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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 T1lXYhAWS  
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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。 - waX#U T=  
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    模型 SW3wMPy&s  
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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。 nURvy}<r  
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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. +7Sf8tg\  
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    光源 lN);~|IOv7  
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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。 '/Cg*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。 NV:>a  
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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。 6e,Apj 0  
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    图2. 字母F光源的设定方法光 zs4>/9O  
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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 %'$f ?y  
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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。 o(:{InpV%A  
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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。 y^9bfMA  
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    图5. 视网膜重点采样规格设定
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    脚本 a/#+92C  
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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: N"S3N)wgd  
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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。 : -E,   
    余下的脚本计算与屈光度有关的所有参数。 c2/"KT  
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    分析 (m6EQoW^s+  
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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。 >xZ5 ac I  
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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 |ribWCv0  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ;;M"hI3@  
    \Ps5H5Qk;  
    Dim entity As T_ENTITY tbg*_ZQO u  
    Dim op As T_OPERATION ^ s=*J=k  
    Dim mat As T_MODELMATERIAL 2_ wv C  
    Dim A As Double w:v=se"U  
    Dim pupilDiam As Double ]{<saAmJC  
    Dim eID As Long ?5`{7daot  
    Dim parID As Long Zgy7!AF!  
    Dim count As Integer aFyh,  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double >d#3|;RY  
    Dim tlens As Double, nlens As Double Sg_O?.r  
    Dim curv As Double, conic As Double [O(m/  
    Dim ok As Long u >4ArtF  
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    Sub Main "$r 1$mBi  
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        '用户输入对话框 r|<6Aae&  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 \Y+")  
            TextBox 220,21,40,21,.TextBox1 'default: 0 P:qz2Hw  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 c+~Lp SQ  
            OKButton 40,91,90,21 cu)U7  
            CancelButton 190,91,90,21 bf1)M>g,O  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 N\'TR6_,b  
            TextBox 220,49,40,21,.TextBox2 'default: 4 rmsQt  
        End Dialog g &*mozs  
        Dim dlg As UserDialog (#If1[L  
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        ok = Dialog (dlg) i*'Z3Z)  
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        If ok=0 Then    'cancel button was pressed a_MFQf&KV  
            Print "Execution cancelled." VtWT{y5Ec  
            End `UQEXoB)  
        End If W tVf wC_  
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        'Assign accommodation and pupil diameter & use defaults if field left empty Cs#w72N  
        If dlg.TextBox1 = "" Then Q,~x#  
            A = 0           'Default accommodation yyjw?#\8  
        Else iy}xICt  
            A = CDbl(dlg.TextBox1) '$?du~L-  
        End If ~;8I5Sge  
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        If dlg.TextBox2 = "" Then Y.NE^Vn0  
            pupilDiam = 4   'Default pupil diameter dZDK7UL  
        Else T<6GcI>A  
            pupilDiam = CDbl(dlg.TextBox2) x9&p!&*&IT  
        End If }vY.EEy!  
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        Print " " M$H`^Pv  
        Print "Accommodation = " & A & " Diopters" #|?8~c;RWG  
        Print "Pupil Diameter = " & pupilDiam & " mm" l sr?b  
    D"!jbVz]*  
        ' Calculate new parameters with accommodation x6v,lR  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness oqYt/4^Q  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens !D;c,{Oz  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens NH4?q!'G  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens %J!NL0x_  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens [,b)YjO~Xd  
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        tlens = 3.767 + 0.04*A                  'Lens thickness #)]E8=}  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction c0ZaFJ  
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        'Adjust parameters to account for accommodation r^5jh1  
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        '************************************************************************* 'yr{^Pek  
        'Aqueous thickness (Position of Lens) =) }nLS3t  
        '************************************************************************* $@.jZ_G  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) pV=@sz,G  
        GetCustomElement eID, entity `*k@4.J{  
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        parID = FindFullName( "Geometry.Arizona Eye" ) !^?qU;|  
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        ' Delete any shift(s) in z " #v%36U  
        count = 0 x*q35K^PE  
        While GetOperationCount(eID)>count ,H{={aln  
            GetOperation eID, count, op J^:n* C  
            If op.Type="ShiftZ" Then 9.s,:?5e  
                DeleteOperation eID,count dB7ZT0L\  
                count=count-1 Ww`&i  
            End If KUKI qAA  
            count=count+1 R6P\T\~E  
        Wend 2Wl{Br.  
