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    [转载]FRED运用:Arizona眼睛模型 [复制链接]

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    离线xunjigd
     
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    只看楼主 倒序阅读 楼主  发表于: 2016-02-24
    简介 iHBetkAu  
    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。 _3~/Z{z8  
    e ?sMOBPlv  
    模型 K2|2Ks_CS  
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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。 1cq"H/N  
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    Table 1. AZ眼睛模型的定义
    w`KqB(36  
    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. 3b{ 7Z 2  
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    光源 ,Pi!%an w  
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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。 &rs   
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    图1. 光源和提示信息使用
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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。 O2{~Q{p  
    (w[#h9j  
    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。 03p D<  
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    图2. 字母F光源的设定方法光 R5Pk>-KF  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 +}VaQ8ti4  
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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。 JkShtLEr  
    %cO^:  
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    图4. 视网膜朗伯散射设定
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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。 ^/~ZP?%]  
    \+)aYP2Hu  
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    图5. 视网膜重点采样规格设定
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    脚本 @>fsg-|  
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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: I1 pnF61U  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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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。 jj&mRF0gCb  
    余下的脚本计算与屈光度有关的所有参数。 %*zV&H   
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    分析 J@o_-\@  
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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。 a<0q%A x  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 (%c&Km7K  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 3$?nzKTW\  
    ;Fo7 -kK  
    Dim entity As T_ENTITY 4.Q[Tu  
    Dim op As T_OPERATION 2TG2<wqvE  
    Dim mat As T_MODELMATERIAL Q<NQ9lX  
    Dim A As Double 2D(sA  
    Dim pupilDiam As Double \2!.  
    Dim eID As Long rK3KxG  
    Dim parID As Long  &.(iS  
    Dim count As Integer ^q_wtuQ  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double $EHF f$M  
    Dim tlens As Double, nlens As Double k.7!)jL7  
    Dim curv As Double, conic As Double ,RDWx  
    Dim ok As Long :f:&B8  
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    Sub Main kL8 E#  
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        '用户输入对话框 fN@ZJ~F%j  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 %y\5L#T!>  
            TextBox 220,21,40,21,.TextBox1 'default: 0 Tay$::V  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 !vSq?!y6*P  
            OKButton 40,91,90,21 </Y(4Xwf=  
            CancelButton 190,91,90,21 dGj0;3FI%  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 N p*T[J  
            TextBox 220,49,40,21,.TextBox2 'default: 4 7x77s  
        End Dialog oOc-1C y  
        Dim dlg As UserDialog S(U9Dlyarg  
    J+Fev.9>  
        ok = Dialog (dlg) u  Fw1%  
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        If ok=0 Then    'cancel button was pressed `#w#!@s#@  
            Print "Execution cancelled." qou\4YZ  
            End r7].48D  
        End If {chZ&8)f  
    oH&@F@r:+  
        'Assign accommodation and pupil diameter & use defaults if field left empty -9 .lFuI  
        If dlg.TextBox1 = "" Then [3qH? 2&  
            A = 0           'Default accommodation w&T\8k=  
        Else fVgN8b|&'  
            A = CDbl(dlg.TextBox1) 4X*U~}  
        End If _&\'Va$  
    XkkzY5rxOc  
        If dlg.TextBox2 = "" Then %o4v} mzV  
            pupilDiam = 4   'Default pupil diameter - AgD  
        Else lw gwdB  
            pupilDiam = CDbl(dlg.TextBox2) &*'^uCna  
        End If GDC@s<[k  
    t_xK?``  
        Print " " &4KUXn[F  
        Print "Accommodation = " & A & " Diopters" 5@r6'Z  
        Print "Pupil Diameter = " & pupilDiam & " mm" %*!6R:gAp  
    kppi>!6  
        ' Calculate new parameters with accommodation mjg@c|rTG  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 7gV9m9#  
    2Sa{=x N)  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ~GX ]K H  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 0Fon`3(^\  
    VpY D/Oj4;  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens sRZ<c  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens p&V64L:V  
    j!!s>7IZ  
        tlens = 3.767 + 0.04*A                  'Lens thickness l3ogMRq@  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction  QtG6v<A  
    J^7M0A4K  
        'Adjust parameters to account for accommodation $V`1<>4  
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        '************************************************************************* 'Ca;gi !U  
        'Aqueous thickness (Position of Lens) \+sa[jK  
        '************************************************************************* XC~"T6F  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) KWjhkRK4]  
        GetCustomElement eID, entity ^yc8is'`  
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        parID = FindFullName( "Geometry.Arizona Eye" ) !',%kvJI  
