[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 xY U.D+RY  
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。
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模型 'XofD}dm  

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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。 EG0auzW?  
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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. \,&co  
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光源 FwY&/\J7V  
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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。 W4U@%b do  
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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。 M=*bh5t%]  
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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。 UH>F|3"d  
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视网膜的散射 )r z+'|,  
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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。 {}m PEd b  
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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。 G,<T/f .{$  
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脚本 maY4g&'f  
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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： 8W+gl=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。 9F- )r'  
余下的脚本计算与屈光度有关的所有参数。 P;8>5;U4-  
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分析 a7/-wk  
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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。 0\~Z5k`IT  
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脚本代码 !.<T"8BUpv  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. \^K&vW;  
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Dim entity As T_ENTITY (zYy}g#n  
Dim op As T_OPERATION $W42vjr4  
Dim mat As T_MODELMATERIAL )Vk6;__  
Dim A As Double >x@P|\  
Dim pupilDiam As Double o{kbc5_  
Dim eID As Long asgF1?r  
Dim parID As Long tPyyZ#,  
Dim count As Integer uw7{>9  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double _uu<4c   
Dim tlens As Double, nlens As Double m&oi8 P-6  
Dim curv As Double, conic As Double F'?I-jtI  
Dim ok As Long >71&]/Rv  
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Sub Main  5q<zN  
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    '用户输入对话框 "?
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 a)! g7u  
        TextBox 220,21,40,21,.TextBox1 'default: 0 7W9d6i)  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 kF V7l  
        OKButton 40,91,90,21 t.hm9}UQ  
        CancelButton 190,91,90,21 ,C
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 %im#ww L%  
        TextBox 220,49,40,21,.TextBox2 'default: 4 L1)@z8]
 
    End Dialog 8Chu"PM%-J  
    Dim dlg As UserDialog GfyX'(ge  
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    ok = Dialog (dlg) AdoZs8Q  
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    If ok=0 Then    'cancel button was pressed ]`w}+B'/  
        Print "Execution cancelled." <B&R6<]T  
        End $ 'QdFkOr  
    End If `Xcirfp  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Cw,D{  
    If dlg.TextBox1 = "" Then <3O T>E
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        A = 0           'Default accommodation P8gXCX!>U  
    Else TQ1WVq }*  
        A = CDbl(dlg.TextBox1) nyT[^n  
    End If Hwe)T
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    If dlg.TextBox2 = "" Then re,.@${H  
        pupilDiam = 4   'Default pupil diameter *R`MMm  
    Else z]$j7dp  
        pupilDiam = CDbl(dlg.TextBox2) I8op>^N"  
    End If Gwd{#7FM`  
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    Print " " '3kcD7  
    Print "Accommodation = " & A & " Diopters" ~k
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    Print "Pupil Diameter = " & pupilDiam & " mm" O'}llo  
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    ' Calculate new parameters with accommodation JA
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness i&@,5/'-_O  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens #Y,A[Y5jX  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens A@$fb}CF  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ZZ A.a  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens R~B0+:6  
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    tlens = 3.767 + 0.04*A                  'Lens thickness bGh0<r7
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 1BD6l2y  
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    'Adjust parameters to account for accommodation ,p,Du F  
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    '************************************************************************* r2G*!qK*1  
    'Aqueous thickness (Position of Lens) X
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    '************************************************************************* Yn[x #DS  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) z=?0)e(H,  
    GetCustomElement eID, entity W<gD6+=8  
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    parID = FindFullName( "Geometry.Arizona Eye" ) x9`ZO<L$  
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    ' Delete any shift(s) in z (4)3W^/kk?  
    count = 0 owMuT^x?  
    While GetOperationCount(eID)>count 8)Tj
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        GetOperation eID, count, op `QCD$=  
        If op.Type="ShiftZ" Then q lY\*{x4  
            DeleteOperation eID,count k`IrZHMw
 
