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    [分享]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2020-12-09
    简介 yfU<UQ!1  
    P;PQeXKw  
    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。 &D%(~|'  
    E,n}HiAz7V  
    模型 K/ &?VIi`z  
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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。 B*htN  
    :|o<SZ  
    Table 1. AZ眼睛模型的定义
    s] /tYJYl  
    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. c:83LZ  
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    光源 W)(^m},*8D  
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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。 6 \B0^  
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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。 6.t',LTB  
    >hY" 3  
    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。 .k TG[)F0b  
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    图2. 字母F光源的设定方法光 -st7_3  
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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 tU"raP^ =  
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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。 (I@bkMp  
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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 QU"Ved  
    4Ij-Ilg)%  
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    图5. 视网膜重点采样规格设定
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    脚本 W:i?t8y\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: *zO&N^X.4  
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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。 _DRrznaw  
    余下的脚本计算与屈光度有关的所有参数。 \Mv":Lm1  
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    分析 c41: !u^  
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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。 -#-p1^v}  
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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 57F%j3.|/  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 9Qj2W  
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    Dim entity As T_ENTITY ryO$6L  
    Dim op As T_OPERATION "S~_[/q  
    Dim mat As T_MODELMATERIAL HEK-L)S. *  
    Dim A As Double Ct$82J  
    Dim pupilDiam As Double dsK&U\ej}  
    Dim eID As Long Ju@Q6J5  
    Dim parID As Long "Clz'J]{  
    Dim count As Integer 'NZGQeb K  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double m}VM+=  
    Dim tlens As Double, nlens As Double N#N0Q0W=  
    Dim curv As Double, conic As Double WUAJjds  
    Dim ok As Long j-]&'-h}#  
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    Sub Main IL7`0cN(  
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        '用户输入对话框 3l!NG=R  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 D-9\~gvh  
            TextBox 220,21,40,21,.TextBox1 'default: 0 `=tyN@VC  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 oFg5aey4  
            OKButton 40,91,90,21 :lcea6iO  
            CancelButton 190,91,90,21 ^Cz YDq  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1  ]^"k8v/  
            TextBox 220,49,40,21,.TextBox2 'default: 4 uK*Nu^  
        End Dialog eR']#Q46{T  
        Dim dlg As UserDialog "YFls#4H-  
    )"@t6.  
        ok = Dialog (dlg) .uZ7 -l  
    }{7e7tW6  
        If ok=0 Then    'cancel button was pressed _X5_ez^/=  
            Print "Execution cancelled." @b!"joEy  
            End HgJb4Fi  
        End If !7H6i#g*  
    O^{1RV3:,T  
        'Assign accommodation and pupil diameter & use defaults if field left empty L3y5a?G  
        If dlg.TextBox1 = "" Then r$)$n&j  
            A = 0           'Default accommodation upn8n vy4(  
        Else x49!{}  
            A = CDbl(dlg.TextBox1) o|S)C<w  
        End If aP~gaSx  
    mAqD jRV1  
        If dlg.TextBox2 = "" Then _[Gb)/@mM  
            pupilDiam = 4   'Default pupil diameter (4~WWU (iT  
        Else hsce:TB  
            pupilDiam = CDbl(dlg.TextBox2) /dHs &SU,  
        End If Iur9I>8h  
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        Print " " Wz=OSH7"f  
        Print "Accommodation = " & A & " Diopters" %j]ST D.E  
        Print "Pupil Diameter = " & pupilDiam & " mm" N} />rD  
    "mj^+u-  
        ' Calculate new parameters with accommodation QrjDF>   
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness OS7R Qw1  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ?_4^le[;  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 3_ 2hC!u!K  
    )y50Mb0+  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens &W_th\%  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens /J%do]PDl  
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        tlens = 3.767 + 0.04*A                  'Lens thickness 744=3v  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction k'13f,o}  
    aPIr_7e  
        'Adjust parameters to account for accommodation HFh /$VM  
    ")\aJ8  
        '************************************************************************* L=A\ J^%  
        'Aqueous thickness (Position of Lens) tjzA)/T,4  
        '************************************************************************* ~@M7&%]  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) VyZV (k  
        GetCustomElement eID, entity `"<2)yq?  
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        parID = FindFullName( "Geometry.Arizona Eye" ) b :\D\X  
    }""p)Y&  
        ' Delete any shift(s) in z 8]*Q79  
        count = 0 iz x[  
        While GetOperationCount(eID)>count c>MY$-PD  
            GetOperation eID, count, op )mD \d|7f  
            If op.Type="ShiftZ" Then JLUms  
                DeleteOperation eID,count {g=b]yg\o  
                count=count-1 3"i% {  
            End If v5Y@O|i#  
            count=count+1 H1UL.g%d=  
        Wend "Gh#`T0#a  
    Y^eX@dE FR  
        'Set new shift in EVz9WY  
        op.Type = "ShiftZ" Y?!/>q  
        op.val1 = taq [b`$\o'-  
        op.parent = parID u8uW9 <  
        AddOperation eID, op ZrcPgcF  
        Print "Set aqueous humor thickness = " & taq-0.55 N{pa) /  
    m!!;/e?yx  
        '************************************************************************* >\\5"S f  
        'Radius and conic constant of anterior lens m.1 46  
        '************************************************************************* i+U51t<  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) (4ZLpsbJ  
        GetConic eID, entity, curv, conic eiB(VOJ  
    m+$/DD^-zl  
        SetConic eID, entity, 1/Rant, CCant RK3.-  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 3;D?|E]1  
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        '************************************************************************* c% yh(g  
        'Radius and conic constant of posterior lens .HOY q  
        '************************************************************************* ScHlfk p  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) It\BbG=  
        GetConic eID, entity, curv, conic TQ~&Y)".  
