[技术]Arizona眼睛模型 [复制链接]

简介 ANhtz1Fl  
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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。 MgJ6{xzz  
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模型 NfgXOLthM  
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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。 F(G..XJQ  
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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. ?*fa5=ql  
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光源 }T?X6LA$I8  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 mk>; 3m*  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 %6m/ve  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 !m@cTB7i   
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视网膜的散射 jRK}H*uem  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 Q dj(D\.  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 VeA@HC`?"  
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脚本 42Z:J 0  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： :@L7RZ`_  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 tr0b#4  
余下的脚本计算与屈光度有关的所有参数。 !nmZ"n|}p  
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分析 Xb_ V\b0  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 14,)JZN  
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脚本代码 ]iV]7g8:  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. r:QLU]   
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Dim entity As T_ENTITY 1c$pz:$vX  
Dim op As T_OPERATION V.~kG ,Ht  
Dim mat As T_MODELMATERIAL \8{SQ%  
Dim A As Double ?JuJu1  
Dim pupilDiam As Double 1$*8F  
Dim eID As Long Ac_P^  
Dim parID As Long 579Q&|L.  
Dim count As Integer x\yM|WGL  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double > X~\(|EM  
Dim tlens As Double, nlens As Double _}{KS, f]0  
Dim curv As Double, conic As Double ZU\$x<,  
Dim ok As Long WIWo4[(  
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Sub Main !r/i<~'Bx  
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    '用户输入对话框 Y>$5j}K  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 rZI63S  
        TextBox 220,21,40,21,.TextBox1 'default: 0 %`Ce#b()'  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 (B#FLoK  
        OKButton 40,91,90,21 lxn/97rA  
        CancelButton 190,91,90,21 htB2?%S=T  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ]OpGD5jZ  
        TextBox 220,49,40,21,.TextBox2 'default: 4 HNZ$CaJh  
    End Dialog E~y8X9HZ)  
    Dim dlg As UserDialog XDK Me}  
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    ok = Dialog (dlg) IADSWzQ@  
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    If ok=0 Then    'cancel button was pressed ?V`-z#y7  
        Print "Execution cancelled." i4YskhT  
        End ra~=i|s  
    End If uQdeKp4(  
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    'Assign accommodation and pupil diameter & use defaults if field left empty p\zqZ=s  
    If dlg.TextBox1 = "" Then c&;" Y{  
        A = 0           'Default accommodation )CXlPbhY?  
    Else ".jO2GO^  
        A = CDbl(dlg.TextBox1) /KH85/s  
    End If lBP?7`U  
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    If dlg.TextBox2 = "" Then p5]W2i.,  
        pupilDiam = 4   'Default pupil diameter dV$[O`F*b  
    Else *)[fGxz \  
        pupilDiam = CDbl(dlg.TextBox2) 3]S*p ErY  
    End If EWJB/iED  
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    Print " " +[}y` -t  
    Print "Accommodation = " & A & " Diopters" GW {tZaB  
    Print "Pupil Diameter = " & pupilDiam & " mm" cc${[yj
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    ' Calculate new parameters with accommodation ]Zb9F[  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness u?>},M/  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens z,;XWv?  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 'e:4  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens aPJTH0u  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Xau%v5r  
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    tlens = 3.767 + 0.04*A                  'Lens thickness D[^K0<-Z  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction )d[n-Si  
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    'Adjust parameters to account for accommodation /yU#UZ4;  
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    '************************************************************************* $`OyGeq"T  
    'Aqueous thickness (Position of Lens) e# Y{YtE  
    '************************************************************************* 7 \xCNOKh  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z6B$\Q5Od  
    GetCustomElement eID, entity [( xPX  
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    parID = FindFullName( "Geometry.Arizona Eye" ) pI f6RwH}%  
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    ' Delete any shift(s) in z >~d'i
 
    count = 0 !ak760*A  
    While GetOperationCount(eID)>count 7 @\i5  
        GetOperation eID, count, op / 8O=3  
        If op.Type="ShiftZ" Then 8XVRRk  
            DeleteOperation eID,count NvzPZ9=@-  
            count=count-1 5XT^K)'  
        End If 7j|CWurvq  
        count=count+1 2KO`+
  
    Wend x7B;\D#`i/  
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    'Set new shift in ['>ZC3?"h  
    op.Type = "ShiftZ" ^coCsV^CW"  
    op.val1 = taq NJJ=c
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    op.parent = parID zw'%n+5m  
    AddOperation eID, op = y^5PjN  
    Print "Set aqueous humor thickness = " & taq-0.55 3LyNi$`f  
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    '************************************************************************* XFTqt]
 
