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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 j=AJs<  
    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。 \7j)^  
    Fo G<$9  
    模型 `X^e}EGWu  
    \34|9#*z-  
    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。 W"-nzdAJ5  
    `p?E{k.N  
    Table 1. AZ眼睛模型的定义
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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. Ys_YjlMIbl  
    ;Z`)*TRp4  
    光源 |wb7`6g  
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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。 wwAT@=X*}  
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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。 2DC#PX)i  
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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。 4B y-+C*  
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    图2. 字母F光源的设定方法光 L,D>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 h^0mjdSp,  
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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。 :9YQX(l8  
    S }n;..{  
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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。 L&N"&\K2U  
    Xp~]kRm9  
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    图5. 视网膜重点采样规格设定
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    脚本 7asq]Y}<  
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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: }m H>lN  
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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
    Vd0GTpB?1  
    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。 4PWr;&  
    余下的脚本计算与屈光度有关的所有参数。 yx2.7h3  
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    分析 Y2X1!Em>B  
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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。 (OqJet2{+  
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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 _o.Z`]  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. %jxuH+L   
    =b7&(x  
    Dim entity As T_ENTITY "AouiZkh  
    Dim op As T_OPERATION M: "ci;*$  
    Dim mat As T_MODELMATERIAL doc  
    Dim A As Double TyWy5J< :+  
    Dim pupilDiam As Double \vsrBM  
    Dim eID As Long C.E> )  
    Dim parID As Long hzLGmWN2j8  
    Dim count As Integer $Jm2,Yv  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double :*@|"4  
    Dim tlens As Double, nlens As Double \=7=>x_  
    Dim curv As Double, conic As Double pYVy(]1I(3  
    Dim ok As Long H040-Q;S'  
    y.:-  
    Sub Main Yd;r8rN  
    ['emP1g~  
        '用户输入对话框 Z]TVH8%|k  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 d5y2Y/QO  
            TextBox 220,21,40,21,.TextBox1 'default: 0  s7 o*|Xv  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 d;SRK @  
            OKButton 40,91,90,21 |V\.[F2Fe  
            CancelButton 190,91,90,21 j dhml%pAd  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ZPsY0IzLo  
            TextBox 220,49,40,21,.TextBox2 'default: 4 !2| `aa  
        End Dialog Sqf.#}u<=  
        Dim dlg As UserDialog iwJ-<v_:h  
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        ok = Dialog (dlg) oRThJB  
    2U'JzE^Do  
        If ok=0 Then    'cancel button was pressed a<'$`z|s  
            Print "Execution cancelled." Zk#i9[g9*  
            End bM^A9BxD  
        End If 8.Ef5-m  
    HoE.//b  
        'Assign accommodation and pupil diameter & use defaults if field left empty jL+}F/~r  
        If dlg.TextBox1 = "" Then #}7m'F  
            A = 0           'Default accommodation DG*o w^  
        Else +N$7=oGC  
            A = CDbl(dlg.TextBox1) = )l:^+q  
        End If 8+a<#? ;  
    wT~;tOw~  
        If dlg.TextBox2 = "" Then |C6(0fgWd  
            pupilDiam = 4   'Default pupil diameter [l%fL9  
        Else ?VZXJO{^  
            pupilDiam = CDbl(dlg.TextBox2) 7]xz8t  
        End If kqigFcz!Y  
    >?W;>EUH  
        Print " " liw 9:@+V  
        Print "Accommodation = " & A & " Diopters" fyq] M_5  
        Print "Pupil Diameter = " & pupilDiam & " mm" 8+|V!q   
    JJ9e{~0 I  
        ' Calculate new parameters with accommodation x";.gjI |g  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness <<On*#80w  
    *!]Epb  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ^ $+f3Z'  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens V@n(v\F  
    @~#79B"9&  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 7cmr *y  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens y~c4:*L3  
    O4d^ig-xaH  
        tlens = 3.767 + 0.04*A                  'Lens thickness 0?Tk* X  
    KT;C RO>  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction aRO_,n9  
    )-?uX.E{  
        'Adjust parameters to account for accommodation %Di 7u- x  
    ?Y6la.bc{  
        '************************************************************************* />^`*e_  
        'Aqueous thickness (Position of Lens) JIbzh?$aD  
        '************************************************************************* &>zy_)  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) qe6C|W~n  
        GetCustomElement eID, entity E0)mI)RW.  
