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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 qM F'&  
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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。 WjZJQK  
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    模型 )&di c6r  
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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。 %Kd&A*  
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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. %+oWW5q7  
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    光源 _+0l+a*D  
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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。 <)y44x|S'  
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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。 <apsG7(7  
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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。 g~_cYy  
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    图2. 字母F光源的设定方法光 j"o`K}C  
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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 (gBP`*2  
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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。 E",s]  
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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。 m`C(y$8fU  
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    图5. 视网膜重点采样规格设定
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    脚本 KquHc-fzqr  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: j Efrxlj  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 P8!Vcy938  
    余下的脚本计算与屈光度有关的所有参数。 k:PO"<-U  
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    分析 dA> t  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 &'V_80vA  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 I z~#G6]M  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 6XUcJ0  
    *%(8z~(\  
    Dim entity As T_ENTITY 1C+Y|p?KA  
    Dim op As T_OPERATION '-3AWBWI1  
    Dim mat As T_MODELMATERIAL &H,5f#  
    Dim A As Double /Ik_U?$*  
    Dim pupilDiam As Double s<'^ @Y  
    Dim eID As Long OQaM47"  
    Dim parID As Long o!L1Qrh  
    Dim count As Integer ,eOOV@3C  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 6~?7CK  
    Dim tlens As Double, nlens As Double owZj Q  
    Dim curv As Double, conic As Double 1B= vrGq  
    Dim ok As Long 3;~1rw=$<  
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    Sub Main +o(t5O[G  
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        '用户输入对话框 0z/tceW'F  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Lx,"jA/  
            TextBox 220,21,40,21,.TextBox1 'default: 0 hXM8`iFW5  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 xksQMS2#  
            OKButton 40,91,90,21 C$ oY,A,  
            CancelButton 190,91,90,21 w_pEup\`  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 MBs]<(RJZ  
            TextBox 220,49,40,21,.TextBox2 'default: 4 &#v^y 3r  
        End Dialog UBqA[9  
        Dim dlg As UserDialog ZT4._|2  
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        ok = Dialog (dlg)  Fwyv>U  
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        If ok=0 Then    'cancel button was pressed r4dG83qg  
            Print "Execution cancelled." ,)'!E^n  
            End |M#b`g$JO,  
        End If _IOeO  
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        'Assign accommodation and pupil diameter & use defaults if field left empty QZef=  
        If dlg.TextBox1 = "" Then X'.}#R1  
            A = 0           'Default accommodation QD]Vfj4+  
        Else o,9E~Q'`{  
            A = CDbl(dlg.TextBox1) 5 g99t$p9  
        End If ?H eC+=/Z  
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        If dlg.TextBox2 = "" Then ^tsIgK^9H  
            pupilDiam = 4   'Default pupil diameter LdI)  
        Else 6[wej$ u  
            pupilDiam = CDbl(dlg.TextBox2) yxQxc5/X)  
        End If 4Cke(G  
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        Print " " 'Kxs>/y3  
        Print "Accommodation = " & A & " Diopters" \.myLkm  
        Print "Pupil Diameter = " & pupilDiam & " mm" !vfjo[v  
    "6^tG[G%  
        ' Calculate new parameters with accommodation \6)l(b;  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness H&E c *MT  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens v3Tr6[9  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 0`"]mYH  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 6hXL`A&},  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 1lfkb1BM  
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        tlens = 3.767 + 0.04*A                  'Lens thickness X/lLM`  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \E9Z H3;  
    @cAv8i K  
        'Adjust parameters to account for accommodation D^=_408\  
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        '************************************************************************* -Vn9YeH+  
        'Aqueous thickness (Position of Lens) AnU,2[(  
        '************************************************************************* Vi23pDZ5  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) /tc*jXB  
        GetCustomElement eID, entity F)j-D(c4  
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        parID = FindFullName( "Geometry.Arizona Eye" ) :g2?)Er-  
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        ' Delete any shift(s) in z Bt[`p\p@  
        count = 0 %Z 9<La  
        While GetOperationCount(eID)>count 8/U=~*` _  
            GetOperation eID, count, op Ah='E$t  
            If op.Type="ShiftZ" Then Hhr/o~?;}#  
                DeleteOperation eID,count {\ P$5O{%  
                count=count-1 { > {|3  
            End If cn v4!c0  
            count=count+1 l^:m!SA_  
        Wend m'KY;C  
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        'Set new shift in kwMuL>5  
        op.Type = "ShiftZ" = PcmJG]  
        op.val1 = taq 'M|W nR  
        op.parent = parID \U4O*lq  
        AddOperation eID, op kCL)F\v"iT  
        Print "Set aqueous humor thickness = " & taq-0.55 a k@0M[d  
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        '************************************************************************* m/| >4~  
        'Radius and conic constant of anterior lens 4wX{N   
        '************************************************************************* chQt8Ar3  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ^-w:D  
        GetConic eID, entity, curv, conic 7e/Uc!&*  
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        SetConic eID, entity, 1/Rant, CCant }+nC}A"BC  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ! o:m*:  
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        '************************************************************************* lInq=  
        'Radius and conic constant of posterior lens 24:;vcb  
        '************************************************************************* ; @ h{-@  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +)^F9LPl  
        GetConic eID, entity, curv, conic >1`FR w<  
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        SetConic eID, entity, 1/Rpost, CCpost 2" ~!Pu^.j  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;/N[tO?Q  
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        '************************************************************************* `FH Hh  
        'Lens thickness (Position of posterior lens surface) 0AY23/  
        '************************************************************************* S]KcAz(fX  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) o\@1\#a  
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        ' Delete any z-shift(s) ^b~&}uU  
        count = 0 }pbyC  
        While GetOperationCount(eID)>count W'E!5T^  
            GetOperation eID, count, op Vl{CD>$,  
            If op.Type="ShiftZ" Then <^U B@'lCm  
                DeleteOperation eID,count p^&' C_?  
