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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 g)$/'RB  
    XSk*w'xO  
    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。 [wU e"{  
    /T _{k.  
    模型 f~Y;ZvB  
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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。 Y TpiOPf  
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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. OQW%nF9~  
    ')N[)&&Q{  
    光源 Kb X&E0  
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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。 L4O.=*P1  
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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。 $%BI8_  
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 Cj%n?-  
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    图2. 字母F光源的设定方法光 cWtuI(.  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 [ Y+Ta,  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 [)+wke9  
    9xi nX-x;n  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 (E;+E\E  
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    图5. 视网膜重点采样规格设定
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    脚本 oyB gF\  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: *\.8*6*$!  
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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。 "uli~ {IU  
    余下的脚本计算与屈光度有关的所有参数。 y'aK92pF:  
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    分析 @)\4 $#+-  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。  nU4to  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 W#)X@TlE  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. cJMi`PQ;  
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    Dim entity As T_ENTITY ]]0Yh  
    Dim op As T_OPERATION y8_$YA/g  
    Dim mat As T_MODELMATERIAL t"zi'9$t  
    Dim A As Double {d XTj7  
    Dim pupilDiam As Double AsD$M*It  
    Dim eID As Long 5(gWK{R)*  
    Dim parID As Long z&cM8w:  
    Dim count As Integer lE gjv,  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double t~7OtPF  
    Dim tlens As Double, nlens As Double 0kSM$D_  
    Dim curv As Double, conic As Double Q^;:Kl.b  
    Dim ok As Long IyI0|&r2A  
    Bn9#F#F<  
    Sub Main O\CnKNk,  
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        '用户输入对话框 "~=-Q#xO  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ,z<1:st]<  
            TextBox 220,21,40,21,.TextBox1 'default: 0 3.@LAF  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 y XKddD  
            OKButton 40,91,90,21 EK= y!>  
            CancelButton 190,91,90,21 RC}m]!Uz  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 #i .,+Q  
            TextBox 220,49,40,21,.TextBox2 'default: 4 "u]&~$  
        End Dialog C6EGM/m8  
        Dim dlg As UserDialog ,{mv6?_  
    D Qz+t  
        ok = Dialog (dlg) Vpne-PW  
    "={*0P  
        If ok=0 Then    'cancel button was pressed PtYG%/s  
            Print "Execution cancelled." Y)DAR83  
            End Pz34a@%"  
        End If O/|))H?C  
    AT)b/ycC  
        'Assign accommodation and pupil diameter & use defaults if field left empty jz`3xFy *]  
        If dlg.TextBox1 = "" Then I?S t}Tl  
            A = 0           'Default accommodation k_{?{:X;y  
        Else 67hfve  
            A = CDbl(dlg.TextBox1) ^*i0~_  
        End If Q5ff&CE  
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        If dlg.TextBox2 = "" Then 5[g\.yi2_]  
            pupilDiam = 4   'Default pupil diameter pmUf*u-  
        Else J^`5L7CO  
            pupilDiam = CDbl(dlg.TextBox2) ,#FP]$FK  
        End If [zBi*%5O  
    4w~%MZA^  
        Print " " A+!,{G  
        Print "Accommodation = " & A & " Diopters" R|}N"J_  
        Print "Pupil Diameter = " & pupilDiam & " mm" Pw| h`[h  
    L-}J=n\  
        ' Calculate new parameters with accommodation J,:&U wkv  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Bcarx<P-p  
    t[J=8rhER  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens En1LGi4#  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens W^H3=hZ  
     *<W8j[?  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens /zt M'  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens PWyf3  
    ! ig& 8:  
        tlens = 3.767 + 0.04*A                  'Lens thickness JC%&d1  
    /ZD6pF  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction H)i|?3Ip  
    &}[P{53sr  
        'Adjust parameters to account for accommodation *Q^ z4UY  
    =V]0G,,\  
        '************************************************************************* n Syq}Y3  
        'Aqueous thickness (Position of Lens) r":anR( ;  
        '************************************************************************* IC&P-X_aP  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) A $gn{ c  
        GetCustomElement eID, entity 3q}j"x?  
    /$CTz xd1  
        parID = FindFullName( "Geometry.Arizona Eye" ) jtlRom}  
    t|eH'"N%o  
        ' Delete any shift(s) in z hK{H7Ey*  
        count = 0 } 1e4u{  
        While GetOperationCount(eID)>count Z.Yq)\it  
            GetOperation eID, count, op q6)fP4MQ]  
            If op.Type="ShiftZ" Then <M@-|K"Eb  
                DeleteOperation eID,count GM0Q@`d  
                count=count-1 xy[#LX)RW  
            End If /3,Lp-kp  
            count=count+1 NDP" @  
        Wend :${tts2g  
    Q0Ft.b  
        'Set new shift in VwE4:/7YN  
        op.Type = "ShiftZ" >< $LV&  
        op.val1 = taq /T)E&=Ds  
        op.parent = parID o]4\Geg$  
        AddOperation eID, op &jHsFS  
        Print "Set aqueous humor thickness = " & taq-0.55 R,G*]/r`  
    qU7_%Z  
        '************************************************************************* X}v*"`@Q  
        'Radius and conic constant of anterior lens T:$^1"\  
        '************************************************************************* ![\-J$  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) %`yfi+e  
        GetConic eID, entity, curv, conic h<U?WtWT-p  
    :.,9}\LK  
        SetConic eID, entity, 1/Rant, CCant o=3hWbe  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant O`9c!_lis  
    `SFeln{1B  
        '************************************************************************* >MHlrSH2  
        'Radius and conic constant of posterior lens Bi:lC5d5?  
