[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 iqghcY)  
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。 (hd^  
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模型 52tIe|KwL  
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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。 X}_}`wIn  
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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. P@p(Y2&~g  
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光源 bP6QF1L  
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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。 6J6MR<5'  
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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。 8=T;R&U^M  
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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。 V{$(#r  
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视网膜的散射 Gk8"fs  
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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。 /lm;.7_J+  
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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。 `z-4OJ8~  
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脚本 N/TUcG|m\  
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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： 0lF.!\9  
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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。 +e`f|OQ  
余下的脚本计算与屈光度有关的所有参数。 F5gL-\6  
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分析 n wToZxHZ~  
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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。 Cv>|>Ob#  
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脚本代码 EJ.oq*W!*J  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. @T._   
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Dim entity As T_ENTITY ANc)igo  
Dim op As T_OPERATION 7UejK r  
Dim mat As T_MODELMATERIAL 0_}OKn)J  
Dim A As Double $}jp=?,t  
Dim pupilDiam As Double 2#kR1rJP  
Dim eID As Long 4v33{sp  
Dim parID As Long >t)vQ&:;u  
Dim count As Integer f/~"_O%  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double *j?tcxq
 
Dim tlens As Double, nlens As Double ,u#uk7V  
Dim curv As Double, conic As Double <MB]W
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Dim ok As Long
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Sub Main BDNn~aU#m  
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    '用户输入对话框 sD7Qt  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 9 #TzW9  
        TextBox 220,21,40,21,.TextBox1 'default: 0 {2vk<  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 -ZlBg~E  
        OKButton 40,91,90,21 +J} wYind  
        CancelButton 190,91,90,21 n`2d  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 FAfk;<#'n+  
        TextBox 220,49,40,21,.TextBox2 'default: 4 s:7^R-"
 
    End Dialog .9 mwRYgD  
    Dim dlg As UserDialog ,=O`'l>K  
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    ok = Dialog (dlg) /1F%w8Iqh  
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    If ok=0 Then    'cancel button was pressed k<Z^93 S  
        Print "Execution cancelled." [4"1TyW  
        End gS_)(  
    End If f_}/JF  
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    'Assign accommodation and pupil diameter & use defaults if field left empty =@AWw:!:,  
    If dlg.TextBox1 = "" Then svCD&~|K#  
        A = 0           'Default accommodation K 4QJDC8  
    Else OXe+=Lp<  
        A = CDbl(dlg.TextBox1) 1uZ[Ewl]  
    End If I 8vv  
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    If dlg.TextBox2 = "" Then ;,[6 n|M  
        pupilDiam = 4   'Default pupil diameter 
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    Else Ehi)n)HhG"  
        pupilDiam = CDbl(dlg.TextBox2) 'DO^($N  
    End If G#gUd'=M  
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    Print " " N+ZDQa[  
    Print "Accommodation = " & A & " Diopters" AD#]PSB  
    Print "Pupil Diameter = " & pupilDiam & " mm"
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    ' Calculate new parameters with accommodation 4z#{nZG  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness _BO:~x  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [zl@7X1{_  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens gyj.M`+y  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens gD10C,{  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens  N-`Vb0;N  
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    tlens = 3.767 + 0.04*A                  'Lens thickness h6<abT@I  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 6zh<PETa03  
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    'Adjust parameters to account for accommodation mbB,j~;^6H  
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    '************************************************************************* ;Pf |\q  
    'Aqueous thickness (Position of Lens) 'N^\9X0
  
    '************************************************************************* 
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) vQ/}E@?u  
    GetCustomElement eID, entity ]Q,;5>#W  
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    parID = FindFullName( "Geometry.Arizona Eye" ) A'r 3%mC  
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    ' Delete any shift(s) in z .Uq?SmK  
    count = 0 rCfr&>nn  
    While GetOperationCount(eID)>count ~,+n_KST;  
        GetOperation eID, count, op E .^5N~.  
        If op.Type="ShiftZ" Then nfpkWyIu{  
            DeleteOperation eID,count _J(n~"eR  
            count=count-1 ?T=]?[  
        End If D,q=?~  
        count=count+1 jXA!9_L7  
    Wend !$Aijd s5  
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    'Set new shift in y_EkW f  
    op.Type = "ShiftZ" rE0?R(_  
    op.val1 = taq aEU[k>&  
    op.parent = parID BCsz
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    AddOperation eID, op Y$xO&\&)  
    Print "Set aqueous humor thickness = " & taq-0.55 D`p&`]k3v  
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    '************************************************************************* Rs_0xh  
    'Radius and conic constant of anterior lens ah<1&UG,  
    '************************************************************************* rMXIw  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 9ZvBsG)  
    GetConic eID, entity, curv, conic 'F%4[3a$\n  
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    SetConic eID, entity, 1/Rant, CCant ?CO\jW_ *n  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant j.FA
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    '************************************************************************* .N2yn`
  
