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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 S4`X^a}pY  
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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。 :MY=Q]l  
    ! #_2 ![  
    模型 F5RL+rU(h  
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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。 lUB?eQuN_  
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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. YB7n}r23  
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    光源 !e$ZOYe  
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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。 X':FFD4h  
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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。 +4_,, I  
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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。 sdZ$3oE.  
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    图2. 字母F光源的设定方法光 P0}{xq'k9v  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 88v8lt;R  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 s{Qae=$Q  
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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。 ]"Uzn  
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    图5. 视网膜重点采样规格设定
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    脚本 bpwA|H%{M  
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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: / S]RP>cQ  
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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。 "u7[[.P)  
    余下的脚本计算与屈光度有关的所有参数。 ;yomaAr  
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    分析 -i:WA^yKgw  
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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。 " _2 k 3  
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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 RH;ulAD6(~  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. _M`ZF*o=c  
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    Dim entity As T_ENTITY z9ADF(J?0'  
    Dim op As T_OPERATION ?Tc#[B  
    Dim mat As T_MODELMATERIAL (0NffM1  
    Dim A As Double Q 84t=  
    Dim pupilDiam As Double I@KM2 KMN  
    Dim eID As Long _eiqs  
    Dim parID As Long 2/*u$~  
    Dim count As Integer 0qJ (RB  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 6h>#;M  
    Dim tlens As Double, nlens As Double B[@q.n  
    Dim curv As Double, conic As Double SUUNC06V  
    Dim ok As Long +-@n}xb@  
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    Sub Main |X8?B =  
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        '用户输入对话框 h+1|.d  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ~JXz  
            TextBox 220,21,40,21,.TextBox1 'default: 0 w1)TnGT  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 \s*M5oN]]  
            OKButton 40,91,90,21 T o["o!(;z  
            CancelButton 190,91,90,21 [nO3%7t@  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 v@Uk% O/  
            TextBox 220,49,40,21,.TextBox2 'default: 4 1<BKTMBq?{  
        End Dialog @-)?uYw:r  
        Dim dlg As UserDialog ;Sivu-%  
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        ok = Dialog (dlg) 5I2,za&e  
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        If ok=0 Then    'cancel button was pressed <==uK>pET  
            Print "Execution cancelled." TWpw/osW  
            End n?@zp<  
        End If %VO+\L8Fs  
    MV"n{1B  
        'Assign accommodation and pupil diameter & use defaults if field left empty s?EQ  
        If dlg.TextBox1 = "" Then  `M I;.t  
            A = 0           'Default accommodation $t;:"i>  
        Else 1nAm\/&  
            A = CDbl(dlg.TextBox1) Nu"v .]Y2  
        End If ~b~Tq  
    ^+P.f[  
        If dlg.TextBox2 = "" Then /qIQE&V-  
            pupilDiam = 4   'Default pupil diameter _aFe9+y  
        Else r W`7<3  
            pupilDiam = CDbl(dlg.TextBox2) vkE`T5??  
        End If "b hK %N;  
    |0i{z(B  
        Print " " _c>ww<*3  
        Print "Accommodation = " & A & " Diopters" F\D iT|?}  
        Print "Pupil Diameter = " & pupilDiam & " mm" :01d9|#  
    yI: ;+K  
        ' Calculate new parameters with accommodation r/sSkF F  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness `}?;Ow&2CY  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens m%[e_eS  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \AwkK3  
    dkw.o.e  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens }%u #TwZ  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens L(;$(k-/(  
    \\dUp>1=  
        tlens = 3.767 + 0.04*A                  'Lens thickness =>;&M)+q  
    /"Vd( K2Z  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction <r#FI8P;X  
    oy8jc];SO  
        'Adjust parameters to account for accommodation v?VDASR2`  
    ^K<3_D>1>  
        '************************************************************************* \|0z:R;X  
        'Aqueous thickness (Position of Lens) /i,n75/y?  
