[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 P,"z  
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。 +a&-'`7g  
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模型 fB5Bh;K  
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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。 <69/ZI),Y{  

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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. L%a ni}V  
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光源 .2hQ!)+  
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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。 V/+r"le  
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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。 +asJV1a  
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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。 ]Bs ?  
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视网膜的散射 w2~(/RgO  
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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。 ,ewg3mYHC&  
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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。 UL[4sv6\9  
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脚本 hzPx8sO  
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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： yQhrPw> m  

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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。 {H $\,  
余下的脚本计算与屈光度有关的所有参数。 8Mg4y1)RU  
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分析 v!@/  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 %8$JL=c  
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脚本代码 ynM{hN.+H  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. K;6K!6J:[  
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Dim entity As T_ENTITY 'QT(TF>  
Dim op As T_OPERATION qvYY
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Dim mat As T_MODELMATERIAL M=o,Sav5*  
Dim A As Double 9aZ3W<N`M  
Dim pupilDiam As Double j\dkv_L  
Dim eID As Long rxa"ji!)  
Dim parID As Long ![abDT5![  
Dim count As Integer {yt]7^  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double r.i.w0B(  
Dim tlens As Double, nlens As Double 5B2x# m|8  
Dim curv As Double, conic As Double AV d  
Dim ok As Long )r?i^D&4  
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Sub Main |,sUD/rt  
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    '用户输入对话框 nZ\,
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 d*A>P  
        TextBox 220,21,40,21,.TextBox1 'default: 0 U%k e5uwP  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 K/\#FJno  
        OKButton 40,91,90,21 }%k"qW<Y  
        CancelButton 190,91,90,21 yH#;k:O=  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ~O1*]  
        TextBox 220,49,40,21,.TextBox2 'default: 4 a _  
    End Dialog 5)$U<^uy  
    Dim dlg As UserDialog @/$mZ]|T  
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    ok = Dialog (dlg) xo@N~
 
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    If ok=0 Then    'cancel button was pressed /mD KQ<  
        Print "Execution cancelled." n;Iey[7_E`  
        End RTY$oUqlZ  
    End If !+hX$_RT  
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    'Assign accommodation and pupil diameter & use defaults if field left empty LG<lZ9+y  
    If dlg.TextBox1 = "" Then B.P64"w  
        A = 0           'Default accommodation -|)[s[T~m  
    Else W^=8
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        A = CDbl(dlg.TextBox1) $}KYpSV  
    End If 4uftx1o   
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    If dlg.TextBox2 = "" Then `=KrV#/758  
        pupilDiam = 4   'Default pupil diameter  v$tS2N2  
    Else HqF8:z?v  
        pupilDiam = CDbl(dlg.TextBox2) A+F-r_]}db  
    End If ~ml\|  
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    Print " " ]#:xl}'LS  
    Print "Accommodation = " & A & " Diopters" _-!
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    Print "Pupil Diameter = " & pupilDiam & " mm" E,6E-9  
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    ' Calculate new parameters with accommodation "V^jAPDXb  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness XdS<51 C  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens "mH^Owai  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens F_r eBPx  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ^|K*lI/  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ffB]4  
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    tlens = 3.767 + 0.04*A                  'Lens thickness _:K}DU'6  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction <bjy<98LT  
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    'Adjust parameters to account for accommodation /Z@.;M  
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    '************************************************************************* z::2O/ho  
    'Aqueous thickness (Position of Lens) 4dok/ +Ec  
    '************************************************************************* .X
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) (,TO|  
    GetCustomElement eID, entity PA=BNKlH  
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    parID = FindFullName( "Geometry.Arizona Eye" ) aLq;a  
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    ' Delete any shift(s) in z 5 O6MI4:  
    count = 0 LtU+w*Gj  
    While GetOperationCount(eID)>count h/k`+  
        GetOperation eID, count, op X@G`AD'.M  
        If op.Type="ShiftZ" Then jFc{$#g-
 
