[技术]Arizona眼睛模型 [复制链接]

简介 3,S5>~R=  
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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。 3Akb|r  
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模型 d+[hB4!l2  
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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。 ~Se/uL;*  
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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. ZWh:&e(  
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光源 //_v"dqP{)  
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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。 )I$_wB
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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。 (B7M*e  
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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。 &yp_wW-  
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视网膜的散射 57%:0loW  
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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。 p`T7Y\\#!  
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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。 !!DHfAV]  
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脚本 7z5AI!s_  
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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： E{(7]Wri  
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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>tO\mo  
余下的脚本计算与屈光度有关的所有参数。 n;
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分析 }
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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。 -jFvDf,M,D  
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脚本代码 k`'^e
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. j^Bo0{{  
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Dim entity As T_ENTITY 118A6qyi  
Dim op As T_OPERATION ROW8YTYb  
Dim mat As T_MODELMATERIAL !%_}Rv!JT  
Dim A As Double _@ev(B  
Dim pupilDiam As Double !QSL8v@c  
Dim eID As Long =M*31>"I0  
Dim parID As Long "!+q0l1]@  
Dim count As Integer /!P,o}l7  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double i%:oO KI  
Dim tlens As Double, nlens As Double N0vr>e`  
Dim curv As Double, conic As Double Zb^0EbV  
Dim ok As Long Kj
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Sub Main MOJKz!%  
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    '用户输入对话框 L^Fni~  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ~Yb5FYE  
        TextBox 220,21,40,21,.TextBox1 'default: 0 qa.nm4"6+  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ;S7MP`o@  
        OKButton 40,91,90,21 4`7N}$j#,  
        CancelButton 190,91,90,21 <V5(5gx  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 u$X[=  
        TextBox 220,49,40,21,.TextBox2 'default: 4 +>M^p2l*&  
    End Dialog [?Cv^t${+  
    Dim dlg As UserDialog %7xx"$P:R  
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    ok = Dialog (dlg) AD_")_B|i  
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    If ok=0 Then    'cancel button was pressed N>/!e787OU  
        Print "Execution cancelled." I~-W4
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        End sC(IeGbX
 
    End If K
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    'Assign accommodation and pupil diameter & use defaults if field left empty ; $i{>mDT  
    If dlg.TextBox1 = "" Then qRZv[T%*Q  
        A = 0           'Default accommodation -Wd2FD^x  
    Else .D!0$W mOZ  
        A = CDbl(dlg.TextBox1) nQy.?*X  
    End If sf<S#;aYqn  
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    If dlg.TextBox2 = "" Then J<'[P$D  
        pupilDiam = 4   'Default pupil diameter ]bLI!2Kr  
    Else %JF^@\E!|  
        pupilDiam = CDbl(dlg.TextBox2) 4>-'wMW")  
    End If :PE{2*  
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    Print " " ePv3M&\J  
    Print "Accommodation = " & A & " Diopters" |r>+\" X  
    Print "Pupil Diameter = " & pupilDiam & " mm" _~/F-  
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    ' Calculate new parameters with accommodation *?x$q/a  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Kkcb'a
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens =PYfk6j9  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Y3=5J\d!a  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens |;sL*Vr  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens iO 9.SF0:  
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    tlens = 3.767 + 0.04*A                  'Lens thickness &W+lwEu  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction +O"!*  
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    'Adjust parameters to account for accommodation 'K&^y%~py,  
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    '************************************************************************* !xk`o
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    'Aqueous thickness (Position of Lens) Oy EOb>  
    '************************************************************************* v=5H,4UMA  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7+ +Fak  
    GetCustomElement eID, entity C# zYZ JZ  
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    parID = FindFullName( "Geometry.Arizona Eye" ) &n$kVNE  
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    ' Delete any shift(s) in z Cm@rXA/  
    count = 0 _|+}4 ap  
    While GetOperationCount(eID)>count m';j#j)w  
        GetOperation eID, count, op bpP-wA^Hd  
        If op.Type="ShiftZ" Then I
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            DeleteOperation eID,count -&q@|h'  
            count=count-1 ;>hRj!  
        End If gxnIur)  
        count=count+1 #dA9v7  
    Wend {=K);z  
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    'Set new shift in eJbZA&:  
    op.Type = "ShiftZ" 43wm_4C!H  
    op.val1 = taq gy5^JL  
    op.parent = parID 1.24ZX  
    AddOperation eID, op T*o!#E.  
