[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 $dP)8_Z2  
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。 gQuw|u  
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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。 UTQKlwPa  
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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. Xa@wN/"F  
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光源 /[? F1Q  
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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。 NVeRn  
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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。 5}xni  
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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。 ^\&g
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视网膜的散射 qb4;l\SfT  
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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。 k|3(dXLG  
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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。 ocqB-C
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脚本 dB+GT
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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： c^Jgr(Ow  
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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。 C9U{^  
余下的脚本计算与屈光度有关的所有参数。 rz}l<t~H  
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分析 D}/=\J/  
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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。 Q 95
 
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脚本代码 ~}
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 6IY}SI0N  
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Dim entity As T_ENTITY zrU$SWU  
Dim op As T_OPERATION Bdq"6SK>  
Dim mat As T_MODELMATERIAL ]Ec[")"kT  
Dim A As Double StZRc\k  
Dim pupilDiam As Double j]B$(pt  
Dim eID As Long >?9 WeXG  
Dim parID As Long e#6&uFce  
Dim count As Integer o`K^Wy~+k#  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double UW/3{2  
Dim tlens As Double, nlens As Double R;E"Qdt  
Dim curv As Double, conic As Double Gr#rM/AfCK  
Dim ok As Long jqGo-C~  
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Sub Main JNFT6T)T15  
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    '用户输入对话框 CoUd16*"JM  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 wEfz2Eq  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ]EM)_:tRf  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 H@2v<e@  
        OKButton 40,91,90,21 %V%#y $l  
        CancelButton 190,91,90,21 r$r&4dY  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 bN4&\d*u#  
        TextBox 220,49,40,21,.TextBox2 'default: 4 B!r48<p  
    End Dialog 0"kE^=  
    Dim dlg As UserDialog loC5o|Wh  
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    ok = Dialog (dlg) ^KZAYB9C  
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    If ok=0 Then    'cancel button was pressed <Sprp]n 7  
        Print "Execution cancelled." F/h:&B:;  
        End n.a=K2H:V  
    End If => uVp  
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    'Assign accommodation and pupil diameter & use defaults if field left empty [^U;  
    If dlg.TextBox1 = "" Then _ 7BF+*T  
        A = 0           'Default accommodation X&9^&U=e  
    Else FU5LYXCs  
        A = CDbl(dlg.TextBox1) ?K4.L?D#J  
    End If ?79SPp)oo  
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    If dlg.TextBox2 = "" Then 17i<4f#  
        pupilDiam = 4   'Default pupil diameter EFRZ% Y  
    Else #0?"J)  
        pupilDiam = CDbl(dlg.TextBox2) d(X\B{  
    End If #Z|%0r_~  
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    Print " " y/X:=d6"  
    Print "Accommodation = " & A & " Diopters" #}/cM2m  
    Print "Pupil Diameter = " & pupilDiam & " mm" Q$?7)yyu+  
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    ' Calculate new parameters with accommodation -[zdX}x.:  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Ms:KM{T0  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 0NCOz(L/  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens L876$  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens U^[cYT
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 1A%N0#_(Md  
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    tlens = 3.767 + 0.04*A                  'Lens thickness |&elZ}8  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction
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    'Adjust parameters to account for accommodation i
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    '************************************************************************* 3}>:  
    'Aqueous thickness (Position of Lens) 6[+\CS7Lt  
    '************************************************************************* bU;}!iVc]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) lfxuc7Rdla  
    GetCustomElement eID, entity ( oQ'4,
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    parID = FindFullName( "Geometry.Arizona Eye" ) MB
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    ' Delete any shift(s) in z aUypt(dv  
    count = 0 tJUVw=  
    While GetOperationCount(eID)>count =@
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        GetOperation eID, count, op 9GMH*=3[=  
        If op.Type="ShiftZ" Then %^a]J"Ydi8  
            DeleteOperation eID,count DC?21[60  
            count=count-1 iEiu%T>  
        End If h]kn%?fpmB  
        count=count+1 42b.7E  
    Wend "bD+/\ z  
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    'Set new shift in RDUT3H6~  
    op.Type = "ShiftZ" E|HSwTHe  
    op.val1 = taq 5~@?>)TBv  
    op.parent = parID o2
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    AddOperation eID, op p//T7rs  
    Print "Set aqueous humor thickness = " & taq-0.55 lo cW_/  
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    '************************************************************************* ~gu=x&{  
    'Radius and conic constant of anterior lens u|(Ux~O  
    '************************************************************************* J+{Ou rWt  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ]YCPyc:  
    GetConic eID, entity, curv, conic $T"h";M)s  
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    SetConic eID, entity, 1/Rant, CCant r0)JUc}Fyq  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 6yE'/VB<  
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    '************************************************************************* f"vk# 3  
    'Radius and conic constant of posterior lens rpUy$qrRc  
    '************************************************************************* 6D/uo$1Y  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) <KKDu$W|T  
    GetConic eID, entity, curv, conic L<bYRGz  
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    SetConic eID, entity, 1/Rpost, CCpost JT4wb]kdV  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost HwB {8S?sm  
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    '************************************************************************* r)gCTV(kb  
    'Lens thickness (Position of posterior lens surface) <v]z6B@9!  
    '************************************************************************* +C'XS{K,#  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) (jMtN?&0H-  
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    ' Delete any z-shift(s) dw~[9oh  
    count = 0 ypH8QfxLTr  
    While GetOperationCount(eID)>count (VR"Mi4  
        GetOperation eID, count, op ERF,tLa!  
        If op.Type="ShiftZ" Then q^5yk=2fq  
            DeleteOperation eID,count 0Y7$d`  
            count=count-1 kB8 Mi
 
