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    [转载]FRED运用:Arizona眼睛模型 [复制链接]

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    只看楼主 倒序阅读 楼主  发表于: 2016-02-24
    简介 DPU%4te  
    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。 1kiS."77x  
    U_-9rkUa  
    模型 0X`sQNx  
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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。 9^;)~ G  
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    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. vS! TnmF  
    B{#*PAK=  
    光源 '^T Q Ubw  
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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。 }`O_  
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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。 qoNVp7uv  
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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。 ileqI/40f  
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    图2. 字母F光源的设定方法光 ?B)jnBh|  
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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 1;; is  
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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。 =F(fum;zH  
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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。 =~)J:x\F  
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    图5. 视网膜重点采样规格设定
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    脚本 $VWeo#b  
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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: o\_@4hXf  
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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。 aoLYw 9  
    余下的脚本计算与屈光度有关的所有参数。 Jj<UtD+  
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    分析 EcBJ-j 6d  
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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。 t0 [H_  
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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 6x1 !!X+)+  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. -`z`K08sT  
    - P;_j,~U  
    Dim entity As T_ENTITY :Hk:Goo2  
    Dim op As T_OPERATION =j%B`cJ66_  
    Dim mat As T_MODELMATERIAL '$5.{o`s*1  
    Dim A As Double TM|M#hMS  
    Dim pupilDiam As Double 0JQ0lzk1  
    Dim eID As Long VDCG 5QP6(  
    Dim parID As Long %SV5 PO@  
    Dim count As Integer &<!DNXQ  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 2OXcP!\Y  
    Dim tlens As Double, nlens As Double ZI'MfkEZ*  
    Dim curv As Double, conic As Double RUJkfi=$  
    Dim ok As Long Dc,h( 2  
    gW{<:6}!*  
    Sub Main 5r=xhOe`  
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        '用户输入对话框 G_GPnKdd  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 2$>"4 N  
            TextBox 220,21,40,21,.TextBox1 'default: 0 ]0`*gKA  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 _j$"fg  
            OKButton 40,91,90,21 g7($lt>  
            CancelButton 190,91,90,21 AlW0GK=N-p  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 W6. )7Y,  
            TextBox 220,49,40,21,.TextBox2 'default: 4 K[tQ>C@s2  
        End Dialog sFqLxSo_I  
        Dim dlg As UserDialog <qG4[W,[  
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        ok = Dialog (dlg) "O{_LOJ  
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        If ok=0 Then    'cancel button was pressed ?2hS<qXX  
            Print "Execution cancelled." axJuJ`+Y  
            End fj2pD Cic  
        End If {Y>5 [gp  
    a;=)`  
        'Assign accommodation and pupil diameter & use defaults if field left empty "N"$B~W*  
        If dlg.TextBox1 = "" Then "m*.kB)e7  
            A = 0           'Default accommodation {!? @u?M  
        Else @Q!Jzw#B  
            A = CDbl(dlg.TextBox1) XCCh*qym  
        End If K? ;_T$^K  
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        If dlg.TextBox2 = "" Then g"k1O  
            pupilDiam = 4   'Default pupil diameter Vu @2  
        Else _a;E>   
            pupilDiam = CDbl(dlg.TextBox2) 5a$Q}!6E.Y  
        End If K gN=b  
    'r&az BO  
        Print " " \!!qzrq  
        Print "Accommodation = " & A & " Diopters" XJx$HM&0M  
        Print "Pupil Diameter = " & pupilDiam & " mm" .YV{wL@cB  
    xvP=i/SO  
        ' Calculate new parameters with accommodation !Zo we*`  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness m:kXr^!D  
    ~d0:>8zQR  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens !+sC'/  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens G`n|fuv  
    /z<7gd~oU  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens nkI+"$Rz0  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 2nNBX2 o&_  
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        tlens = 3.767 + 0.04*A                  'Lens thickness 9Fo00"q  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction a`c#- je  
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        'Adjust parameters to account for accommodation #@ClhpLD  
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        '************************************************************************* 8Zj=:;  
        'Aqueous thickness (Position of Lens) zD#$]?@ b  
        '************************************************************************* 9+:SS1_  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) eAU0 8gM.  
        GetCustomElement eID, entity bQU{)W  
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        parID = FindFullName( "Geometry.Arizona Eye" ) `IP?w&k)  
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        ' Delete any shift(s) in z xwuGJ   
        count = 0 CbvP1*1  
        While GetOperationCount(eID)>count L/ L#[  
            GetOperation eID, count, op /{)}y  
            If op.Type="ShiftZ" Then !,Ou:E?Bb  
                DeleteOperation eID,count @nC][gNv  
                count=count-1 Cz1Q@<)  
            End If :B^YK].  
