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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 V&J'2Lq  
    #7p!xf^  
    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。 L=V.@?  
    aQglA  
    模型 9 f= ~E8P  
    &r1]A&  
    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。 !p{CsR8c  
    ,d$D0w  
    Table 1. AZ眼睛模型的定义
    Pd;Gc@'~  
    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. K aNO&%qX  
    aBWA hn  
    光源 w7b\?]}@  
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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。 [Lq9lw&   
    eR:C?v  
    EjP9/V G@=  
    图1. 光源和提示信息使用
    !AN;  
    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。 0n*D](/NK  
    I9*BT T]  
    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。 /-Z}=  
    U[W &D%'  
    图2. 字母F光源的设定方法光 J7+[+Y  
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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 2&XNT-Qm  
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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。 5Kw?#  
    ry0YS\W  
    <"{VVyK  
    图4. 视网膜朗伯散射设定
    . Ky)Co  
    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。 "w3%BbIx  
    1H \  
    8yk4#CZ  
    图5. 视网膜重点采样规格设定
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    脚本 a] 7nK+N  
    @;}vK=6L  
    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: P~s u]+  
    bD. KD)5  
    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
    2@Oz_?O=  
    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。 *auT_*  
    余下的脚本计算与屈光度有关的所有参数。 jcHyRR1R  
    &cwN&XBY  
    分析 KkCsQ~po  
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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。 "EwzuM8 f  
    /h8100  
    图7. 字母F在视网膜上颜色分析
    c2-oFLNP=  
    脚本代码 R]3j6\  
    hR~&}sxN  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. l2ie\4dK@  
    '3?-o|v@D  
    Dim entity As T_ENTITY )YW"Zo8~!1  
    Dim op As T_OPERATION a[p$e?gka  
    Dim mat As T_MODELMATERIAL e8S4=W  
    Dim A As Double %<fs \J^k  
    Dim pupilDiam As Double -F_c Bu81V  
    Dim eID As Long C-XJe~  
    Dim parID As Long {.ypZ8JU  
    Dim count As Integer m|3 Q'  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Z<,Hz+  
    Dim tlens As Double, nlens As Double aJ}hlM>  
    Dim curv As Double, conic As Double _|T{2LvwT  
    Dim ok As Long |K9*><P?)2  
    2_}oOt?qiM  
    Sub Main FC WF$'cO  
    A]ZQ?- L/  
        '用户输入对话框 Gn<0Fy2  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 'KDt%?24  
            TextBox 220,21,40,21,.TextBox1 'default: 0 'x5p ?m  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 7M8cF>o  
            OKButton 40,91,90,21 -[}Aka,f!  
            CancelButton 190,91,90,21 q3C  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 "Mz#1Laby`  
            TextBox 220,49,40,21,.TextBox2 'default: 4 &hrMpD6z6i  
        End Dialog W]XM<# ^^  
        Dim dlg As UserDialog >@Pw{Zh$  
    _>ZC;+c?  
        ok = Dialog (dlg) q"EW*k+ )  
    :zY;eJKm  
        If ok=0 Then    'cancel button was pressed LH.Gf  
            Print "Execution cancelled." a,(nf1@5  
            End P^!g0K  
        End If T?RN} @D  
    \iaZV.#f  
        'Assign accommodation and pupil diameter & use defaults if field left empty (H"{r  
        If dlg.TextBox1 = "" Then 4>OS2b`.;  
            A = 0           'Default accommodation fef y`J  
        Else B!&y>Z^$  
            A = CDbl(dlg.TextBox1) &xA>(|a\&-  
        End If L9XfR$7,z  
    g rCQ#3K*?  
        If dlg.TextBox2 = "" Then rIb~@cR)  
            pupilDiam = 4   'Default pupil diameter @,7r<6E  
        Else $2+s3)  
            pupilDiam = CDbl(dlg.TextBox2) &*Xrh7K2e  
        End If E 0/>E  
    Ghc U ~  
        Print " " K^o{lyK;@~  
        Print "Accommodation = " & A & " Diopters" \o=9WKc  
        Print "Pupil Diameter = " & pupilDiam & " mm" T+aNX/c|>  
    ` &bF@$((  
        ' Calculate new parameters with accommodation d3 i(UN]  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness yf!7 Q>_G^  
    > ;#Y0  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens W -HOl!)  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens _|W&tB *  
    t- TUP>_  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens KC"&3  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens K F_Uu  
    &@'%0s9g  
        tlens = 3.767 + 0.04*A                  'Lens thickness ij#v_~g3  
    ,X1M!'  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction U;TS7A3  
    kZo# Ny  
        'Adjust parameters to account for accommodation w=<E)  
    UJQTArf  
        '************************************************************************* d}tmZ*q  
        'Aqueous thickness (Position of Lens) 6" Lyv  
        '************************************************************************* mtkZF{3Jx  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~k-'  
        GetCustomElement eID, entity \!30t1EZ  
    G6qZ>-GiL  
        parID = FindFullName( "Geometry.Arizona Eye" ) D\+x/r?-I  
    ' `c \Dq  
        ' Delete any shift(s) in z G_5{5Ar  
        count = 0  maHz3:  
        While GetOperationCount(eID)>count B~k{f}  
            GetOperation eID, count, op Mpyza%zj  
            If op.Type="ShiftZ" Then gK;dfrU.8Y  
                DeleteOperation eID,count r7>FH!=:  
                count=count-1 7O k-T10  
            End If -?:8s v*X  
            count=count+1 AzF*4x  
        Wend /3k[3  
    V6](_w!  
