[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 ) 'xyK  
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。 _-vlN  
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模型 WuE]pm]c  
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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。 r#WqXh_uk  
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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&+k`b
  
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光源 K_+M?ap_  
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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。 A@~9r9Uf  
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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。 gIweL{Pc  
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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。 v3[ZPc;;  
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视网膜的散射 Lwtp,.)pR  
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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。 QX?moW6UW  
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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。 E}zGY2Xx  
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脚本 :V6t5I'_  
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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： hw`pi6  
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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。 s,mt%^
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余下的脚本计算与屈光度有关的所有参数。 m1K4_a)^[  
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分析 B$OV^iwxK  
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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。 =Y
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脚本代码 #l*w=D?  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. +~==qLsU  
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Dim entity As T_ENTITY ;S&anC#E  
Dim op As T_OPERATION 39pA:3iTd  
Dim mat As T_MODELMATERIAL ym` 4v5w  
Dim A As Double ~XXNzz]?  
Dim pupilDiam As Double j5smmtM`s  
Dim eID As Long |NTqJ j  
Dim parID As Long +'w6=qI  
Dim count As Integer D)[(  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double $EdL^Q2KAy  
Dim tlens As Double, nlens As Double Lv)1 )'v0  
Dim curv As Double, conic As Double 6!Mm")  
Dim ok As Long J9J/3O Q=  
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Sub Main & \C1QkI  
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    '用户输入对话框 SC3_S.  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 L{XW2c$h  
        TextBox 220,21,40,21,.TextBox1 'default: 0 y M-k]_  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 =L?2[a$2;  
        OKButton 40,91,90,21 nYBa+>3BDf  
        CancelButton 190,91,90,21 hdmKD0  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 CZ{7?:^f  
        TextBox 220,49,40,21,.TextBox2 'default: 4 gC_KT,=H;  
    End Dialog nuA 0%K  
    Dim dlg As UserDialog bFH`wLW  
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    ok = Dialog (dlg) _S-@|9\&#  
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    If ok=0 Then    'cancel button was pressed _lm^v%J$  
        Print "Execution cancelled." Krl9O]H/[  
        End 5;HCNwX  
    End If bUYjmb2g)  
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    'Assign accommodation and pupil diameter & use defaults if field left empty uaky
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    If dlg.TextBox1 = "" Then S a
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        A = 0           'Default accommodation ?|\wJrM ]  
    Else |WOc0M[U  
        A = CDbl(dlg.TextBox1) GY^;$?  
    End If M9Nr/jE  
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    If dlg.TextBox2 = "" Then !?+q7U  
        pupilDiam = 4   'Default pupil diameter K%Bz6 ~  
    Else ,@Kn@%?$  
        pupilDiam = CDbl(dlg.TextBox2) :)&vf<JL  
    End If VYt<j<ba  
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    Print " " GJs~aRiz  
    Print "Accommodation = " & A & " Diopters" J(wFJg\/  
    Print "Pupil Diameter = " & pupilDiam & " mm" @7V~CNB+  
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    ' Calculate new parameters with accommodation A r>BL2@  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Wcm8,?*  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ;-;lM6zP  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens TY'61xWi  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 4"\cA:
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ItZYOt|Hn  
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    tlens = 3.767 + 0.04*A                  'Lens thickness lBAu@M  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction sf# px|~9  
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    'Adjust parameters to account for accommodation $CX3P)% `  
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    '************************************************************************* XoL DqN!  
