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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 wEJzLFCn  
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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。 Dh?I   
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    模型 W7!iYxO  
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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。 R:R<Xt N`5  
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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. kLU-4W5t  
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    光源 5/7(>ivn  
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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。 Q[K)Yd  
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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。 a_?b <  
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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。 ?2dI8bG  
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    图2. 字母F光源的设定方法光 )7o? }"I  
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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 18Z1F  
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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。 ~ A=Gra  
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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。 " r o'?  
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    图5. 视网膜重点采样规格设定
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    脚本 0`-b57lF&  
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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: ,$> l[G;Bm  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 i$PO#}  
    余下的脚本计算与屈光度有关的所有参数。 ^7YNM<_%@  
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    分析 mTxqcQc:7  
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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。 O#=%t  
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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 {5<fvMO!6  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. n-l_PhPQ`  
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    Dim entity As T_ENTITY -bHlFNRm  
    Dim op As T_OPERATION c3g`k"3*`  
    Dim mat As T_MODELMATERIAL dgoAaS2M  
    Dim A As Double t(uvc{K *  
    Dim pupilDiam As Double *URT-+'  
    Dim eID As Long m:[I$b6AY  
    Dim parID As Long WGUw`sc\  
    Dim count As Integer 4^bt~{}  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 9,`i[Dzp  
    Dim tlens As Double, nlens As Double a{hc{  
    Dim curv As Double, conic As Double R )Arr77  
    Dim ok As Long /3~L#jS  
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    Sub Main 5}ftiy[Yc  
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        '用户输入对话框 U{M3QOF  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ?{B5gaU9F  
            TextBox 220,21,40,21,.TextBox1 'default: 0 nM2<u[{gF  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 A?!RF7v  
            OKButton 40,91,90,21 52tc|j6~#  
            CancelButton 190,91,90,21 ~a`[p\  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 0r1GGEW`s  
            TextBox 220,49,40,21,.TextBox2 'default: 4 __.MS6"N  
        End Dialog C:5- h(#  
        Dim dlg As UserDialog N n FR;  
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        ok = Dialog (dlg) i:0v6d  
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        If ok=0 Then    'cancel button was pressed J~]@#=,v  
            Print "Execution cancelled." =N\; ?eF(  
            End L4m Vk  
        End If jL"V0M]c  
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        'Assign accommodation and pupil diameter & use defaults if field left empty iiIns.V  
        If dlg.TextBox1 = "" Then bAZoi0LR  
            A = 0           'Default accommodation ;98b SR/  
        Else EpMxq7*  
            A = CDbl(dlg.TextBox1) 9Sxr9FLW~  
        End If :)lG}c  
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        If dlg.TextBox2 = "" Then nJN-U+)u  
            pupilDiam = 4   'Default pupil diameter W{"sB:E  
        Else \~E?;q!  
            pupilDiam = CDbl(dlg.TextBox2) nZ(]WPIN"  
        End If v7 *L3Ol  
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        Print " " x'x5tg  
        Print "Accommodation = " & A & " Diopters" =?6c&Z  
        Print "Pupil Diameter = " & pupilDiam & " mm" Intuda7e1  
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        ' Calculate new parameters with accommodation h2Nt@  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness s;OGb{H7  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens M0fN[!*z  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens qS/}aDk&  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 8c)GUx  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens {kk%_q  
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        tlens = 3.767 + 0.04*A                  'Lens thickness -K =.A* }  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction K'Ywv@  
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        'Adjust parameters to account for accommodation -a)1L'R  
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        '************************************************************************* ]{6/6jl  
        'Aqueous thickness (Position of Lens) {q)d  
        '************************************************************************* %@Gy<t,  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) _HHvL=  
        GetCustomElement eID, entity 8)1q,[:M  
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        parID = FindFullName( "Geometry.Arizona Eye" ) AyO%,6p[  
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        ' Delete any shift(s) in z paIjXaU1Mb  
        count = 0 Z|n|gxe  
        While GetOperationCount(eID)>count /=p[k^A  
            GetOperation eID, count, op $UH:r  
            If op.Type="ShiftZ" Then $M)i]ekm  
                DeleteOperation eID,count c36p+6rJk=  
                count=count-1 (Ut8pa+yX  
            End If !YAX.e  
            count=count+1 5,gT|4|B\g  
        Wend RD:G 9[  
    MWv@]P_0p!  