        End If @!e~G'j%VD  
        count=count+1 os[ZIHph  
    Wend d]8_l1O  
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    'Set new z-shift q%>7L<r  
    op.Type = "ShiftZ" ba8 6 N  
    op.val1 = tlens ZT6V/MD7T.  
    op.parent = parID J7:9_/e0T  
    AddOperation eID, op W]_g4,T>  
    Print "Set lens thickness = " & tlens [q1Unm  
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    '************************************************************************* 80|onP
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    'Lens index of refraction flP>@i:e6  
    '************************************************************************* IhE9snJ[  
    eID = FindMaterial( "Lens" ) fuMN"T 6%+  
    GetModelMaterial eID, mat b4C
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    mat.Nd = nlens kae2 73"  
    SetModelMaterial eID, mat _wz2  
    Print "Set lens index of refraction = " & nlens _%{0?|=  
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    '************************************************************************* }S*/b1  
    'Pupil diameter X]!D;7^  
    '************************************************************************* W .U+.hR  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) }z wX  
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    'Adjust pupil diameter (trimming volume inner hole) m2(E>raV6  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ox[ .)v  
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    ' Adjust pupil location to just in front of the lens y@3Q;~l,  
    parID = FindFullName( "Geometry.Arizona Eye" ) n3$gx,KL  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) \,R!S/R#  
    count = 0 [/cIUQ  
    While GetOperationCount(eID)>count [(ygisqt  
        GetOperation eID, count, op s)ky/ce  
        If op.Type="ShiftZ" Then H@D;e  
            DeleteOperation eID,count h=6xZuA\  
            count=count-1 > H BJk:  
        End If \lEkfcc  
        count=count+1 ,hWcytzEw  
    Wend r+S;B[Vd  
    op.Type = "ShiftZ" 9Kbw GmSU  
    op.val1 = taq-0.01 w{`Acu  
    op.parent = parID a8Uk[^5  
    AddOperation eID, op z]=8eV\  
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    Print "Set pupil diameter = " & pupilDiam _R^y\1Qu  

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    'Update AZ Eye subassembly Description 6{=_718l`  
    eID = FindFullName( "Geometry.Arizona Eye" ) P
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    GetEntity eID, entity .'j29 6[u  
    entity.Description = "Accommodation = " & A & "D" #!})3_Qc(y  
    SetEntity eID, entity JoJukoy}F  
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    Update k!3 cq)  
    Print "DONE!" VRbQdiZ{  
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End Sub &RO7{,`  
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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： o=_c2m   
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Accommodation = 4 Diopters !E0!-UpY  
Pupil Diameter = 4 mm ,lm=M5b  
Set aqueous humor thickness = 2.81 H)>sTST(  
Set anterior lens radius = 10.4 and conic constant = -2.375869 `/4:I  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 S^N{wZo  
Set lens thickness = 3.927 m Ni2b*k  
Set lens index of refraction = 1.42672 $a(`ve|  
Set pupil diameter = 4 8lP6-VA  
DONE! Td hTQ  
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