[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 %5jxq9:K  
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。 kVZ>Dc2M  
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模型 [G4#DP\t>p  
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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。 `<q{
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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. Ch^Al2)=  
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光源 >lN{FJ  
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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。 AgO:"'c
 
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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。 bZ:w_z[3=  
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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。 l\jf]BHX'  
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视网膜的散射 ~~b[X\1  
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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。 !SKEL6~7  
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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。 l^WFMeMD3a  
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脚本 'l!tQD!  
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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： ]7fqVOiOu  
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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。 r8}GiP0|  
余下的脚本计算与屈光度有关的所有参数。 }I9\=jT  
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分析 CXb)k.L  
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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。 jun>(7  
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脚本代码 ccZ A  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. {xMY2I++  
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Dim entity As T_ENTITY k#w[GL|T  
Dim op As T_OPERATION ,ZC^,Vq  
Dim mat As T_MODELMATERIAL AFF7fK  
Dim A As Double +i!/J  
Dim pupilDiam As Double =k2In_  
Dim eID As Long =ugxPgn  
Dim parID As Long /~K-0K#w  
Dim count As Integer k]] (I<2  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ~ubGx  
Dim tlens As Double, nlens As Double )?:V5UO\  
Dim curv As Double, conic As Double XA-
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Dim ok As Long "'~'xaU!=a  
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Sub Main %
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    '用户输入对话框 "nf.kj:>  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 
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        TextBox 220,21,40,21,.TextBox1 'default: 0 1t WKH  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 q1;}~}W;z4  
        OKButton 40,91,90,21 0-oR { {  
        CancelButton 190,91,90,21 I;S[Ft8
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 tq8B)<(]  
        TextBox 220,49,40,21,.TextBox2 'default: 4 $21+
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    End Dialog X@*$3z#Z  
    Dim dlg As UserDialog S ])Ap'E  
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    ok = Dialog (dlg) pE[ul  
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    If ok=0 Then    'cancel button was pressed ?H#]+SpOcv  
        Print "Execution cancelled." !i&^H,  
        End FYFP6ti  
    End If !=;^Grv>  
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    'Assign accommodation and pupil diameter & use defaults if field left empty %fGS< W;  
    If dlg.TextBox1 = "" Then %K@D{)r_^  
        A = 0           'Default accommodation cE '`W7&A  
    Else @kK${  
        A = CDbl(dlg.TextBox1) n4h@{Xg  
    End If 7?:7}xb-  
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    If dlg.TextBox2 = "" Then AkrUb$ }  
        pupilDiam = 4   'Default pupil diameter {0+gPTp  
    Else c^S^"M|  
        pupilDiam = CDbl(dlg.TextBox2) HF" v \  
    End If "gADHt=MIR  
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    Print " " Jtnuo]{R  
    Print "Accommodation = " & A & " Diopters" \Lv eZ_h5  
    Print "Pupil Diameter = " & pupilDiam & " mm" JV=d!Gi[C  
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    ' Calculate new parameters with accommodation , |CT|2D>  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness yd2v_  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens j(F
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens aL$m  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ,R5NKWo  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens @C{IgV  
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    tlens = 3.767 + 0.04*A                  'Lens thickness L:"i,K#P  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction _Il/ i&  
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    'Adjust parameters to account for accommodation Pou-AzEP$  
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    '************************************************************************* |FGt'  
    'Aqueous thickness (Position of Lens) `X'-4/Y  
    '************************************************************************* W|_ @ju  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) $p30?\  
    GetCustomElement eID, entity S^? @vj  
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    parID = FindFullName( "Geometry.Arizona Eye" ) "z)dz,&T  
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    ' Delete any shift(s) in z w'oP{=y[  
    count = 0 3YVG|Bc~_  
    While GetOperationCount(eID)>count h4N!zj[  
        GetOperation eID, count, op
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        If op.Type="ShiftZ" Then rT9
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            DeleteOperation eID,count h?5$-#q~  
