[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 ]z8/S!?  
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。 );_/0:  
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模型 " DLIx}  
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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。 TC44*BHq  
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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. }9
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光源 .VNz(s  
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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。 Y\WVkd(+G  
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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。 X%znNx  
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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。 K]Vp! G  
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视网膜的散射 Z<^EZX3N  
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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。 tKcC{  
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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。 +Ek1~i.  
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脚本 e1E_$oJP  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： @mxaZ5Vv}  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 3(|,:"9g  
余下的脚本计算与屈光度有关的所有参数。 %+,*$wk#*  
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分析 wd<{%qK`{  
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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。 %HtgZeY  
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脚本代码 <]KQ$8dtD  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. g]}!  
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Dim entity As T_ENTITY EirZ}fDJzB  
Dim op As T_OPERATION hgW1g#
  
Dim mat As T_MODELMATERIAL [xrsa!$   
Dim A As Double DUl+Jqn4B  
Dim pupilDiam As Double !03JA9lo  
Dim eID As Long N\Lu+ x5  
Dim parID As Long OaY89ko  
Dim count As Integer PH:5  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double {D..(f1*u  
Dim tlens As Double, nlens As Double :Z2997@Y  
Dim curv As Double, conic As Double qwJp&6  
Dim ok As Long NQ[X=a8N  
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Sub Main G'}N?8s1  
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    '用户输入对话框 F7*)u-4Yn  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 X
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        TextBox 220,21,40,21,.TextBox1 'default: 0 MI(#~\Y~P  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 cUG^^3!  
        OKButton 40,91,90,21 [?9 `x-Q  
        CancelButton 190,91,90,21 )$i,e`T   
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 r"
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        TextBox 220,49,40,21,.TextBox2 'default: 4 B|"i`{>  
    End Dialog ! M CV@5$  
    Dim dlg As UserDialog iEr?s-or  
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    ok = Dialog (dlg) <dD!_S6@,  
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    If ok=0 Then    'cancel button was pressed ,K\7y2/  
        Print "Execution cancelled." R_+:nCB@,  
        End =$gBWS  
    End If *'A*!=5(  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ~MH^R1=]  
    If dlg.TextBox1 = "" Then =Hd#"9-  
        A = 0           'Default accommodation
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    Else FI?J8a  
        A = CDbl(dlg.TextBox1) d^6-P R_  
    End If V-go?b`  
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    If dlg.TextBox2 = "" Then 5m0lk|`  
        pupilDiam = 4   'Default pupil diameter 2 G*uv+=  
    Else d ([~o  
        pupilDiam = CDbl(dlg.TextBox2) pQ0*)}l,  
    End If `4xQ#K.-  
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    Print " " Zv9JkY=+@  
    Print "Accommodation = " & A & " Diopters" P
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    Print "Pupil Diameter = " & pupilDiam & " mm" #CI0G  
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    ' Calculate new parameters with accommodation =0EKrG  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 9^n0<(99b  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ^ }5KM87  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 80Fa i  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 1irSI,j%z  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens rm3/R<  
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    tlens = 3.767 + 0.04*A                  'Lens thickness G,?a8(  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 'R-\6;3E>9  
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    'Adjust parameters to account for accommodation yeta)@nH  
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    '************************************************************************* =,N"% }
 
    'Aqueous thickness (Position of Lens) %au>D  
    '************************************************************************* b,+KXx  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Lm`-q(!7w  
    GetCustomElement eID, entity }2RbX,0l9  
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    parID = FindFullName( "Geometry.Arizona Eye" ) fm^`
 
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    ' Delete any shift(s) in z &XcPHZy'  
    count = 0 Qu'#~#L`  
    While GetOperationCount(eID)>count OwNM`xSa|\  
        GetOperation eID, count, op 
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        If op.Type="ShiftZ" Then PZJn/A1  
            DeleteOperation eID,count b~tu;:  
            count=count-1 j96}E/gF  
        End If C|Gk}  
        count=count+1 !^MwE]  
    Wend 6g#yzex  
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    'Set new shift in B;8Zlm9  
    op.Type = "ShiftZ" fOSk> gK  
    op.val1 = taq pl@K"PRE  
    op.parent = parID |gxPuAXa)  
    AddOperation eID, op  Hk4k  
    Print "Set aqueous humor thickness = " & taq-0.55 = )3\B  
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    '************************************************************************* v+g:0 C5 (  
    'Radius and conic constant of anterior lens "dt}k$Gr  
    '************************************************************************* \ Qx%76  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) tpA-IL?KQw  
    GetConic eID, entity, curv, conic 1QmOUw}yj  
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    SetConic eID, entity, 1/Rant, CCant -U$;\1--  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant zTMLE~w  
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    '************************************************************************* kzCJs  
    'Radius and conic constant of posterior lens W(ryL_#;  
    '************************************************************************* +\ "NPK@3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) |n;);T(  
    GetConic eID, entity, curv, conic fATVAv  
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    SetConic eID, entity, 1/Rpost, CCpost 4*f+np  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost s1[.L~;J  
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    '************************************************************************* G^h:#T
  