    Print "Set aqueous humor thickness = " & taq-0.55 ~:FF"T>  
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    '************************************************************************* La>fvm  
    'Radius and conic constant of anterior lens ^_\S)P2c  
    '************************************************************************* TOT#l6yqdd  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) u,RR|/@  
    GetConic eID, entity, curv, conic tJBj9{  
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    SetConic eID, entity, 1/Rant, CCant f \ E9u}  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ='A VI-go5  
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    '************************************************************************* 3d>8~ANi=%  
    'Radius and conic constant of posterior lens wqxChTbs  
    '************************************************************************* [>$?/DM  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 1X5M
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    GetConic eID, entity, curv, conic 3vXa#f>P<  
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    SetConic eID, entity, 1/Rpost, CCpost -7Bg5{FA  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 1.0:  
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    '************************************************************************* &x?m5%^l  
    'Lens thickness (Position of posterior lens surface) :6gRoMb]  
    '************************************************************************* m!5MGq~  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) V15/~  
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    ' Delete any z-shift(s) &|-jU+r}B  
    count = 0 ZH)Jq^^RI  
    While GetOperationCount(eID)>count ~6A;
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        GetOperation eID, count, op FuC#w 9_  
        If op.Type="ShiftZ" Then .oS[ DTn5S  
            DeleteOperation eID,count ?;]Xc~  
            count=count-1 r2%Qk  
        End If FMX^k  
        count=count+1 >,x&L[3  
    Wend l{I.l  
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    'Set new z-shift K 0e*K=UM  
    op.Type = "ShiftZ" 1%$t;R  
    op.val1 = tlens E4$y|Ni"  
    op.parent = parID qTrM*/m:]L  
    AddOperation eID, op 5BJn_<  
    Print "Set lens thickness = " & tlens CKnPMvmz  
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    '************************************************************************* VS\| f'E  
    'Lens index of refraction s !IvUc7'  
    '************************************************************************* :}UjX|D  
    eID = FindMaterial( "Lens" ) wP7 E8'  
    GetModelMaterial eID, mat )[ QT?;  
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    mat.Nd = nlens {[4.<|2
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    SetModelMaterial eID, mat u4tv=+jh  
    Print "Set lens index of refraction = " & nlens 1Ep7CV-n}  
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    '************************************************************************* j#~ S"t  
    'Pupil diameter 2KlVj]!7  
    '************************************************************************* 2:RFPK  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) T[evh]koB  
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    'Adjust pupil diameter (trimming volume inner hole) u9{SG^  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" mBxMDnh  
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    ' Adjust pupil location to just in front of the lens d\R "?Sg  
    parID = FindFullName( "Geometry.Arizona Eye" ) -_xTs(;|8  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) JXV#V7  
    count = 0 Z;z,dw  
    While GetOperationCount(eID)>count :IX,mDO  
        GetOperation eID, count, op l,6' S8=  
        If op.Type="ShiftZ" Then L&KL]n  
            DeleteOperation eID,count (}5};v  
            count=count-1 e(?1`1  
        End If *k,{[b  
        count=count+1 ~W-l|-eogz  
    Wend `z`=!1  
    op.Type = "ShiftZ" K8
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    op.val1 = taq-0.01 'C=(?H)M  
    op.parent = parID ![!,i\x  
    AddOperation eID, op 1LaJ hrp?  
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    Print "Set pupil diameter = " & pupilDiam _%3p&1ld  
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    'Update AZ Eye subassembly Description i%GiWanG  
    eID = FindFullName( "Geometry.Arizona Eye" ) 2%v6h  
    GetEntity eID, entity guVuO  
    entity.Description = "Accommodation = " & A & "D" 1Vkb}A,'  
    SetEntity eID, entity )gz]F_  
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    Update :]4s;q:m  
    Print "DONE!" r:PYAb=g  
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End Sub 2c51kG77E  
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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： )6B
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Accommodation = 4 Diopters qo}yEl1  
Pupil Diameter = 4 mm ~$ Po3]{s  
Set aqueous humor thickness = 2.81 D-D8La?0p  
Set anterior lens radius = 10.4 and conic constant = -2.375869 
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 3s?ZyQy  
Set lens thickness = 3.927 P^ht$)Y  
Set lens index of refraction = 1.42672 uP$i2Cy  
Set pupil diameter = 4 @NiLKcL#  
DONE! 1cx%+-