[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 gA/8Df\G:l  
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。 )r +o51gp  
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模型 d8V)eZYXy~  

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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。 !=t.AgmL  
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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. ~V:@4P  
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光源 +kdZfv>  
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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。 w<54mGMOLr  
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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。 JPt0k  

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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。 NR@n%p  
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视网膜的散射
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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。 J-3%.fX,  
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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。 U$+G9  
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脚本
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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： N*CcJp{Q  
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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。 %=t8   
余下的脚本计算与屈光度有关的所有参数。 NZh\{!  
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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。 = "N?v-  
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脚本代码 +LEU|#  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 6$k"B/k  
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Dim entity As T_ENTITY UW?(-_8  
Dim op As T_OPERATION BA 9c-Ay  
Dim mat As T_MODELMATERIAL \dzHG/e  
Dim A As Double %x2_njDd  
Dim pupilDiam As Double D+u#!t[q  
Dim eID As Long )>X C_ R  
Dim parID As Long B{^ojV;]m  
Dim count As Integer Z<2j#rd  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 8:=EA3  
Dim tlens As Double, nlens As Double E#L"*vh  
Dim curv As Double, conic As Double PAUepO_  
Dim ok As Long -{tB&V~+v  
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Sub Main }bZcVc2  
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    '用户输入对话框 QwaAGUA  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 4*vV9*'!  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Y>l92=G  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 zKP{A Sk  
        OKButton 40,91,90,21 F6$QEiDu@  
        CancelButton 190,91,90,21 `c)//o  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ?;dfA/  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Up/s)8$.  
    End Dialog F^mMyK  
    Dim dlg As UserDialog "yo~;[  
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    ok = Dialog (dlg) 4-wCk=I  
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    If ok=0 Then    'cancel button was pressed *co=<g]4KY  
        Print "Execution cancelled." ofu {g  
        End >n^| eAH  
    End If <Z -d5D>  
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    'Assign accommodation and pupil diameter & use defaults if field left empty l1utk8'-  
    If dlg.TextBox1 = "" Then l\NVnXv:>  
        A = 0           'Default accommodation "kHQ}#6r  
    Else Gop;!aV1*  
        A = CDbl(dlg.TextBox1) ycr\vn t  
    End If 1$]hyC/f  
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    If dlg.TextBox2 = "" Then h ?Ni5  
        pupilDiam = 4   'Default pupil diameter wy1xZQ<5  
    Else :k"VR,riF  
        pupilDiam = CDbl(dlg.TextBox2) O6[,K1,  
    End If x<
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    Print " " )U~,q>H+ %  
    Print "Accommodation = " & A & " Diopters" =y>g:}G7  
    Print "Pupil Diameter = " & pupilDiam & " mm" >\x   
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    ' Calculate new parameters with accommodation *s"dCc  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness \"X<\3z2  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens <![]=~z$  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 20O\@}2q2M  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens B}(+\Q$I  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens C_RxJWka  
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    tlens = 3.767 + 0.04*A                  'Lens thickness )Hp{
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction BfcpB)N&.K  
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    'Adjust parameters to account for accommodation 9qHbV 9,M  
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    '************************************************************************* {5$.:Y  
    'Aqueous thickness (Position of Lens) ]4$t'wI.  
    '************************************************************************* 3%g\)Cs  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) {!$E\e^d  
    GetCustomElement eID, entity bw@"MF{  
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    parID = FindFullName( "Geometry.Arizona Eye" ) |#6B<'e'  
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    ' Delete any shift(s) in z RoG `U  
    count = 0 ?dJ[?<aG  
    While GetOperationCount(eID)>count  u Z(vf  
        GetOperation eID, count, op h7}D//~p  
        If op.Type="ShiftZ" Then ^
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            DeleteOperation eID,count 6eUM[C.  
            count=count-1 xUiSAKrcM  
        End If sO5~!W>Z  
        count=count+1 OMi_')J  