    'Radius and conic constant of anterior lens DhxS@/  
    '************************************************************************* RKzO$T  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) z}}P+P/  
    GetConic eID, entity, curv, conic {KDN|o+%  
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    SetConic eID, entity, 1/Rant, CCant /7#MJH5b6  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 6RI
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    '************************************************************************* z3[J sE%  
    'Radius and conic constant of posterior lens 7Wv.-LD6  
    '************************************************************************* ?!m\|'s-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) %J'/cmR&  
    GetConic eID, entity, curv, conic qu#xc0?  
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    SetConic eID, entity, 1/Rpost, CCpost =x?WZMO  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost .[eC w  
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    '************************************************************************* bGB$a0  
    'Lens thickness (Position of posterior lens surface) @=z.^I30  
    '************************************************************************* h+Lpj^<2a  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7L:Eg  
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    ' Delete any z-shift(s) 5'DY)s-K  
    count = 0 Uufig)6  
    While GetOperationCount(eID)>count 2\&3x}@  
        GetOperation eID, count, op 0N)DHD?U  
        If op.Type="ShiftZ" Then vaQsG6q[  
            DeleteOperation eID,count 3 ;"[WOv  
            count=count-1 izcjI.3e,  
        End If mc`Z;D/mt  
        count=count+1 ;`xCfOY(  
    Wend =!DX,S7  
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    'Set new z-shift #?\(l%  
    op.Type = "ShiftZ" ml|FdQ  
    op.val1 = tlens t@R n#(~"  
    op.parent = parID Q3hSWXq'  
    AddOperation eID, op fp(zd;BSQ  
    Print "Set lens thickness = " & tlens 2::YR?  
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    '************************************************************************* K@:omT  
    'Lens index of refraction gREk,4DAv  
    '************************************************************************* YH+(N  
    eID = FindMaterial( "Lens" ) H}_R`S  
    GetModelMaterial eID, mat cGm?F,/`  
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    mat.Nd = nlens 569p/?  
    SetModelMaterial eID, mat sMVk]Mb  
    Print "Set lens index of refraction = " & nlens x'?p?u~[  
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    '************************************************************************* UpD4'!<buV  
    'Pupil diameter S8kzAT  
    '************************************************************************* H)S!%(x4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) {A< 961  
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    'Adjust pupil diameter (trimming volume inner hole) 7vRp<  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 7f k)a  
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    ' Adjust pupil location to just in front of the lens \}4*}Lr  
    parID = FindFullName( "Geometry.Arizona Eye" ) XUVj<U  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) KX;JX*)J  
    count = 0 2[(~_VJ  
    While GetOperationCount(eID)>count IUEpE9_  
        GetOperation eID, count, op zjow %  
        If op.Type="ShiftZ" Then x'\C'zeF  
            DeleteOperation eID,count du~V=%9  
            count=count-1 S[7^#O.)  
        End If ig YYkt  
        count=count+1 NZZy^p&O  
    Wend |,=^P`#%  
    op.Type = "ShiftZ" : qK-Rku  
    op.val1 = taq-0.01 |/xx**?  
    op.parent = parID N2HD=[*cr  
    AddOperation eID, op iFI+W<QR  
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    Print "Set pupil diameter = " & pupilDiam &L+.5i  
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    'Update AZ Eye subassembly Description KIv_ AMr  
    eID = FindFullName( "Geometry.Arizona Eye" ) (y6}xOa(  
    GetEntity eID, entity sCt)Yp+8}B  
    entity.Description = "Accommodation = " & A & "D" /W*Z.  
    SetEntity eID, entity ORF:~5[YS`  
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    Update OE0G*`m  
    Print "DONE!" :] U\{;q2  
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End Sub +'5I8FE-  
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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： vK+reXE  
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Accommodation = 4 Diopters Bf#cBI  
Pupil Diameter = 4 mm >w7KOVbN3  
Set aqueous humor thickness = 2.81 ZQf
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Set anterior lens radius = 10.4 and conic constant = -2.375869 eBxm  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 l"}_+5  
Set lens thickness = 3.927 T_D] rMl  
Set lens index of refraction = 1.42672 _ {wP:dI "  
Set pupil diameter = 4 |BZrV3;H  
DONE! N%Ta.`r