[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 73.b9mF  
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。 .wSAysiQ|P  
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模型 N@$%0!  
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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。 GSH{1VS_b  
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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. on\\;V_/Q  
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光源 5dk,!Cjg  
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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。 '3Ie0QO]"%  
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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。 K;l'IN"N  
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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。 !)=o,sVA  
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视网膜的散射 U:9vjY  
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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。 JPG!c
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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。 MVdx5,t  
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脚本 X;:xGZ-oY  
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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： {@AcL:Eit  
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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。 C5UDez  
余下的脚本计算与屈光度有关的所有参数。 2\de|'  
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分析 /p0LtUMu  
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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。 ,IE0+!I  
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脚本代码 u0b-JJ7)BQ  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. t8 "-zd8  
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Dim entity As T_ENTITY u$8MVP  
Dim op As T_OPERATION o q)"1  
Dim mat As T_MODELMATERIAL A>A'dQ69  
Dim A As Double CJ  
Dim pupilDiam As Double 22~X~=  
Dim eID As Long  a|uZJ*  
Dim parID As Long 1C=P#MU`  
Dim count As Integer {+9\o ~  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double MPN=K|*  
Dim tlens As Double, nlens As Double Y26l,XIV  
Dim curv As Double, conic As Double 4 GW[GT  
Dim ok As Long z,YUguc|  
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Sub Main 5O ;^Mk|  
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    '用户输入对话框 ya g  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 v:1Vli.  
        TextBox 220,21,40,21,.TextBox1 'default: 0 u#k,G`  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 =[os<+  
        OKButton 40,91,90,21 arVf"3a  
        CancelButton 190,91,90,21 B-'BJ|*4I  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 M|e n>P  
        TextBox 220,49,40,21,.TextBox2 'default: 4 xGv,%'
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    End Dialog _kX/LR"L+  
    Dim dlg As UserDialog mIEaWE;E"  
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    ok = Dialog (dlg) }IkEyJsk  
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    If ok=0 Then    'cancel button was pressed DeQ'U!?+N  
        Print "Execution cancelled." <D
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        End +gCy@_2;  
    End If @aN=U=  
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    'Assign accommodation and pupil diameter & use defaults if field left empty )"jn{%/t  
    If dlg.TextBox1 = "" Then *Ne2l`!1m  
        A = 0           'Default accommodation b(-t)5^}  
    Else udI:]:,P  
        A = CDbl(dlg.TextBox1) `+Z#*lj|@  
    End If 7C7(bg,7^  
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    If dlg.TextBox2 = "" Then (`.qG &6p  
        pupilDiam = 4   'Default pupil diameter wDMB  
    Else s1 ^mk]  
        pupilDiam = CDbl(dlg.TextBox2) c0Ro3j\p  
    End If ?WtG|w  
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    Print " " pXj/6+^  
    Print "Accommodation = " & A & " Diopters" )LrCoI =|  
    Print "Pupil Diameter = " & pupilDiam & " mm" 7cP
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    ' Calculate new parameters with accommodation .O%1)p  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness '7LJuMp$#  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens h)l&K%4;  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens fQTA@WAr  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens o7a6 )2JK  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens +'Y(V&  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 2|H91Y2  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction R ms
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    'Adjust parameters to account for accommodation R{xyme@"^  
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    '************************************************************************* ctUF/[_w;  
    'Aqueous thickness (Position of Lens) w
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    '************************************************************************* .Lr)~  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) CNRU"I+jU  
    GetCustomElement eID, entity "kBqY+:Cn  
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    parID = FindFullName( "Geometry.Arizona Eye" ) )4L%zl7  
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    ' Delete any shift(s) in z qzlMn)e  
    count = 0 :CkR4J!m3  
    While GetOperationCount(eID)>count a[74%L?  
