[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 !#~KSO}zW2  
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。 5*+DN U@  
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模型 v9FR  
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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)6G:cD  
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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. :5$ErI  
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光源 `"PHhCG+z  
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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,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。 6rj iZ%  
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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。 Q)BSngW+  
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视网膜的散射 p`rjWpH  
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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。 $]xH"Z%"  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 y9]7LETv\M  
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脚本 \m}a%/  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： =OtW!vx#R.  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 p/Q< VV  
余下的脚本计算与屈光度有关的所有参数。 -T1R}ew*t  
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分析 "%+||IyW  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 "~EAt$  
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脚本代码 \Gk}Fer  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. "Dk@-Ac  
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Dim entity As T_ENTITY 1|-C(UW>  
Dim op As T_OPERATION frm[<-~w0  
Dim mat As T_MODELMATERIAL bZgo}`o%  
Dim A As Double lul  
Dim pupilDiam As Double ^`dMjeF  
Dim eID As Long .pe.K3G&  
Dim parID As Long m(:R(K(je  
Dim count As Integer eYoc(bG(+  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ZVJ6 {DS/  
Dim tlens As Double, nlens As Double CdCY#$Z  
Dim curv As Double, conic As Double (zy|>u  
Dim ok As Long g#l!b%$  
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Sub Main }j1;0kb?  

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    '用户输入对话框 .Wp(@l'Hd  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 }*%=C!m4R!  
        TextBox 220,21,40,21,.TextBox1 'default: 0 C"`\[F`.k  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ^t<L  
        OKButton 40,91,90,21 ;,TT!vea  
        CancelButton 190,91,90,21 FMn|cO.vEP  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 E=S_1  
        TextBox 220,49,40,21,.TextBox2 'default: 4 [:e>FXV  
    End Dialog Ekrpg^3qp"  
    Dim dlg As UserDialog ]v@ng8  
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    ok = Dialog (dlg) 7KRNTnd  
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    If ok=0 Then    'cancel button was pressed L
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        Print "Execution cancelled." hHcevSr  
        End _}']h^@Z  
    End If d/3&3>/  
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    'Assign accommodation and pupil diameter & use defaults if field left empty _f "I%QTL  
    If dlg.TextBox1 = "" Then v[x 5@$  
        A = 0           'Default accommodation n31nORx50  
    Else F{7 BY~d  
        A = CDbl(dlg.TextBox1) hhylsm  
    End If Ebi~gGo  
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    If dlg.TextBox2 = "" Then P??pWzb6HH  
        pupilDiam = 4   'Default pupil diameter <>-gQ9  
    Else j9RpYz  
        pupilDiam = CDbl(dlg.TextBox2) F3Vvqt*2  
    End If 6~s{HI!  
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    Print " " \B/( H)Cd*  
    Print "Accommodation = " & A & " Diopters" EOqV5$+  
    Print "Pupil Diameter = " & pupilDiam & " mm" _Bn8i(  
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    ' Calculate new parameters with accommodation *x2u  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness \4
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens FEa%wS{  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens lu1T+@t  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens {=R vFA  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens X/Fip0i  
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    tlens = 3.767 + 0.04*A                  'Lens thickness u<j.XPK  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction F>@z&a}(  
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    'Adjust parameters to account for accommodation dwzk+@]8  
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    '************************************************************************* <sGioMr  
    'Aqueous thickness (Position of Lens) &j{IG`Trl  
    '************************************************************************* )@.ODW;`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) wYHyVY2tj2  
    GetCustomElement eID, entity tE=$#  
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    parID = FindFullName( "Geometry.Arizona Eye" ) \nVoBW(  
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    ' Delete any shift(s) in z <("P5@cExU  
    count = 0 ,?GAFgK:  
    While GetOperationCount(eID)>count _8z  
        GetOperation eID, count, op hJJo+NNN  
        If op.Type="ShiftZ" Then ux7g%Q^"  
            DeleteOperation eID,count KiNluGNt  
            count=count-1 kRzqgVr%  
        End If xoE,3Sn  
        count=count+1 +n8,=}  
    Wend LA837%)  
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    'Set new shift in E|B1h!!\c  
    op.Type = "ShiftZ" @eDL j}  
    op.val1 = taq 8ax3"G  
    op.parent = parID :OY7y`hRG  
    AddOperation eID, op Z:MU5(Te  
    Print "Set aqueous humor thickness = " & taq-0.55 K9'AYFse  
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    '************************************************************************* vnz}Pr! c  
    'Radius and conic constant of anterior lens v[?eL0Z  
    '************************************************************************* B;L^!sL
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Aa%ks+1  
    GetConic eID, entity, curv, conic =G<S!qW  
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    SetConic eID, entity, 1/Rant, CCant s0'Xihsw6  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant \6Hu&WHy  
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    '************************************************************************* gB#$"mq,  
    'Radius and conic constant of posterior lens zd[cp@  
    '************************************************************************* TWQ{, B  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) V6 ,59
  
