[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 N;7Xt9l  
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。 *VH!<k[n  
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模型 ~U#afGH$  
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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。 L8N`<a5T  
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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. T>s~bIzL*e  
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光源 WY#A9i5Ge  
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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。 7OX5"u!2  
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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。 )
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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。 $5ZBNGr  
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视网膜的散射 3JM0 m (  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 nS)U+q-x&o  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 Ac
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脚本 p/L|;c  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： awh<CmcZ  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 :["iBrFp  
余下的脚本计算与屈光度有关的所有参数。 H)z}6[`  
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分析 HZC^Q7]hy  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 \=PnC}
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脚本代码 N,fEta6  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. \Fg%V>  
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Dim entity As T_ENTITY yXP+$oox9  
Dim op As T_OPERATION S?ELFq(g  
Dim mat As T_MODELMATERIAL TtTp,If  
Dim A As Double .Qk T-12  
Dim pupilDiam As Double *P2_l Q=  
Dim eID As Long Z6C!-a  
Dim parID As Long XE8>&&X  
Dim count As Integer KSkT6_<  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double j=b?WNK  
Dim tlens As Double, nlens As Double ScOiOz:Ha  
Dim curv As Double, conic As Double -P#PyZEH&I  
Dim ok As Long z6 T3vw
  
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Sub Main |j:"n3~6  
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    '用户输入对话框 %gUf
  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 
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        TextBox 220,21,40,21,.TextBox1 'default: 0 [`pp[J-~7  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 SR)jJ=R3  
        OKButton 40,91,90,21 ou8V7  
        CancelButton 190,91,90,21 I!sh+e  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Wk<heF  
        TextBox 220,49,40,21,.TextBox2 'default: 4 \%&BK.t  
    End Dialog wJc~AP)I%z  
    Dim dlg As UserDialog Y$JGpeq8w  
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    ok = Dialog (dlg) ; '6`hZ  
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    If ok=0 Then    'cancel button was pressed s4V-brCM$|  
        Print "Execution cancelled." ZAATV+Z  
        End -DAkVFsN  
    End If 0F48T<i  
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    'Assign accommodation and pupil diameter & use defaults if field left empty b;Nm$`2  
    If dlg.TextBox1 = "" Then c,@&Z#IZ`  
        A = 0           'Default accommodation Rhw- 49AWx  
    Else ?X $#J'U;  
        A = CDbl(dlg.TextBox1) \vg(@)$q   
    End If gR5 EK$  
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    If dlg.TextBox2 = "" Then 4)Jtc2z7Z\  
        pupilDiam = 4   'Default pupil diameter au=A+  
    Else R:N4_4& C~  
        pupilDiam = CDbl(dlg.TextBox2) <O<Kf:i&c1  
    End If <'T:9  
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    Print " " @FNaCmBX  
    Print "Accommodation = " & A & " Diopters" {"v~1W)  
    Print "Pupil Diameter = " & pupilDiam & " mm" I:|<};mm  
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    ' Calculate new parameters with accommodation )NF5,eD  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness rgo#mTQ_  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens bF2RP8?en  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens [|qV*3|?  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens  lL\%eQ  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens }>93X0%r  
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    tlens = 3.767 + 0.04*A                  'Lens thickness KUD.hK.  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction !l6Ez_'  
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    'Adjust parameters to account for accommodation #}xw *)3  
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    '************************************************************************* V><,.p8  
    'Aqueous thickness (Position of Lens) gPE`mE  
    '************************************************************************* 6y+_x'  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) {<}9r6k;f  
    GetCustomElement eID, entity !V^wq]D2  
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    parID = FindFullName( "Geometry.Arizona Eye" ) XJZ\ss  
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    ' Delete any shift(s) in z QjlQsN!  
    count = 0 c1ga{c`Z  
    While GetOperationCount(eID)>count K0aT(Rc e  
        GetOperation eID, count, op Vi m::  
        If op.Type="ShiftZ" Then A:$4cacu9  
            DeleteOperation eID,count WqO4_;X6/  
            count=count-1 8@ZZ[9kt  
        End If Wa
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        count=count+1 ROhhd.  