        GetOperation eID, count, op ZOrTbik  
        If op.Type="ShiftZ" Then ci_v7Jnwo  
            DeleteOperation eID,count e=n{f*KG`  
            count=count-1 ZYA.1VrM  
        End If sAD P~xvU  
        count=count+1 |CZnq-,C  
    Wend B`?N0t%X  
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    'Set new shift in [N95.aD  
    op.Type = "ShiftZ" C/CfjRzd  
    op.val1 = taq BvZ^^IUb  
    op.parent = parID @X|i@{<';  
    AddOperation eID, op u_6B
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    Print "Set aqueous humor thickness = " & taq-0.55 !,6v=n[Nz  
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    '************************************************************************* B/sBYVU  
    'Radius and conic constant of anterior lens -
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    '************************************************************************* >\?z37:T  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) H?`)[#  
    GetConic eID, entity, curv, conic J%\~<_2ny  
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    SetConic eID, entity, 1/Rant, CCant NHFEr
 
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant CEX}`I*-  
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    '************************************************************************* pe!dm}!h[  
    'Radius and conic constant of posterior lens .?i-rTF:  
    '************************************************************************* AJ#m6`M+EK  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) s=nVoc{Yt  
    GetConic eID, entity, curv, conic uFm+Y]h  
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    SetConic eID, entity, 1/Rpost, CCpost znQ'm^h  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ~gfA](N  
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    '************************************************************************* ^)hAVf~E  
    'Lens thickness (Position of posterior lens surface) ,XeyE;||  
    '************************************************************************* 9b"9m*gC  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 62MRI  
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    ' Delete any z-shift(s) mZbWRqP[|_  
    count = 0 `\/toddUh[  
    While GetOperationCount(eID)>count P>{US1t  
        GetOperation eID, count, op J+}+"h~.  
        If op.Type="ShiftZ" Then FI1THzW4J  
            DeleteOperation eID,count e' U"`)S  
            count=count-1 bSrRsgKvT  
        End If |-(IJG#)  
        count=count+1 b(}Gm@#  
    Wend jF38kj3O7  
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    'Set new z-shift CYPazOfj  
    op.Type = "ShiftZ" atLV`U&t  
    op.val1 = tlens fjIcB+Z  
    op.parent = parID 6WE&((r^  
    AddOperation eID, op ?o~:'Z  
    Print "Set lens thickness = " & tlens Ic[}V0dk  
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    '************************************************************************* ;m@1Ec@*p  
    'Lens index of refraction fJ)N:q`  
    '************************************************************************* MvFM,  
    eID = FindMaterial( "Lens" ) Lh8bQH  
    GetModelMaterial eID, mat >H0) ph  
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    mat.Nd = nlens <`R|a *  
    SetModelMaterial eID, mat JcTp(fnW.~  
    Print "Set lens index of refraction = " & nlens F . K2  
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    '************************************************************************* QP6z?j.  
    'Pupil diameter 24T@N~\g  
    '************************************************************************* 4meidKw]  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) K
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    'Adjust pupil diameter (trimming volume inner hole) _\ .  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" V#ndyUM;  
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    ' Adjust pupil location to just in front of the lens X}oj_zsy;^  
    parID = FindFullName( "Geometry.Arizona Eye" ) 7"ylN"syZ
 
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 5/& 1Oxo  
    count = 0 ss?]  
    While GetOperationCount(eID)>count 5cD XWF  
        GetOperation eID, count, op XzlKP;r0  
        If op.Type="ShiftZ" Then R<f#r03@|  
            DeleteOperation eID,count 9o-!ecx}  
            count=count-1 B0f_kH
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        End If 9pWi.J  
        count=count+1 UdT&cG  
    Wend 5^)?mA  
    op.Type = "ShiftZ" [f<"p[  
    op.val1 = taq-0.01 BJ~ivT<  
    op.parent = parID cyW;,uT)D  
    AddOperation eID, op M'yO+bu  
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    Print "Set pupil diameter = " & pupilDiam Da"yZ\4  
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    'Update AZ Eye subassembly Description *;<e '[Y7f  
    eID = FindFullName( "Geometry.Arizona Eye" ) 5a'yXB}  
    GetEntity eID, entity ;aq`N}d  
    entity.Description = "Accommodation = " & A & "D" l iw,O 6  
    SetEntity eID, entity `vudS?  
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    Update $Axng J c  
    Print "DONE!" (~S<EUc$  
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End Sub (nGkZ}p  
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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： @gNpJB]V  
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Accommodation = 4 Diopters _3|6ZO  
Pupil Diameter = 4 mm 8KFj<N>'  
Set aqueous humor thickness = 2.81 SU/G)&Mi  
Set anterior lens radius = 10.4 and conic constant = -2.375869 t
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 sF y]+DB  
Set lens thickness = 3.927 DL,[k (  
Set lens index of refraction = 1.42672 cn$5:%IK  
Set pupil diameter = 4 Zb]/nP1P  
DONE! bZiyapM  
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