    T g\hx>  
        SetConic eID, entity, 1/Rpost, CCpost Ys+N,:#R  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 3:O+GQ*  
    x 8M#t(hw  
        '************************************************************************* P=pY8X:  
        'Lens thickness (Position of posterior lens surface) ]-rczl|o  
        '************************************************************************* {jUvKB_x  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) G4);/#  
    g1dmkX  
        ' Delete any z-shift(s) xOgq-@`  
        count = 0 o@@_J@}#  
        While GetOperationCount(eID)>count ?:JdRnH\  
            GetOperation eID, count, op XWf7"]%SX  
            If op.Type="ShiftZ" Then ZU^Q1}</5  
                DeleteOperation eID,count !xJFr6G~8  
                count=count-1 [BE:+ ID3  
            End If ndB@J*Imu  
            count=count+1 Lqq*Nr  
        Wend c}8 -/P=  
    {'&8`d  
        'Set new z-shift \|Y{jG<cu  
        op.Type = "ShiftZ" mR6E]TuM  
        op.val1 = tlens y,1S& k  
        op.parent = parID 8}J(c=4Gk  
        AddOperation eID, op Ta,u-!/ I  
        Print "Set lens thickness = " & tlens ~|qXtds$  
    =X<)5IS3  
        '************************************************************************* k~ZBJ+ 94  
        'Lens index of refraction I(y`)$}  
        '************************************************************************* [I_BCf  
        eID = FindMaterial( "Lens" ) 6J]~A0vsi}  
        GetModelMaterial eID, mat 0rGj|@+;  
     ,&4zKm  
        mat.Nd = nlens ul}4p{ m[  
        SetModelMaterial eID, mat QM7[O]@  
        Print "Set lens index of refraction = " & nlens fg< ( bXC  
    kS[Dy$AB/2  
        '************************************************************************* s%hU*^ 8  
        'Pupil diameter J~fuW?a]r  
        '************************************************************************* +0SW ?#%  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) i<0D Z_rub  
    ho(5r5SNE  
        'Adjust pupil diameter (trimming volume inner hole) ?@yank|  
    ,WzG.3^m  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ,q/tyGj  
    _ Eszr(zJ  
        ' Adjust pupil location to just in front of the lens vRq=m8  
        parID = FindFullName( "Geometry.Arizona Eye" ) .59KE]u  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ,,zd.9n  
        count = 0 / O|Td'Z  
        While GetOperationCount(eID)>count <e$5~Spc  
            GetOperation eID, count, op !XkymIX~O.  
            If op.Type="ShiftZ" Then \=$EmHF  
                DeleteOperation eID,count {/th`#o4b  
                count=count-1 t00\yb^vJ8  
            End If +.XZK3  
            count=count+1 cA2^5'$$  
        Wend m j'"Z75  
        op.Type = "ShiftZ" +"TI_tK, S  
        op.val1 = taq-0.01 qr7 X-[&  
        op.parent = parID z (c@(UD-_  
        AddOperation eID, op EY,;e\7O,  
    (rau8  
        Print "Set pupil diameter = " & pupilDiam 8Pl+yiB/o`  
    jdV .{8@  
        'Update AZ Eye subassembly Description *1 n;p)K  
        eID = FindFullName( "Geometry.Arizona Eye" ) $,xtif0  
        GetEntity eID, entity /8 e2dw: \  
        entity.Description = "Accommodation = " & A & "D" Kx(76_XD  
        SetEntity eID, entity V=G b>_d  
    fho=<|-  
        Update V[BY/<z)A  
        Print "DONE!" 7yc9`j}]  
         hr )+Pk  
    End Sub z }FiU[Hs  
    CwTS/G  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: qAS70XjOF  
    6R$ F =MB  
    Accommodation = 4 Diopters .E?bH V  
    Pupil Diameter = 4 mm ~%cSckE  
    Set aqueous humor thickness = 2.81 z v L>(R  
    Set anterior lens radius = 10.4 and conic constant = -2.375869  =F",D=  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 l044c,AW(  
    Set lens thickness = 3.927 0A #9C09  
    Set lens index of refraction = 1.42672 z 'vdC  
    Set pupil diameter = 4 Ba"^K d`  
    DONE! `'A(`. CL  
    7eaA]y~H  
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    QQ:2987619807 kxr6sO~  
     
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