[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 $XzlW=3y  
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。 Lr]Hvd  
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模型 U0=zuRr n  
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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。 tWy<9TF  
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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. mAERZ<I  
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光源 rm;"98~zJ?  
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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。 833t0Ml1A/  
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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。 4B,A+{3yL  
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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。 + {dIs
 
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视网膜的散射 gx.]4v  
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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。 G+p>39P   
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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。 !~kzxY  
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脚本 WHT%m|yn  
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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： +5
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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。 QQcj"s
 
余下的脚本计算与屈光度有关的所有参数。 9D21e(7X  
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分析 U$Z}<8  
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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。 |g!# \  
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脚本代码 vRs5-T  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. U0T N8O}Z  
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Dim entity As T_ENTITY b>EUa> h  
Dim op As T_OPERATION EC/R|\d?Un  
Dim mat As T_MODELMATERIAL Uc2#so$9  
Dim A As Double RkM!BcB  
Dim pupilDiam As Double bc-)y3gHU  
Dim eID As Long m8'1@1d|  
Dim parID As Long b5R*]  
Dim count As Integer *
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double j+/*NM_y3  
Dim tlens As Double, nlens As Double }IL@j A
 
Dim curv As Double, conic As Double }lVUa{ubf  
Dim ok As Long aoS1Yt'@  
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Sub Main .EwK>ro4  
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    '用户输入对话框 ?CDq^)T[  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 }XU- JAn  
        TextBox 220,21,40,21,.TextBox1 'default: 0 PMcyQ2R->  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 f'S"F  
        OKButton 40,91,90,21 l<?wB|1'  
        CancelButton 190,91,90,21 " cg>g/  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 cO9Aw!  
        TextBox 220,49,40,21,.TextBox2 'default: 4 7(Kc9sJC%%  
    End Dialog WTx;,TNG  
    Dim dlg As UserDialog ":ycyN@g  
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    ok = Dialog (dlg) J;dFmZOk  
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    If ok=0 Then    'cancel button was pressed dGe  
        Print "Execution cancelled." &@+;]t  
        End \mloR '  
    End If +L6d$+  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ;Lu|fQ#u*  
    If dlg.TextBox1 = "" Then \ :.p8`  
        A = 0           'Default accommodation b8&9pLl  
    Else /Y:
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        A = CDbl(dlg.TextBox1) p
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    End If O/Vue  
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    If dlg.TextBox2 = "" Then :|Cf$2k7  
        pupilDiam = 4   'Default pupil diameter |a+8-@-Tj  
    Else WyP1"e^9  
        pupilDiam = CDbl(dlg.TextBox2) 2X`M&)"X  
    End If
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    Print " " :nI.Qa'"H  
    Print "Accommodation = " & A & " Diopters" 2ip~qZNw><  
    Print "Pupil Diameter = " & pupilDiam & " mm" *6L^A`_1]  
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    ' Calculate new parameters with accommodation Eh+lLtZ  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness =
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens gQ~4udla.  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens @p;4g_F  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Iu
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens !k:j+h/  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Ts\7)6|F  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction @,]v'l!u  
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    'Adjust parameters to account for accommodation e(Verd:c  
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    '************************************************************************* qF?S[Z;  
    'Aqueous thickness (Position of Lens) (
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    '************************************************************************* MEu-lM7v  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) (
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    GetCustomElement eID, entity vd~O:=)4  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 39"'Fz?1  
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    ' Delete any shift(s) in z
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    count = 0 B?jF1F!9  
    While GetOperationCount(eID)>count ;.Kzc3yz}  
        GetOperation eID, count, op rO NLbrj  
        If op.Type="ShiftZ" Then q~qig,$Y  
            DeleteOperation eID,count \vI_%su1N  
            count=count-1 A)xI.Q6  
        End If =xgW$c/yB  
        count=count+1 }~7>S5  
    Wend }V 1sY^C  
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    'Set new shift in PSRGlxdO  
    op.Type = "ShiftZ" -$7Jc=:>  
    op.val1 = taq @wo9;DW`  
    op.parent = parID 4AGc2e'u  
    AddOperation eID, op X@arUs
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    Print "Set aqueous humor thickness = " & taq-0.55 :!%oQQO  
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    '************************************************************************* @t_<oOI2  
    'Radius and conic constant of anterior lens .m<-)Kx  
    '************************************************************************* oR+Fn}mG  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) p'H5yg3h  
    GetConic eID, entity, curv, conic 7l?=$q>k"  
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    SetConic eID, entity, 1/Rant, CCant "PX~Yc  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant <a'j8pw9i  
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    '************************************************************************* 6)W9/V-W  
    'Radius and conic constant of posterior lens A3Su&0uaB  
    '************************************************************************* PgVM>_nHk  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Iv{}U\ u  
    GetConic eID, entity, curv, conic lU\|F5O@#  
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    SetConic eID, entity, 1/Rpost, CCpost u", [ulP  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }RD,JgmV  
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    '************************************************************************* 4-m}W;igu  
    'Lens thickness (Position of posterior lens surface) `aCcTs7~]p  
    '************************************************************************* QPBf++|  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Ar|_UV>Zf  
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    ' Delete any z-shift(s) }+SnY8A=KZ  
    count = 0 [P 8e=;  
    While GetOperationCount(eID)>count c0tv!PSw  
        GetOperation eID, count, op vZ*593C8  
        If op.Type="ShiftZ" Then o<x2,uT  
            DeleteOperation eID,count Z!*Wn`d-k  
            count=count-1 9;:
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        End If ?A]:`l_"  
        count=count+1 b6#V0bDXHD  
    Wend `AY
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    'Set new z-shift grv 3aa@  
    op.Type = "ShiftZ" ZVI.s
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    op.val1 = tlens {Bu^%JEn  
    op.parent = parID uHy^ Bq  
    AddOperation eID, op CnJO]0Op3  
    Print "Set lens thickness = " & tlens zV%U4P)Dao  
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    '************************************************************************* J.~$^
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    'Lens index of refraction @*F NWT6  
    '************************************************************************* [IiwpC  
    eID = FindMaterial( "Lens" ) n`}vcVL;  
    GetModelMaterial eID, mat si)920?E&  
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    mat.Nd = nlens YrA#NTB_o  
    SetModelMaterial eID, mat Zpg$:Rr  
    Print "Set lens index of refraction = " & nlens uQrD}%GI  
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    '************************************************************************* e
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    'Pupil diameter `NrxoU=  
    '************************************************************************* o ;.j_
 