    Wend KKPQ[3g  
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    'Set new shift in w;LIP!T#  
    op.Type = "ShiftZ" q13bV  
    op.val1 = taq \fHtk _  
    op.parent = parID vp"b_x1-  
    AddOperation eID, op V*uoGWL]+  
    Print "Set aqueous humor thickness = " & taq-0.55 WB:NV=&^  
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    '************************************************************************* cVx#dDdA  
    'Radius and conic constant of anterior lens LQ7.RK  
    '************************************************************************* 6@"lIKeP  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) th$?#4SbR  
    GetConic eID, entity, curv, conic ?"d25LyN  
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    SetConic eID, entity, 1/Rant, CCant QO0#p1fom'  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant {z4v_[-2CF  
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    '************************************************************************* iiWs]5  
    'Radius and conic constant of posterior lens )} I>"n  
    '************************************************************************* !rK,_wH  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) /M}jF*5N  
    GetConic eID, entity, curv, conic D*Cn!v$  
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    SetConic eID, entity, 1/Rpost, CCpost s/;iZiWK  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost rF/k$_bFt  
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    '************************************************************************* 6AM-^S@  
    'Lens thickness (Position of posterior lens surface) rq[+p  
    '************************************************************************* D7D:?VoR  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) *8ZaG]L  
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    ' Delete any z-shift(s) 9Y6Ear .W  
    count = 0 _{eH" ,(  
    While GetOperationCount(eID)>count F5hOKUjv  
        GetOperation eID, count, op TA2?Ia;@xV  
        If op.Type="ShiftZ" Then &!kD81?Mm  
            DeleteOperation eID,count 8&g`Uy/b  
            count=count-1 &jg..R  
        End If ([mC!d@a  
        count=count+1 sQ4~oZZ  
    Wend i`FskEoijq  
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    'Set new z-shift *dTI4k  
    op.Type = "ShiftZ" cZ<@1I5QK  
    op.val1 = tlens }JF,:g Lk  
    op.parent = parID '@{'T LMCi  
    AddOperation eID, op Ti{~  
    Print "Set lens thickness = " & tlens ~{8X$xs  
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    '************************************************************************* LW"p/`#<  
    'Lens index of refraction UBgheu  
    '************************************************************************* ?qdZ]M4e  
    eID = FindMaterial( "Lens" ) \-Oq/g{j  
    GetModelMaterial eID, mat Po ,zTz  
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    mat.Nd = nlens 6 4fB$  
    SetModelMaterial eID, mat yY3Mv/R  
    Print "Set lens index of refraction = " & nlens QSaJb?I  
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    '************************************************************************* g9rsw7  
    'Pupil diameter l$>))cW!  
    '************************************************************************* p+t79F.js  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) f|U J%}$v;  
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    'Adjust pupil diameter (trimming volume inner hole) *c0\<BI  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"
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    ' Adjust pupil location to just in front of the lens )|Ho"VEmg  
    parID = FindFullName( "Geometry.Arizona Eye" ) zvDg1p  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) wva| TZ  
    count = 0 _olhCLIR-  
    While GetOperationCount(eID)>count Ot^<:\<`G  
        GetOperation eID, count, op 4X()D {uR  
        If op.Type="ShiftZ" Then , :10  
            DeleteOperation eID,count 0cpI2  
            count=count-1 EYsf<8cl  
        End If
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        count=count+1 h=1cD\^|qw  
    Wend '&|]tu:q  
    op.Type = "ShiftZ" ~&UfnO  
    op.val1 = taq-0.01 f`[gRcZ-  
    op.parent = parID x}c%8dO#J  
    AddOperation eID, op @S-p[u  
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    Print "Set pupil diameter = " & pupilDiam &ND8^lR=Y;  
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    'Update AZ Eye subassembly Description ;)SWUXa;{  
    eID = FindFullName( "Geometry.Arizona Eye" ) pYtvenBy  
    GetEntity eID, entity ,rO>5$w.  
    entity.Description = "Accommodation = " & A & "D" ~@v<B I
 
    SetEntity eID, entity WX2w7O'R  
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    Update t!u{sr{j=  
    Print "DONE!" I1TzP
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End Sub :kaHvf  
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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： :We}l;.jQ  
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Accommodation = 4 Diopters clcj5
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Pupil Diameter = 4 mm !R`)S7!  
Set aqueous humor thickness = 2.81 fV\ eksBF  
Set anterior lens radius = 10.4 and conic constant = -2.375869 %)|_&Rh  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 gk*Md+  
Set lens thickness = 3.927 xIrRFK9[Q  
Set lens index of refraction = 1.42672 r2Wx31j{  
Set pupil diameter = 4 M[Kk43;QY!  
DONE! 3XOf-v:~  
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