    `k{ff  
        parID = FindFullName( "Geometry.Arizona Eye" ) gc2|V6(  
    ?9zoQ[  
        ' Delete any shift(s) in z jU4)zN/`r  
        count = 0 `YmI'  
        While GetOperationCount(eID)>count |6(qg5"  
            GetOperation eID, count, op (ln  
            If op.Type="ShiftZ" Then ~b$z\|Y  
                DeleteOperation eID,count ~0[G/A$]  
                count=count-1 8A8xY446)  
            End If 1f@U :<:  
            count=count+1 0(U3~ k6  
        Wend $~G0#JL  
    ~Miin   
        'Set new shift in fJn3"D'  
        op.Type = "ShiftZ" $E`i qRB  
        op.val1 = taq 01-\:[{  
        op.parent = parID 76IALJ00V  
        AddOperation eID, op *`g-gk  
        Print "Set aqueous humor thickness = " & taq-0.55 *<.WL"Qhl  
    )kL` &+#>  
        '************************************************************************* iUxDEt[t*  
        'Radius and conic constant of anterior lens =Y]'5cn{  
        '************************************************************************* .sJys SA\  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) =hugnX<9  
        GetConic eID, entity, curv, conic / UaNYv/  
    S4k^&$;  
        SetConic eID, entity, 1/Rant, CCant `Dz]z_  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !4 4mT'Y  
    K.V!@bPlw9  
        '************************************************************************* %7C%`)T]  
        'Radius and conic constant of posterior lens p;n3`aVh  
        '************************************************************************* n&YW".iG  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) <(#xOe  
        GetConic eID, entity, curv, conic qUEd E`B  
    9 N*S-Po=  
        SetConic eID, entity, 1/Rpost, CCpost k}I5x1>&  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost wcdW72   
    *@ <8&M9x  
        '************************************************************************* #!8^!}nFO  
        'Lens thickness (Position of posterior lens surface) z,}c?BP  
        '************************************************************************* x^M5D+o  
    AT%* ~tr  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) M\\e e3Ih  
    h7de9Rt  
        ' Delete any z-shift(s) 8u:v:>D.'  
        count = 0 @pqY9_:P1  
        While GetOperationCount(eID)>count kO..~@ aY  
            GetOperation eID, count, op )tN?: l  
            If op.Type="ShiftZ" Then NRHr6!f>  
                DeleteOperation eID,count ( E"&UC[  
                count=count-1 (<]\,pP0_  
            End If vDK:v$g  
            count=count+1 o;M.Rt\A  
        Wend p@cfY]<7  
    )d770Xg+  
        'Set new z-shift F.~n  
        op.Type = "ShiftZ" 2d5}`>  
        op.val1 = tlens "4Lg8qm  
        op.parent = parID Wz6]*P`qv  
        AddOperation eID, op ;xW8Z<\-  
        Print "Set lens thickness = " & tlens :"OZc7 ~  
    Eu`2w%qz  
        '************************************************************************* c W81  
        'Lens index of refraction J^+_8  
        '************************************************************************* ^f^-.X  
        eID = FindMaterial( "Lens" ) r,`Z.A  
        GetModelMaterial eID, mat $'A4RVVT  
    ,h%D4EVx  
        mat.Nd = nlens 1&X}1  
        SetModelMaterial eID, mat KXoL,)Hl  
        Print "Set lens index of refraction = " & nlens jgo e^f  
    ^3Z7dIUww  
        '************************************************************************* ;=5@h!@R  
        'Pupil diameter ONjC(7  
        '************************************************************************* HpB!a,R6B  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) s jL*I  
    -:)DX++  
        'Adjust pupil diameter (trimming volume inner hole) J- t=1  
    #d }0}7ue  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" CTh1+&Pa  
    ;yk9(wea}"  
        ' Adjust pupil location to just in front of the lens jgk{'_ j  
        parID = FindFullName( "Geometry.Arizona Eye" ) A5CdLwk  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) h|J;6Sm@  
        count = 0 {c v;w  
        While GetOperationCount(eID)>count K(-G: |  
            GetOperation eID, count, op fkdf~Vb  
            If op.Type="ShiftZ" Then :`:xP  
                DeleteOperation eID,count e+NWmu{<_  
                count=count-1 ^-gfib|VGe  
            End If /HB+ami,  
            count=count+1 o\_ Td  
        Wend *0=fT}&!  
        op.Type = "ShiftZ" [MV`pF)x  
        op.val1 = taq-0.01 D3<IuWeM  
        op.parent = parID Ak xH  
        AddOperation eID, op r/UYC"K3  
    ^7i^ \w0  
        Print "Set pupil diameter = " & pupilDiam 8!Wfd)4=,F  
    Iv'RLM  
        'Update AZ Eye subassembly Description pBlRd{#fL  
        eID = FindFullName( "Geometry.Arizona Eye" ) L_tjcfVo  
        GetEntity eID, entity ,]0S4h67  
        entity.Description = "Accommodation = " & A & "D" 4a\n4KO X  
        SetEntity eID, entity U8 Z~Y}29  
    4 hL`=[AB  
        Update gsW=3m&`  
        Print "DONE!" wY' "ab  
         ^{),+S  
    End Sub t{+ M|Y  
    77+| #< J  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: * eA{[  
    IO}+[%ptc*  
    Accommodation = 4 Diopters TcR=GR*cJ  
    Pupil Diameter = 4 mm /m97CC#+  
    Set aqueous humor thickness = 2.81 9OPK4-  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 MinbE13?U  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 WLE%d]'%M  
    Set lens thickness = 3.927 6a7vlo  
    Set lens index of refraction = 1.42672 +#0~:&!9  
    Set pupil diameter = 4 7;^((.]ln  
    DONE! q_-ma_F#s  
    Xwn3+tSIa  
    (文章来源:讯技光电)
     
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