[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 W,6q1  
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。 En9J7es_  
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模型 :XFQ}Cl  
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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。 =Pw{1m|k  
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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. ~Ze!F"  
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光源 >8I~i:hn  
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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。 ]vz6DJs  
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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。 -c?x5
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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。 ^g6v#]&WA  
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视网膜的散射 g]L8Jli  
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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。 Al*=%nY  
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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。 qzxWv5UH  
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脚本 +BtLd+)R  
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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： 4h!yh2c..  
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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。 qbq2Bi'a  
余下的脚本计算与屈光度有关的所有参数。 L@[}sMdq(  
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分析 5,MM`:{{  
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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。 S;Sy.Lp  
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脚本代码 z.
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. }|Q\@3&  
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Dim entity As T_ENTITY G2wSd'n*y  
Dim op As T_OPERATION C<a&]dN/  
Dim mat As T_MODELMATERIAL H?r~% bh  
Dim A As Double Pl'lmUR  
Dim pupilDiam As Double <ndY6n3  
Dim eID As Long \kyoA Z  
Dim parID As Long ?H_@/?  
Dim count As Integer -2}ons(  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Z:h'kgG&  
Dim tlens As Double, nlens As Double *^[6uaa
 
Dim curv As Double, conic As Double q/*veL  
Dim ok As Long 6bj77CoB  
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Sub Main ]]r;}$  
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    '用户输入对话框 Jb> X$|N'%  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 jt6_1^   
        TextBox 220,21,40,21,.TextBox1 'default: 0 {Q$8p2W  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 t3.;qDy  
        OKButton 40,91,90,21 )g8Kicox5  
        CancelButton 190,91,90,21 =[aiW|Y  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 GBS+ 4xL|  
        TextBox 220,49,40,21,.TextBox2 'default: 4 M*T!nwb  
    End Dialog e9'0CH<  
    Dim dlg As UserDialog t 4M-;y  
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    ok = Dialog (dlg) tIV9Y=ckr0  
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    If ok=0 Then    'cancel button was pressed % mPv1$FH  
        Print "Execution cancelled." Y<Ae_yLa  
        End @||nd,i`n~  
    End If be-HF;lZe'  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 0
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    If dlg.TextBox1 = "" Then er BerbEEH  
        A = 0           'Default accommodation t&JOASY
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    Else j7I?K :op=  
        A = CDbl(dlg.TextBox1) j)ln"u0R^B  
    End If MR4k#{:w  
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    If dlg.TextBox2 = "" Then 73u97oe>1  
        pupilDiam = 4   'Default pupil diameter w?*79 u  
    Else ep5`&g]3  
        pupilDiam = CDbl(dlg.TextBox2) SCn)j:gH;  
    End If 4,YL15.  
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    Print " " p/LV^TQ  
    Print "Accommodation = " & A & " Diopters" N2j^fZd_  
    Print "Pupil Diameter = " & pupilDiam & " mm" 2Kr8#_) 0  
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    ' Calculate new parameters with accommodation keQRS+9  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness lOb(XH
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens !YO'u'4<aK  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens "85)2*+  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 'O2/
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens %)d7iT~M  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 3,hu3"@k  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction /Wl8Jf7'  
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    'Adjust parameters to account for accommodation &+hk5?c /  
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    '************************************************************************* hhU\$'0B-  
    'Aqueous thickness (Position of Lens) !"hzGgOOX  
    '************************************************************************* yP` K [/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) C(>g4.-p8  
    GetCustomElement eID, entity T~XKV`LQ  
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    parID = FindFullName( "Geometry.Arizona Eye" ) TZg1,Z  
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    ' Delete any shift(s) in z 9G7Brs:  
    count = 0 @x[A^  
    While GetOperationCount(eID)>count b>#dMRK  
        GetOperation eID, count, op ^rY18?XC+:  
        If op.Type="ShiftZ" Then y^Q);siSy  
            DeleteOperation eID,count IZQ*D)  
            count=count-1 ESFJN}Q%0.  
        End If M,oZ_tY%  
        count=count+1 qrZ3`@C4k  
    Wend &b%2Jx[+  
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    'Set new shift in m' |wlI[lq  
    op.Type = "ShiftZ" `q |
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    op.val1 = taq '<e$ c  
    op.parent = parID Zrgv*  
    AddOperation eID, op u2fp~.'P  
    Print "Set aqueous humor thickness = " & taq-0.55 ]|K6Z>V  
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    '************************************************************************* z/WGL  
    'Radius and conic constant of anterior lens ^e$!19g  
    '************************************************************************* A|U0e`Iw  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) VKlC`k8L  
    GetConic eID, entity, curv, conic KCp9P2kv.  
