[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 :H#D4O8UiH  
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。 8Q0/kG  
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模型 \w&R`;b8w  
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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。 $@w,9J\  
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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. m8eoD{  
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光源 e;LC\*dG  
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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。 H_ NoW  
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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。 QWWI  
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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。 eT?vZH[N  
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视网膜的散射 h\5~&}Hp  
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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。 nITkgN:s  
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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。 Ef3="}AI;  
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脚本 i?V:+0#q\]  
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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： 9`CJhu  
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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。 Tt_QAIl  
余下的脚本计算与屈光度有关的所有参数。 .3SP#mI  
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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。 rKTc6h:)  
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脚本代码 <"S`ZOn  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. umpa!q};  
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Dim entity As T_ENTITY \_)mWK,h  
Dim op As T_OPERATION @lqI,Ce5  
Dim mat As T_MODELMATERIAL H1 i+j;RN  
Dim A As Double ^e8
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Dim pupilDiam As Double *8/
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Dim eID As Long > lI2r}  
Dim parID As Long )Q<u0AxAn  
Dim count As Integer gRw? <U^  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double :#UA!|nV  
Dim tlens As Double, nlens As Double L9l]0C37e  
Dim curv As Double, conic As Double Wi*HLP!lNC  
Dim ok As Long 2Y;iqR  
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Sub Main D+h`Z]"|  
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    '用户输入对话框 ,8DjQz0ZPo  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 xj5MKX{CJT  
        TextBox 220,21,40,21,.TextBox1 'default: 0 y+7A?"s)  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 kZcGe*  
        OKButton 40,91,90,21 ^~3{n  
        CancelButton 190,91,90,21 :Yi 4Ia  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 BtQqUk#L2  
        TextBox 220,49,40,21,.TextBox2 'default: 4 bV*q~@xh  
    End Dialog mE9ytFH\k  
    Dim dlg As UserDialog 5X^`qUSv  
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    ok = Dialog (dlg) 2W/*1K}  
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    If ok=0 Then    'cancel button was pressed .G/RQn]x}  
        Print "Execution cancelled." R?:(~ X\  
        End x139Ckn  
    End If ciN*gwI)  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Tq%##  
    If dlg.TextBox1 = "" Then G.^^zmsM`  
        A = 0           'Default accommodation ~S0T+4$  
    Else :
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        A = CDbl(dlg.TextBox1) .0dx@Sbv  
    End If i>=y3x"  
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    If dlg.TextBox2 = "" Then )2F%^<gZ#  
        pupilDiam = 4   'Default pupil diameter |+1k7S,  
    Else :eSwXDy&  
        pupilDiam = CDbl(dlg.TextBox2) f%%'M.is  
    End If %,udZyO3uR  
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    Print " " `yM9XjEl>  
    Print "Accommodation = " & A & " Diopters" djDE0-QxcR  
    Print "Pupil Diameter = " & pupilDiam & " mm" W"s)s  
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    ' Calculate new parameters with accommodation $o*p#LU  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness UJ&gm_M+kL  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens -B:O0;f  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens okBaQH2lUl  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens o H]FT{  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens (U*Zz+ R   

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    tlens = 3.767 + 0.04*A                  'Lens thickness @SAJ*hfb0  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction n:JG+1I  
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    'Adjust parameters to account for accommodation !6*4^$i#o  
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    '************************************************************************* [Ib17#74  
    'Aqueous thickness (Position of Lens) sV`XJ9e|  
    '************************************************************************* 1<wolTf  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) m8&
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    GetCustomElement eID, entity o q cu<]  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ns&(
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    ' Delete any shift(s) in z PjU.4aZ  
    count = 0 @Hst-H.l<l  
    While GetOperationCount(eID)>count jq+:&8!8(e  
        GetOperation eID, count, op {ALOs^_-  
        If op.Type="ShiftZ" Then |bjLmGb  
            DeleteOperation eID,count w%f51Ex  
            count=count-1 oX[I4i%G  
        End If #M8>
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        count=count+1 13I~   
    Wend `wNJ*`  
