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    [分享]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: 2020-12-09
    简介 g.wp }fz  
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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。 9yU(ei:GUo  
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    模型 >K }j}M%  
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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。 )-D{]>8  
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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. {}r#s>  
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    光源 T5* t~`bfU  
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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。 bC_qoI<  
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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。 z_Em%X  
    #2`ST=#  
    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。 F1m 1%  
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    图2. 字母F光源的设定方法光 ^|u7+b'|t  
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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 :{:R5d(_I  
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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。 ,8=`Y9#  
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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。 V*xo3hU  
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    图5. 视网膜重点采样规格设定
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    脚本 >XTDN  
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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<V[:~-o  
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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。 +JyD W%a:L  
    余下的脚本计算与屈光度有关的所有参数。 &@g~o0  
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    分析 EC`!&Yp+  
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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*Z8C9)  
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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 *Sd}cDCO%  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. y\a@'LFL  
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    Dim entity As T_ENTITY ID{62>R  
    Dim op As T_OPERATION )$EmKOTt:  
    Dim mat As T_MODELMATERIAL Ff eX;pi  
    Dim A As Double Ch] `@(l  
    Dim pupilDiam As Double v&7yqEm}B  
    Dim eID As Long "3&bh>#qY  
    Dim parID As Long L=7Y~aL=  
    Dim count As Integer 9Dat oi  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double EgE% NY~  
    Dim tlens As Double, nlens As Double vkR,Sn  
    Dim curv As Double, conic As Double `, lnBP3D"  
    Dim ok As Long 4Nb&(p  
    %`]&c)&#Z  
    Sub Main r$8(Q'  
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        '用户输入对话框 (h8RthQt  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 8QJ^@|7  
            TextBox 220,21,40,21,.TextBox1 'default: 0 DB=^Z%%Z  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 /JqNiqvh  
            OKButton 40,91,90,21 i?HN  
            CancelButton 190,91,90,21 Z2t'?N|_  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 )ajF ca@v  
            TextBox 220,49,40,21,.TextBox2 'default: 4 q0m> NA   
        End Dialog S9 p*rk ~  
        Dim dlg As UserDialog K/flg|uZ/V  
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        ok = Dialog (dlg) iQT$#"m n  
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        If ok=0 Then    'cancel button was pressed &UFj U%Z%  
            Print "Execution cancelled." 'DhH:PR  
            End ,J@A5/B,AA  
        End If JEL.*[/  
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        'Assign accommodation and pupil diameter & use defaults if field left empty RJ+["[k  
        If dlg.TextBox1 = "" Then -$2B!#]3  
            A = 0           'Default accommodation HV?Q{X K.b  
        Else iB XS   
            A = CDbl(dlg.TextBox1) 4[XiD*  *  
        End If &6@# W]_  
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        If dlg.TextBox2 = "" Then rOo |.4w  
            pupilDiam = 4   'Default pupil diameter )N'-A p$g  
        Else F97HFt6{  
            pupilDiam = CDbl(dlg.TextBox2) U =i=E}'  
        End If ;irAq|  
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        Print " " o>l/*i0I  
        Print "Accommodation = " & A & " Diopters" lf9mdbm  
        Print "Pupil Diameter = " & pupilDiam & " mm" N51e.;  
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        ' Calculate new parameters with accommodation my}l?S[2d@  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness )*`cJ_t  
    P+Q}bTb8  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 4/N{~  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens +H  SKFp  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ]r(&hqdR  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens \c\z 6;j  
    (7 O?NS  
        tlens = 3.767 + 0.04*A                  'Lens thickness 0F-%C>&g  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 3%(BZ23  
    -}CMNh   
        'Adjust parameters to account for accommodation oXgi#(y  
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        '************************************************************************* V6!1(|  
        'Aqueous thickness (Position of Lens) hQ80R B  
        '************************************************************************* >$:_M*5  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) v\G+t2{  
        GetCustomElement eID, entity )qeed-{  
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        parID = FindFullName( "Geometry.Arizona Eye" ) (7A-cC  
