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    [转载]FRED运用:Arizona眼睛模型 [复制链接]

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    离线xunjigd
     
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    只看楼主 倒序阅读 楼主  发表于: 2016-02-24
    简介 %PQldPL8  
    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。 Yw~;g: =  
    ur/Oc24i1n  
    模型 84[|qB,ML  
    0M#N=%31  
    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。 tSEA999  
    sTKab :  
    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. -d|BO[4j  
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    光源 9"WRIHt'c  
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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。 " t5 +*  
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    图1. 光源和提示信息使用
    8s QQK.N(  
    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。 D-Bv(/Pz]$  
    -/M9 vS  
    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。 J Z %`%rA  
    }Q`/K;yq  
    图2. 字母F光源的设定方法光 ijvNmn1k  
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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 e ZynF<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。 rU; g0'4e  
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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。 utq.r_  
    V)2"l"Kt  
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    图5. 视网膜重点采样规格设定
    ])N|[|$  
    脚本 >ysriPnQ  
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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: nA>*IU[  
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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。 '!pAnsXfO  
    余下的脚本计算与屈光度有关的所有参数。 =ZG<BG_  
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    分析 buRhQ"  
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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。 u06tDJ[  
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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 MO[c0n%  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. )y6QAp  
     NI^{$QMj  
    Dim entity As T_ENTITY Z#CxQ D%\  
    Dim op As T_OPERATION {":c@I  
    Dim mat As T_MODELMATERIAL M#`{>R|  
    Dim A As Double TKK,Y{{  
    Dim pupilDiam As Double aZP 2R"  
    Dim eID As Long :){)JZ}-95  
    Dim parID As Long bi+9R-=&  
    Dim count As Integer Cm^Yl p  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Xc{ZN1 4n  
    Dim tlens As Double, nlens As Double 9`&?hi49nK  
    Dim curv As Double, conic As Double ol50d73B  
    Dim ok As Long w_\nB}_  
    iA]DE`S  
    Sub Main VXiui'/(  
    [9LxhPi  
        '用户输入对话框 [U swf3  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 RZ*<n$#6  
            TextBox 220,21,40,21,.TextBox1 'default: 0 J l\'V  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 U4]30B{;H  
            OKButton 40,91,90,21 ?fB5t;~E  
            CancelButton 190,91,90,21 =`JW1dM  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 )5U !>,fT  
            TextBox 220,49,40,21,.TextBox2 'default: 4 g#w`J \iz  
        End Dialog ;"D~W#0-v  
        Dim dlg As UserDialog -=5EbNPwG  
    xF&6e&nv  
        ok = Dialog (dlg) vlvvi()  
    _wmI(+_  
        If ok=0 Then    'cancel button was pressed <o2,HTWNPS  
            Print "Execution cancelled." ^1R"7h  
            End Mw+v"l&mU  
        End If 3\1#eK'TK.  
    -ovoRI^6`}  
        'Assign accommodation and pupil diameter & use defaults if field left empty B& "RS  
        If dlg.TextBox1 = "" Then d)\2U{  
            A = 0           'Default accommodation hzv3F9.x  
        Else .wP/ai>}  
            A = CDbl(dlg.TextBox1) ;ed#+$Na  
        End If w\Iqzpikr  
    t-x[:i  
        If dlg.TextBox2 = "" Then },&h[\N{6  
            pupilDiam = 4   'Default pupil diameter pp<E))&R  
        Else 4oV {=~V  
            pupilDiam = CDbl(dlg.TextBox2) pziq0  
        End If X~Cq  
    l~NEGb  
        Print " " *Z >  
        Print "Accommodation = " & A & " Diopters" *U_S1>0n  
        Print "Pupil Diameter = " & pupilDiam & " mm" z{=v)F5y  
    ##v`(#fu  
        ' Calculate new parameters with accommodation vTHq)C.7G  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness $2QYxY9s  
    V3Yd&HVWNQ  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens lY8`5Uz  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens nZxSMN0]  
    8TW5(fl  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens GB =bG%Tb  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens )nOE 8y/  
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        tlens = 3.767 + 0.04*A                  'Lens thickness AX;c}0g  
    =DC 3a3&%  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction s%O Y<B@V2  
    eVx~n(m!}  
        'Adjust parameters to account for accommodation \sITwPA[z  