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) CmM K\R.  
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    'Adjust pupil diameter (trimming volume inner hole) k|1/gd5  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" gaVWfG  
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    ' Adjust pupil location to just in front of the lens }VdohX-  
    parID = FindFullName( "Geometry.Arizona Eye" ) tZwZZ0]Z  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) `5Q0U%`W  
    count = 0 vTN$SgzfCU  
    While GetOperationCount(eID)>count UZv^3_,qz  
        GetOperation eID, count, op }~yhkt5K  
        If op.Type="ShiftZ" Then !\2Xr{f  
            DeleteOperation eID,count V{ECDgP  
            count=count-1 B xq(+^T  
        End If  GVe[)R  
        count=count+1 +wr2TT~  
    Wend pGzzv{H  
    op.Type = "ShiftZ" f8!*4Bw  
    op.val1 = taq-0.01 F:1w%#6av  
    op.parent = parID /{^Qup  
    AddOperation eID, op YqrieDFay!  
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    Print "Set pupil diameter = " & pupilDiam DhYQ>Gv8U  
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    'Update AZ Eye subassembly Description Z-.`JkKd8  
    eID = FindFullName( "Geometry.Arizona Eye" ) K#kU6/  
    GetEntity eID, entity gYw4YP0Gz  
    entity.Description = "Accommodation = " & A & "D" `~
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    SetEntity eID, entity +g>)Bur  
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    Update 0ERA(=w5  
    Print "DONE!" a^>0XXr}Y  
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End Sub =a$7OV.  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： B;@7  
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Accommodation = 4 Diopters +:+q,0~*]  
Pupil Diameter = 4 mm =`Pgo5A  
Set aqueous humor thickness = 2.81 1 \:5ow&a  
Set anterior lens radius = 10.4 and conic constant = -2.375869 TFjb1a,)  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ozy~`$;c  
Set lens thickness = 3.927 :q/%uca9  
Set lens index of refraction = 1.42672 <k+dJ=f  
Set pupil diameter = 4 a6cq0g[#z  
DONE! T%B&HsH  
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