    'Aqueous thickness (Position of Lens) oD1k7Gq1  
    '************************************************************************* X{OWDy  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) -B&(
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    GetCustomElement eID, entity />/e  
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    parID = FindFullName( "Geometry.Arizona Eye" ) j%^4 1y  
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    ' Delete any shift(s) in z -)VjjKz]8  
    count = 0 pt,L  
    While GetOperationCount(eID)>count nPqpat`E  
        GetOperation eID, count, op x
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        If op.Type="ShiftZ" Then |?8nO.C~V  
            DeleteOperation eID,count g$?^bu dxv  
            count=count-1 tqCkqmyC  
        End If 6=;(~k&x9:  
        count=count+1 ^879sI  
    Wend ZH9Fs'c=  
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    'Set new shift in jy?*`q1]  
    op.Type = "ShiftZ" =CZRX' +yN  
    op.val1 = taq dIlpo0; F  
    op.parent = parID r]Wt!oHm5  
    AddOperation eID, op |D"L!+J-$  
    Print "Set aqueous humor thickness = " & taq-0.55 G[yzi  
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    '************************************************************************* Zr2!}jD9a  
    'Radius and conic constant of anterior lens 1BZ##xV*:G  
    '************************************************************************* s(3HZ>qx;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) fs&$?mHL){  
    GetConic eID, entity, curv, conic QOS
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    SetConic eID, entity, 1/Rant, CCant 7Y(Dg`8G  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant $["HC-n?.k  
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    '************************************************************************* *qy \%A  
    'Radius and conic constant of posterior lens KGg S"d  
    '************************************************************************* C9sU^]#F  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) _#:7S sJ  
    GetConic eID, entity, curv, conic 4^l9d  
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    SetConic eID, entity, 1/Rpost, CCpost wGKxT ap  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost t~/:St  
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    '************************************************************************* vf{$2rC  
    'Lens thickness (Position of posterior lens surface) t:fz%IOe  
    '************************************************************************* Cd 2<r6i  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) uH%b rbrU  
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    ' Delete any z-shift(s) IONo&~-l  
    count = 0 (4/"uj5  
    While GetOperationCount(eID)>count zdrP56rzZ  
        GetOperation eID, count, op B=& [Z2  
        If op.Type="ShiftZ" Then _uMG?Sbx  
            DeleteOperation eID,count *m+FMyr  
            count=count-1 ISs&1`Y  
        End If l_Lz9k  
        count=count+1 B#%QY\<X  
    Wend }_zN%Tf
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    'Set new z-shift 9d#?,:JG  
    op.Type = "ShiftZ" &'W7-Z\j-  
    op.val1 = tlens |7c],SHm  
    op.parent = parID zP #:Tv'  
    AddOperation eID, op K?'m#}]  
    Print "Set lens thickness = " & tlens `+n#CWZ"Y  
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    '************************************************************************* E0
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    'Lens index of refraction *eIX"&ba  
    '************************************************************************* xB Wl|j  
    eID = FindMaterial( "Lens" ) #C&';HB;y  
    GetModelMaterial eID, mat Q^2dZXk~  
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    mat.Nd = nlens [S,$E6&j$"  
    SetModelMaterial eID, mat :a;F3N
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    Print "Set lens index of refraction = " & nlens +a.2\Qt2A  
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    '************************************************************************* yO%^[c?  
    'Pupil diameter u'l4=e  
    '************************************************************************* Az:~|P  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) %eDSo9Y  
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    'Adjust pupil diameter (trimming volume inner hole) 'fU#v`i  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" QvZ"{  
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    ' Adjust pupil location to just in front of the lens wz`% (\  
    parID = FindFullName( "Geometry.Arizona Eye" ) 3oLF^^^g  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) #Pg`0xiV  
    count = 0 l}L81t7f  
    While GetOperationCount(eID)>count ,M3hE/rb/  
        GetOperation eID, count, op (dSYb&]  
        If op.Type="ShiftZ" Then tJ;q
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            DeleteOperation eID,count >B0AJW/u  
            count=count-1 }[JB%  
        End If hO8xH +;  
        count=count+1 yk?bz  
    Wend ,@f"WrQ  
    op.Type = "ShiftZ" Y`j$7!j  
    op.val1 = taq-0.01 H^n@9U;[K
 
    op.parent = parID h^=;
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    AddOperation eID, op .S54:vs  
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    Print "Set pupil diameter = " & pupilDiam 0(-4"u>?  
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    'Update AZ Eye subassembly Description xS1n,gTA  
    eID = FindFullName( "Geometry.Arizona Eye" ) &B(z**+9  
    GetEntity eID, entity JGHj(0j  
    entity.Description = "Accommodation = " & A & "D" x>EL|Q=?  
    SetEntity eID, entity -8qCCV&1i  
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    Update 7zw0g~+  
    Print "DONE!" LhLAQ2~  
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End Sub DW7E ]
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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： T)I)r239h  
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Accommodation = 4 Diopters A3/[9}(U  
Pupil Diameter = 4 mm \09A"fs{  
Set aqueous humor thickness = 2.81 {4 Yxh8  
Set anterior lens radius = 10.4 and conic constant = -2.375869 LMoZI0)x  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 0}<blU  
Set lens thickness = 3.927 (o|bst][S  
Set lens index of refraction = 1.42672 [M[#f&=Z  
Set pupil diameter = 4 V_~lM
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DONE! nu\AEFT  
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