        '************************************************************************* rk W7;!  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) x%=CEe?6  
        GetConic eID, entity, curv, conic Wr%ov6:  
    A/>Q5)  
        SetConic eID, entity, 1/Rpost, CCpost i]%f94  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost MqnUym  
    N $) G 8  
        '************************************************************************* <bKtAf  
        'Lens thickness (Position of posterior lens surface) >#|%'Us  
        '************************************************************************* cRVL1ne  
    TwPQ8}pj?  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) TU0-L35P1  
    js<d"m*  
        ' Delete any z-shift(s) Io]FDPN  
        count = 0 P35DVKS  
        While GetOperationCount(eID)>count =0=#M(w  
            GetOperation eID, count, op HrBJi  
            If op.Type="ShiftZ" Then = ^NvUrK  
                DeleteOperation eID,count G;l7,1;MU:  
                count=count-1 A)&FcMO*z  
            End If R@\}iyM  
            count=count+1 (`.OS)&  
        Wend R ZY=c  
    >ou= }/<  
        'Set new z-shift 32[}@f2q  
        op.Type = "ShiftZ" X&pYLm72;  
        op.val1 = tlens [tpiU'/Zl  
        op.parent = parID <?nIO  
        AddOperation eID, op );gY8UL^  
        Print "Set lens thickness = " & tlens Tn}`VW~  
    0>sa{Z  
        '************************************************************************* !%G]~  
        'Lens index of refraction r)iEtT!p*  
        '************************************************************************* <k:I2LF_  
        eID = FindMaterial( "Lens" ) + Q-b}  
        GetModelMaterial eID, mat ;5j|B|v  
    $Z@*!B^  
        mat.Nd = nlens hC<ROD  
        SetModelMaterial eID, mat VL9wRu;  
        Print "Set lens index of refraction = " & nlens ^c\O , *:  
    E=s,-  
        '************************************************************************* y&NqVR=   
        'Pupil diameter nje7?Vz  
        '************************************************************************* ~Ru\Z-q1  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 4XN \p  
     )d2Z g  
        'Adjust pupil diameter (trimming volume inner hole) $o[-xNn1  
    /f3/}x!po  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" =0)|psCsM  
    P1eSx#3bR  
        ' Adjust pupil location to just in front of the lens (9]Uuvfp6"  
        parID = FindFullName( "Geometry.Arizona Eye" ) <7^|@L 6  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) +0pI}a\  
        count = 0 ]RCo@QW  
        While GetOperationCount(eID)>count y(COB6r  
            GetOperation eID, count, op ${ {4L ?7  
            If op.Type="ShiftZ" Then ,{_i{WV  
                DeleteOperation eID,count / FcRp,"  
                count=count-1 Mn0.! J "  
            End If yLa@27T\A  
            count=count+1 9M96$i`P  
        Wend Z=JKBoAY  
        op.Type = "ShiftZ" X1^VdJE  
        op.val1 = taq-0.01 ^Oz~T|)  
        op.parent = parID 46:<[0Psl/  
        AddOperation eID, op \O|SPhaIf  
    tdm7MPM  
        Print "Set pupil diameter = " & pupilDiam PIri|ZS  
    LDlYLs F9  
        'Update AZ Eye subassembly Description F!vrvlD`s  
        eID = FindFullName( "Geometry.Arizona Eye" ) .WF"vUp  
        GetEntity eID, entity LDt6<D8,Q  
        entity.Description = "Accommodation = " & A & "D" 4=yzf  
        SetEntity eID, entity ?2<) Jw  
    \*$^}8  
        Update hfwJZ\_60  
        Print "DONE!" 9Dx~! (  
         Bz]tKJ  
    End Sub b'z $S+  
    Af|h*V4Xu  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: R]"Zv'M(AM  
    !M~:#k  
    Accommodation = 4 Diopters ,>j3zjf^  
    Pupil Diameter = 4 mm 6<&A}pp  
    Set aqueous humor thickness = 2.81 uMcI'=  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 N^;lp<{6?  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 !1$x4 qxS  
    Set lens thickness = 3.927 1w>[&#7  
    Set lens index of refraction = 1.42672 4$Ai!a  
    Set pupil diameter = 4 i 8sv,P  
    DONE! ' @!&{N  
    # &v4c  
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    QQ:2987619807 yq~  
     
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