    'Radius and conic constant of posterior lens OQzJRu)mF#  
    '************************************************************************* }s)MDq9  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) b`"E(S/  
    GetConic eID, entity, curv, conic q/y4HT,x  

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    SetConic eID, entity, 1/Rpost, CCpost L9tjHC]
 
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ZeewGa^r  
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    '************************************************************************* @X`~r8&  
    'Lens thickness (Position of posterior lens surface) AA][}lU:5  
    '************************************************************************* GMmz`O XN  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) *9:oTN  
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    ' Delete any z-shift(s) u I$|M  
    count = 0 Z(Da?6#1  
    While GetOperationCount(eID)>count zNSix!F  
        GetOperation eID, count, op V]b1cDx{  
        If op.Type="ShiftZ" Then 5.gM]si  
            DeleteOperation eID,count m-f"EFmP  
            count=count-1 csn/h$`-@  
        End If q6A!xQs<  
        count=count+1 R=M"g|U6  
    Wend }e3M5LI1L  
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    'Set new z-shift .G[y^w)w}  
    op.Type = "ShiftZ" z;1y7W!v  
    op.val1 = tlens p7(Pymkd  
    op.parent = parID /dTy%hZC}  
    AddOperation eID, op ^NJ]~h{n$  
    Print "Set lens thickness = " & tlens 9hAS#|vK  

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    '************************************************************************* p:M#F:  
    'Lens index of refraction U3r[ysf  
    '************************************************************************* +EJwWDJ!%  
    eID = FindMaterial( "Lens" ) <>aBmJs4  
    GetModelMaterial eID, mat Z09FW>"u  
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    mat.Nd = nlens /CpUq;^  
    SetModelMaterial eID, mat /64jO?mp  
    Print "Set lens index of refraction = " & nlens ~ILig}I  
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    '************************************************************************* pAS!;t=n,  
    'Pupil diameter ZJ(/cD  
    '************************************************************************* :T~Aa(%(  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) $q*kD#;mh  
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    'Adjust pupil diameter (trimming volume inner hole) V~LZ%NZ8  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" _3$@s{k-TI  
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    ' Adjust pupil location to just in front of the lens ]D^dQ%{  
    parID = FindFullName( "Geometry.Arizona Eye" ) 0P`wh=")  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) F\1nc"K/(  
    count = 0 mhT
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    While GetOperationCount(eID)>count C("PCD   
        GetOperation eID, count, op b ABx'E  
        If op.Type="ShiftZ" Then H"(:6 `  
            DeleteOperation eID,count G)gf +
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            count=count-1 VlW#_.  
        End If ~`2w ul  
        count=count+1 Rf@D]+v  
    Wend 8D]:>[|E  
    op.Type = "ShiftZ" *nNzhcuR  
    op.val1 = taq-0.01 Mq) n=M  
    op.parent = parID 3WyK!@{  
    AddOperation eID, op 7SzY0})<U  
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    Print "Set pupil diameter = " & pupilDiam ,2S <#p!  
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    'Update AZ Eye subassembly Description ZWMX!>o<  
    eID = FindFullName( "Geometry.Arizona Eye" ) /uI/8>p(  
    GetEntity eID, entity oTZ?x}Z1  
    entity.Description = "Accommodation = " & A & "D" xrx{8pf  
    SetEntity eID, entity eux_tyC  
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    Update zO{$kT\r&  
    Print "DONE!" 5_Yv>tx  
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End Sub TH
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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： H
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Accommodation = 4 Diopters ^vm[`M  
Pupil Diameter = 4 mm .Pq8C  
Set aqueous humor thickness = 2.81 hM E|=\  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ub6\m=Y7  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 =1^a/  
Set lens thickness = 3.927 .G+}Kn9!  
Set lens index of refraction = 1.42672 ~C5iyXR  
Set pupil diameter = 4 *pP"u::S  
DONE! nzy =0Ox[  
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