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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 &xU[E!2H%  
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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。 `68@+|#  
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    模型 ;dkYf24  
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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。 eVEV}`X  
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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. l3{-z4mw  
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    光源 '50OgF'  
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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。 WO7z  
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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。 e|g5=2(Pr&  
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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。 R6 y#S&]x  
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    图2. 字母F光源的设定方法光 a]$1D!Anc  
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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 ]l;o}+`G  
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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。 -zCH**y%1  
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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。 1m'k|Ka  
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    图5. 视网膜重点采样规格设定
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    脚本 k)i3   
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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: ^dI424  
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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。 3BzNi'  
    余下的脚本计算与屈光度有关的所有参数。 mWv3!i;G<s  
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    分析 UgRhWV~f0  
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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。 R1s`z|?  
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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 ,D5cjaX<  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. EHSlK5bD,  
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    Dim entity As T_ENTITY $ux,9H'[  
    Dim op As T_OPERATION q'+)t7!  
    Dim mat As T_MODELMATERIAL #9=Vg  
    Dim A As Double pXtl 6K%  
    Dim pupilDiam As Double @Rg/~\K  
    Dim eID As Long $&Gu)4'+  
    Dim parID As Long tCw<Ip  
    Dim count As Integer R%Hi+#/dr-  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double !:)s"|=  
    Dim tlens As Double, nlens As Double [m- >5H  
    Dim curv As Double, conic As Double r^2p*nr}  
    Dim ok As Long bs+f,j-oBN  
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    Sub Main HUcq% .  
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        '用户输入对话框 \h+AXs<j  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 )tG\vk=@  
            TextBox 220,21,40,21,.TextBox1 'default: 0 +|*IZ:w)  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 8aZ=?_gvT  
            OKButton 40,91,90,21 nz%DM<0$  
            CancelButton 190,91,90,21 G%BjhpL  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ;$HftG>B  
            TextBox 220,49,40,21,.TextBox2 'default: 4 3Nl <p"=  
        End Dialog 5b5x!do  
        Dim dlg As UserDialog +20G>y=+  
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        ok = Dialog (dlg) >3ZFzh&OYQ  
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        If ok=0 Then    'cancel button was pressed p}&#jE  
            Print "Execution cancelled." eFipIn)b  
            End y@1+I ~@  
        End If {vs uPY  
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        'Assign accommodation and pupil diameter & use defaults if field left empty PYQ;``~x  
        If dlg.TextBox1 = "" Then T=<@]$?  
            A = 0           'Default accommodation \1d (9jR  
        Else 6e(Qwt  
            A = CDbl(dlg.TextBox1) Cmu@4j&  
        End If N%kt3vmQ_  
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        If dlg.TextBox2 = "" Then w2Us!<x  
            pupilDiam = 4   'Default pupil diameter `CBZhI%%  
        Else 8Pfb~&X^Ws  
            pupilDiam = CDbl(dlg.TextBox2) i1UiNJh86  
        End If !NIhx109q  
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        Print " " >q#rw  
        Print "Accommodation = " & A & " Diopters" @#<D ^"  
        Print "Pupil Diameter = " & pupilDiam & " mm" ?fiIwF)  
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        ' Calculate new parameters with accommodation ]99|KQ<s  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 0\H\lKcK  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens tW.9yII  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens kh!FR u h  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens [I0:=yJ+  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens \?w2a$?6w  
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        tlens = 3.767 + 0.04*A                  'Lens thickness C\\~E9+  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ? 8)'oMD  
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        'Adjust parameters to account for accommodation !-ok"k0,u  
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        '************************************************************************* @u.58H& }R  
        'Aqueous thickness (Position of Lens) ) dn(G@5  
        '************************************************************************* O80<Z#%j`  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^b/ Z)3  
        GetCustomElement eID, entity " f <Z=c  
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        parID = FindFullName( "Geometry.Arizona Eye" ) |"?M1*g  
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        ' Delete any shift(s) in z 6TYY UM"&  
        count = 0 *,3SGcYdJj  
