAL  
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        '************************************************************************* EO|:FcW  
        'Aqueous thickness (Position of Lens) 9CGNn+~YI  
        '************************************************************************* K`}{0@ilCw  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0oA{Jix  
        GetCustomElement eID, entity RhI;;Y#@  
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        parID = FindFullName( "Geometry.Arizona Eye" ) _3iHkQr  
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        ' Delete any shift(s) in z tary6K9K+  
        count = 0 i LBvGZ<9  
        While GetOperationCount(eID)>count g3n'aD@'x  
            GetOperation eID, count, op P`4]-5gE  
            If op.Type="ShiftZ" Then Z#d&|5Xj  
                DeleteOperation eID,count gieN9S  
                count=count-1 ~na!@<zB{  
            End If tbo>%kn  
            count=count+1 0X8t>#uF  
        Wend k;PAh>8  
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        'Set new shift in /StTb,  
        op.Type = "ShiftZ" c'6g*%2k  
        op.val1 = taq MvLs%GE%  
        op.parent = parID k- V,~c  
        AddOperation eID, op +[@z(N-h  
        Print "Set aqueous humor thickness = " & taq-0.55 e"]8T},  
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        '************************************************************************* f|A riM  
        'Radius and conic constant of anterior lens Z 2}ah  
        '************************************************************************* Q'l^9Bz  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) (YBMsh  
        GetConic eID, entity, curv, conic vzzE-(\\e  
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        SetConic eID, entity, 1/Rant, CCant  mvW%  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant `0H g y=  
    |Z\R*b"  
        '************************************************************************* >4Y3]6N0.F  
        'Radius and conic constant of posterior lens h2z_,`iS7  
        '************************************************************************* .M,RFC  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) -50 HB`t  
        GetConic eID, entity, curv, conic %98' @$:0  
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        SetConic eID, entity, 1/Rpost, CCpost ~ * :F{  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost i"zuil  
    -U~   
        '************************************************************************* G)#$]diNuX  
        'Lens thickness (Position of posterior lens surface) ?7:KphFX)  
        '************************************************************************* rrg96WD  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) v}@xlB=  
    ~vLW.:  
        ' Delete any z-shift(s) rn DCqv!'P  
        count = 0 ?oZR.D|SZ  
        While GetOperationCount(eID)>count 7e7 M@8+4  
            GetOperation eID, count, op E r/bO  
            If op.Type="ShiftZ" Then ~pa!w?/bQ  
                DeleteOperation eID,count ~/NKw:  
                count=count-1 s &Dg8$  
            End If A[G0 .>Wk  
            count=count+1 |r ue=QZ  
        Wend zX5!vaEv  
    %6 Q4yk  
        'Set new z-shift >56>*BHD  
        op.Type = "ShiftZ" pZ`|iLNl-  
        op.val1 = tlens bNT9 H`P  
        op.parent = parID ob+euCuJ  
        AddOperation eID, op %1pYE Hn  
        Print "Set lens thickness = " & tlens ]# t6Jwk  
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        '************************************************************************* y"]n:M:(  
        'Lens index of refraction Ehz o05/!  
        '*************************************************************************  zYXV;  
        eID = FindMaterial( "Lens" ) [dtbkQt,c  
        GetModelMaterial eID, mat <Q|d&vDVfV  
    Uax+dl   
        mat.Nd = nlens (F7(^.MG  
        SetModelMaterial eID, mat Gm*X'[\DD  
        Print "Set lens index of refraction = " & nlens 9nu3+.&P  
    'B+ ' (f  
        '************************************************************************* Q{e\}wN  
        'Pupil diameter H>r!i 4l  
        '************************************************************************* :akT 'q#  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 0$r^C6}f  
    >-&R47G  
        'Adjust pupil diameter (trimming volume inner hole) 6c0>gUQx-  
    MX>[^}n  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" F~ Lx|)0M  
    4Llo`K4  
        ' Adjust pupil location to just in front of the lens "~TA SX_?  
        parID = FindFullName( "Geometry.Arizona Eye" ) j*xV!DqC  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Ym;*Y !~[  
        count = 0 8H[:>;S I  
        While GetOperationCount(eID)>count x8GJY~:SW  
            GetOperation eID, count, op ZiLj=bh  
            If op.Type="ShiftZ" Then J>d.dq>r  
                DeleteOperation eID,count (a9d/3M  
                count=count-1 j,]Y$B  
            End If H@]MXP[_  
            count=count+1 <\?wAjc,  
        Wend R$zH]  
        op.Type = "ShiftZ" \h8 <cTQ  
        op.val1 = taq-0.01 iQ{G(^sZN  
        op.parent = parID iR"N13  
        AddOperation eID, op r'gOVi4t1*  
    F;^F+H  
        Print "Set pupil diameter = " & pupilDiam `~eUee3b.~  
    |7x\m t  
        'Update AZ Eye subassembly Description K98i[,rP  
        eID = FindFullName( "Geometry.Arizona Eye" ) gv5*!eI  
        GetEntity eID, entity ^n0]dizB  
        entity.Description = "Accommodation = " & A & "D" @JdZ5Q  
        SetEntity eID, entity YJ$1N!rG  
    q+,Q<2J  
        Update hMtf.3S7c  
        Print "DONE!" S*yjee<@  
         E!S 78 z:  
    End Sub ,AT[@  
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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: +>JjvYx}\  
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    Accommodation = 4 Diopters 37}D9:#5C  
    Pupil Diameter = 4 mm ?7{H|sI  
    Set aqueous humor thickness = 2.81 $ImrOf^qt  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 qe5feky  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 V^;jJ']  
    Set lens thickness = 3.927 Z1"v}g  
    Set lens index of refraction = 1.42672 irjP>3_e  
    Set pupil diameter = 4 4*$G & TX  
    DONE! ->N8#XH2=  
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    W^"AU;^V56  
    QQ:2987619807 m8.U &0  
     
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