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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 'b[O-6v  
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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。 7F2:'3SQ  
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    模型 -=lL{oB1  
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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。 U![$7k>,pr  
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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. < )_#6)z:  
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    光源 @qWClr{`  
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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。 2t0VbAO 1{  
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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。 ^?q(fK%  
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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。 n Jz*}=  
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    图2. 字母F光源的设定方法光 SN7_^F  
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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 8t7r^[T  
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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。 < uV@/fn<  
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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。 z)eNM}cF  
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    图5. 视网膜重点采样规格设定
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    脚本 ;<cCT!A  
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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: ^4[QX -_2  
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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。 l r~>!O  
    余下的脚本计算与屈光度有关的所有参数。 'Vhnio;qC  
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    分析 rc`Il{~k  
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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。 ^|!\IzDp  
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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 6@d/k.3p  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. &u) qw }  
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    Dim entity As T_ENTITY SM<qb0  
    Dim op As T_OPERATION r $LU$F  
    Dim mat As T_MODELMATERIAL f?@M"p@T  
    Dim A As Double -O@/S9]S)  
    Dim pupilDiam As Double '1G0YfG}n  
    Dim eID As Long ~jWpD7px  
    Dim parID As Long mndEB!b  
    Dim count As Integer 6Tq2WZ}<'  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Ghe@m6|D  
    Dim tlens As Double, nlens As Double ILHn~d IC  
    Dim curv As Double, conic As Double l`:-B 'WM  
    Dim ok As Long kWbY&]ZO  
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    Sub Main #S|On[Q!  
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        '用户输入对话框 0 zjGL7  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 1"1ElH  
            TextBox 220,21,40,21,.TextBox1 'default: 0 On+0@hh  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 zHW&i~  
            OKButton 40,91,90,21 PhmtCp0-7-  
            CancelButton 190,91,90,21 iZ(p]0aP7  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 (+TL ]9P  
            TextBox 220,49,40,21,.TextBox2 'default: 4 g(F2IpUm/  
        End Dialog a uve&y"R  
        Dim dlg As UserDialog %VrMlG4hx  
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        ok = Dialog (dlg) You~ 6d6Om  
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        If ok=0 Then    'cancel button was pressed D6P/39}W  
            Print "Execution cancelled." N VDvd6  
            End 368H6 Jj  
        End If od3b,Q  
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        'Assign accommodation and pupil diameter & use defaults if field left empty NE@P8pQ>  
        If dlg.TextBox1 = "" Then 7. eiM!7g  
            A = 0           'Default accommodation ><)fK5x  
        Else u3PM 7z!~  
            A = CDbl(dlg.TextBox1) ]mi)x6 3^  
        End If 7{[i)  
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        If dlg.TextBox2 = "" Then (8GA;:G7G  
            pupilDiam = 4   'Default pupil diameter )U2%kmt  
        Else \@7 4I7  
            pupilDiam = CDbl(dlg.TextBox2) DEenvS`,P  
        End If w< |Lx#L}  
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        Print " " rT{ 2  
        Print "Accommodation = " & A & " Diopters" K$ |!IXs  
        Print "Pupil Diameter = " & pupilDiam & " mm" t`x_@pr  
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        ' Calculate new parameters with accommodation PO0/C q)  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Sr6?^>A@t  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ,j[1!*Z_[  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens .wuRT>4G)G  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens fR lJ`\ t  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens p,2H8I){  
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        tlens = 3.767 + 0.04*A                  'Lens thickness ze#ncnMo  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction I8:G:s:  
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        'Adjust parameters to account for accommodation |Fzt| \  
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        '************************************************************************* { *Wc`ZBY  
        'Aqueous thickness (Position of Lens) zm^ 5WH  
        '************************************************************************* _jk+$`[9PL  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) l8N5}!N  
        GetCustomElement eID, entity ^|%7}=e  
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        parID = FindFullName( "Geometry.Arizona Eye" )  W o$UV  
