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    [分享]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: 2020-12-09
    简介 @$$ J}~{  
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    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。 4Sdj#w  
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    模型 z\K %  
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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。 1L\r:mx3  
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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. t 0p  
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    光源 +x4*T  
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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。 ('d,Sh  
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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。 "EWq{l_I5$  
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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。 jC?l :m?  
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    图2. 字母F光源的设定方法光 U56g|V  
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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 rploQF~OFF  
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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。 +9<:z\B|  
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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。 hW;n^\lF#e  
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    图5. 视网膜重点采样规格设定
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    脚本 F^}d>2W(  
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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: ,&Zk63V  
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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。 ;oVOq$ql  
    余下的脚本计算与屈光度有关的所有参数。 ^R7X!tOq4  
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    分析 sULsUt#  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 <l+hcYam  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 jOK !k  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. y4&x`|tv  
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    Dim entity As T_ENTITY mFd|JbW  
    Dim op As T_OPERATION vP%:\u:{  
    Dim mat As T_MODELMATERIAL ~!%G2E!  
    Dim A As Double plNw>rFa  
    Dim pupilDiam As Double +p]@b  
    Dim eID As Long !rG-[7K  
    Dim parID As Long TA#pA(k  
    Dim count As Integer zMO xJ   
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double *ck'vV'@  
    Dim tlens As Double, nlens As Double [DtMT6F3  
    Dim curv As Double, conic As Double ;9Wimf]G,E  
    Dim ok As Long J10&iCr{r*  
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    Sub Main t0^)Q$  
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        '用户输入对话框 ,wyEo>>4)  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 \vW'\}  
            TextBox 220,21,40,21,.TextBox1 'default: 0 c/(Dg$DbX  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 I}]UQ4XJ  
            OKButton 40,91,90,21 zYftgH_o  
            CancelButton 190,91,90,21 N Zwi3  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :e}j$v F  
            TextBox 220,49,40,21,.TextBox2 'default: 4 f\Q_]%^W  
        End Dialog v~YGef;D  
        Dim dlg As UserDialog [Qqss8a  
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        ok = Dialog (dlg) i&)OJy  
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        If ok=0 Then    'cancel button was pressed 7!6v4ZA  
            Print "Execution cancelled." %F:; A  
            End oS_YQOoD  
        End If =>GGeEL  
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        'Assign accommodation and pupil diameter & use defaults if field left empty ~ D/1U)kt  
        If dlg.TextBox1 = "" Then $bZ5@)E  
            A = 0           'Default accommodation Ve40H6 Ox  
        Else pE.TG4  
            A = CDbl(dlg.TextBox1) xp]9Z]J1l  
        End If ~O3VX75f  
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        If dlg.TextBox2 = "" Then TEC#owz  
            pupilDiam = 4   'Default pupil diameter Rgz zbW  
        Else &uf|Le4  
            pupilDiam = CDbl(dlg.TextBox2) +9# qNkP  
        End If G P ' -  
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        Print " " |HwEwL+  
        Print "Accommodation = " & A & " Diopters" [X@JH6U r  
        Print "Pupil Diameter = " & pupilDiam & " mm" LvL2[xh%&  
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        ' Calculate new parameters with accommodation acj-*I  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness NK%Ok  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens >U]KPL[%  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ^Qxv5HS2  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Y&$puiH-j  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens m RC   
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        tlens = 3.767 + 0.04*A                  'Lens thickness &=wvlI52`  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction I(Vg  
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        'Adjust parameters to account for accommodation p.x2R,CU  
    '7.4!I0'  
        '************************************************************************* KfQR(e9n   
        'Aqueous thickness (Position of Lens) $A T kCO  
        '************************************************************************* h)z2#qfc  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,!P}Y[|  
        GetCustomElement eID, entity b]N&4t  
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        parID = FindFullName( "Geometry.Arizona Eye" ) *lQa^F  
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        ' Delete any shift(s) in z mR8tW"Z2  
        count = 0 @Z<Z//^k  
        While GetOperationCount(eID)>count P4 #j;k4P  
            GetOperation eID, count, op `A8ErfA  
            If op.Type="ShiftZ" Then 1 r3} V7  
                DeleteOperation eID,count D4~]:@v~n  
                count=count-1 4Ujy_E?^  
            End If h]j>S  
            count=count+1 +R;s< pZ^  
        Wend ;ssI8\LG  
    9xFI%UOb#  
        'Set new shift in z A/Fh(uX  
        op.Type = "ShiftZ" xRq A^Ad  
        op.val1 = taq o3h>)4  
        op.parent = parID  #J  
        AddOperation eID, op pv"s!q&  
        Print "Set aqueous humor thickness = " & taq-0.55 Sar1NkD#  
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        '************************************************************************* o1uM(  
        'Radius and conic constant of anterior lens s3 VD6xi7  
        '************************************************************************* @\W-=YKLg  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) {P )O#  
        GetConic eID, entity, curv, conic R'fEw3^  
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        SetConic eID, entity, 1/Rant, CCant Ep3I*bQ Y  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant %N0m$*  
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        '************************************************************************* YWL7.Y>%5  
        'Radius and conic constant of posterior lens flOXV   
        '************************************************************************* ]kF1~kXBe  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @3bVjQ`4f  
        GetConic eID, entity, curv, conic vb}c)w dp?  