        'Set new shift in N\&VJc  
        op.Type = "ShiftZ" lhJY]tQt/  
        op.val1 = taq ;di .U,  
        op.parent = parID F):kF_ho  
        AddOperation eID, op Gey-8  
        Print "Set aqueous humor thickness = " & taq-0.55 H.]V-|U  
    BeQ'\#q,  
        '************************************************************************* l3BN,HNv+  
        'Radius and conic constant of anterior lens 88 X]Uw(+  
        '************************************************************************* VyN F)$'T  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) &&52ji<3  
        GetConic eID, entity, curv, conic 9S17Lr*c  
    UMBeY[ ?  
        SetConic eID, entity, 1/Rant, CCant x1`(Z|RJ  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 9<y{:{i  
    K$D+TI)  
        '************************************************************************* Lg,ObVt!  
        'Radius and conic constant of posterior lens eN|zD?ba&  
        '************************************************************************* ZL0k  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) mt0v (  
        GetConic eID, entity, curv, conic E&z^E2  
    zVtTv-DU  
        SetConic eID, entity, 1/Rpost, CCpost A{B$$7%  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost W ^Fkjqpv  
    J Q*~le*  
        '************************************************************************* MIl\Bn  
        'Lens thickness (Position of posterior lens surface) roAHkI  
        '************************************************************************* g8&& W_BI  
    ]e5aHpgR=  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) |0u qW1  
    4IB`7QJq  
        ' Delete any z-shift(s) `|"o\Bg<  
        count = 0 .Wp(@l'Hd  
        While GetOperationCount(eID)>count 8KigGhY'ms  
            GetOperation eID, count, op r/0 #D+A  
            If op.Type="ShiftZ" Then :N^B54o%6  
                DeleteOperation eID,count )>b1%x} =  
                count=count-1 y c<%f  
            End If P| ?nx"c  
            count=count+1 WdC7CK  
        Wend s2QgR37s>  
    pp*MHM)x|q  
        'Set new z-shift Yz0HB EA  
        op.Type = "ShiftZ" o](ORS$~  
        op.val1 = tlens :4X,5X7tW=  
        op.parent = parID y|*4XF<b  
        AddOperation eID, op X2| Z!  
        Print "Set lens thickness = " & tlens *kF/yN  
    ,g?M[(wtc  
        '************************************************************************* Vu~fF@ |  
        'Lens index of refraction +|+fDQI  
        '************************************************************************* )PU\|I0|)e  
        eID = FindMaterial( "Lens" ) 0{o 8-#  
        GetModelMaterial eID, mat R*W1<W%q=  
    cw~GH  
        mat.Nd = nlens wT;;B=u}G  
        SetModelMaterial eID, mat F3Da-6T@  
        Print "Set lens index of refraction = " & nlens W0U|XX!&  
    em^2\*sxpA  
        '************************************************************************* s%> u[-9U  
        'Pupil diameter U'5p;j)_  
        '************************************************************************* .g}Y! l  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) [tt_>O  
    DX3jE p2  
        'Adjust pupil diameter (trimming volume inner hole) MfLus40;n  
    R~TG5^(  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" rvnm*e,  
    M5`m5qc3  
        ' Adjust pupil location to just in front of the lens _ J"J[$  
        parID = FindFullName( "Geometry.Arizona Eye" ) QiRx2Z*\  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) }gX4dv B  
        count = 0 Xe/7rhov  
        While GetOperationCount(eID)>count ;yZY2)L   
            GetOperation eID, count, op cx)x="c  
            If op.Type="ShiftZ" Then hiR+cPSF  
                DeleteOperation eID,count 7#*O|t/'  
                count=count-1 ' e x/IqbK  
            End If Pm24;'  
            count=count+1 a,M/i&.e`  
        Wend ]Qx-f* D6  
        op.Type = "ShiftZ" )5;|mV  
        op.val1 = taq-0.01 ?PB}2*R  
        op.parent = parID \jkDRR[  
        AddOperation eID, op V-i:t,*lk(  
    <sGioMr  
        Print "Set pupil diameter = " & pupilDiam &j{I G`Trl  
    )@.ODW;`  
        'Update AZ Eye subassembly Description wYHyVY2tj2  
        eID = FindFullName( "Geometry.Arizona Eye" ) tE=$#  
        GetEntity eID, entity A#79$[>w  
        entity.Description = "Accommodation = " & A & "D" \nVoBW(  
        SetEntity eID, entity .8|5;!`WB  
    <("P5@cExU  
        Update ,?GAFg K:  
        Print "DONE!"  _8z  
         etP`q:6^c  
    End Sub 0R,Y[).U  
    [vCZD8"Y8  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: :Sk<0VVd7  
    +n8,=}  
    Accommodation = 4 Diopters LA837%)  
    Pupil Diameter = 4 mm 90$`AMR  
    Set aqueous humor thickness = 2.81 9>5]y}.{  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 GlXzH1wZ  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 FC8= ru  
    Set lens thickness = 3.927 rk?G[C)2c  
    Set lens index of refraction = 1.42672 f6HDfJmE  
    Set pupil diameter = 4 QlxlT$o}  
    DONE! K9'AYFse  
    +(hr5  
    j7Lw( AJ  
    QQ:2987619807 @j4~`~8  
     
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