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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 % 9D@W*Z  
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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。 (&*F`\  
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    模型 sMS`-,37u  
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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。 8_,ZJ9l ;  
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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. VDPN1+1*  
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    光源 r#Fu<so,  
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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。 ZkIQ-;wx  
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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。 ^`!Daqk  
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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。 O+8`.  
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    图2. 字母F光源的设定方法光 -0X> y  
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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 I7~|!d6  
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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。 Fq9[:  
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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。 XJzXxhk2  
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    图5. 视网膜重点采样规格设定
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    脚本 oSl>%}  
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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: jyGVbno`  
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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。 Ds87#/Yfv  
    余下的脚本计算与屈光度有关的所有参数。 ~{+{pcO}  
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    分析 *jK))|%  
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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。 ~qS/90,  
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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 S |x)7NC  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. Y*k<NeDyn  
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    Dim entity As T_ENTITY uB1!*S1f  
    Dim op As T_OPERATION k^pu1g=6I  
    Dim mat As T_MODELMATERIAL A7C+&I!L  
    Dim A As Double 2 mZ/ 3u  
    Dim pupilDiam As Double 6Qb)Uq3}]  
    Dim eID As Long [bv@qBL  
    Dim parID As Long *?D2gaCta  
    Dim count As Integer 2Nkn C>9(\  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double l~YNmmv_  
    Dim tlens As Double, nlens As Double w.aFaR)04  
    Dim curv As Double, conic As Double ^,K.)s  
    Dim ok As Long AfN   
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    Sub Main LtztjAm.  
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        '用户输入对话框 z[%v _S  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 6\Vu#r  
            TextBox 220,21,40,21,.TextBox1 'default: 0 _-\s[p5  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 #L.}CzAz  
            OKButton 40,91,90,21 p qN[G=0  
            CancelButton 190,91,90,21 9'q/&uH  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 0juIkN#  
            TextBox 220,49,40,21,.TextBox2 'default: 4 t!SQLgA  
        End Dialog TDIOK  
        Dim dlg As UserDialog iT5SuIv  
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        ok = Dialog (dlg) ,?<h] !aQ  
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        If ok=0 Then    'cancel button was pressed 5?L:8kHsH  
            Print "Execution cancelled." 0~b6wuFl  
            End Gu`Vk/&  
        End If 37- y  
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        'Assign accommodation and pupil diameter & use defaults if field left empty @Q\$dneY  
        If dlg.TextBox1 = "" Then /v)!m&6]>  
            A = 0           'Default accommodation q>(u>z!  
        Else Q(5:~**I  
            A = CDbl(dlg.TextBox1) 0nz@O^*g(  
        End If ,XG|oo -  
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        If dlg.TextBox2 = "" Then _@pf1d$  
            pupilDiam = 4   'Default pupil diameter $;i$k2n:  
        Else m2uML*&O5K  
            pupilDiam = CDbl(dlg.TextBox2) L +rySP  
        End If #D/ }u./  
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        Print " " 9=~H6(m>  
        Print "Accommodation = " & A & " Diopters" w+9C/U;|s  
        Print "Pupil Diameter = " & pupilDiam & " mm" 3b)T}g  
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        ' Calculate new parameters with accommodation 0rJ\e  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 199hQxib:  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens @52=3  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 8pL>wL &C  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ZYR,8y  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Rc:cVK  
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        tlens = 3.767 + 0.04*A                  'Lens thickness #D LT-G0  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ?sf2h:\N  
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        'Adjust parameters to account for accommodation :KV,:13`D  
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        '************************************************************************* BRU9LS  
        'Aqueous thickness (Position of Lens) ?fa,[r|G  
        '************************************************************************* `b#nC[b6|v  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ),p]n  
        GetCustomElement eID, entity w[ YkTv  
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        parID = FindFullName( "Geometry.Arizona Eye" ) ~?`9i>3W~  
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        ' Delete any shift(s) in z Q0q)n=i }]  
        count = 0 !/Bw,y ri<  
        While GetOperationCount(eID)>count fv j5[Q  
            GetOperation eID, count, op wO_pcNYZ8  
            If op.Type="ShiftZ" Then 4&]To@>  
                DeleteOperation eID,count iVpA @p   
                count=count-1 BV }(djx  
            End If Qk~0a?#y5  
            count=count+1 mWN1Q<vn,l  
        Wend M~z (a3@[V  
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        'Set new shift in ;!0.Kk 4  
        op.Type = "ShiftZ" APQQ:'>N4~  
        op.val1 = taq {GX &)c4  
        op.parent = parID =JbdsYI(  
        AddOperation eID, op <^*+8{*  
        Print "Set aqueous humor thickness = " & taq-0.55 )Vg{Y [!  