    7n&yv9"  
        'Set new shift in 30d#Lq  
        op.Type = "ShiftZ" }#/l N  
        op.val1 = taq JD lBVZ!  
        op.parent = parID {SdO9Yy?@7  
        AddOperation eID, op hB>^'6h+  
        Print "Set aqueous humor thickness = " & taq-0.55 1tGgDbJU  
    = F<:}Tx)C  
        '************************************************************************* X=,6d9,  
        'Radius and conic constant of anterior lens Nfaf;;J}  
        '************************************************************************* LGVlc@0'  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) fRNP#pi0u  
        GetConic eID, entity, curv, conic IaasHo\  
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        SetConic eID, entity, 1/Rant, CCant =/}X$,@2  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant HeozJ^u\?  
    mb{q(WEPP  
        '************************************************************************* @GeHWv  
        'Radius and conic constant of posterior lens <5IQc[3]aP  
        '************************************************************************* Uk'U?9O  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) a+ GJVJ  
        GetConic eID, entity, curv, conic {y-`QS  
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        SetConic eID, entity, 1/Rpost, CCpost xS+rHC  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost D^?_"wjW  
    -oh7d$~  
        '************************************************************************* UA(;fZ@  
        'Lens thickness (Position of posterior lens surface) lT,+bU  
        '************************************************************************* [W;[v<E;  
    *eGM7o*\X  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) N!c gN  
    D=&K&6rr  
        ' Delete any z-shift(s) M-Sv1ZLh  
        count = 0 9XOyj5  
        While GetOperationCount(eID)>count Dbz]{_Y;  
            GetOperation eID, count, op 7'eh)[T  
            If op.Type="ShiftZ" Then _yVPpA[a  
                DeleteOperation eID,count i0ybJOa4  
                count=count-1 c<jB6|.=2  
            End If ^73=7PZ  
            count=count+1 O-!,Jm   
        Wend E474l  
    VMHC/jlX@r  
        'Set new z-shift =bL{i&&  
        op.Type = "ShiftZ" 2C1+_IL   
        op.val1 = tlens 8&.-]{Z  
        op.parent = parID M[s\E4l:t  
        AddOperation eID, op o;QZe&  
        Print "Set lens thickness = " & tlens tlGWl0V?7Q  
    #ZTLrq5b  
        '************************************************************************* y x;h  
        'Lens index of refraction a5V=!OoMk  
        '************************************************************************* Tl3"PIb  
        eID = FindMaterial( "Lens" ) VGZ6  
        GetModelMaterial eID, mat aYVDp{_  
    RIjM(P  
        mat.Nd = nlens ]>8)|]O6n  
        SetModelMaterial eID, mat )4uq iA6  
        Print "Set lens index of refraction = " & nlens 9L"?wv  
    [Vp\$;\nT  
        '************************************************************************* !<r8~A3!(  
        'Pupil diameter ^'W%X  
        '************************************************************************* oEIqA  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) r/Dd& x  
    N-QCfDao  
        'Adjust pupil diameter (trimming volume inner hole) e /94y6*>  
    IG|\:Xz  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 40.AM1Z0f  
    }n[Bq#  
        ' Adjust pupil location to just in front of the lens WG%2<Q^  
        parID = FindFullName( "Geometry.Arizona Eye" ) HNMBXXf, B  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ) ,Npv3(  
        count = 0 6x4_b  
        While GetOperationCount(eID)>count kzi|$Gs<  
            GetOperation eID, count, op e1 ^l.>2d6  
            If op.Type="ShiftZ" Then os**hFPk;1  
                DeleteOperation eID,count B_&^ER5j  
                count=count-1 ZNL5({lv  
            End If } 07r  
            count=count+1 Ja [#[BJ?  
        Wend Q|//Z  
        op.Type = "ShiftZ" @p]UvqtB@  
        op.val1 = taq-0.01 KN, 4@4  
        op.parent = parID OjATSmZ@@  
        AddOperation eID, op @C_ =*  
    4J}3,+  
        Print "Set pupil diameter = " & pupilDiam Q>%E`h  
    b1)\Zi  
        'Update AZ Eye subassembly Description wY`#$)O0*  
        eID = FindFullName( "Geometry.Arizona Eye" ) OG}KqG!n  
        GetEntity eID, entity 0WXVc  
        entity.Description = "Accommodation = " & A & "D" FG# nap{  
        SetEntity eID, entity ^A#x<J+  
    w4A#>;Qu*  
        Update `^e*T'UPl  
        Print "DONE!" y5%5O xB  
         }4KW@L[g  
    End Sub 9b%j.Q-W  
    ?i%nMlcc  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: A]xCF{*)&  
    ]bu9-X&T&  
    Accommodation = 4 Diopters DKHM\yt  
    Pupil Diameter = 4 mm iAHZ0Du  
    Set aqueous humor thickness = 2.81 e^WqJ7j  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ArX]L$ D  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 H &fTh  
    Set lens thickness = 3.927 L!vWRwZwC  
    Set lens index of refraction = 1.42672 |D+p$^L  
    Set pupil diameter = 4 M:(&n@e  
    DONE! CjV7q y  
    D-D #`  
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    QQ:2987619807 #G~wE*VR$  
     
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