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    SetConic eID, entity, 1/Rant, CCant X(#8EY}X  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 3U!=R-  
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    '************************************************************************* OOABn*  
    'Radius and conic constant of posterior lens g2M1zRm;  
    '************************************************************************* 2BT+[  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 6T_Ya)  
    GetConic eID, entity, curv, conic DqmKDU  
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    SetConic eID, entity, 1/Rpost, CCpost sK/ymEfRv  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost qM2m!  
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    '************************************************************************* 6iHY{WcDj  
    'Lens thickness (Position of posterior lens surface) )1GJ^h$l  
    '************************************************************************* %uiCC>cC  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3rJ LLYR  
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    ' Delete any z-shift(s) ]F;1l3I-  
    count = 0 6g#E/{kQw  
    While GetOperationCount(eID)>count ;K4uu<e\  
        GetOperation eID, count, op ~6QV?j  
        If op.Type="ShiftZ" Then <*/Z>Z_c2  
            DeleteOperation eID,count k;SKQN  
            count=count-1 pu?COA  
        End If 3Q7PY46  
        count=count+1 k$DRX)e  
    Wend 7*WO9R/  
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    'Set new z-shift ip*^eS^  
    op.Type = "ShiftZ" W?ghG  
    op.val1 = tlens W(-son~I  
    op.parent = parID y~M6  
    AddOperation eID, op vkG%w;  
    Print "Set lens thickness = " & tlens +;oR_]l  
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    '************************************************************************* ~xws5n}F  
    'Lens index of refraction p=i6~   
    '************************************************************************* =`CK`x  
    eID = FindMaterial( "Lens" ) $j@P8<M7  
    GetModelMaterial eID, mat o,0 Z^"|  
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    mat.Nd = nlens 9d=\BBNZ  
    SetModelMaterial eID, mat \-[ >bsg  
    Print "Set lens index of refraction = " & nlens a6It1%a+  
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    '************************************************************************* *7L1SjZw  
    'Pupil diameter #P!M"_z  
    '************************************************************************* '9&@?P;  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) %*gg6Q  
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    'Adjust pupil diameter (trimming volume inner hole) zQu
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" <1_3`t  
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    ' Adjust pupil location to just in front of the lens 3e\IRF xzb  
    parID = FindFullName( "Geometry.Arizona Eye" ) i;IhsKO0R  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) T5:xia>8O  
    count = 0 3mg:9]X9  
    While GetOperationCount(eID)>count Rz*GRe
 
        GetOperation eID, count, op Z,~@_;F  
        If op.Type="ShiftZ" Then CqU^bVs  
            DeleteOperation eID,count T+%P+  
            count=count-1 N+pCC  
        End If z XUr34jF  
        count=count+1 XSh[#qJ  
    Wend ;W\?lGOs{  
    op.Type = "ShiftZ"   
    op.val1 = taq-0.01 1
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    op.parent = parID X_,R!$wbg:  
    AddOperation eID, op sEL0h4  
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    Print "Set pupil diameter = " & pupilDiam Y^8'P /A  
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    'Update AZ Eye subassembly Description )vuIO(8F#  
    eID = FindFullName( "Geometry.Arizona Eye" ) hVd_1|/X  
    GetEntity eID, entity #|=lU4Bf  
    entity.Description = "Accommodation = " & A & "D" (rBYE[@,  
    SetEntity eID, entity u1.0-Y?  
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    Update cXYE!(  
    Print "DONE!" w2lO[o~x}  
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End Sub x>T+k8[n  
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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： T~g`;Q%i  
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Accommodation = 4 Diopters ~K(mt0T)  
Pupil Diameter = 4 mm %;aB#:p6  
Set aqueous humor thickness = 2.81 ?<Mx*l  
Set anterior lens radius = 10.4 and conic constant = -2.375869 `9\^.g)  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 )gAqWbkB  
Set lens thickness = 3.927 \,lIPA/L  
Set lens index of refraction = 1.42672 K\mFb  
Set pupil diameter = 4 g\iSc~%?  
DONE! GSfU*@L3  
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