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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 " cg>g/  
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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。 t,_[nu(~8%  
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    模型 7j8_O@_  
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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。 dGe  
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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. T~>:8i  
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    光源 [qB=OxH?  
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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。 =_Rd0,  
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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。 5]E5V@C   
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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。 FmPF7  
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    图2. 字母F光源的设定方法光 OgX."pK  
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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 DNPK1e3a{  
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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。 x{E[qH_1Fm  
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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。 q2y:b qLWl  
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    图5. 视网膜重点采样规格设定
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    脚本 UWHC]V?  
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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: <OUAppH  
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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。 _~!,x.Dbp  
    余下的脚本计算与屈光度有关的所有参数。 8'y|cF%U  
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    分析 L<: ya  
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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。 #!2gxm;g  
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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 4[?Q*f!  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. rTH@PDk>)  
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    Dim entity As T_ENTITY m#Cp.|>kP4  
    Dim op As T_OPERATION )~6974  
    Dim mat As T_MODELMATERIAL NoMC* ",b>  
    Dim A As Double 3]'3{@{} H  
    Dim pupilDiam As Double 7Ny>W(8  
    Dim eID As Long ?@~FT1"6G  
    Dim parID As Long q9OIw1xQr*  
    Dim count As Integer SV.*Z|"^N  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double QwhPN'U  
    Dim tlens As Double, nlens As Double wdg[pt />  
    Dim curv As Double, conic As Double HBt?cA '  
    Dim ok As Long Y , P-@(  
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    Sub Main 2dC)%]aLme  
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        '用户输入对话框 X **w RF  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ^C(AMT  
            TextBox 220,21,40,21,.TextBox1 'default: 0 k z#DBh!&  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 BjA|H  
            OKButton 40,91,90,21 CTwP{[%Pk  
            CancelButton 190,91,90,21 8w{V[@QLn  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 k=LY 6  
            TextBox 220,49,40,21,.TextBox2 'default: 4 ?B-aj  
        End Dialog 9`xq3EL2T  
        Dim dlg As UserDialog 3}"VUS0wh  
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        ok = Dialog (dlg) toF@@ %  
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        If ok=0 Then    'cancel button was pressed ar6Z?v$  
            Print "Execution cancelled." a@%FwfIu  
            End qB8<(vBP+  
        End If ^0r @",  
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        'Assign accommodation and pupil diameter & use defaults if field left empty 6:e0?R^aD"  
        If dlg.TextBox1 = "" Then 1r;Q5[@  
            A = 0           'Default accommodation dZZHk  
        Else pM>.z9  
            A = CDbl(dlg.TextBox1) L|c01  
        End If oL<^m?-u  
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        If dlg.TextBox2 = "" Then .9`.\v6R  
            pupilDiam = 4   'Default pupil diameter l!`m}$  
        Else 7Q^t(  
            pupilDiam = CDbl(dlg.TextBox2) g >X!Q  
        End If nF7Ozxm#  
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        Print " " Orz Dr  
        Print "Accommodation = " & A & " Diopters" \wTW hr0  
        Print "Pupil Diameter = " & pupilDiam & " mm" C<{k[!N%zm  
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        ' Calculate new parameters with accommodation 9X!OQxmg  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness =s;7T!7!  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens eQMY3/#  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ,UY],;ib  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens vRm;H|[%S  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens J.~$^-&!  
    @*F NWT6  
        tlens = 3.767 + 0.04*A                  'Lens thickness ;X\,-pjv  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction x H\5T!  
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        'Adjust parameters to account for accommodation Zsaz#z|xW  
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        '************************************************************************* {gzL}KL  
        'Aqueous thickness (Position of Lens) y6;A4p>  
        '************************************************************************* ZE4~rq/W  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) {D$#m  
        GetCustomElement eID, entity zxXm9zrLo  
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        parID = FindFullName( "Geometry.Arizona Eye" ) _8kZ>w(L  
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        ' Delete any shift(s) in z 1H%LUA  
        count = 0 Ow<=K:^  
        While GetOperationCount(eID)>count 5_{C \S`T  
            GetOperation eID, count, op g;vG6!;E\  
            If op.Type="ShiftZ" Then ?PLf+S  
                DeleteOperation eID,count `5Q0U%`W  
                count=count-1 &Zd! |u  
            End If K`D>G<  
            count=count+1 Wcw$ Zv  
        Wend !fjDO!,!  
