[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 =*zde0T?l  
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。 _V0%JE'  
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模型 hsYE&Np_Q  
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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。 TiG?r$6v%  
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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. gSj0+|  
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光源 EwuRIe;D  
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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。 Q"c/]Sk)  
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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。 KK6z3"tk5  
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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。 h;y}g/HZ  
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视网膜的散射 \Y8 sIs  
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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。 Iu5 9W>  
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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。 F#RNm5  
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脚本 r ?<kWR?w  
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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： so/0f1R?~  
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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。 +xsGa{`  
余下的脚本计算与屈光度有关的所有参数。 6BEpnw>p(  
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分析 ^6F, lS_t  
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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。 pzUr9  
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脚本代码 1LhZmv  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. %hw4IcWJ|  
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Dim entity As T_ENTITY m,
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Dim op As T_OPERATION [Ob'E!;<  
Dim mat As T_MODELMATERIAL Li0+%ijM  
Dim A As Double bb\XZ~)F  
Dim pupilDiam As Double }u$c*}  
Dim eID As Long i+< v7?:`#  
Dim parID As Long rnp; R  
Dim count As Integer [e@m-/B  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double A{k1MA<F6  
Dim tlens As Double, nlens As Double Y6hV ;[\F  
Dim curv As Double, conic As Double wq!9wk9  
Dim ok As Long f8=qnY2j  
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Sub Main MU2kA&LH  
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    '用户输入对话框 f7!48
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 rz-61A) _  
        TextBox 220,21,40,21,.TextBox1 'default: 0 {D|ST2:E  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 x _d   
        OKButton 40,91,90,21 NZADHO@0  
        CancelButton 190,91,90,21 H\E%.QIx  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 &m[}%e%~0  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ' S,g3  
    End Dialog -MsL>F.
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    Dim dlg As UserDialog F$|:'#KN  
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    ok = Dialog (dlg) qwnVtD  
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    If ok=0 Then    'cancel button was pressed
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        Print "Execution cancelled." v*.iNA;&i  
        End BhbfPQ  
    End If gW4fwE^  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ePIN<F;
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    If dlg.TextBox1 = "" Then n5BD0q  
        A = 0           'Default accommodation )+8r$ i  
    Else 
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        A = CDbl(dlg.TextBox1) G|-RscPe  
    End If c9Cc%EK  
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    If dlg.TextBox2 = "" Then ].aFdy  
        pupilDiam = 4   'Default pupil diameter :sLg$OF  
    Else m-;8O /  
        pupilDiam = CDbl(dlg.TextBox2) ,O-_Pv  
    End If >hq{:m  
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    Print " " *icaKy3  
    Print "Accommodation = " & A & " Diopters" _5(p=Zc  
    Print "Pupil Diameter = " & pupilDiam & " mm" h"Wpb}FT  
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    ' Calculate new parameters with accommodation 5WxN
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness w2/
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens /38I(0  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens YPq:z"`-y4  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 'NfsAE  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens mvt-+K?U  

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    tlens = 3.767 + 0.04*A                  'Lens thickness ZF#n(Y?  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction $^czqA-&  
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    'Adjust parameters to account for accommodation aUc#,t;Qd  
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    '************************************************************************* KU0Ad);e  
    'Aqueous thickness (Position of Lens) L>E{~yh  
    '************************************************************************* ^J^FGo|M  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) n<> ^cD  
    GetCustomElement eID, entity Fn4yx~0  
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    parID = FindFullName( "Geometry.Arizona Eye" ) B~qo^ppVU  
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    ' Delete any shift(s) in z O&;d82IA{  
    count = 0 ;qbK[3.  
    While GetOperationCount(eID)>count t:P]bp^#  
        GetOperation eID, count, op EL z5P}L6  
        If op.Type="ShiftZ" Then wmXI8'~F&  
            DeleteOperation eID,count
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            count=count-1 i1KjQ1\a+  
        End If c>3? T^=  
        count=count+1 J]S30&?  
    Wend ~7g$TAe{  
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    'Set new shift in t>*(v#WeZ  
    op.Type = "ShiftZ" 60A!Gob  
    op.val1 = taq 8<C@I/  
    op.parent = parID Z0y~%[1X  
    AddOperation eID, op l.
