[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 5avO48;Vc  
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。 (Pd>*G\  
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模型 CiuN26>  
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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。 
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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. .LhmYbQ2WE  
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光源 Bs?
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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。 2-0cB$W+  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 BA-nxR  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 kW&Z%k  
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视网膜的散射 9M]"%E!s  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 3|Sy'J0'K  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ==1/N{{R  
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脚本 rs Uw(K^  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： ;-pvc<_c<  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 M#]|$\v(  
余下的脚本计算与屈光度有关的所有参数。 R.IUBw5;/  
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分析
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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。 1{x~iZa  
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脚本代码 b+].Uc  

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Option Explicit     'Remove this to enable non-dimensioned variables to be used. .xkV#ol  
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Dim entity As T_ENTITY I"32[?0 (;  
Dim op As T_OPERATION xPMyG);  
Dim mat As T_MODELMATERIAL P^3m:bE
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Dim A As Double ]Wd`GI  
Dim pupilDiam As Double 
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Dim eID As Long 9LO.8Jy  
Dim parID As Long %C`'>,t>  
Dim count As Integer `3y!XET  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double cbCE $  
Dim tlens As Double, nlens As Double M=[q+A  
Dim curv As Double, conic As Double `x$}~rP&)!  
Dim ok As Long e*2&s5 #RT  
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Sub Main 8#]7`o  
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    '用户输入对话框 >}DjHLTW\  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 zz 'dg-F  
        TextBox 220,21,40,21,.TextBox1 'default: 0 '+!S|U,{  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 {8#N7(%z  
        OKButton 40,91,90,21 $;
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        CancelButton 190,91,90,21 ))IgB).3M  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 =F
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        TextBox 220,49,40,21,.TextBox2 'default: 4 Qw<kX*fxrI  
    End Dialog X}j'L&{F@  
    Dim dlg As UserDialog I*W9VhIOV  
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    ok = Dialog (dlg) Ukx/jNyYv  

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    If ok=0 Then    'cancel button was pressed 1x\VdT  
        Print "Execution cancelled." 
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        End we\b]  
    End If ~w1{zxs  
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    'Assign accommodation and pupil diameter & use defaults if field left empty nI*
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    If dlg.TextBox1 = "" Then n=G>y7b  
        A = 0           'Default accommodation RUS7Z~5  
    Else 9xK4!~5V  
        A = CDbl(dlg.TextBox1) mI7rx`4H  
    End If Fp5NRM*-!  
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    If dlg.TextBox2 = "" Then ayH%  qp  
        pupilDiam = 4   'Default pupil diameter mo|PrLV  
    Else EtR@sJ<  
        pupilDiam = CDbl(dlg.TextBox2) xxLgC;>[  
    End If h\=p=M  
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    Print " " ?GUz?'d  
    Print "Accommodation = " & A & " Diopters" }RA3$%3  
    Print "Pupil Diameter = " & pupilDiam & " mm" Bbl)3$`,  
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    ' Calculate new parameters with accommodation Et}C`vZ+Ve  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness HzD>-f  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 23}BW_m  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens P~Te+ -jX}  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ~T>jBYI0  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens nr<WO~Xw~  
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    tlens = 3.767 + 0.04*A                  'Lens thickness aCU7w5  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ><;l:RGK|  
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    'Adjust parameters to account for accommodation qJ{r!NJJ 8  
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    '************************************************************************* c&7Do}  
    'Aqueous thickness (Position of Lens) JCw{ ?^F"  
    '************************************************************************* WFU?o[k-O  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) l zfD)TWb  
    GetCustomElement eID, entity _`bS[%CJ  
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    parID = FindFullName( "Geometry.Arizona Eye" ) JqI6k6~Q^  
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    ' Delete any shift(s) in z M1AZ}bc0]  
    count = 0 6}VUD -}B  
    While GetOperationCount(eID)>count .9T.3yQ  
        GetOperation eID, count, op o &BPG@n  
        If op.Type="ShiftZ" Then "n{9- VEmN  
            DeleteOperation eID,count YPF&U4CN  
            count=count-1 x @1px&^  
        End If +M44XhT  
        count=count+1 KY4d+~2  
    Wend y#]}5gJ  
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    'Set new shift in -Bo86t)F  
    op.Type = "ShiftZ" <A#5v\{.;~  
    op.val1 = taq IXGW2z;  
    op.parent = parID -M"IVyy@  
    AddOperation eID, op E4Y"X  
    Print "Set aqueous humor thickness = " & taq-0.55 w) =eMdj\o  
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    '************************************************************************* o;ik Z*+*  
    'Radius and conic constant of anterior lens +VSZhg,Np8  
    '************************************************************************* ?Wwh _TO  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) =y?#^  
    GetConic eID, entity, curv, conic _FL<egK  
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    SetConic eID, entity, 1/Rant, CCant )r ULT$;i@  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ^[ET&"  
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    '************************************************************************* j h; 9 [  
    'Radius and conic constant of posterior lens ^fkCyE;=  
    '************************************************************************* n4^*h4J7  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) N1PECLS?  
