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    [技术]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: 2021-10-22
    简介 ,<Ag&*YE4  
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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。 g+( Cs  
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    模型 ?=u/&3Cw  
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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。 h?Y->!'  
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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. qu8!fFQjYL  
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    光源 ot%^FvQ[c  
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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。 a:q>7V|%$  
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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。 0f_+h %%=  
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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。 tfKf*Um  
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    图2. 字母F光源的设定方法光 <w,NMu"  
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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 {th=MldJ?  
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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。 %#_"I e  
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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。 Vx Vpl@  
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    图5. 视网膜重点采样规格设定
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    脚本 $yn7XonS  
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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: =%)Y, )"  
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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。 [ pe{,lp  
    余下的脚本计算与屈光度有关的所有参数。 2iWS k6%R  
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    分析 Yy 8? X9r.  
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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。 f,}(= u  
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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 WR.>?IG2E  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. '=WPi_Z5:C  
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    Dim entity As T_ENTITY @zC p/fo3  
    Dim op As T_OPERATION $eq*@5B  
    Dim mat As T_MODELMATERIAL R<<U(.E  
    Dim A As Double mx!EuF$I  
    Dim pupilDiam As Double n1Wo<$#  
    Dim eID As Long Bjp4:;Bb  
    Dim parID As Long ~Fe$/*v  
    Dim count As Integer h(/& ;\Cr  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 5$?)f&M  
    Dim tlens As Double, nlens As Double KSYHG  
    Dim curv As Double, conic As Double |muZv!,E  
    Dim ok As Long *-';ycOvr  
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    Sub Main 1\X_B`xwD  
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        '用户输入对话框 R*`=Bk0+  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 /8? u2 q  
            TextBox 220,21,40,21,.TextBox1 'default: 0 6QYHPz  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 96d&vm~m1  
            OKButton 40,91,90,21 Djr/!j  
            CancelButton 190,91,90,21 $vLGX>H  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 RI3GAd  
            TextBox 220,49,40,21,.TextBox2 'default: 4 <'N~|B/yZ  
        End Dialog Y'+mC  
        Dim dlg As UserDialog =&"a:l  
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        ok = Dialog (dlg) ]^0mh["  
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        If ok=0 Then    'cancel button was pressed 6n:oEXM>  
            Print "Execution cancelled." )eVn1U2*z.  
            End 0<)Ep~!  
        End If !DkIM}.  
    bcYGkvGbO  
        'Assign accommodation and pupil diameter & use defaults if field left empty Vz]yJ:  
        If dlg.TextBox1 = "" Then )E*-  
            A = 0           'Default accommodation yTR5*{?j  
        Else 9yK\<6}}QH  
            A = CDbl(dlg.TextBox1) ;3\'}2^|l  
        End If jSQM3+`b  
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        If dlg.TextBox2 = "" Then f%/6kz  
            pupilDiam = 4   'Default pupil diameter 7?ILmYBw  
        Else qV)hCc/ ~  
            pupilDiam = CDbl(dlg.TextBox2) \HL66%b[  
        End If 4*9BAv  
    wWVB'MRXB,  
        Print " " xQ! Va  
        Print "Accommodation = " & A & " Diopters" |,T"_R_K  
        Print "Pupil Diameter = " & pupilDiam & " mm" AHzm9U @  
    w :9M6+mM^  
        ' Calculate new parameters with accommodation |F +n7  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness s{:Thgv,9  
    zHD 8 \*  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens &-L9ws  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Q">wl  
    e8&7W3 m  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens E <N%  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Xb@dQRVX  
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        tlens = 3.767 + 0.04*A                  'Lens thickness H<"EE15  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ;;N#'.xD  
    I9h{fB  
        'Adjust parameters to account for accommodation |\RN%w7E8  
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        '************************************************************************* P! P` MX  
        'Aqueous thickness (Position of Lens) R@KWiV  
        '************************************************************************* SC--jhDZ  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) +hcJ!$J7  
        GetCustomElement eID, entity Of#"nu  
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        parID = FindFullName( "Geometry.Arizona Eye" ) tILnD1q  
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        ' Delete any shift(s) in z !1mAq+q!  
        count = 0 iV:\,<8d  
        While GetOperationCount(eID)>count y\:,.cZ+TQ  
            GetOperation eID, count, op .uB[zJc  
            If op.Type="ShiftZ" Then ]dT]25V  
                DeleteOperation eID,count RN$q,f[#  
                count=count-1 Q6n8,2*  
            End If !iAZEOkRR  
            count=count+1 Pr,C)uch  
        Wend X*a7`aL  
    (L!u[e0[#  
        'Set new shift in /U>8vV+C  
        op.Type = "ShiftZ" UMH~Q`"  
        op.val1 = taq 'i;ofJ[.c  
        op.parent = parID ie/QSte  
        AddOperation eID, op W+.?J 60  
        Print "Set aqueous humor thickness = " & taq-0.55 GYonb) F  
    )O\l3h"  
        '************************************************************************* f5R%F ~  
        'Radius and conic constant of anterior lens [-\DC*6  
        '************************************************************************* )+.AgqxI  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) :(I=z6  
        GetConic eID, entity, curv, conic G }M!  