            count=count+1 mu#I F'|b  
        Wend z3n273W>6  
    ZmLA4<  
        'Set new shift in :Dt]sE _d  
        op.Type = "ShiftZ" /9SEW!E  
        op.val1 = taq |IcA8[  
        op.parent = parID lEZODc+%Y  
        AddOperation eID, op Zz,j,w0 Z  
        Print "Set aqueous humor thickness = " & taq-0.55 u%t/W0xi  
    (Q]Ww_r~  
        '************************************************************************* dd+hX$,  
        'Radius and conic constant of anterior lens lfJvN  
        '************************************************************************* aru;yR  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) -dto46X  
        GetConic eID, entity, curv, conic xK*G'3Ge  
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        SetConic eID, entity, 1/Rant, CCant e/7rr~"|  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant {6I)6}w!k  
    `4SwdW n  
        '************************************************************************* R|@?6<  
        'Radius and conic constant of posterior lens +g9C klJ  
        '************************************************************************* \CU-a`n  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" )  JT,[;  
        GetConic eID, entity, curv, conic qjm6\ii:)  
    \ u*R6z  
        SetConic eID, entity, 1/Rpost, CCpost MJ\^i4  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost gAudL)X  
    A"3"f8P8a  
        '************************************************************************* ^g'P H{68  
        'Lens thickness (Position of posterior lens surface) YigDrW  
        '************************************************************************* QmKEl|/{u  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9#>t% IF~  
    tLE7s_^  
        ' Delete any z-shift(s) c]/X >8;  
        count = 0 ?wi^R:2|j  
        While GetOperationCount(eID)>count 5y~ Srb?2  
            GetOperation eID, count, op &cpqn2Z  
            If op.Type="ShiftZ" Then @$7'{*  
                DeleteOperation eID,count !'z"V_x~  
                count=count-1 V;LV),R?  
            End If j5:/Gl8  
            count=count+1 9Ro7xSeD  
        Wend \Dx;AKs  
    Z[G[.\0  
        'Set new z-shift A4tb>O M  
        op.Type = "ShiftZ" D[ v2#2  
        op.val1 = tlens Yq-Vwh/  
        op.parent = parID B9: i.rQ  
        AddOperation eID, op 0{'m":D9  
        Print "Set lens thickness = " & tlens 4T>d%Tt+)  
    V r7L9%/wg  
        '************************************************************************* &5y|Q?  
        'Lens index of refraction D~zk2  
        '************************************************************************* +zg3/C4 S  
        eID = FindMaterial( "Lens" ) 0: Nw8J  
        GetModelMaterial eID, mat gSk0#Jt  
    Kgw, ]E&7  
        mat.Nd = nlens %BwvA_T'Q  
        SetModelMaterial eID, mat AsfmH-4)  
        Print "Set lens index of refraction = " & nlens _[pbf ua  
    o_sb+Vn|  
        '************************************************************************* B%I<6E[D  
        'Pupil diameter B'-n ^';  
        '************************************************************************* SUb:0GUa  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) S[e> 8  
    -4v2]  
        'Adjust pupil diameter (trimming volume inner hole) q\G7T{t$.  
    ?&JK q^9\I  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" X?$"dqA  
    Gm[XnUR7V  
        ' Adjust pupil location to just in front of the lens BC)1FxsGf  
        parID = FindFullName( "Geometry.Arizona Eye" ) IP!`;?T=  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]64pb;w"$D  
        count = 0 Xd@ d$  
        While GetOperationCount(eID)>count l@5kw]6  
            GetOperation eID, count, op ckkm}|&m  
            If op.Type="ShiftZ" Then ,R}9n@JI^Y  
                DeleteOperation eID,count 6J<R;g23R]  
                count=count-1 gn:&akg  
            End If U E-1p  
            count=count+1 KjK-#F,@  
        Wend 3~\,VO''  
        op.Type = "ShiftZ" 5i-VnG  
        op.val1 = taq-0.01 (H;,E-  
        op.parent = parID bl-D{)X  
        AddOperation eID, op v(]dIH  
    {ceY:49  
        Print "Set pupil diameter = " & pupilDiam Tq,dlDDOR  
    moCR64n  
        'Update AZ Eye subassembly Description -VvN1G6.x?  
        eID = FindFullName( "Geometry.Arizona Eye" ) =C- b#4Q  
        GetEntity eID, entity fuT Bh6w&  
        entity.Description = "Accommodation = " & A & "D" m#^;V  
        SetEntity eID, entity bh+m_$X~  
    0|| 5 r#  
        Update [ZL<Q  
        Print "DONE!" A3.*d:A  
         <q`|,mc  
    End Sub c#Qlr{ES  
    S])*LUi  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: M9.FtQhK/  
    <m> m"|G  
    Accommodation = 4 Diopters A}[x ))r  
    Pupil Diameter = 4 mm $U"pdf  
    Set aqueous humor thickness = 2.81 8M,$|\U  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 L0qL\>#ejr  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 -Np}<O`./  
    Set lens thickness = 3.927  = Atyy  
    Set lens index of refraction = 1.42672 eMtQa;Lc9o  
    Set pupil diameter = 4 x$z>.4  
    DONE! _adW>-wQ!d  
    |Es,$  
    (文章来源:讯技光电)
     
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