    ."F'5eTT~  
        '************************************************************************* 3vRL g b  
        'Radius and conic constant of anterior lens y\|-O<8O  
        '************************************************************************* z%}CB Tm  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) iB}LnC:  
        GetConic eID, entity, curv, conic :rTKqX&"j  
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        SetConic eID, entity, 1/Rant, CCant MgH1d&R  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant @\6nXf  
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        '************************************************************************* s;-78ejj7  
        'Radius and conic constant of posterior lens a_ 9|xI  
        '************************************************************************* mV**9-"  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) XUQW;H  
        GetConic eID, entity, curv, conic G%j/eTTf  
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        SetConic eID, entity, 1/Rpost, CCpost x  tYV"  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Z/NGv  
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        '************************************************************************* RFZU}.*K$  
        'Lens thickness (Position of posterior lens surface) KD%xo/Z.  
        '************************************************************************* j'#jnP*P  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) iL7-4Lv#  
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        ' Delete any z-shift(s) 7,W]zKH  
        count = 0 {FV,j.D  
        While GetOperationCount(eID)>count JK(`6qB>(6  
            GetOperation eID, count, op C;d|\[7Z  
            If op.Type="ShiftZ" Then !7mvyc!'!  
                DeleteOperation eID,count V 5e\%  
                count=count-1  Vp(D|}P  
            End If koncWyW  
            count=count+1 o;M.Rt\A  
        Wend p@cfY]<7  
    )d770Xg+  
        'Set new z-shift 0\\ueMj  
        op.Type = "ShiftZ" bxd3  
        op.val1 = tlens TZ&4  
        op.parent = parID pW*{Mx  
        AddOperation eID, op  Z;j/K  
        Print "Set lens thickness = " & tlens LaIW,+  
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        '************************************************************************* 2y9:'c|  
        'Lens index of refraction R/ ALR  
        '************************************************************************* x38SSzG:L  
        eID = FindMaterial( "Lens" ) TRs[~K)n  
        GetModelMaterial eID, mat 0%;N9\  
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        mat.Nd = nlens #Acon7R p  
        SetModelMaterial eID, mat )CC?vV  
        Print "Set lens index of refraction = " & nlens jgo e^f  
    ^3Z7dIUww  
        '************************************************************************* 7af?E)}v  
        'Pupil diameter eW\?eq+ `A  
        '************************************************************************* JYZ2k=zh  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 88Fb1!a5Z  
    2gQY8h8  
        'Adjust pupil diameter (trimming volume inner hole) 8Zcol$XS'  
    ! 6p>P4TT  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" i_ |9<7a  
    Ez06:]Jd  
        ' Adjust pupil location to just in front of the lens l 8O"w&  
        parID = FindFullName( "Geometry.Arizona Eye" ) *A~($ZtL  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) C-s>1\I  
        count = 0 ]4Nvh\/P9  
        While GetOperationCount(eID)>count 6V'wQqJ  
            GetOperation eID, count, op Zvd ;KGO(a  
            If op.Type="ShiftZ" Then 33=Mm/<m$P  
                DeleteOperation eID,count RpHpMtvNo/  
                count=count-1 ?60>'Xj j  
            End If aqcFY8b '  
            count=count+1 j4E H2v  
        Wend %iK%$  
        op.Type = "ShiftZ" d4jVdOq2  
        op.val1 = taq-0.01 ]*bAF^8i  
        op.parent = parID mDb-=[W5  
        AddOperation eID, op MC4284A5  
    9uA, +  
        Print "Set pupil diameter = " & pupilDiam th5,HO~  
    [Z#+gh  
        'Update AZ Eye subassembly Description 9T8|y]0F  
        eID = FindFullName( "Geometry.Arizona Eye" ) j`>?"1e@x  
        GetEntity eID, entity  5Waw?1GL  
        entity.Description = "Accommodation = " & A & "D" >pgQb9 T+_  
        SetEntity eID, entity l_^T&xq8  
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        Update 6P0y-%[Gk  
        Print "DONE!" TF BYY{Y  
         kxwNbxC  
    End Sub @)9REA(U  
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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: !nec 7  
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    Accommodation = 4 Diopters [?;`x&y~y  
    Pupil Diameter = 4 mm U5|B9%:&  
    Set aqueous humor thickness = 2.81 dVvZu% DFp  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 x$~3$E  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 &J\B\`  
    Set lens thickness = 3.927 bBA$}bv  
    Set lens index of refraction = 1.42672 =Nw2;TkB[  
    Set pupil diameter = 4 `2>XH:+7F  
    DONE! fr8Xoa%1=  
     
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