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    [技术]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: 2021-10-22
    简介 ">o/\sXeH  
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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。 \yqiv"'  
    #SdaTMLFf  
    模型 IO+z:D{  
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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。 JjwuxZVr O  
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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. 1li`+~L F  
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    光源 TcC=_je460  
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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。 rk~/^(!  
    Xk3Ufz]QN  
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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。 \bg^E>-  
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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。 )sQbDA|p  
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    图2. 字母F光源的设定方法光 #wo_  
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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 5Ql6?U HD  
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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。 L/ZZe5I  
    k4@GjO1"$  
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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。 lyV]-w  
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    图5. 视网膜重点采样规格设定
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    脚本 2vwT8/  
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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: 8dpVB#]pp,  
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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。 AkF1Hj  
    余下的脚本计算与屈光度有关的所有参数。 D&'".N,}  
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    分析 bUBuJ  
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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。 H1w;Wb1se  
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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 >?kt3.IQ!X  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. T4UY%E!0  
    h$k(|/+  
    Dim entity As T_ENTITY ]*@7o^4i  
    Dim op As T_OPERATION c" l~=1Dr  
    Dim mat As T_MODELMATERIAL u&<LW4  
    Dim A As Double Wc)^@f[~<  
    Dim pupilDiam As Double d ] [E;$  
    Dim eID As Long K)k!`du!6  
    Dim parID As Long [)a,rrhj  
    Dim count As Integer CN >q`[!  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double uIR_p \)  
    Dim tlens As Double, nlens As Double 3w-0v"j U  
    Dim curv As Double, conic As Double $UH_)Q2#J^  
    Dim ok As Long 55AG>j&41  
    ^yX W.s  
    Sub Main =#W{&Te;  
    6"wY;E  
        '用户输入对话框 Ug9o/I@}C  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 > 1r>cZn  
            TextBox 220,21,40,21,.TextBox1 'default: 0 %=| I;kI?  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 j/W#=\xz  
            OKButton 40,91,90,21 Z?b. PC/  
            CancelButton 190,91,90,21 v\<`"  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 bi_R.sfK&  
            TextBox 220,49,40,21,.TextBox2 'default: 4 _[<I&^%  
        End Dialog ?GFVV->i  
        Dim dlg As UserDialog gcz1*3)  
    s^AYPmR6  
        ok = Dialog (dlg) ZpwB"%e$  
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        If ok=0 Then    'cancel button was pressed @P8q=j}l9  
            Print "Execution cancelled." 8g$ 8]'M^T  
            End ?=\h/C  
        End If 4(Mt6{q  
    Z8:iaP)  
        'Assign accommodation and pupil diameter & use defaults if field left empty IX3r$}4  
        If dlg.TextBox1 = "" Then gDA hl  
            A = 0           'Default accommodation osnDW aN  
        Else h;B'#$_  
            A = CDbl(dlg.TextBox1) Q8P;AN_JS  
        End If 'al-C;Z  
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        If dlg.TextBox2 = "" Then dCc*<S  
            pupilDiam = 4   'Default pupil diameter Hj5b.fB  
        Else D6 M:pIN*  
            pupilDiam = CDbl(dlg.TextBox2) 6I>W(_T  
        End If <=0_[M  
    %7{6>6%  
        Print " " ){6;o& CC:  
        Print "Accommodation = " & A & " Diopters" YT-t$QyL  
        Print "Pupil Diameter = " & pupilDiam & " mm" No[>1]ds  
    |#S!qnXB  
        ' Calculate new parameters with accommodation QN0Ik 2L  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 7%0PsF _  
    Q.5a"(d@  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens #-@dc  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens }g`A*y;t  
    =EIsqk^*  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens &^z~wJ,]  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens r<"1$K~Ka  
    \ii^F?+b  
        tlens = 3.767 + 0.04*A                  'Lens thickness uD+;5S]us  
    LNr2YRpyz  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction +pDuRr  
    ] qrO"X=  
        'Adjust parameters to account for accommodation 6-<r@{m$  
    =!p6}5Z  
        '************************************************************************* VD1*br^,  
        'Aqueous thickness (Position of Lens) LEk W^Mv  
        '************************************************************************* 4u"O/rt  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) H1q>UU:  
        GetCustomElement eID, entity thkL<  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 5 1 L:%Af  
    ^D\#*pIO  
        ' Delete any shift(s) in z G66vzwO   
        count = 0 k8w8I$QEM  
        While GetOperationCount(eID)>count &ts!D!Hj  
            GetOperation eID, count, op }bHd U]$}  
            If op.Type="ShiftZ" Then f\Pd#$3  
                DeleteOperation eID,count q7X /"Dfx  
                count=count-1 |JrG?:n  
            End If Yj;$hV8j(  
            count=count+1 B:Msn)C~  
        Wend 3:S Ex;d+  
    g{dyDN$5|w  
        'Set new shift in In]h+tG?rN  
        op.Type = "ShiftZ" .O~)zM x  
        op.val1 = taq ]2tX'=X  
        op.parent = parID / EWF0XV!  