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    Print "Set aqueous humor thickness = " & taq-0.55 NYG!\u\Rm  
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    '************************************************************************* kv+^U^WoU  
    'Radius and conic constant of anterior lens |F<iu2\  
    '************************************************************************* <}8G1<QZ'.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) /Lm~GmPt  
    GetConic eID, entity, curv, conic 2P@6Qe ?  
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    SetConic eID, entity, 1/Rant, CCant Mk973'K'  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant >m<T+{`  
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    '************************************************************************* v+79#qWK|n  
    'Radius and conic constant of posterior lens kdV9F  
    '************************************************************************* Yjd/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) n$7*L9)(C  
    GetConic eID, entity, curv, conic D2gyn-]\  
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    SetConic eID, entity, 1/Rpost, CCpost ,`YBTU  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost P7bb2"_9  
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    '************************************************************************* ~$j;@4  
    'Lens thickness (Position of posterior lens surface) l`:u5\ rM  
    '************************************************************************* $G }9iV7  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /'_<~A  
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    ' Delete any z-shift(s) k
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    count = 0 S-~)|7d.  
    While GetOperationCount(eID)>count HJym|G>%?  
        GetOperation eID, count, op XIZN9/;  
        If op.Type="ShiftZ" Then kw gLK@@%1  
            DeleteOperation eID,count LayK&RwL  
            count=count-1 aot2F60J,  
        End If ]vs}-go  
        count=count+1 -%%Xx5D  
    Wend Iu`S0#+  
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    'Set new z-shift AL,7rYZG$  
    op.Type = "ShiftZ" .sM,U  
    op.val1 = tlens ^Ekx
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    op.parent = parID N81M9#,["~  
    AddOperation eID, op y0&vsoT  
    Print "Set lens thickness = " & tlens UF }[%Sa  
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    '************************************************************************* /N<aN9Z<x,  
    'Lens index of refraction r7R.dD/.  
    '************************************************************************* -KfK~P3PF  
    eID = FindMaterial( "Lens" ) c?}G;$  
    GetModelMaterial eID, mat XOI"BLd
 
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    mat.Nd = nlens mD&I6F[s  
    SetModelMaterial eID, mat <-n^h~,4  
    Print "Set lens index of refraction = " & nlens *mJ#|3I<  
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    '************************************************************************* $U9]v5  
    'Pupil diameter t6mv  
    '************************************************************************* 'kY/=*=Q  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) yE,qLiH  
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    'Adjust pupil diameter (trimming volume inner hole) c?. i;4yh  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" EU|IzUjFj|  
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    ' Adjust pupil location to just in front of the lens IpSWg  
    parID = FindFullName( "Geometry.Arizona Eye" ) :b %2qBv  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) |mHf7gCX  
    count = 0 8Q)|8xpYS  
    While GetOperationCount(eID)>count `aG_m/7|  
        GetOperation eID, count, op G}+@C]  
        If op.Type="ShiftZ" Then v@q&B|0  
            DeleteOperation eID,count U.I w/T-5  
            count=count-1 C,$o+q*)W9  
        End If X;UEq]kcmn  
        count=count+1 |&W4Dkn  
    Wend %D:VcY9OC  
    op.Type = "ShiftZ" Yk?q\1  
    op.val1 = taq-0.01 zp}pS2DU  
    op.parent = parID ^dhx/e%s  
    AddOperation eID, op }d>.Nj#zh  
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    Print "Set pupil diameter = " & pupilDiam FJCORa@?_  
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    'Update AZ Eye subassembly Description y?O-h1"3,  
    eID = FindFullName( "Geometry.Arizona Eye" ) vazA@|^8  
    GetEntity eID, entity ISFNP
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    entity.Description = "Accommodation = " & A & "D" c^pQitPv  
    SetEntity eID, entity "a~r'+'<  
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    Update ob2_=hQnC  
    Print "DONE!" Y%0rji  
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End Sub (GpP=lSSeY  
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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： a)=|{QR>W  
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Accommodation = 4 Diopters rXMc0SPk  
Pupil Diameter = 4 mm se2Y:v  
Set aqueous humor thickness = 2.81 hE`d@  
Set anterior lens radius = 10.4 and conic constant = -2.375869 'Rsr*gX#  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 9{j`eAUZl  
Set lens thickness = 3.927 K\;4;6g  
Set lens index of refraction = 1.42672 ~1}fL 1~5  
Set pupil diameter = 4 c_+fA  
DONE! 4^:dmeMZ`  
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