    GetConic eID, entity, curv, conic r|7hm:F)  
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    SetConic eID, entity, 1/Rpost, CCpost iW<B1'dp  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Wv)2dD2I
 
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    '************************************************************************* !Lj+&D|z  
    'Lens thickness (Position of posterior lens surface) 6~Xe$fP(  
    '************************************************************************* X?.LA7)CK  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) dCMWv~>  
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    ' Delete any z-shift(s) *YY:JLe  
    count = 0 [mk!]r  
    While GetOperationCount(eID)>count }vdhk0  
        GetOperation eID, count, op ;-65~i0Iu  
        If op.Type="ShiftZ" Then %S4pkFR  
            DeleteOperation eID,count %7rWebd-  
            count=count-1 b$
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        End If ^?tF'l`
 
        count=count+1 +hS}msu'  
    Wend E>?T<!r~j  
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    'Set new z-shift enT.9|vm/  
    op.Type = "ShiftZ" P/FO,S-V  
    op.val1 = tlens jW+L0RkX  
    op.parent = parID L$FLQyDR  
    AddOperation eID, op cB7=4:U  
    Print "Set lens thickness = " & tlens Iih~rWJ  
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    '*************************************************************************  0$l D  
    'Lens index of refraction E8Wgm 8  
    '************************************************************************* s&$Zgf6Z  
    eID = FindMaterial( "Lens" ) %k3a34P@  
    GetModelMaterial eID, mat PV%7m7=x  
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    mat.Nd = nlens &sQtS  
    SetModelMaterial eID, mat e&u HU8k*  
    Print "Set lens index of refraction = " & nlens Y&5h_3K;<  
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    '************************************************************************* l$Y7CIH  
    'Pupil diameter `7|v  
    '************************************************************************* KyAQzN9  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ZUMzWK5Th  
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    'Adjust pupil diameter (trimming volume inner hole) w]\O3'0Js  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" TlZ|E '_C  
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    ' Adjust pupil location to just in front of the lens T;}pMRd%  
    parID = FindFullName( "Geometry.Arizona Eye" ) E7axINca  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) F/}PN1#T  
    count = 0 DP*[t8  
    While GetOperationCount(eID)>count W$P)fPU'  
        GetOperation eID, count, op nK6{_Y>  
        If op.Type="ShiftZ" Then j4Cad  
            DeleteOperation eID,count $3%EKi  
            count=count-1 -q\1Tlc]3  
        End If !UlG!820  
        count=count+1 e?G] fz  
    Wend hM(|d@)  
    op.Type = "ShiftZ"
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    op.val1 = taq-0.01 z/N~HSh!d  
    op.parent = parID ueYZM<],  
    AddOperation eID, op Xi1/wbC  
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    Print "Set pupil diameter = " & pupilDiam nYMdYt04sl  
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    'Update AZ Eye subassembly Description l>S~)FNwXJ  
    eID = FindFullName( "Geometry.Arizona Eye" ) >e"CpbZ'  
    GetEntity eID, entity -2mm 5E~N  
    entity.Description = "Accommodation = " & A & "D" X%S?o  
    SetEntity eID, entity i}+K;,Da:8  
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    Update <`a!%_LC [  
    Print "DONE!" grnlJ=  
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End Sub Z@ *^4Ve  
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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： {KE858  
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Accommodation = 4 Diopters e&E""ye  
Pupil Diameter = 4 mm U*=ebZno  
Set aqueous humor thickness = 2.81 W :jC2,s!m  
Set anterior lens radius = 10.4 and conic constant = -2.375869 -D0kp~AO4N  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 a}+|2k_  
Set lens thickness = 3.927 F%t`dz!L  
Set lens index of refraction = 1.42672 _CBG?  
Set pupil diameter = 4 *)ZDN~z7o  
DONE! R-"A*/A 2  
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