        While GetOperationCount(eID)>count -1 FPkp  
            GetOperation eID, count, op ^.1)};i  
            If op.Type="ShiftZ" Then uya.sF0]9B  
                DeleteOperation eID,count 00'%EYO  
                count=count-1 Diy8gt  
            End If KmMzH`t}`  
            count=count+1 BD68$y  
        Wend U [*FCD!~  
    ]"J~:{, d  
        'Set new shift in b+,' ;bW  
        op.Type = "ShiftZ" O|\J}rm'  
        op.val1 = taq g@rb  
        op.parent = parID gaQdG=G8$  
        AddOperation eID, op 7_%"BVb"  
        Print "Set aqueous humor thickness = " & taq-0.55 Fa?~0H/DL  
    :S.9eFfa  
        '************************************************************************* a,xycX:U  
        'Radius and conic constant of anterior lens PjZvQ\Z  
        '************************************************************************* 6tB+JF  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) S\4tzz @  
        GetConic eID, entity, curv, conic 11TL~ xFh  
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        SetConic eID, entity, 1/Rant, CCant .}^g!jm~h  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant O9vQp  
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        '************************************************************************* 7"aN#;&  
        'Radius and conic constant of posterior lens `q?8A3A  
        '************************************************************************* K$>%e36Cc  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) _XG/Pp)  
        GetConic eID, entity, curv, conic _  <WJ7  
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        SetConic eID, entity, 1/Rpost, CCpost !HrKXy 0{  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost M|6A0m#Q  
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        '************************************************************************* B$- R-S6  
        'Lens thickness (Position of posterior lens surface) G.rrv  
        '************************************************************************* 0>C T=(A  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?>hPO73{  
    }B8IBveu  
        ' Delete any z-shift(s) IHe/xQ@  
        count = 0 }M1`di4e  
        While GetOperationCount(eID)>count L_vISy%\b  
            GetOperation eID, count, op DAS/43\  
            If op.Type="ShiftZ" Then ]or>?{4g  
                DeleteOperation eID,count ]j'p :v  
                count=count-1 pv*,gSS  
            End If @HQ`~C#Z'  
            count=count+1 !6BW@GeF]  
        Wend #i@;J]x(  
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        'Set new z-shift |s"nM<ZNZ  
        op.Type = "ShiftZ"  U mNa[ s  
        op.val1 = tlens 1xD=ffM>8N  
        op.parent = parID  5V6G=H  
        AddOperation eID, op D&/kCi=R  
        Print "Set lens thickness = " & tlens `!XY]PI+e  
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        '************************************************************************* W{%TlN  
        'Lens index of refraction {)"iiJ  
        '************************************************************************* /s?r`'j[  
        eID = FindMaterial( "Lens" ) hn^<;av=  
        GetModelMaterial eID, mat #1`-*.u  
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        mat.Nd = nlens NPCs('cd>?  
        SetModelMaterial eID, mat }2<r,  
        Print "Set lens index of refraction = " & nlens afv~r>q(-  
    )^ m%i]L _  
        '************************************************************************* mX\T D0$d  
        'Pupil diameter |zR8rqBX;  
        '************************************************************************* {XNREjhm  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 3^R&:|,  
    9;_sC  
        'Adjust pupil diameter (trimming volume inner hole) Qy.w=80kf  
    *+-}P|S:  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" z54EG:x.7^  
    $]{k+Jf  
        ' Adjust pupil location to just in front of the lens ~KW,kyXBnD  
        parID = FindFullName( "Geometry.Arizona Eye" ) fIj|4a+  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) "$N#p5  
        count = 0 :,Pn3xl  
        While GetOperationCount(eID)>count p89wNSMl[  
            GetOperation eID, count, op n;(\5{a  
            If op.Type="ShiftZ" Then wT `a3Ymm  
                DeleteOperation eID,count ~V&aUDO>/  
                count=count-1 l% ?T2Fm3>  
            End If OlAs'TE^  
            count=count+1 ,=tD8@a<  
        Wend ?**+e%$$  
        op.Type = "ShiftZ" ?*E'^~,H)  
        op.val1 = taq-0.01 dE:+k/  
        op.parent = parID y$@ZN~8  
        AddOperation eID, op )#.<]&P}  
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        Print "Set pupil diameter = " & pupilDiam F_;vO%}  
    nyBJb(5"B  
        'Update AZ Eye subassembly Description &Rx{.9  
        eID = FindFullName( "Geometry.Arizona Eye" ) 'f[T&o&L/  
        GetEntity eID, entity q0$ !y!~  
        entity.Description = "Accommodation = " & A & "D" an|x$e7|?  
        SetEntity eID, entity sA'6ty  
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        Update 1jy9lP=  
        Print "DONE!" nx8a$vI-TY  
         {.QEc0-  
    End Sub c:-!'l$ !  
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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: "Jt.lL ]5  
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    Accommodation = 4 Diopters QS{1CC9$  
    Pupil Diameter = 4 mm r9 ui|>U"  
    Set aqueous humor thickness = 2.81 W6"v)Jc>_  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 /RHo1  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 |`lzfe  
    Set lens thickness = 3.927 t: #6sF  
    Set lens index of refraction = 1.42672 o3I Tr';  
    Set pupil diameter = 4 EGZb7:Y?  
    DONE! dgA-MQ5{  
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    QQ:2987619807 #$c Rkw  
     
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