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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 m.pB]yq&  
    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。 ('xIFi  
    J:Ea|tXK^  
    模型 >8D!K0?E  
    R2vT\ 6xv  
    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。 BaZ$pO^  
    M(KsLu1   
    Table 1. AZ眼睛模型的定义
    #(F/P!qk  
    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. @X+m,u  
    ]W~\%`#8?  
    光源 0_q8t!<xJw  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 p:Ry F4{b2  
    &a5UQ>  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 a$r- U_?  
    83K)j"!<X  
    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。 `ltc)$  
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    图2. 字母F光源的设定方法光 WvR-0>E  
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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 G d~ v _  
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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。 @&?E3?5ll  
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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。 6D|[3rXr  
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    图5. 视网膜重点采样规格设定
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    脚本 uP, iGA  
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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: R d'P\  
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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。 -!;2?6R9{  
    余下的脚本计算与屈光度有关的所有参数。 WoM;)Q  
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    分析 _D~l2M  
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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。 @<kY,ox@~  
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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 "uCO?hv0  
    ' ` _TFTO  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. GWFF.Mo^  
    `_aX>fw  
    Dim entity As T_ENTITY Drm#z05i[g  
    Dim op As T_OPERATION /2^"c+/'p  
    Dim mat As T_MODELMATERIAL !LI6_Oq  
    Dim A As Double JLd-{}A""-  
    Dim pupilDiam As Double "5<:Dj/W  
    Dim eID As Long @$}Ct  
    Dim parID As Long m)AF9#aT2  
    Dim count As Integer n*A?>NV  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 0JFS%Yjw[  
    Dim tlens As Double, nlens As Double riR(CJ}Ff  
    Dim curv As Double, conic As Double +YZ*>ki  
    Dim ok As Long E{;F4wT_@  
    [|".j#ZlK  
    Sub Main Fn>KdoByN  
    }1fi#  
        '用户输入对话框 nTsKJX%\  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 '9{`Czc(Gb  
            TextBox 220,21,40,21,.TextBox1 'default: 0 +3uPHpMB-  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 R [ZY;g:p  
            OKButton 40,91,90,21 m)7Ql!l  
            CancelButton 190,91,90,21 Az7 ] qb  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 cwuzi;f  
            TextBox 220,49,40,21,.TextBox2 'default: 4 6am g*=]  
        End Dialog ZnKjU ]m  
        Dim dlg As UserDialog U$yy7}g  
    8 Y4mTW  
        ok = Dialog (dlg) R + ~b@  
    M"Dv -#f  
        If ok=0 Then    'cancel button was pressed LBxmozT  
            Print "Execution cancelled." ?(Se$iTZ  
            End Ii9[[I  
        End If \sMe2OL#z  
    H )51J:4  
        'Assign accommodation and pupil diameter & use defaults if field left empty 44NM of8N  
        If dlg.TextBox1 = "" Then HQvJ*U4++  
            A = 0           'Default accommodation GO?hB4 9T  
        Else xi51,y+(5  
            A = CDbl(dlg.TextBox1) 3 ,zW6 -}  
        End If 0iYo&q'n  
    lZAXDxhnT  
        If dlg.TextBox2 = "" Then NSa6\.W)  
            pupilDiam = 4   'Default pupil diameter 5?MaKNm}  
        Else ]_BH"ng}  
            pupilDiam = CDbl(dlg.TextBox2) ZDG~tCh=@  
        End If yk y% +@2q  
    e2e!"kEF  
        Print " " G9^xv  
        Print "Accommodation = " & A & " Diopters" IRGcE&m  
        Print "Pupil Diameter = " & pupilDiam & " mm" :8K}e]!c1  
    y8_$YA/g  
        ' Calculate new parameters with accommodation t"zi'9$t  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness {d XTj7  
    AsD$M*It  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 5(gWK{R)*  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens M8V c5  
    lE gjv,  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens k".kbwcaF  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens <UF0Xc&X'  
    (3Q$)0t  
        tlens = 3.767 + 0.04*A                  'Lens thickness nY7gST  
    QChncIqc  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Esu {c9,  
    ta6>St7.  
        'Adjust parameters to account for accommodation jST4O"DjM  
    eT Fep^[  
        '************************************************************************* /ej[oR  
        'Aqueous thickness (Position of Lens) j+fib} 8}  
        '************************************************************************* W]oa7VAq  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^2H;  
        GetCustomElement eID, entity |h }4J  
    ZNne 8  
        parID = FindFullName( "Geometry.Arizona Eye" ) n$`+03a  
    8v z h5,U  
        ' Delete any shift(s) in z `m#-J;la  
        count = 0 %ufh  
        While GetOperationCount(eID)>count !zvjgDlZv  
            GetOperation eID, count, op 8\"Gs z  
            If op.Type="ShiftZ" Then Fgi`g{N  
                DeleteOperation eID,count ,jEc4ih4  
                count=count-1 L2+cVR  
            End If =\_gT=tZ  
            count=count+1 Q-<Qm?  