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        ' Delete any shift(s) in z "I45=nf  
        count = 0 >  ,P,{"  
        While GetOperationCount(eID)>count x@<!#d+  
            GetOperation eID, count, op )$E'2|Gm/  
            If op.Type="ShiftZ" Then ?B:],aztf  
                DeleteOperation eID,count lJBZ0  
                count=count-1 ;UWp0d%  
            End If 7e<\11uI]a  
            count=count+1 ~ePtK~,dv  
        Wend o%73M!-  
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        'Set new shift in 3+:uV  
        op.Type = "ShiftZ" $ 4A!Y  
        op.val1 = taq V4x6,*)e  
        op.parent = parID \&%y4=y<sE  
        AddOperation eID, op 3- 4jSN\  
        Print "Set aqueous humor thickness = " & taq-0.55 AG,;1b,:81  
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        '************************************************************************* ~2?UEv6  
        'Radius and conic constant of anterior lens %'[ pucEF  
        '************************************************************************* %{";RfSVX%  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 0XrOOYmx  
        GetConic eID, entity, curv, conic vTYgWR,h  
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        SetConic eID, entity, 1/Rant, CCant >U') ICD~  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 3x~AaC.j  
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        '************************************************************************* ^]?Yd)v  
        'Radius and conic constant of posterior lens 05vu{>  
        '************************************************************************* 8]0?mV8iOE  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) |0a GX]Y  
        GetConic eID, entity, curv, conic Qx !! Ttd{  
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        SetConic eID, entity, 1/Rpost, CCpost oJ)v6"j  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost . aqP=  
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        '************************************************************************* I'16-  
        'Lens thickness (Position of posterior lens surface) 7)+%;|~  
        '************************************************************************* &5;y&dh  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) W/I D8+:i  
    lIL{*q(  
        ' Delete any z-shift(s) |m>n4 -5QL  
        count = 0 h2Jdcr#@FF  
        While GetOperationCount(eID)>count dq$C COC^F  
            GetOperation eID, count, op r=pb7=M#LN  
            If op.Type="ShiftZ" Then z[ N_3n  
                DeleteOperation eID,count q5(Z   
                count=count-1 FUU/=)^P$  
            End If (Qys`D   
            count=count+1 $8,/[V A  
        Wend ]gGCy '*)  
    * ;C8g{  
        'Set new z-shift " ^:$7~%bA  
        op.Type = "ShiftZ" h^6Yjy  
        op.val1 = tlens B[Fuyy?  
        op.parent = parID i#y3QCNqf^  
        AddOperation eID, op -,#LTW<.  
        Print "Set lens thickness = " & tlens {^n\ r^5  
    k/ ZuFTN  
        '************************************************************************* `m Tc  
        'Lens index of refraction -#?p16qz5  
        '************************************************************************* ec` $2u  
        eID = FindMaterial( "Lens" ) ew cgg  
        GetModelMaterial eID, mat V2?&3Z) W  
    "ZyWU f  
        mat.Nd = nlens ]tVXao  
        SetModelMaterial eID, mat 2i~qihx5^  
        Print "Set lens index of refraction = " & nlens g"Z X1X  
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        '************************************************************************* J]|lCwF  
        'Pupil diameter \aO.LwYm;:  
        '************************************************************************* q#~]Hp=W5  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) |E)IJj 3  
    (^Kcyag4  
        'Adjust pupil diameter (trimming volume inner hole) !zNMU$p  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" h8!;RN[  
    z3[0BWXs  
        ' Adjust pupil location to just in front of the lens :i6k6=  
        parID = FindFullName( "Geometry.Arizona Eye" ) a/wkc*}}/  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 5CsJghTw  
        count = 0 /U%Xs}A)  
        While GetOperationCount(eID)>count rn?:utP  
            GetOperation eID, count, op ZSTpA,+6  
            If op.Type="ShiftZ" Then zSi SZMP"  
                DeleteOperation eID,count vK\;CSk  
                count=count-1 ~=,|dGAa$  
            End If jF\J+:5M  
            count=count+1 1Bz'$u;  
        Wend &,Xs=Lv mq  
        op.Type = "ShiftZ" .baS mfc  
        op.val1 = taq-0.01 GBZx@B[TY  
        op.parent = parID q#RVi8('  
        AddOperation eID, op {-]/r  
    E5M*Gs  
        Print "Set pupil diameter = " & pupilDiam z.[ Ok  
    ntSPHK|'  
        'Update AZ Eye subassembly Description {[4Y(l1  
        eID = FindFullName( "Geometry.Arizona Eye" ) [D H@>:"dd  
        GetEntity eID, entity ]AGJPuX  
        entity.Description = "Accommodation = " & A & "D" zSYWNmj&  
        SetEntity eID, entity 4>gMe3]0  
    qu[x=LZ_  
        Update {=,?]Z+  
        Print "DONE!" D(&${Mnac  
         LTY@}o]\U  
    End Sub m//(1hWv7  
    .JpYZ |  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: qb ^4G  
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    Accommodation = 4 Diopters 2 f]9I1{  
    Pupil Diameter = 4 mm 4\?I4|{pC  
    Set aqueous humor thickness = 2.81 [j5 ^Zb&0  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 c(bh i  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 nYuZg6K  
    Set lens thickness = 3.927 u+zq:2)H6  
    Set lens index of refraction = 1.42672 flLC\   
    Set pupil diameter = 4 n\ma5"n0=\  
    DONE! s&lZxnIjc  
     
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