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        SetConic eID, entity, 1/Rant, CCant 5;[0Q  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 3]>YBbXvE  
    (CE2]Nv9")  
        '************************************************************************* #Z]<E6<=9  
        'Radius and conic constant of posterior lens !9^GkFR6n  
        '************************************************************************* YGi_7fTyc=  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 7A  
        GetConic eID, entity, curv, conic VKi3z%kwK  
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        SetConic eID, entity, 1/Rpost, CCpost Ds\f?\Em  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost /sl#M  
    ^fM=|.?  
        '************************************************************************* iz-O~T/^  
        'Lens thickness (Position of posterior lens surface) mW)"~sA  
        '************************************************************************* ~5Rh7   
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) &0mhO+g   
    .\)p3pC)  
        ' Delete any z-shift(s) XB%`5wwd  
        count = 0 JM*rPzp  
        While GetOperationCount(eID)>count 'eoI~*}3WQ  
            GetOperation eID, count, op h#8 {fr)6  
            If op.Type="ShiftZ" Then tI2p-d9B  
                DeleteOperation eID,count CzT_$v_  
                count=count-1 <pUc( tPoz  
            End If m>b i$Y  
            count=count+1  ^9kdd[  
        Wend <zu)=W'R]  
    BimM)4g  
        'Set new z-shift ||?wRMV  
        op.Type = "ShiftZ" <7X+-%yb;  
        op.val1 = tlens wSs78c=  
        op.parent = parID yNQ 9~P2  
        AddOperation eID, op sQT,@'"  
        Print "Set lens thickness = " & tlens 3*b!]^d:D  
    Vs[!WJ 7  
        '************************************************************************* !Jo.Un7  
        'Lens index of refraction UmQ'=@^kR  
        '************************************************************************* wT\dzp>/  
        eID = FindMaterial( "Lens" ) . LNqU#a  
        GetModelMaterial eID, mat q}5&B =2pM  
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        mat.Nd = nlens lc0ZfC  
        SetModelMaterial eID, mat GG_A'eX:I  
        Print "Set lens index of refraction = " & nlens SHPZXJ{  
    9a_(_g>S  
        '************************************************************************* dkbKnY&  
        'Pupil diameter ;d  >  
        '************************************************************************* sfNAGez  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) jfrUOl'l  
    2!Ex55  
        'Adjust pupil diameter (trimming volume inner hole) O~&l.>??  
    ?jzadCel  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" xE.=\UzJ  
    h-h}NCP  
        ' Adjust pupil location to just in front of the lens DSHpM/7  
        parID = FindFullName( "Geometry.Arizona Eye" ) ("BFI  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Yui:=GgUrr  
        count = 0 ( ]o6Pi  
        While GetOperationCount(eID)>count +NEP*mk  
            GetOperation eID, count, op 7f td2lv  
            If op.Type="ShiftZ" Then VbX$i!>8  
                DeleteOperation eID,count mwTn}h3N  
                count=count-1 9P)<CD0  
            End If )u&_}6z  
            count=count+1 Bf88f<Z  
        Wend PX'I:B]x*  
        op.Type = "ShiftZ" +e"}"]n  
        op.val1 = taq-0.01 Dl/_jM  
        op.parent = parID p:ST$ 1 K  
        AddOperation eID, op 4%j&]PASa1  
    :<IW'  
        Print "Set pupil diameter = " & pupilDiam 49Ue2=PP#  
    "WYcw\@U  
        'Update AZ Eye subassembly Description jIc;jjAF  
        eID = FindFullName( "Geometry.Arizona Eye" ) IJXH_H_%*  
        GetEntity eID, entity c\4n7m,y  
        entity.Description = "Accommodation = " & A & "D" Bv@m)$9\+3  
        SetEntity eID, entity AQ 7e  
    c)E[K-u  
        Update |:r/K  
        Print "DONE!" KwQO,($,]  
         L}a3!33)C  
    End Sub <CmsnX  
    5\Y/so=  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: Pe wPl0  
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    Accommodation = 4 Diopters [Iihk5TT  
    Pupil Diameter = 4 mm iK %Rq  
    Set aqueous humor thickness = 2.81 o>`/,-!  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 X)f"`$  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 nLfnikw&  
    Set lens thickness = 3.927 YJ16vb9  
    Set lens index of refraction = 1.42672 M9OFK\)  
    Set pupil diameter = 4 -6tF   
    DONE! C${TC+z  
     
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