    'Lens thickness (Position of posterior lens surface) Tzjv-9^V  
    '************************************************************************* v]Pyz<+  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 58HAl_8W  
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    ' Delete any z-shift(s) hfbu+w):  
    count = 0 D{7^y>8_Y-  
    While GetOperationCount(eID)>count {y5 L  
        GetOperation eID, count, op !9r%d8!z  
        If op.Type="ShiftZ" Then U&*%KPy`  
            DeleteOperation eID,count 5/U{b5  
            count=count-1 5"b1: w@  
        End If K@[Hej6d  
        count=count+1 +C7W2!I[G2  
    Wend lq3D!+m  

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    'Set new z-shift CflyK@  
    op.Type = "ShiftZ" (4q/LuP^d  
    op.val1 = tlens HWFTI /]  
    op.parent = parID &
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    AddOperation eID, op e&!c8\F  
    Print "Set lens thickness = " & tlens U8>4ClJ4  
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    '************************************************************************* ]FvGAG.*  
    'Lens index of refraction 6Xo"?f  
    '************************************************************************* 3 .j/D^  
    eID = FindMaterial( "Lens" ) g<^A(zM  
    GetModelMaterial eID, mat $f+I#uJ  
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    mat.Nd = nlens RiQg]3oY  
    SetModelMaterial eID, mat nW\W<[O9  
    Print "Set lens index of refraction = " & nlens GJS(  
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    '************************************************************************* }|8^+V&  
    'Pupil diameter Y%TY%"<  
    '************************************************************************* :6(@P1vA 6  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Cq<Lj  
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    'Adjust pupil diameter (trimming volume inner hole) {gu3KV  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" *+6iXMwe  
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    ' Adjust pupil location to just in front of the lens %c]N-  
    parID = FindFullName( "Geometry.Arizona Eye" ) PC255  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) e87a9ZPm  
    count = 0 S{MB$JA  
    While GetOperationCount(eID)>count "u$XEA  
        GetOperation eID, count, op u+6D|  
        If op.Type="ShiftZ" Then %Q}(.h%M  
            DeleteOperation eID,count >fT%CGLC0  
            count=count-1 y#`;[!  
        End If b-<@3N.9]  
        count=count+1 !vK0|eV3  
    Wend jVoD9H F/  
    op.Type = "ShiftZ" "dOQ)<;  
    op.val1 = taq-0.01 pJl/d;Cyrb  
    op.parent = parID b-@9Xjv  
    AddOperation eID, op ?< yYm;B  
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    Print "Set pupil diameter = " & pupilDiam #^aa&*<D_  
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    'Update AZ Eye subassembly Description suWO:]FR  
    eID = FindFullName( "Geometry.Arizona Eye" ) hz<TjWXv'  
    GetEntity eID, entity }$uwAevP{y  
    entity.Description = "Accommodation = " & A & "D" 1#AxFdm
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    SetEntity eID, entity a
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    Update O<@L~S]  
    Print "DONE!" !5[SNr3^  
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End Sub &AeNrtGu  
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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： :mLXB75gH  
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Accommodation = 4 Diopters {+{p.  
Pupil Diameter = 4 mm _"t>72 `  
Set aqueous humor thickness = 2.81 |tLD^`bt  
Set anterior lens radius = 10.4 and conic constant = -2.375869 uz$p'Q  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 NZ!I >  
Set lens thickness = 3.927 w0H#M)c  
Set lens index of refraction = 1.42672 ;GOu'34j  
Set pupil diameter = 4 @y * TVy  
DONE! L5|g\Y`  
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