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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 (TEo_BW|+  
    M`0(!Q}  
    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。 N@Xg5huO  
    ";PG%_(  
    模型 8To7c  
    :O9P(X*  
    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。 >vlQ|/C  
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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. }FPM-M3y  
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    光源 2B HKS-J*  
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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。 \s=QiPK  
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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。 KHvIN}V5?3  
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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。 xN6?yr  
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    图2. 字母F光源的设定方法光 3PfiQ|/b  
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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 aSRjFL^  
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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。 GGCqtA^@7d  
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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。 {3_Gjb5\\4  
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    图5. 视网膜重点采样规格设定
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    脚本 'r~8  
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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: d>Un J)V}  
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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。 W/sY#"  
    余下的脚本计算与屈光度有关的所有参数。 ^[#=L4  
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    分析 /w0sj`;"  
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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。 [~COYjp  
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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  m;c3Z-  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. "rsSW 3_  
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    Dim entity As T_ENTITY 0 <g{ V  
    Dim op As T_OPERATION gSb,s [p&+  
    Dim mat As T_MODELMATERIAL . @@an;C  
    Dim A As Double sdrWOq  
    Dim pupilDiam As Double sZKEUSFD #  
    Dim eID As Long JRXRi*@  
    Dim parID As Long u\f3qc,]F  
    Dim count As Integer %yfE7UPS]  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double J smB^  
    Dim tlens As Double, nlens As Double T<P0T<  
    Dim curv As Double, conic As Double k=`$6(>Fz  
    Dim ok As Long q(gjT^aN  
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    Sub Main 33 : @*  
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        '用户输入对话框 W2hA-1  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 w//omF'`  
            TextBox 220,21,40,21,.TextBox1 'default: 0 t{zBC?c R  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 h/HH Kn  
            OKButton 40,91,90,21 Kk=LXmL2  
            CancelButton 190,91,90,21 QXs8:;T  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 KzNm^^#/$A  
            TextBox 220,49,40,21,.TextBox2 'default: 4 _lX8K:C(  
        End Dialog l[oe*aYN7  
        Dim dlg As UserDialog ^^U%cuKg  
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        ok = Dialog (dlg) >g]ON9CGH  
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        If ok=0 Then    'cancel button was pressed &<Zdyf?[Ou  
            Print "Execution cancelled." aBxiK[[`  
            End %m`zWg-  
        End If $Asr`Q1i   
    WI&lj<*  
        'Assign accommodation and pupil diameter & use defaults if field left empty rEM#D]k  
        If dlg.TextBox1 = "" Then '#q4Bc1  
            A = 0           'Default accommodation 1'Rmg\(  
        Else 2)9r'ai?a  
            A = CDbl(dlg.TextBox1) FshC )[w,  
        End If <( EyXV  
    ;|HL+je;Z  
        If dlg.TextBox2 = "" Then lL0M^Nv  
            pupilDiam = 4   'Default pupil diameter U*\17YU6h  
        Else ~x#vZ=]8  
            pupilDiam = CDbl(dlg.TextBox2) OhFW*v  
        End If y3JMbl[S0  
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        Print " " A[)C:q,  
        Print "Accommodation = " & A & " Diopters" 4x=(Zw_X  
        Print "Pupil Diameter = " & pupilDiam & " mm" X{\jK]O  
    QIK 9  
        ' Calculate new parameters with accommodation G\kpUdj}  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness `*_CElpP"  
    <#*.}w~  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 2w?hgNz  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ?aWx(dVQ  
    hqDqt"dKz  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens '3Q3lM'lh  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 8:dQ._#v  
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        tlens = 3.767 + 0.04*A                  'Lens thickness e.8$ga{  
    i\Wdo/c-H  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction UQPU"F7.  
    Ej"u1F14J  
        'Adjust parameters to account for accommodation x-;`-Uo%  
    !MV@) (.  