    Wend T?g%I  
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    'Set new shift in `VrQ?s  
    op.Type = "ShiftZ" Zxw cqN  
    op.val1 = taq i7XM7+}  
    op.parent = parID U-*`I?~=4  
    AddOperation eID, op ,+4*\yI3l  
    Print "Set aqueous humor thickness = " & taq-0.55 ey]WoUZ  
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    '************************************************************************* Cut7  
    'Radius and conic constant of anterior lens Lcz`  
    '************************************************************************* 4{QD: D(D  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) OWys`2W  
    GetConic eID, entity, curv, conic g-~]^$  
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    SetConic eID, entity, 1/Rant, CCant ge4QaK  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant /jl/SV+  
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    '************************************************************************* HfPu~P  
    'Radius and conic constant of posterior lens q4T98s2J  
    '************************************************************************* hHk9O?  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) O?`_RN4l  
    GetConic eID, entity, curv, conic (PC)R9r5  
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    SetConic eID, entity, 1/Rpost, CCpost ES)@iM?5  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 5{xK&[wR*  
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    '************************************************************************* `aDVN_h{6  
    'Lens thickness (Position of posterior lens surface) h e[2,  
    '************************************************************************* iv ~<me0F  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /E-sg, k  
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    ' Delete any z-shift(s) .(7m[-iF!  
    count = 0 cN:dy#  
    While GetOperationCount(eID)>count u[HamGxx$u  
        GetOperation eID, count, op hkB|rhJgm  
        If op.Type="ShiftZ" Then 7NRm\%^q  
            DeleteOperation eID,count ] T<#bNK\1  
            count=count-1 mndKUI}d  
        End If 5]*!N  
        count=count+1 5.LfN{gE)  
    Wend {kghZur  
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    'Set new z-shift u}.mJDL  
    op.Type = "ShiftZ" ?IG[W+M8  
    op.val1 = tlens ,u=+%6b)A  
    op.parent = parID q?qH7={,eu  
    AddOperation eID, op =gB8(1g8  
    Print "Set lens thickness = " & tlens ffMk.Sq
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    '************************************************************************* r=/$}l4  
    'Lens index of refraction ?=im~  
    '************************************************************************* w6h*dh$w  
    eID = FindMaterial( "Lens" ) SZUo RWx  
    GetModelMaterial eID, mat 3lTnfc&  
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    mat.Nd = nlens D\| U_>  
    SetModelMaterial eID, mat Q-7L,2TL  
    Print "Set lens index of refraction = " & nlens fDRG+/q(+  
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    '************************************************************************* BV6B:=E0  
    'Pupil diameter CQPq5/@Y4  
    '************************************************************************* "A> _U<Y  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) e{H(  
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    'Adjust pupil diameter (trimming volume inner hole) \EXa 9X2  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" D/afa8>LQH  
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    ' Adjust pupil location to just in front of the lens /I((A/ks  
    parID = FindFullName( "Geometry.Arizona Eye" ) fRT4>So  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) w"37sv  
    count = 0 %OsxXO?  
    While GetOperationCount(eID)>count ExM VGe  
        GetOperation eID, count, op tH~>uOZW  
        If op.Type="ShiftZ" Then cwOa"]t}  
            DeleteOperation eID,count FU(2,V
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            count=count-1 W4bN']?  
        End If !b=W>5h  
        count=count+1 X:lStO#5  
    Wend dai+"  
    op.Type = "ShiftZ" _Ie
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    op.val1 = taq-0.01  d0i|^  
    op.parent = parID nwMq~I*1  
    AddOperation eID, op S>)[n]f  
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    Print "Set pupil diameter = " & pupilDiam UZs'H"K  
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    'Update AZ Eye subassembly Description vvu $8n  
    eID = FindFullName( "Geometry.Arizona Eye" ) *<[zG7+&[  
    GetEntity eID, entity J"F
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    entity.Description = "Accommodation = " & A & "D" Y;'SD{On  
    SetEntity eID, entity WEJ-K<A(  
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    Update 5fMlOP_  
    Print "DONE!" ]1pB7XL  
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End Sub 1+Uem  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： IA{W-RRb  
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Accommodation = 4 Diopters 7A) E4f'  
Pupil Diameter = 4 mm T:Ovh.$  
Set aqueous humor thickness = 2.81 hsT&c|  
Set anterior lens radius = 10.4 and conic constant = -2.375869 7xQ:[P!G+  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 -SfU.XlZl  
Set lens thickness = 3.927 bdLi_k  
Set lens index of refraction = 1.42672 c&x1aF "B  
Set pupil diameter = 4 [[w |  
DONE! NuOxEyC  
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