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        ' Delete any shift(s) in z *3A)s O  
        count = 0 H$k2S5,,z  
        While GetOperationCount(eID)>count l_i&8*=Px  
            GetOperation eID, count, op *cy!PF&  
            If op.Type="ShiftZ" Then 2I>`{#fV  
                DeleteOperation eID,count c2Yrg@) [  
                count=count-1 Xk9 8%gv  
            End If :;URLl0  
            count=count+1 uhvn1"  
        Wend oqa8v6yG'  
    q^ eLbivVE  
        'Set new shift in h1+y.4  
        op.Type = "ShiftZ" bWg!/K55  
        op.val1 = taq V)Ze> Pp  
        op.parent = parID 4XgzNwm  
        AddOperation eID, op <T`&NA@%~$  
        Print "Set aqueous humor thickness = " & taq-0.55 YZZog6%  
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        '************************************************************************* 6){nu rDBG  
        'Radius and conic constant of anterior lens c+ukVn`r  
        '************************************************************************* & R,QJ4L  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) PB;j4  
        GetConic eID, entity, curv, conic 'Gqo{wl  
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        SetConic eID, entity, 1/Rant, CCant YM&i  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant <N8z<o4rku  
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        '************************************************************************* Gx;-1  
        'Radius and conic constant of posterior lens srryVqgS  
        '************************************************************************* ~BC~^ D&WD  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +ctJV>  
        GetConic eID, entity, curv, conic [8'^"  
    VK% j45D`  
        SetConic eID, entity, 1/Rpost, CCpost er.;qV'Wz6  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ,0aRHy_^  
    qoSZ+ khS$  
        '************************************************************************* KtcuGI/A  
        'Lens thickness (Position of posterior lens surface) 42=/$V  
        '************************************************************************* /Q2HN(Y  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Rnw v/)  
    E&;;2  
        ' Delete any z-shift(s) T'-kG"lb  
        count = 0 (s,u9vj=>L  
        While GetOperationCount(eID)>count ut^6UdJ+`  
            GetOperation eID, count, op ;v5Jps2^]  
            If op.Type="ShiftZ" Then [tkP2%1  
                DeleteOperation eID,count d0YQLh  
                count=count-1 '[p0+5*x  
            End If Xb.# =R  
            count=count+1 ({mlA`d]  
        Wend bO+ e?&vQ%  
    #c(BBTuX  
        'Set new z-shift )CD-cz6n  
        op.Type = "ShiftZ" {Z}zT1kA  
        op.val1 = tlens cd;~60@K  
        op.parent = parID #:=*n(GT  
        AddOperation eID, op ~H:.&'E  
        Print "Set lens thickness = " & tlens a*qc  
    zYEb#*Kar  
        '************************************************************************* &%4A3.qE  
        'Lens index of refraction EMf"rGXu(  
        '************************************************************************* 7Mb-v}  
        eID = FindMaterial( "Lens" ) sOm&7A?  
        GetModelMaterial eID, mat ,"f2-KC4h  
    !=?Q>mz  
        mat.Nd = nlens Bp/25jy  
        SetModelMaterial eID, mat QG 1vP.K  
        Print "Set lens index of refraction = " & nlens BOme`0A  
    UB]]oC<  
        '************************************************************************* \R,8xID_t  
        'Pupil diameter *l)}o4-$  
        '************************************************************************* rSKZc`<^  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) gp4@6HuUd  
    Xz"xp8Hc(6  
        'Adjust pupil diameter (trimming volume inner hole) lL*"N|Y  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Hd{@e6S  
    @DK`#,  
        ' Adjust pupil location to just in front of the lens }^azj>p5  
        parID = FindFullName( "Geometry.Arizona Eye" ) ddEV@2F  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) }Io5&ww:U  
        count = 0 [E0.4FLT!  
        While GetOperationCount(eID)>count Dyh|F\T  
            GetOperation eID, count, op $ spk.j  
            If op.Type="ShiftZ" Then Hx NoV.q  
                DeleteOperation eID,count 0A F}wz>  
                count=count-1 c"pu"t@/Z  
            End If ORhvo,.u  
            count=count+1 I~ e,']  
        Wend ._6e#=  
        op.Type = "ShiftZ" 8>[o. xV  
        op.val1 = taq-0.01 .QB)Y* z  
        op.parent = parID 0xc|Wn>  
        AddOperation eID, op RU% 4~WC  
    MGsY3~!K  
        Print "Set pupil diameter = " & pupilDiam O|*-J  
    SzyaVBD3  
        'Update AZ Eye subassembly Description !rff/0/x"  
        eID = FindFullName( "Geometry.Arizona Eye" ) N]&:xd5  
        GetEntity eID, entity @k\npFKQm  
        entity.Description = "Accommodation = " & A & "D" {=9"WN    
        SetEntity eID, entity [I=1   
    ,OBJ>_5  
        Update !_>o2  
        Print "DONE!"  e,T^8_>  
         y':65NMda  
    End Sub /.Jq]"   
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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: CM;B{*En  
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    Accommodation = 4 Diopters z|O3pQn~  
    Pupil Diameter = 4 mm $8>II0C.  
    Set aqueous humor thickness = 2.81 *@g>~q{`  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 6@Ir|o  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 9z7rv,  
    Set lens thickness = 3.927 HH|N~pBJB  
    Set lens index of refraction = 1.42672 |};-.}u^`h  
    Set pupil diameter = 4 1'b}Y 8YO  
    DONE! tfVlIY<  
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    QQ:2987619807 '?d5L+9  
     
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