        'Set new shift in $VHIU1JjZ  
        op.Type = "ShiftZ" 9?,i+\)qK@  
        op.val1 = taq `#ruZM066  
        op.parent = parID GfELL `yz  
        AddOperation eID, op wPM>-F  
        Print "Set aqueous humor thickness = " & taq-0.55 6AJk6 W^Z  
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        '************************************************************************* dzOco)y  
        'Radius and conic constant of anterior lens p$ \>3\  
        '************************************************************************* ~6i'V?>  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) }"TQ\v$  
        GetConic eID, entity, curv, conic i4|R0>b  
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        SetConic eID, entity, 1/Rant, CCant $@'BB=i  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ?-)!dl%N  
    ({j8|{)+  
        '************************************************************************* IADHe\.  
        'Radius and conic constant of posterior lens &K0b3AWc  
        '************************************************************************* GmR3 a  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Li6|c*K'  
        GetConic eID, entity, curv, conic xZ`z+)  
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        SetConic eID, entity, 1/Rpost, CCpost pZ>yBY?R8>  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost I0zx'x)F  
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        '*************************************************************************  !vf:mMo  
        'Lens thickness (Position of posterior lens surface) CKn2ZL  
        '************************************************************************* "HJ^>%ia  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Bn]=T  
    i=#`7pt%'a  
        ' Delete any z-shift(s) B$2b =\  
        count = 0 .1[.f}g$J  
        While GetOperationCount(eID)>count D:Q#%wJ  
            GetOperation eID, count, op 32 i6j  
            If op.Type="ShiftZ" Then ~g=& wT11  
                DeleteOperation eID,count d/9YtG%q  
                count=count-1 =T9h7c R  
            End If #sc!H4  
            count=count+1 P_5aHeiJ  
        Wend Eto"B"  
    a5#G48'X  
        'Set new z-shift /7D5I\  
        op.Type = "ShiftZ" HMF2sc$N  
        op.val1 = tlens qt@/  
        op.parent = parID ym{@w3"S  
        AddOperation eID, op O(W"QY  
        Print "Set lens thickness = " & tlens R/v|ZvI  
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        '************************************************************************* !-}Q{<2@W  
        'Lens index of refraction &AJ bx  
        '************************************************************************* our ^J8  
        eID = FindMaterial( "Lens" ) X0 |U?Ib?  
        GetModelMaterial eID, mat Vbv^@Kp  
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        mat.Nd = nlens 0FcDO5ia  
        SetModelMaterial eID, mat ="$w8iRU  
        Print "Set lens index of refraction = " & nlens ,CyX*k8o  
    <CVX[R]U  
        '************************************************************************* mj'~-$5T  
        'Pupil diameter 5&s6(?,Eu  
        '*************************************************************************  <)TIj6  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ( 3B1X  
    c]E pg)E  
        'Adjust pupil diameter (trimming volume inner hole) @}4>:\es  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" i$] :Y`3h  
    :<P4=P P  
        ' Adjust pupil location to just in front of the lens KhWy  
        parID = FindFullName( "Geometry.Arizona Eye" ) E'\gd7t ;  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Fl.?*KBz  
        count = 0 !d()'N  
        While GetOperationCount(eID)>count YxM\qy {Vr  
            GetOperation eID, count, op 1!^BcrG.  
            If op.Type="ShiftZ" Then 5L c@=,/0  
                DeleteOperation eID,count ,Sgo_bC/|  
                count=count-1 }BM`4/  
            End If \L(jNN0_R  
            count=count+1 neu+h6#H  
        Wend b~&cYk'  
        op.Type = "ShiftZ" %EU_OS(u.{  
        op.val1 = taq-0.01 ouCh2Y/_  
        op.parent = parID ` 1+*-g^r  
        AddOperation eID, op W\Pd:t  
    N-2#-poDe  
        Print "Set pupil diameter = " & pupilDiam /rZk^/'  
    ynA_Z^j  
        'Update AZ Eye subassembly Description :4zPYG o  
        eID = FindFullName( "Geometry.Arizona Eye" ) &qWg$_Yh  
        GetEntity eID, entity ,5zY1C==Ut  
        entity.Description = "Accommodation = " & A & "D" B`QF;,3S  
        SetEntity eID, entity S=P}Jpq?Y;  
    WILa8"M  
        Update AT I=&O`  
        Print "DONE!" dsw^$R}   
         =k<b* 8  
    End Sub ;cf$u}+  
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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: D-@6 hWh~  
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    Accommodation = 4 Diopters {Yxvb**  
    Pupil Diameter = 4 mm 8US35t:M  
    Set aqueous humor thickness = 2.81 4OM ]8I!  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 (+v':KH3_  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 :a Cf@:']  
    Set lens thickness = 3.927 &c-V QP(  
    Set lens index of refraction = 1.42672 BD]J/o  
    Set pupil diameter = 4 !KXcg9e  
    DONE! ;sA 5&a>!  
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    QQ:2987619807 w;@v#<q6  
     
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