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        ' Delete any shift(s) in z D6?h 6`J  
        count = 0 Q <D_QJ  
        While GetOperationCount(eID)>count gt.F[q3  
            GetOperation eID, count, op tF-l=ph}`  
            If op.Type="ShiftZ" Then f1'X<VA  
                DeleteOperation eID,count Yl'8" \HF  
                count=count-1 |:#Ug  
            End If KFO K%vbM  
            count=count+1 +2eri_p  
        Wend #prYZcHv:_  
    x`C"Z7t  
        'Set new shift in /Ta-3Eh!  
        op.Type = "ShiftZ" r_Ou\|jU  
        op.val1 = taq u1UCe  
        op.parent = parID `p* 43nV  
        AddOperation eID, op (2Lmu[  
        Print "Set aqueous humor thickness = " & taq-0.55 2BF455e   
    3J 5,V  
        '************************************************************************* g)$KN,gGuO  
        'Radius and conic constant of anterior lens | Z7 j s"  
        '************************************************************************* V0 Z8VqV  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) <+ [N*  
        GetConic eID, entity, curv, conic (gVN<Es  
    )hQ]>o@i{  
        SetConic eID, entity, 1/Rant, CCant d*6/1vyjT  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant _e>N3fT  
    @uV]7d"z(  
        '************************************************************************* [tt{wl"E  
        'Radius and conic constant of posterior lens DHeZi3&i  
        '************************************************************************* 3`{ vx  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Gukvd6-g9b  
        GetConic eID, entity, curv, conic Hu6Qr  
    XMZ$AeF@  
        SetConic eID, entity, 1/Rpost, CCpost pnp8`\cIH  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost jwLZC  
    Ev3'EA~`  
        '************************************************************************* svxjad@l/  
        'Lens thickness (Position of posterior lens surface) z<fd!g+^  
        '************************************************************************* I;wxgWOP  
    (b[=~Nh'  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) E.Th}+  
    p8-$MF]] 6  
        ' Delete any z-shift(s) `5Z'8^  
        count = 0 *3={s"a.(  
        While GetOperationCount(eID)>count EJ<L,QH3  
            GetOperation eID, count, op "m6G;cv  
            If op.Type="ShiftZ" Then wVI_SQ<8V  
                DeleteOperation eID,count F{Yr8(UHA  
                count=count-1 <Dgf'Gr J  
            End If ZQ`4'|"  
            count=count+1 z(.,BB[  
        Wend : 4-pnn  
     HRbv%  
        'Set new z-shift toD!RE  
        op.Type = "ShiftZ" ~}ifwm'7 a  
        op.val1 = tlens PcZ<JJ16F$  
        op.parent = parID {%k[Z9*tO  
        AddOperation eID, op \/SOpC  
        Print "Set lens thickness = " & tlens Yuf+d-%  
    }Ptv[{q]GE  
        '************************************************************************* $>_`.*I/  
        'Lens index of refraction _ Dz*%  
        '************************************************************************* CXz9bhn<4  
        eID = FindMaterial( "Lens" ) seAEv0YWz  
        GetModelMaterial eID, mat ) d'H&c3  
    FxK!h.C.  
        mat.Nd = nlens />:$"+gKo  
        SetModelMaterial eID, mat 4 )}>dxv  
        Print "Set lens index of refraction = " & nlens Z]2z*XD  
    $K\e Pfk  
        '************************************************************************* G[>CBh5  
        'Pupil diameter L$!2<eK  
        '************************************************************************* Jc5Y Gj7  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) =2rdbq6R  
    !U2<\!_  
        'Adjust pupil diameter (trimming volume inner hole) e~># M $  
    >Q"3dw  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" _^RN$4.R>  
    Uh1UZ r  
        ' Adjust pupil location to just in front of the lens x@O )QaBN!  
        parID = FindFullName( "Geometry.Arizona Eye" ) !~7lY]_U  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) #7:ah  
        count = 0 z$g__q-  
        While GetOperationCount(eID)>count k+i0@G'C(  
            GetOperation eID, count, op A4d3hF~l`  
            If op.Type="ShiftZ" Then Dh#5-Kf%  
                DeleteOperation eID,count ei1;@k/  
                count=count-1 4~oRcO8!Y  
            End If %Rr_fSoV  
            count=count+1 TL$w~dY  
        Wend Y Fj#{C.  
        op.Type = "ShiftZ" N(J#<;!yb  
        op.val1 = taq-0.01 [;-;{ *{G  
        op.parent = parID  '@.Lg0`  
        AddOperation eID, op I`g&>  
    i~<.@&vt  
        Print "Set pupil diameter = " & pupilDiam Abmi=]\bx  
    ^aJ]|*m  
        'Update AZ Eye subassembly Description -<T> paE9  
        eID = FindFullName( "Geometry.Arizona Eye" ) #\xy,C'Y  
        GetEntity eID, entity %g>k0~TRf#  
        entity.Description = "Accommodation = " & A & "D" |KPNl\%ID  
        SetEntity eID, entity #-"C_~-MH  
    l;aO"_E1m  
        Update aDLlL?r3  
        Print "DONE!" ,PKUgL}w  
         i"DyXIrk2  
    End Sub 6y?uH; SL  
    D^];6\=.i  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: E2.!|u2  
    H#nJWe_9A  
    Accommodation = 4 Diopters &g*1If  
    Pupil Diameter = 4 mm mB bGj3u;  
    Set aqueous humor thickness = 2.81 J=O_nup6C  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 G$/Qcr6W<  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 mmNn,>AO!  
    Set lens thickness = 3.927 I>-1kFma;  
    Set lens index of refraction = 1.42672 Pum&\.l  
    Set pupil diameter = 4 Ts=TaRwWf  
    DONE! fp3`O9+em  
    pOl6x iMx  
    (文章来源:讯技光电)
     
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