        AddOperation eID, op 3vmZB2QG  
        Print "Set aqueous humor thickness = " & taq-0.55 {L3lQ8Z  
    rjfQ\W;}U  
        '************************************************************************* y_\vXY'  
        'Radius and conic constant of anterior lens Z~$fTW6g  
        '************************************************************************* w!tQU9+ *  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) b[H& vp  
        GetConic eID, entity, curv, conic )PR{ia64;<  
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        SetConic eID, entity, 1/Rant, CCant L{osh0  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant \9<aCJxN  
    /G\-v2iD  
        '************************************************************************* O'o`  
        'Radius and conic constant of posterior lens t[7YMk  
        '************************************************************************* m &s0Ub  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) :MpIx&  
        GetConic eID, entity, curv, conic o9>r -  
    nB"q  
        SetConic eID, entity, 1/Rpost, CCpost P|c79  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 389T6sP]  
    S+_}=25  
        '************************************************************************* |Q.t]TR'P  
        'Lens thickness (Position of posterior lens surface) QD q2<  
        '************************************************************************* qH$G_R#)8B  
    <(;"L<?D<C  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) &QLCij5:  
    [\eUCt F  
        ' Delete any z-shift(s) $d4eGL2S  
        count = 0 ~%(r47n  
        While GetOperationCount(eID)>count (lT H EiX  
            GetOperation eID, count, op \2pJ ]  
            If op.Type="ShiftZ" Then &A]*"lt|w  
                DeleteOperation eID,count l 8n#sGA%  
                count=count-1 >\[sNCkf  
            End If w=y!|F  
            count=count+1 A\k@9w\Ll;  
        Wend kR9G;IZ8s  
    lD. PNwM  
        'Set new z-shift DSD#',  
        op.Type = "ShiftZ" hPP+lqY[  
        op.val1 = tlens 5fSDdaO  
        op.parent = parID ,r+=>vre  
        AddOperation eID, op 9^)ochY3  
        Print "Set lens thickness = " & tlens ;"wU+  
    2j*\n|"}{  
        '************************************************************************* zH}u9IR3`  
        'Lens index of refraction y2o?a6`  
        '************************************************************************* q$0^U{j/  
        eID = FindMaterial( "Lens" ) i=]IUjx<  
        GetModelMaterial eID, mat wnN@aO6g*  
    `N;u#z  
        mat.Nd = nlens hQ#'_%:  
        SetModelMaterial eID, mat .9S  
        Print "Set lens index of refraction = " & nlens ` L6H2:pf  
    [P`Q_L,+  
        '************************************************************************* (/Hq8o-Fw  
        'Pupil diameter t? yMuK  
        '************************************************************************* aG?'F`UQ  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) wwmMpK}f  
    Y[X5S{H`wj  
        'Adjust pupil diameter (trimming volume inner hole) G]=U=9ZI  
    !nU  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 0`3ey*  
    x.<^L] "  
        ' Adjust pupil location to just in front of the lens Oh5(8.<y  
        parID = FindFullName( "Geometry.Arizona Eye" ) e}-uU7O  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) w(<; $9  
        count = 0 L_=J(H|  
        While GetOperationCount(eID)>count !D7 [R'RgY  
            GetOperation eID, count, op =3^YKI  
            If op.Type="ShiftZ" Then [`yiD>  
                DeleteOperation eID,count PQlG !  
                count=count-1 BAx)R6kS;  
            End If $Vlfg51ob  
            count=count+1 2sk^A ly  
        Wend uZW ?0W  
        op.Type = "ShiftZ" jgVra*   
        op.val1 = taq-0.01 @L,T/m-HF  
        op.parent = parID >OBuHqC  
        AddOperation eID, op f)vD2_E  
    s[SzE6eQ`l  
        Print "Set pupil diameter = " & pupilDiam *;1G+Q#  
    1e _V@Vy  
        'Update AZ Eye subassembly Description eN,s#/ip]  
        eID = FindFullName( "Geometry.Arizona Eye" ) GmcxN<  
        GetEntity eID, entity psta&u\ q  
        entity.Description = "Accommodation = " & A & "D" {Ejv8UdA9  
        SetEntity eID, entity m Wsegq4  
    tI{pu}/"#  
        Update nv2Y6e}dG  
        Print "DONE!" |rq~.cA  
         u> %r(  
    End Sub +wY3E*hU  
    a+{YTR>0m  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: ;KbnaUAS8  
    fFqK.^Tn  
    Accommodation = 4 Diopters k&n7 _[]n  
    Pupil Diameter = 4 mm FJ!N)`[  
    Set aqueous humor thickness = 2.81 U-Fr[1I6p  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 s^AQJ{X  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 13}=;4O  
    Set lens thickness = 3.927 3r%I *  
    Set lens index of refraction = 1.42672 'N,x=1R5  
    Set pupil diameter = 4 \I/l6H>o3  
    DONE! H]mY6D51"  
     
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