                count=count-1 4;M  
            End If mn{8"@Z  
            count=count+1 nZfTK>)A0  
        Wend +uM1#-+h  
    {:IOTy  
        'Set new z-shift Bz_['7D  
        op.Type = "ShiftZ" COOazXtW  
        op.val1 = tlens ?g}n$%*5y!  
        op.parent = parID +Q_X,gZ  
        AddOperation eID, op Y$--Hp4   
        Print "Set lens thickness = " & tlens /"- k ;jz  
    ];R5[%:5  
        '************************************************************************* n>Y3hY  
        'Lens index of refraction 5>t&)g  
        '************************************************************************* lN,b@;  
        eID = FindMaterial( "Lens" ) !aeL*`;  
        GetModelMaterial eID, mat d0>V^cB'?  
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        mat.Nd = nlens RecA?-0  
        SetModelMaterial eID, mat ~2 T_)l?  
        Print "Set lens index of refraction = " & nlens LXVm0IOFF  
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        '************************************************************************* q+x4Od3  
        'Pupil diameter P0Ds7xh]h  
        '************************************************************************* WVftLIJ  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Fla[YWS  
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        'Adjust pupil diameter (trimming volume inner hole) "monuErg&  
    +%>s\W+?]  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" si/F\NDT   
    j$Vv'on  
        ' Adjust pupil location to just in front of the lens eE>3=1d]w  
        parID = FindFullName( "Geometry.Arizona Eye" ) f/Grem  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) =9\=5_V  
        count = 0 S&6}9r  
        While GetOperationCount(eID)>count $ e+@9LNK  
            GetOperation eID, count, op %aaOws  
            If op.Type="ShiftZ" Then W2wDSP-   
                DeleteOperation eID,count Umm_FEU#]  
                count=count-1 Q0gO1 T  
            End If ,vrdtL  
            count=count+1 ""^9WLH4g-  
        Wend Vt5%A}.VQ  
        op.Type = "ShiftZ" hAOXOj1  
        op.val1 = taq-0.01 Gc~A,_(  
        op.parent = parID $.QnM  
        AddOperation eID, op fm;1Iu#  
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        Print "Set pupil diameter = " & pupilDiam V{HZ/p_Y  
    *-ZD-B*?  
        'Update AZ Eye subassembly Description itm;,Sbg  
        eID = FindFullName( "Geometry.Arizona Eye" ) q+~z# jFX  
        GetEntity eID, entity GLwL'C'591  
        entity.Description = "Accommodation = " & A & "D" =P'=P0G  
        SetEntity eID, entity +; C|5y  
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        Update 3HO 4 h\mp  
        Print "DONE!" ~`#.ZMO  
         a,d\< mx  
    End Sub 56G5JSB=\  
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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: MQQiQ 2  
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    Accommodation = 4 Diopters {Xwin $C  
    Pupil Diameter = 4 mm <z#r3J  
    Set aqueous humor thickness = 2.81 %N/I;`  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 B6 x5E  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 `y;&M8.  
    Set lens thickness = 3.927 b[uTt'p}  
    Set lens index of refraction = 1.42672 nkS6A}i3o  
    Set pupil diameter = 4 }C/}8<  
    DONE! ?b#/*T}ac  
     
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