    GetConic eID, entity, curv, conic M[A-1]'  
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    SetConic eID, entity, 1/Rpost, CCpost Oz:D.V 3~  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost JYPxd~T/-  
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    '************************************************************************* ft{W/ * +_  
    'Lens thickness (Position of posterior lens surface) ]x1p!TSU  
    '************************************************************************* CNut{4  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) rqF"QU=l  
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    ' Delete any z-shift(s) *yrnK3  
    count = 0 u0xQ;BQ  
    While GetOperationCount(eID)>count 6A}eSG3  
        GetOperation eID, count, op xFOBF")  
        If op.Type="ShiftZ" Then 1:_=g#WH  
            DeleteOperation eID,count }xqXd
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            count=count-1 u2 7S%2P  
        End If Z)NrhJC  
        count=count+1 G=1m]>I8  
    Wend 26M~<Ic  
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    'Set new z-shift H-185]7  
    op.Type = "ShiftZ" /M:H9Z8!  
    op.val1 = tlens w}d}hI  
    op.parent = parID Y:wF5pp;  
    AddOperation eID, op f7Zf}1|  
    Print "Set lens thickness = " & tlens &RWM<6JP  
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    '*************************************************************************
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    'Lens index of refraction 90p3V\LO  
    '************************************************************************* 82|q7*M*.  
    eID = FindMaterial( "Lens" ) `0?^[;[u[  
    GetModelMaterial eID, mat B3Mx,uXT\  
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    mat.Nd = nlens u^l*5F%DK  
    SetModelMaterial eID, mat y<|)'(  
    Print "Set lens index of refraction = " & nlens $Buf#8)F*  
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    '************************************************************************* qp\BV#E  
    'Pupil diameter X($6IL6m  
    '************************************************************************* vb %T7  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ?ZaD=nh$mK  
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    'Adjust pupil diameter (trimming volume inner hole) o_O+u%y  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" {|XQO'Wg  
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    ' Adjust pupil location to just in front of the lens (`pNXQ0n  
    parID = FindFullName( "Geometry.Arizona Eye" ) WO
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) [^M|lf   
    count = 0 izf~w^/  
    While GetOperationCount(eID)>count 7 W{~f?Sh  
        GetOperation eID, count, op O~6Q;qP  
        If op.Type="ShiftZ" Then .EG*+,  
            DeleteOperation eID,count n$YE !D'  
            count=count-1 P_}/#N{C  
        End If pqeL%="p;  
        count=count+1 b_l3+'#ofM  
    Wend ]H+{eJB7O  
    op.Type = "ShiftZ" Xem5@  (u  
    op.val1 = taq-0.01 <m0{'xw  
    op.parent = parID uB;_vC  
    AddOperation eID, op )\0q_a  
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    Print "Set pupil diameter = " & pupilDiam um[!|g/  
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    'Update AZ Eye subassembly Description +zsZNJ(U  
    eID = FindFullName( "Geometry.Arizona Eye" ) xs%LRF#u  
    GetEntity eID, entity uY;R8CiD  
    entity.Description = "Accommodation = " & A & "D" G?/c/rG  
    SetEntity eID, entity w;+ br  
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    Update B+Z13;}B  
    Print "DONE!" k2p'G')H  
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End Sub q{E"pyt36R  
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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： 4P%m>[  
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Accommodation = 4 Diopters @rwU 1T33  
Pupil Diameter = 4 mm DjwQ`MA  
Set aqueous humor thickness = 2.81 c 0-w6  
Set anterior lens radius = 10.4 and conic constant = -2.375869 sofu  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 8%ik853`  
Set lens thickness = 3.927 P'tMu6+)  
Set lens index of refraction = 1.42672 Pz@/|&]  
Set pupil diameter = 4 94{)"w]  
DONE! =VSkl;
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