[分享]Arizona眼睛模型 [复制链接]

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  
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模型 F
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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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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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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$3oE.  
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视网膜的散射 88v8lt;R  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 s{Qae=$Q  
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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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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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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。 " _2k3  
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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@KM2KMN  
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?@
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    End If %VO+\L8Fs  
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    'Assign accommodation and pupil diameter & use defaults if field left empty s?EQ  
    If dlg.TextBox1 = "" Then `MI;.t  
        A = 0           'Default accommodation $t;:"i>  
    Else 1nAm\/&  
        A = CDbl(dlg.TextBox1) Nu"v .]Y2  
    End If ~b
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    If dlg.TextBox2 = "" Then /qIQE&V-  
        pupilDiam = 4   'Default pupil diameter _aFe9+y  
    Else r W`7<3  
        pupilDiam = CDbl(dlg.TextBox2) vkE`T5??  
    End If "bhK%N;  
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    Print " " _c>ww<*3  
    Print "Accommodation = " & A & " Diopters" F\DiT|?}  
    Print "Pupil Diameter = " & pupilDiam & " mm" :01d9|#  
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    ' Calculate new parameters with accommodation r/sSkF F  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness `}?;Ow&2CY  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens m%[e_eS  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \AwkK3  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens }%u#TwZ  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens L(;$(k-/(  
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    tlens = 3.767 + 0.04*A                  'Lens thickness
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction <r#FI8P;X  
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    'Adjust parameters to account for accommodation v?VDASR2`  
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    '************************************************************************* \|0z:R;X  
    'Aqueous thickness (Position of Lens) /i,n75/y?  
    '************************************************************************* ZHNL~=r}  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) mWv$eR  
    GetCustomElement eID, entity \n[kzi7  
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    parID = FindFullName( "Geometry.Arizona Eye" ) `<nxXsLe  
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    ' Delete any shift(s) in z 'f6H#V*C  
    count = 0 r84^/+"T  
    While GetOperationCount(eID)>count p]mN)  
        GetOperation eID, count, op G(7%*@SX  
        If op.Type="ShiftZ" Then lbAhP+B  
            DeleteOperation eID,count EHC7b^|3}  
            count=count-1 "-=fi 'D  
        End If k'st^1T  
        count=count+1 tDRR3=9pX  
    Wend )h}IZSm  
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    'Set new shift in eUy*
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    op.Type = "ShiftZ" u!K1K3T6k  
    op.val1 = taq H{Ewj_L  
    op.parent = parID "Pwa}{  
    AddOperation eID, op C-y MWr  
    Print "Set aqueous humor thickness = " & taq-0.55 W0f^!}f(  
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    '************************************************************************* >:-e  
    'Radius and conic constant of anterior lens '{ _ X1  
    '************************************************************************* ^sf,mM~D  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) u+j\PWOtm  
    GetConic eID, entity, curv, conic Rge>20uTl$  
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    SetConic eID, entity, 1/Rant, CCant ["D!IqI:  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant N6._Jb  
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    '************************************************************************* 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!:  
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    SetConic eID, entity, 1/Rpost, CCpost z,aMbgt  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost =Ydrct  
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    '************************************************************************* 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  
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    ' 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~  
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    '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  
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    '************************************************************************* DP@1to@  
    'Lens index of refraction 5[4wN( )  
    '************************************************************************* x[58C+  
    eID = FindMaterial( "Lens" ) M*0^<e~]F  
    GetModelMaterial eID, mat v/ N[)<  
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    mat.Nd = nlens Es+I]o0K  
    SetModelMaterial eID, mat !CU-5bpu  
    Print "Set lens index of refraction = " & nlens yn\c;Z  
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    '************************************************************************* Q/SO%E`E  
    'Pupil diameter >+J}mo=*  
    '************************************************************************* *F1TZ_GS  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) e8<}{N0,n  
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    'Adjust pupil diameter (trimming volume inner hole) _]zX W  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" F- -g?Q^  
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    ' 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" )
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    count = 0 Da 7(jA+  
    While GetOperationCount(eID)>count TnN ythwZ  
        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{
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    op.Type = "ShiftZ" {Phq39g  
    op.val1 = taq-0.01 LG:k}z/T  
    op.parent = parID B<I(t"s  
    AddOperation eID, op d
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    Print "Set pupil diameter = " & pupilDiam
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    '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$Xfu  
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    Update >h8m)Q  
    Print "DONE!" !-`L1D_hy  
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End Sub MZ}0.KmaZ  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： 2FuV%\p  
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Accommodation = 4 Diopters }@HgFM"  
Pupil Diameter = 4 mm \H .Cmm^I  
Set aqueous humor thickness = 2.81 dI\_I]  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ^gcB+  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 32K& IfV  
Set lens thickness = 3.927 !M8_PC*a  
Set lens index of refraction = 1.42672 ta{24{?M\  
Set pupil diameter = 4 "9P @bA  
DONE! ~u$cX1M  
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