        '************************************************************************* Fe!9y2Mg  
        'Aqueous thickness (Position of Lens) qINTCm j  
        '************************************************************************* NBOCt)C;H  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 8@eOTzm  
        GetCustomElement eID, entity L;/n!k.A  
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        parID = FindFullName( "Geometry.Arizona Eye" ) ,H[SI0];  
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        ' Delete any shift(s) in z Z a(|(M H  
        count = 0 ahGT4d`)9  
        While GetOperationCount(eID)>count , ;jGJr  
            GetOperation eID, count, op {/ 2E*|W~I  
            If op.Type="ShiftZ" Then /X#z*GX  
                DeleteOperation eID,count N$#\Xdo  
                count=count-1 Dl,`\b@Fw3  
            End If N+g@8Q2s;5  
            count=count+1 [po "To  
        Wend fY W|p<Q0  
    ."6[:MF  
        'Set new shift in 5o 0Ch  
        op.Type = "ShiftZ" ]?K. S6  
        op.val1 = taq ar ^i|`D  
        op.parent = parID ,={t8lN  
        AddOperation eID, op X.V[0$.;  
        Print "Set aqueous humor thickness = " & taq-0.55 cUk*C  
    a9Y5  
        '************************************************************************* .F2 :!h$  
        'Radius and conic constant of anterior lens caq} &A]C  
        '************************************************************************* `JURQ:l)3^  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 46No%cSiG  
        GetConic eID, entity, curv, conic 5?u}#zO  
    'EhBRU%  
        SetConic eID, entity, 1/Rant, CCant bF-"tm  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant jndGiMA  
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        '************************************************************************* +%0z`E\?M#  
        'Radius and conic constant of posterior lens ]?LB?:6  
        '************************************************************************* r'4:)~]s  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) K$[$4 dX]  
        GetConic eID, entity, curv, conic WAPhv-6  
    4N>>+]MWc  
        SetConic eID, entity, 1/Rpost, CCpost F- rQ3  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost {/8Q)2*>0  
    QP(BZJC  
        '*************************************************************************  9A$m$  
        'Lens thickness (Position of posterior lens surface) k%81f'H  
        '************************************************************************* QlZ@ To  
    u{e-G&]^;  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /X*oS&-M  
    G| m4m.  
        ' Delete any z-shift(s) k$i'v:c|:i  
        count = 0 l=m(mf?QBg  
        While GetOperationCount(eID)>count MuI2?:~:*4  
            GetOperation eID, count, op RHY4P4B<v>  
            If op.Type="ShiftZ" Then xge7r3i  
                DeleteOperation eID,count SNpi=K!yn  
                count=count-1 8Ogv9  
            End If sRhKlUJG  
            count=count+1 H=^K@Ti:  
        Wend qUJ aeQ  
    q_fam,9  
        'Set new z-shift +[-i%b3q  
        op.Type = "ShiftZ" XNH4vG |  
        op.val1 = tlens obH; g*  
        op.parent = parID Yl^mAS[w&  
        AddOperation eID, op Xrqx\X  
        Print "Set lens thickness = " & tlens =H`Q~ Xx  
    [ .,>wo~  
        '************************************************************************* $lwz-^1t.  
        'Lens index of refraction ~Ci{3j :]  
        '************************************************************************* g=8un`]7  
        eID = FindMaterial( "Lens" ) DBH#)4do@  
        GetModelMaterial eID, mat n6Z|Q@F  
    {S.>BXX  
        mat.Nd = nlens R^&q-M=O[  
        SetModelMaterial eID, mat e@<?zS6  
        Print "Set lens index of refraction = " & nlens 7(a2L&k^  
    (P|pRVO  
        '************************************************************************* ;{Ux_JEg  
        'Pupil diameter t*S." q  
        '************************************************************************* M[]A2'fS  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) chI.{Rj  
    J$ut_N):N  
        'Adjust pupil diameter (trimming volume inner hole) \,G#<>S  
    evuZY X@  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" @mQ:7-,~  
    OjE` 1h\  
        ' Adjust pupil location to just in front of the lens sy5 Fn~\R  
        parID = FindFullName( "Geometry.Arizona Eye" ) 2\<.0  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) :D:DnVZ-[@  
        count = 0 -0uV z)  
        While GetOperationCount(eID)>count y' C-[nk  
            GetOperation eID, count, op |UUdz_i!:  
            If op.Type="ShiftZ" Then oYM3Rgxf9Q  
                DeleteOperation eID,count 4"?^UBr  
                count=count-1 W7No ls{  
            End If LV{Q,DrP  
            count=count+1 vIGw6BJI  
        Wend 'fd1Pj9~$  
        op.Type = "ShiftZ" ts~{w; c  
        op.val1 = taq-0.01 F\JUx L@8  
        op.parent = parID oMH.u^b]fT  
        AddOperation eID, op 7A$B{  
    Qx3eLfm  
        Print "Set pupil diameter = " & pupilDiam 5z$,6T  
    V4w=/e _  
        'Update AZ Eye subassembly Description n$L51#'  
        eID = FindFullName( "Geometry.Arizona Eye" ) E+95WF|4k"  
        GetEntity eID, entity uzr\oj+>  
        entity.Description = "Accommodation = " & A & "D" ?9+@+q  
        SetEntity eID, entity I27,mS+]  
    ' I}: !Z  
        Update ]3{0J  
        Print "DONE!" <cN~jv-w$  
         i^`9syD  
    End Sub A#wEuX=[  
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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: 7E$&2U^Js  
    7L5P%zLtB  
    Accommodation = 4 Diopters wucV_p.E  
    Pupil Diameter = 4 mm <=K qc Hb  
    Set aqueous humor thickness = 2.81 Y$>-%KcKeI  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 BHDML.r }M  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 nSx8E7 |V  
    Set lens thickness = 3.927 dtStTT  
    Set lens index of refraction = 1.42672 Ut@RGg+f8  
    Set pupil diameter = 4 (?)7)5H  
    DONE! |s+0~$O;  
     
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