            count=count-1 t$^1A1Ef  
        End If y Dg  
        count=count+1 ye=*m  
    Wend r\Nf309~  
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    'Set new shift in rK)aR  
    op.Type = "ShiftZ" ~n9BN'@x  
    op.val1 = taq /( %Q  
    op.parent = parID e0Cr>I5/e  
    AddOperation eID, op *jM~VTXw
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    Print "Set aqueous humor thickness = " & taq-0.55 p!BZTwP  
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    '************************************************************************* S7&w r@  
    'Radius and conic constant of anterior lens (dn(:<_$  
    '************************************************************************* K-(k6<h  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) W8+Daw1Nr  
    GetConic eID, entity, curv, conic o?@,f/"5  
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    SetConic eID, entity, 1/Rant, CCant k0~mK7k  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ZnSDq_Uk  
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    '************************************************************************* i lk\&J~I  
    'Radius and conic constant of posterior lens G&$+8r  
    '************************************************************************* ~&B{"d  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) HEHTj,T  
    GetConic eID, entity, curv, conic n*~=O'  
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    SetConic eID, entity, 1/Rpost, CCpost Hf!o6 o  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost +>mbBu!7  
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    '*************************************************************************  Ht|No  
    'Lens thickness (Position of posterior lens surface) I:l<t*  
    '************************************************************************* WtOpxAq  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) yx?Z&9z <  
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    ' Delete any z-shift(s) spter35b[  
    count = 0 ^Uss?)jN4  
    While GetOperationCount(eID)>count ov&4&v  
        GetOperation eID, count, op ;/?M&rX  
        If op.Type="ShiftZ" Then .v;$sst5y  
            DeleteOperation eID,count 1sx@Nvlb  
            count=count-1 )cOw9&#s  
        End If t=M:L[bis;  
        count=count+1 oe,I vnt  
    Wend J%`-K"NB  
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    'Set new z-shift EfHo1Yn&  
    op.Type = "ShiftZ" HnU; N S3J  
    op.val1 = tlens "]h4L  
    op.parent = parID *ub]M3O  
    AddOperation eID, op m?cC0(6  
    Print "Set lens thickness = " & tlens *y +T(73  
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    '************************************************************************* 5u +U^D  
    'Lens index of refraction dl_ h0  
    '************************************************************************* ;|_aACina  
    eID = FindMaterial( "Lens" ) ;Q"xXT`;:  
    GetModelMaterial eID, mat Sc03vfmo"N  
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    mat.Nd = nlens d,kh6'g2@  
    SetModelMaterial eID, mat e~]3/0  
    Print "Set lens index of refraction = " & nlens d 7vD  
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    '************************************************************************* rMRM*`Q2  
    'Pupil diameter &KinCh7l L  
    '************************************************************************* / blVm1F  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) "FA&Qm0  
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    'Adjust pupil diameter (trimming volume inner hole) w#]> Nf  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" :pj00  
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    ' Adjust pupil location to just in front of the lens x\taG.'zX  
    parID = FindFullName( "Geometry.Arizona Eye" ) $:IOoS|e  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ^Ud1 ag!-  
    count = 0 }uWIF|h~  
    While GetOperationCount(eID)>count zbQ-l1E  
        GetOperation eID, count, op 2d:<P!B  
        If op.Type="ShiftZ" Then %:i; eUKR  
            DeleteOperation eID,count ~uqpF-.  
            count=count-1 B#RBR<MFC  
        End If }
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        count=count+1 I(LBc  
    Wend kA3nhBH  
    op.Type = "ShiftZ" =`RogjbP  
    op.val1 = taq-0.01 _}MO.&Y  
    op.parent = parID k?r-%oJ7  
    AddOperation eID, op Uedzt  
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    Print "Set pupil diameter = " & pupilDiam pxm{?eBz  
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    'Update AZ Eye subassembly Description #p'Xq }]  
    eID = FindFullName( "Geometry.Arizona Eye" ) !6y<jJ>  
    GetEntity eID, entity Uc oVp}vl  
    entity.Description = "Accommodation = " & A & "D" ee7#PE]}  
    SetEntity eID, entity hcWYz  
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    Update
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    Print "DONE!" <}e2\x  
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End Sub ;. jnRPo";  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： PL+r*M%ll  
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Accommodation = 4 Diopters b| e7mis@  
Pupil Diameter = 4 mm WhPwD6l>  
Set aqueous humor thickness = 2.81 7G,{BBB  
Set anterior lens radius = 10.4 and conic constant = -2.375869 {NmpTb  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 P .I<.e  
Set lens thickness = 3.927 tG!ApL  
Set lens index of refraction = 1.42672 e,j2#wjor  
Set pupil diameter = 4 fL3Px  
DONE! CM$q{;y  
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