            count=count-1 (/q}mB  
        End If *#ompm  
        count=count+1 CB@B.)E  
    Wend [oHOHp/
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    'Set new shift in O&P>x#w  
    op.Type = "ShiftZ" WRMz]|+}4  
    op.val1 = taq lIy/;hIc  
    op.parent = parID HU3Vv<lz  
    AddOperation eID, op 7dhn'TW  
    Print "Set aqueous humor thickness = " & taq-0.55 L9'-  
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    '************************************************************************* s@M  
    'Radius and conic constant of anterior lens $WD +Q@6  
    '************************************************************************* wR1K8b".DC  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) F0:
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    GetConic eID, entity, curv, conic
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    SetConic eID, entity, 1/Rant, CCant g&aT!%QvX+  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant <\xQ7|e  
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    '************************************************************************* M
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    'Radius and conic constant of posterior lens EreAn  
    '************************************************************************* D;yd{
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) IHfSkFz`j  
    GetConic eID, entity, curv, conic ][N) 2_^M  
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    SetConic eID, entity, 1/Rpost, CCpost a j_:|]j  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost .kzms  
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    '************************************************************************* >|S>J+(  
    'Lens thickness (Position of posterior lens surface) 4}PeP^pj  
    '************************************************************************* (HaU,vP  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) {C, #rj  
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    ' Delete any z-shift(s) @%keTT
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    count = 0 IM2/(N.%  
    While GetOperationCount(eID)>count {)jk_&c7  
        GetOperation eID, count, op $/
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        If op.Type="ShiftZ" Then fzOMX z  
            DeleteOperation eID,count y#GCtkhi  
            count=count-1 f#2#g%x  
        End If !}C4{Bgt*  
        count=count+1 f@#w{W,3  
    Wend 5D>BV*"  
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    'Set new z-shift DD)mN) &T  
    op.Type = "ShiftZ" fLc!Sn.Y  
    op.val1 = tlens paUyS1i  
    op.parent = parID :0|Hcg  
    AddOperation eID, op 3 pHn_R  
    Print "Set lens thickness = " & tlens U0ns3LirP  
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    '************************************************************************* ]r]+yM|  
    'Lens index of refraction [cY?!Qd0  
    '************************************************************************* sd]0Hx[  
    eID = FindMaterial( "Lens" ) re2Fv:4{  
    GetModelMaterial eID, mat /6A:J]Q_  
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    mat.Nd = nlens Rs^jk)Z:)  
    SetModelMaterial eID, mat X~`.}
 
    Print "Set lens index of refraction = " & nlens 1'gKZB)TG7  
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    '************************************************************************* jw2
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    'Pupil diameter 2"B}}  
    '************************************************************************* b"*mi  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) _?*rtDzIM  
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    'Adjust pupil diameter (trimming volume inner hole) 8-W"4)@b  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" A)~/~  
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    ' Adjust pupil location to just in front of the lens cS. 7\0$  
    parID = FindFullName( "Geometry.Arizona Eye" ) v[p/c.p?i  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) -d\AiT  
    count = 0 h0&>GY;i  
    While GetOperationCount(eID)>count &zaW"uy3T  
        GetOperation eID, count, op K*J4&5?/  
        If op.Type="ShiftZ" Then f]{1ZU%4  
            DeleteOperation eID,count cWX"e6  
            count=count-1 Qq@_Z=mt  
        End If `lH1IA/3  
        count=count+1 -PIA;#Gs  
    Wend JMl,
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    op.Type = "ShiftZ" ^\Ue7,H-  
    op.val1 = taq-0.01 QYODmeu  
    op.parent = parID 8ItCfbqa6  
    AddOperation eID, op wC4AVJJ^>  
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    Print "Set pupil diameter = " & pupilDiam "\wDS2M)  
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    'Update AZ Eye subassembly Description ;p?42rCIcl  
    eID = FindFullName( "Geometry.Arizona Eye" ) Xs.$2  
    GetEntity eID, entity )VV4HoH]8  
    entity.Description = "Accommodation = " & A & "D" +8?R+0P  
    SetEntity eID, entity y^0HCp{  
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    Update ~jg
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    Print "DONE!" C.Wms}XA  
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End Sub 9!Q $GE?vl  
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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： }+QhW]nO{F  
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Accommodation = 4 Diopters Ah8^^h|TPJ  
Pupil Diameter = 4 mm ePPp)=
 
Set aqueous humor thickness = 2.81 `CTkx?e[  
Set anterior lens radius = 10.4 and conic constant = -2.375869 |zRoXO`]-*  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 :_
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Set lens thickness = 3.927 E@'CU9Fo  
Set lens index of refraction = 1.42672 5KA FUR0  
Set pupil diameter = 4 P_^|KEz  
DONE! 2:6Y83  
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