        '************************************************************************* ZHNL ~=r}  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) mWv$eR  
        GetCustomElement eID, entity \n[kzi7  
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        parID = FindFullName( "Geometry.Arizona Eye" ) `<nxXsLe  
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        ' Delete any shift(s) in z 'f6H#V*C  
        count = 0 r84^/+"T  
        While GetOperationCount(eID)>count p]mN)  
            GetOperation eID, count, op G(7%*@SX  
            If op.Type="ShiftZ" Then lbAhP+B  
                DeleteOperation eID,count EHC7b^|3}  
                count=count-1 "-=fi 'D  
            End If k' st^1T  
            count=count+1 tDRR3=9pX  
        Wend )h}IZSm  
    @s1T|}AJ  
        'Set new shift in eUy*0  
        op.Type = "ShiftZ" u!K1K3T6k  
        op.val1 = taq H{Ewj_L  
        op.parent = parID "Pwa}{  
        AddOperation eID, op C-y MWr  
        Print "Set aqueous humor thickness = " & taq-0.55 W0f^!}f(  
    ^)-[g  
        '*************************************************************************  >:-e  
        'Radius and conic constant of anterior lens '{ _ X1  
        '************************************************************************* ^sf,mM~D  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) u+j\PWOtm  
        GetConic eID, entity, curv, conic Rge>20uTl$  
    iAz0 A  
        SetConic eID, entity, 1/Rant, CCant ["D!IqI :  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant N6._J b  
    Z[nHo'  
        '************************************************************************* n[Q(q[ULV  
        'Radius and conic constant of posterior lens q\@Zf}  
        '************************************************************************* 3Z?ornS  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) rQ.zqr  
        GetConic eID, entity, curv, conic &G"s !:  
    |`o|;A]  
        SetConic eID, entity, 1/Rpost, CCpost z,aMbgt  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost =Ydrct  
     @/s|<*  
        '************************************************************************* j,i9,oF6]  
        'Lens thickness (Position of posterior lens surface)  v%:deaF  
        '************************************************************************* z6R|1L 1  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;}E}N:A  
    F1.Xk1y%  
        ' Delete any z-shift(s) $eFMn$o  
        count = 0 )NZH{G  
        While GetOperationCount(eID)>count UfX~GC;B  
            GetOperation eID, count, op Mc,|C)  
            If op.Type="ShiftZ" Then IB;yL/T  
                DeleteOperation eID,count 46g0 e  
                count=count-1 %C/p+Tg  
            End If .aT@'a{F  
            count=count+1 "B{3q`(  
        Wend :6Nb,Hh~  
    "%Ok3Rvv  
        'Set new z-shift <G}Lc  
        op.Type = "ShiftZ" KM;H '~PZi  
        op.val1 = tlens P\MDD@  
        op.parent = parID Pg8.RvmQ  
        AddOperation eID, op 6=/sEzS'  
        Print "Set lens thickness = " & tlens W/,bz",v3  
    d}Pfj=W  
        '************************************************************************* DP @1to@  
        'Lens index of refraction 5[4wN( )  
        '************************************************************************* x[58C+  
        eID = FindMaterial( "Lens" ) M*0^<e~]F  
        GetModelMaterial eID, mat v/ N[)<  
    v^ ^Ibv  
        mat.Nd = nlens Es+I]o0K  
        SetModelMaterial eID, mat !CU-5bpu  
        Print "Set lens index of refraction = " & nlens yn\c;Z  
    &?R/6"J  
        '************************************************************************* Q/SO%E`E  
        'Pupil diameter >+J}mo=*  
        '************************************************************************* *F1TZ_GS  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) e8<}{N0,n  
    }!_z\'u  
        'Adjust pupil diameter (trimming volume inner hole) _]zX W  
    @4y?XL(n  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" F- -g?Q^  
    v ;\cM/&5  
        ' Adjust pupil location to just in front of the lens "<=4]Z  
        parID = FindFullName( "Geometry.Arizona Eye" ) Ef`'r))  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) W^8  
        count = 0 Da 7(jA+  
        While GetOperationCount(eID)>count TnN yth wZ  
            GetOperation eID, count, op KdkL_GSLT  
            If op.Type="ShiftZ" Then 7<)H?;~;  
                DeleteOperation eID,count j;`pAN('  
                count=count-1 q'8*bu_  
            End If TBt5Nqks-  
            count=count+1 cjL)M=pIS  
        Wend HX2u{2$  
        op.Type = "ShiftZ" {Phq39g  
        op.val1 = taq-0.01 LG:k}z/T  
        op.parent = parID B<I(t"s  
        AddOperation eID, op d'96$e o~  
    [QxP9EC  
        Print "Set pupil diameter = " & pupilDiam w8X5kk   
    'etA1]<N  
        'Update AZ Eye subassembly Description @.7/lRr@bp  
        eID = FindFullName( "Geometry.Arizona Eye" ) )>1}I_1j)  
        GetEntity eID, entity )IcSdS0@M  
        entity.Description = "Accommodation = " & A & "D" QwX81*nx  
        SetEntity eID, entity Ypzmc$Xfu  
    oH w!~ c7  
        Update >h8m)Q  
        Print "DONE!" !-`L1D_hy  
         &j:e<{@  
    End Sub MZ}0.KmaZ  
    //c6vG  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: 2FuV%\p  
    i!2k f  
    Accommodation = 4 Diopters }@HgFM"  
    Pupil Diameter = 4 mm \H .Cmm^I  
    Set aqueous humor thickness = 2.81 dI\_I]  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ^gcB+  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 32K& IfV  
    Set lens thickness = 3.927 !M8_PC*a  
    Set lens index of refraction = 1.42672 ta{24{?M\  
    Set pupil diameter = 4 "9P @bA  
    DONE! ~u$ cX1M  
    9KX% O-'  
    ; +\h$  
    QQ:2987619807 #Gi`s?  
     
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