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        SetConic eID, entity, 1/Rpost, CCpost %.HLO.A  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost =T1Xfib  
    q4,/RZhzh  
        '************************************************************************* WuTkYiF  
        'Lens thickness (Position of posterior lens surface) 8]rObT9>  
        '************************************************************************* G#A6<e/  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) DhD##5a  
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        ' Delete any z-shift(s) .}:*tvot  
        count = 0 f>3)}9?xc}  
        While GetOperationCount(eID)>count |I{3~+E h  
            GetOperation eID, count, op $9:  @M.  
            If op.Type="ShiftZ" Then D|^N9lDaQ  
                DeleteOperation eID,count >7~,w1t  
                count=count-1 eBY/Y6R  
            End If k"%sdYkb!  
            count=count+1 JVr8O`>T  
        Wend c c/nzB  
    M}q;\}  
        'Set new z-shift L!,@_   
        op.Type = "ShiftZ" b~@+6 ?  
        op.val1 = tlens OXn-!J90P  
        op.parent = parID hTmJ ~m'J  
        AddOperation eID, op Nbv b_  
        Print "Set lens thickness = " & tlens {L [   
    !!w(`kmn1  
        '************************************************************************* k4E9=y?  
        'Lens index of refraction W=OryEV?  
        '************************************************************************* 'f CSP|  
        eID = FindMaterial( "Lens" ) \,r* -jr  
        GetModelMaterial eID, mat sf:IA%.4t  
    *xY3F8  
        mat.Nd = nlens %~,Fe7#p  
        SetModelMaterial eID, mat mIqm/5  
        Print "Set lens index of refraction = " & nlens g:GywX W  
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        '************************************************************************* 5)5yH bS  
        'Pupil diameter <K,X5ctM}  
        '************************************************************************* @u: `  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) w.#z>4#3-  
    k 8%@PC$  
        'Adjust pupil diameter (trimming volume inner hole) _6'@#DN  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" .rnT'""i<5  
    (h g6<`  
        ' Adjust pupil location to just in front of the lens "S*@._   
        parID = FindFullName( "Geometry.Arizona Eye" ) OK YbEn#  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) leI ]zDk=  
        count = 0 DbX7?Jr  
        While GetOperationCount(eID)>count S\Le;,5Z  
            GetOperation eID, count, op He}?\C Bo  
            If op.Type="ShiftZ" Then o=K9\l  
                DeleteOperation eID,count LsaX HI/?b  
                count=count-1 Lo5pn  
            End If c\&;Xr  
            count=count+1 v~jm<{={g  
        Wend Gv}Q/v   
        op.Type = "ShiftZ" }pnp._j  
        op.val1 = taq-0.01 {2q0Ko<  
        op.parent = parID lNtxM"G&  
        AddOperation eID, op 5h0Hk<N  
    /e*fsQ>M:  
        Print "Set pupil diameter = " & pupilDiam kqxq'Aq)d  
    c_?^:xs:d  
        'Update AZ Eye subassembly Description <W)F{N?  
        eID = FindFullName( "Geometry.Arizona Eye" ) 8#- Nx]VM  
        GetEntity eID, entity xXa4t4gR  
        entity.Description = "Accommodation = " & A & "D" ,^Q~w b!{  
        SetEntity eID, entity " a,4E{7  
    !H{>c@i  
        Update O:pg+o&  
        Print "DONE!" DT)] [V^w  
         k;2.g$)W[c  
    End Sub =&qH%S6  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: $xq04ejJ  
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    Accommodation = 4 Diopters .Dl ?a>I  
    Pupil Diameter = 4 mm qu dY9_  
    Set aqueous humor thickness = 2.81 1s(]@gt  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 r<Cr)%z!  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 D6+3f #k6  
    Set lens thickness = 3.927 yNn=r;FZQ  
    Set lens index of refraction = 1.42672 x?0K'  
    Set pupil diameter = 4 R5(([C1  
    DONE! $`ptSR  
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    QQ:2987619807 Il(o[Q>jJ3  
     
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