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        'Set new shift in ?~hC.5  
        op.Type = "ShiftZ" c:M~!CXO  
        op.val1 = taq X& pK#=  
        op.parent = parID zJOL\J'  
        AddOperation eID, op YrFB~z.V  
        Print "Set aqueous humor thickness = " & taq-0.55 3 rV)JA  
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        '************************************************************************* wm !Y5  
        'Radius and conic constant of anterior lens SVo:%mX  
        '************************************************************************* hgLwxJu  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) {+!m]-s  
        GetConic eID, entity, curv, conic Ak^g#^c*  
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        SetConic eID, entity, 1/Rant, CCant 5_9mA4gs@  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant L slI!.(  
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        '************************************************************************* ".Luc 7  
        'Radius and conic constant of posterior lens h%9#~gJ})  
        '************************************************************************* 1!~=8FTv  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +QGZ2_vW  
        GetConic eID, entity, curv, conic \x5b=~/   
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        SetConic eID, entity, 1/Rpost, CCpost 7='lu;=,  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost gDa}8!+i  
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        '************************************************************************* Z.ky=vCt  
        'Lens thickness (Position of posterior lens surface) 1/:WA:]1 ,  
        '************************************************************************* 1Ue )&RW  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) KLrxlD4\  
    5ro^<P0f**  
        ' Delete any z-shift(s) W_8N?coM  
        count = 0 SvLI%>B=9  
        While GetOperationCount(eID)>count $F"'= +0  
            GetOperation eID, count, op Nr8#/H2f  
            If op.Type="ShiftZ" Then SfLZVB  
                DeleteOperation eID,count b"DaLwKkz  
                count=count-1 V{+'(<SV  
            End If LVP2jTz  
            count=count+1 fP# !ywgr%  
        Wend LX2rg\a+%  
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        'Set new z-shift Dukvi;\  
        op.Type = "ShiftZ" 6}4?, r  
        op.val1 = tlens 3}~.#`QeY  
        op.parent = parID N@6+DHt  
        AddOperation eID, op wyJ+~  
        Print "Set lens thickness = " & tlens G'<:O(Imu  
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        '************************************************************************* nI]8w6eCV  
        'Lens index of refraction cuzU*QW"g  
        '************************************************************************* A{X:p3$eN  
        eID = FindMaterial( "Lens" ) AtU%S9  
        GetModelMaterial eID, mat xU<WUfS1  
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        mat.Nd = nlens n.is+2t  
        SetModelMaterial eID, mat PgHe;^?j  
        Print "Set lens index of refraction = " & nlens m#w1?y)Z@X  
    1seWR"  
        '************************************************************************* |z1er"zR)  
        'Pupil diameter  /5M0[C E  
        '************************************************************************* *WMI<w~_  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) >V1vw7Pa  
    Hw29V //  
        'Adjust pupil diameter (trimming volume inner hole) Jj%"  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" o0ky]9 P  
    `st3iTLZY  
        ' Adjust pupil location to just in front of the lens jEhPx  
        parID = FindFullName( "Geometry.Arizona Eye" ) %vn"tp  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ^cRAtoa  
        count = 0 A; _Zw[  
        While GetOperationCount(eID)>count qh9d .Q+n  
            GetOperation eID, count, op F-R5Ib-F*A  
            If op.Type="ShiftZ" Then (>]frlEU~  
                DeleteOperation eID,count gpT~3c;l=  
                count=count-1 eYtP396C|  
            End If Z-%zR'-?*  
            count=count+1 JsP<etX  
        Wend iy!SqC  
        op.Type = "ShiftZ" [/=Z2mt A  
        op.val1 = taq-0.01 C*X=nezq  
        op.parent = parID L0\~ K~q  
        AddOperation eID, op i8w/a  
    ,{6 Vf|?  
        Print "Set pupil diameter = " & pupilDiam i1dE.f ;  
    m+|yk.md  
        'Update AZ Eye subassembly Description MD98N{+[|  
        eID = FindFullName( "Geometry.Arizona Eye" ) mP*Ct6628n  
        GetEntity eID, entity 1u8 k}  
        entity.Description = "Accommodation = " & A & "D" $ U=j<^R}a  
        SetEntity eID, entity :%[mc-6.  
    ~n=oPm$pR  
        Update -#Bk  
        Print "DONE!" jhR`%aH4  
         Y;)l  
    End Sub z{H=;"+rh  
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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: eC{St0  
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    Accommodation = 4 Diopters WhT5NE9t  
    Pupil Diameter = 4 mm b9;w3Ba  
    Set aqueous humor thickness = 2.81 p!o-+@ava  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 z[Ah9tM%  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 A('o &H  
    Set lens thickness = 3.927 `O0bba=:=  
    Set lens index of refraction = 1.42672 %63s(ekU  
    Set pupil diameter = 4 v#|yr<  
    DONE! :u]QEZ@@  
     
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