        Wend <}:` Y"  
    "w$,`M?2  
        'Set new shift in e pp04~  
        op.Type = "ShiftZ" ~+j2a3rv-{  
        op.val1 = taq zz[fkH3  
        op.parent = parID >s 6ye  
        AddOperation eID, op &e6UEG  
        Print "Set aqueous humor thickness = " & taq-0.55 UOsK(mB  
    ,#FP]$FK  
        '************************************************************************* [zBi*%5O  
        'Radius and conic constant of anterior lens 5@%.wb4  
        '************************************************************************* $'I&u  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 9@ YKx0  
        GetConic eID, entity, curv, conic ff5 gE'  
    ^~I@]5Pq  
        SetConic eID, entity, 1/Rant, CCant 8 eK8-R$  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 5L:-Xr{  
    CvmIDRP*  
        '************************************************************************* Gc"hU:m  
        'Radius and conic constant of posterior lens WB?HY?[r  
        '************************************************************************* %0}^M1  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) }04mJY[  
        GetConic eID, entity, curv, conic w6Nn x5Ay  
    R2n 2mQ<  
        SetConic eID, entity, 1/Rpost, CCpost qx b]UV,R  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost G~o!u8^;  
    2?GMKd)  
        '************************************************************************* #H w(w  
        'Lens thickness (Position of posterior lens surface) C6[W/,eS  
        '************************************************************************* ) PTvw>  
    7dcR@v`c  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) #kASy 2t  
    6IG?t  
        ' Delete any z-shift(s) 6_4 B!  
        count = 0 Fu_I0z  
        While GetOperationCount(eID)>count ,#UZp\zZ*  
            GetOperation eID, count, op RzjUrt  
            If op.Type="ShiftZ" Then ?T2>juf]5~  
                DeleteOperation eID,count E#!!tH`lgg  
                count=count-1 5\MC5us3  
            End If UPU$SZAIx  
            count=count+1 z,G_&5|f%  
        Wend kFwFPK%B  
    ey=KAt  
        'Set new z-shift H:]cBk^[,  
        op.Type = "ShiftZ" P2a5<#_|  
        op.val1 = tlens [K.1 X=O}  
        op.parent = parID >4jE[$p]"  
        AddOperation eID, op Bj1%}B  
        Print "Set lens thickness = " & tlens LXK!4(xaW  
    /j$=?Rp  
        '************************************************************************* WA8<:#{e  
        'Lens index of refraction /7 Tm2Vj8  
        '************************************************************************* IgG[Pr'D  
        eID = FindMaterial( "Lens" ) v^b4WS+.:  
        GetModelMaterial eID, mat :R,M Y"(  
    iCF},W+  
        mat.Nd = nlens 7Hr_ZwO/^  
        SetModelMaterial eID, mat u1$6:"2@5k  
        Print "Set lens index of refraction = " & nlens QM F   
    GYx0U8MJ[e  
        '************************************************************************* +T$Olz  
        'Pupil diameter _ \6v@  
        '************************************************************************* n?.;*:  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) );h(D!D,  
    @|SeabN^-  
        'Adjust pupil diameter (trimming volume inner hole) l,7& z  
    b<00 %Z  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 5, 1<A@H  
    FAEF  
        ' Adjust pupil location to just in front of the lens  f\<r1  
        parID = FindFullName( "Geometry.Arizona Eye" ) (QiA5!wg  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) e~SK*vR%]  
        count = 0 !k)6r6  
        While GetOperationCount(eID)>count +:.Jl:fx4  
            GetOperation eID, count, op aDK b78 1d  
            If op.Type="ShiftZ" Then 8|i'~BFHs  
                DeleteOperation eID,count $V(]z`b&  
                count=count-1 I_ mus<sE  
            End If JcR|{9ghT  
            count=count+1 jW\:+Taq  
        Wend ~\_VWXXvIW  
        op.Type = "ShiftZ" ;o!p9MEpz;  
        op.val1 = taq-0.01 1.cP3k l  
        op.parent = parID 'RMUjJ-!  
        AddOperation eID, op 'q-q4 QCB  
    -I|xW  
        Print "Set pupil diameter = " & pupilDiam N&NBn(  
    *8Z2zmZtR^  
        'Update AZ Eye subassembly Description [CI&4) #  
        eID = FindFullName( "Geometry.Arizona Eye" ) @'R)$:I%L  
        GetEntity eID, entity .>B'oD  
        entity.Description = "Accommodation = " & A & "D" h=7q;-@7  
        SetEntity eID, entity 'Rn-SD~gIr  
    <?nIO  
        Update VI2lw E3  
        Print "DONE!" /I`TN5~  
         $N=&D_Q  
    End Sub E 5&Z={  
    DXiA4ihr=  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: 6{y7e L3!  
    Cs6`lX >  
    Accommodation = 4 Diopters %#x4wi  
    Pupil Diameter = 4 mm gJ6`Kl985O  
    Set aqueous humor thickness = 2.81 pLB2! +  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 h<G4tjtk  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 q-JTGCFl  
    Set lens thickness = 3.927 n%&L&G  
    Set lens index of refraction = 1.42672 _!03;zrO  
    Set pupil diameter = 4 Sa= tiOv  
    DONE! +~^S'6yB  
    :,l7e  
    (文章来源:讯技光电)
     
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