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    'Set new shift in 
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    op.Type = "ShiftZ" [,mcvO;  
    op.val1 = taq yx/qp<=  
    op.parent = parID "z|%V/2b3  
    AddOperation eID, op ZmJHLn[B  
    Print "Set aqueous humor thickness = " & taq-0.55 'Ie
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    '************************************************************************* b]\V~ZaXG  
    'Radius and conic constant of anterior lens Tq5F'@e  
    '************************************************************************* +,bgOq\aG  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" )
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    GetConic eID, entity, curv, conic X[o"9O|<  
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    SetConic eID, entity, 1/Rant, CCant &/lmg!6  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant C,3yu,'  
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    '************************************************************************* 3S1`av(tD  
    'Radius and conic constant of posterior lens LY(h>`  
    '************************************************************************* SlUt&+)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) O;<YLS^|6  
    GetConic eID, entity, curv, conic Px
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    SetConic eID, entity, 1/Rpost, CCpost M.}QXta  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost F84?Mi{r2  
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    '************************************************************************* hdee]qLS  
    'Lens thickness (Position of posterior lens surface) ]mvVX31T  
    '************************************************************************* DR#[\RzNI  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Qmn'G4#@E  
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    ' Delete any z-shift(s) U>_#,j  
    count = 0 g].hL  
    While GetOperationCount(eID)>count AkRZUj\  
        GetOperation eID, count, op bLyG3~P;0  
        If op.Type="ShiftZ" Then Zu%oIk  
            DeleteOperation eID,count eE;")t,  
            count=count-1 ;={Z Bx  
        End If X+XbIbUuL  
        count=count+1 F`YxH*tO7  
    Wend Fgg4QF  
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    'Set new z-shift x+5y287#  
    op.Type = "ShiftZ" H[8P]"*z*i  
    op.val1 = tlens -2Azpeh  
    op.parent = parID s *1%I$=@  
    AddOperation eID, op B 9AE*  
    Print "Set lens thickness = " & tlens A)q,VSR8  
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    '************************************************************************* ihdtq  
    'Lens index of refraction ss>?fyA  
    '************************************************************************* j>OB<4?.+  
    eID = FindMaterial( "Lens" )  %;9+`U  
    GetModelMaterial eID, mat \M`fkR,,'  
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    mat.Nd = nlens D?"TcA  
    SetModelMaterial eID, mat F /:2+  
    Print "Set lens index of refraction = " & nlens gJ>HFid_C  
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    '************************************************************************* >ak53Ij$  
    'Pupil diameter )ozN{&B6  
    '************************************************************************* \i#0:3s.  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) %U)M?UNjw  
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    'Adjust pupil diameter (trimming volume inner hole) {m%X\s;ni  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" oFRb+H(E  
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    ' Adjust pupil location to just in front of the lens %C[ ;&  
    parID = FindFullName( "Geometry.Arizona Eye" ) LvNk:99:<  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ,FPgbs  
    count = 0 aJDu_  
    While GetOperationCount(eID)>count [Pt5c6L:  
        GetOperation eID, count, op ?iBHJ{  
        If op.Type="ShiftZ" Then o*u A+7n  
            DeleteOperation eID,count wFaWLC|&  
            count=count-1 g3%t+>$*  
        End If %j=,c{`Q  
        count=count+1 ?%HtPm2< %  
    Wend W$B
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    op.Type = "ShiftZ" oB$D&  
    op.val1 = taq-0.01 ;G3{ e  
    op.parent = parID <ZNa`  
    AddOperation eID, op EF{_-FXY  
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    Print "Set pupil diameter = " & pupilDiam O"mU#3?
 
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    'Update AZ Eye subassembly Description O,[aL;v  
    eID = FindFullName( "Geometry.Arizona Eye" ) }r/L 9  
    GetEntity eID, entity BI=Ie?  
    entity.Description = "Accommodation = " & A & "D" k>Qr
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    SetEntity eID, entity mHox  
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    Update W3K"5E0ck  
    Print "DONE!" Q_#X*I  
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End Sub <..%@]+  
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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： [:!#F7O-  
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Accommodation = 4 Diopters r/L
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Pupil Diameter = 4 mm b\?#O}  
Set aqueous humor thickness = 2.81 $(}kau  
Set anterior lens radius = 10.4 and conic constant = -2.375869 );;
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 n@g[VR
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Set lens thickness = 3.927 a(8]y.`Tv  
Set lens index of refraction = 1.42672 s:cS 9A8  
Set pupil diameter = 4 9&'Mb[C`"  
DONE! Z[`J'}?|  
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