            DeleteOperation eID,count s-ou;S3s  
            count=count-1 l )4OV>  
        End If a;zcAeX  
        count=count+1 V&nN/CF  
    Wend Cn<kl^!Q-  
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    'Set new shift in tp]|/cx4  
    op.Type = "ShiftZ" C;ye%&g>  
    op.val1 = taq MDq@:t  
    op.parent = parID 4<Y?#bm'  
    AddOperation eID, op *,p
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    Print "Set aqueous humor thickness = " & taq-0.55 xVe!  
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    '************************************************************************* Ygl!fC 4b  
    'Radius and conic constant of anterior lens F)IP~BE-k  
    '************************************************************************* 9e5UTJ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) `otQ'e~+t  
    GetConic eID, entity, curv, conic f1{ckHAY55  
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    SetConic eID, entity, 1/Rant, CCant k);!H+  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant )?WoLEjq  
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    '************************************************************************* *+z({S_Nv  
    'Radius and conic constant of posterior lens x'qgpG}?]  
    '************************************************************************* O?!"15  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ep!.kA=\  
    GetConic eID, entity, curv, conic <gy'@w?  
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    SetConic eID, entity, 1/Rpost, CCpost ^PI49iB  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ]3C8  
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    '************************************************************************* .<B1i  
    'Lens thickness (Position of posterior lens surface) e'Pa@]VaC  
    '************************************************************************* i&$uG[&P  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZS+2.)A  
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    ' Delete any z-shift(s) {V8Pn2mlo  
    count = 0 ?2TH("hV$  
    While GetOperationCount(eID)>count 2&m7pcls  
        GetOperation eID, count, op Z:_y,( 1Q  
        If op.Type="ShiftZ" Then [oj"Tn(  
            DeleteOperation eID,count f+
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            count=count-1 :9b RuUm  
        End If =-qsz^^a-  
        count=count+1 qo;\dp1  
    Wend )R4<* /C:w  
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    'Set new z-shift Xd6y7s  
    op.Type = "ShiftZ" Y"qY@`  
    op.val1 = tlens J.nq[/
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    op.parent = parID q1y4B`  
    AddOperation eID, op v(iUo&Ge  
    Print "Set lens thickness = " & tlens <B`V  
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    '************************************************************************* Q6K)EwN  
    'Lens index of refraction o1Ln7r.  
    '************************************************************************* ZAZCvN@5  
    eID = FindMaterial( "Lens" ) 2XHk}M|  
    GetModelMaterial eID, mat R5"p7>  
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    mat.Nd = nlens o3=kF  
    SetModelMaterial eID, mat 0,/x#  
    Print "Set lens index of refraction = " & nlens .a*$WGb  
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    '************************************************************************* Pc'?p  
    'Pupil diameter Bv8C_-lV/  
    '************************************************************************* ''uI+>Y  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) m+vEs,W.  
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    'Adjust pupil diameter (trimming volume inner hole) b U NYTF{  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" y6}):|  
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    ' Adjust pupil location to just in front of the lens gf?^yP ;V  
    parID = FindFullName( "Geometry.Arizona Eye" ) 5>)jNtZ  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) lIg2iun[n  
    count = 0 dU6LB+A  
    While GetOperationCount(eID)>count @ WaYU  
        GetOperation eID, count, op AvZ)1(  
        If op.Type="ShiftZ" Then or}*tSKX  
            DeleteOperation eID,count e-9unnk  
            count=count-1 G:`Jrh  
        End If Bq@wS\W>b}  
        count=count+1 070IBAk}_  
    Wend G4' U;  
    op.Type = "ShiftZ" 1i:g /H  
    op.val1 = taq-0.01 +o]BjgG  
    op.parent = parID 'hO;sL  
    AddOperation eID, op ?bAFYF0!I  
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    Print "Set pupil diameter = " & pupilDiam acQNpT  
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    'Update AZ Eye subassembly Description 8"mW!M  
    eID = FindFullName( "Geometry.Arizona Eye" ) .A)Un/k7  
    GetEntity eID, entity dM{~Ubb  
    entity.Description = "Accommodation = " & A & "D" ;bZ*6-\!-  
    SetEntity eID, entity /v4S@SQ+  
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    Update xY2_
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    Print "DONE!"
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End Sub o!`O i5  
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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： Ir"Q%>K0f  
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Accommodation = 4 Diopters Uy5!H1u  
Pupil Diameter = 4 mm ~h0BT(p/  
Set aqueous humor thickness = 2.81 lk1Gs{(qhH  
Set anterior lens radius = 10.4 and conic constant = -2.375869 'h>5&=r  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 cuaNAJ  
Set lens thickness = 3.927 9,f<Nb(\  
Set lens index of refraction = 1.42672 'QojSq   
Set pupil diameter = 4 Y{vwOs  
DONE! Q4Fq=kTE  
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