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        '************************************************************************* ]+ZM/'X  
        'Aqueous thickness (Position of Lens) {yS;NU`2  
        '************************************************************************* )b9_C O}  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) !VRo*[yD@  
        GetCustomElement eID, entity uFo/s&6K  
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        parID = FindFullName( "Geometry.Arizona Eye" ) s&VOwU  
    o,*=$/or  
        ' Delete any shift(s) in z WL1\y|  
        count = 0 Pj&A=  
        While GetOperationCount(eID)>count `;cz;"  
            GetOperation eID, count, op tDt :^Bc  
            If op.Type="ShiftZ" Then 6OtVaT=}<O  
                DeleteOperation eID,count GyK(Vb"h6  
                count=count-1 bcn7,ht  
            End If ]Jn2Ra"j  
            count=count+1 @vt$MiOi  
        Wend VE$t%QT  
    Kp&3=e;vn{  
        'Set new shift in l `R KqT+  
        op.Type = "ShiftZ" "mA1H]r3  
        op.val1 = taq `XgFga)  
        op.parent = parID PS}73Y#  
        AddOperation eID, op d@ (vg  
        Print "Set aqueous humor thickness = " & taq-0.55 ({ k7#1 h8  
    >pdnCv_c  
        '************************************************************************* ?oKL &I@  
        'Radius and conic constant of anterior lens i/*,N&^  
        '************************************************************************* ISBF\ wQY  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) *)D1!R<\,R  
        GetConic eID, entity, curv, conic >f@ G>H)+  
    ]2$x| #Gg}  
        SetConic eID, entity, 1/Rant, CCant `{o$F ::(  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant OaaH$B  
    8wmQ4){  
        '************************************************************************* V;;#/$oU:4  
        'Radius and conic constant of posterior lens .&|L|q}  
        '************************************************************************* (O0byu}  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) NzlAC  
        GetConic eID, entity, curv, conic v2>Z^  
    M*`hDdS  
        SetConic eID, entity, 1/Rpost, CCpost 8UM0vNk  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost #xp(B5  
    ~OCZz$qA  
        '************************************************************************* ]0-<>  
        'Lens thickness (Position of posterior lens surface) YlKFw|=  
        '************************************************************************* D/:3R ZF  
    `eD1|Go9  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5v|EAjB6o  
    MGaiTN^_<  
        ' Delete any z-shift(s) u"Y]P*[k  
        count = 0 [.&[<!,.  
        While GetOperationCount(eID)>count "dtlME{Bx  
            GetOperation eID, count, op NwpS)6<-  
            If op.Type="ShiftZ" Then ti2  
                DeleteOperation eID,count =/}X$,@2  
                count=count-1 HeozJ^u\?  
            End If mb{q(WEPP  
            count=count+1 @GeHWv  
        Wend <5IQc[3]aP  
    Uk'U?9O  
        'Set new z-shift S>t>6&A  
        op.Type = "ShiftZ" "+h/-2rA  
        op.val1 = tlens yU_9a[$V  
        op.parent = parID T*+A.G@L"  
        AddOperation eID, op '[ 0YIn  
        Print "Set lens thickness = " & tlens @i1q]0  
    -nR\,+N  
        '************************************************************************* bE I!Ja  
        'Lens index of refraction U^?= 0+  
        '************************************************************************* (U9a@ 1  
        eID = FindMaterial( "Lens" ) 3U;1D2"AE  
        GetModelMaterial eID, mat e U;jP]FA  
    Y /lN@  
        mat.Nd = nlens ti9}*8  
        SetModelMaterial eID, mat P {H{UKs#  
        Print "Set lens index of refraction = " & nlens vr4S9`,  
    ] .5O X84  
        '************************************************************************* - _t&+5]  
        'Pupil diameter WQKj]:qk0  
        '************************************************************************* ZqK]jT6V/X  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" )  AP w6  
    HJ@5B"  
        'Adjust pupil diameter (trimming volume inner hole) lRND  
    (oYW]c}G,  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" \_U*t!  
    *Hunp Y  
        ' Adjust pupil location to just in front of the lens ug&92Hdvy3  
        parID = FindFullName( "Geometry.Arizona Eye" ) XA3s],Rk  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) SdI1}&  
        count = 0 w~N-W8xNR  
        While GetOperationCount(eID)>count _]o5R7[MQ  
            GetOperation eID, count, op X4Xf2aXI  
            If op.Type="ShiftZ" Then o5 WW{)Q  
                DeleteOperation eID,count hk;bk?:m  
                count=count-1 784;]wdy\  
            End If TQ'e  
            count=count+1 :Tb7r6  
        Wend w1i?# !|  
        op.Type = "ShiftZ" Euu ,mleM  
        op.val1 = taq-0.01 #T"64%dX  
        op.parent = parID 3cThu43c  
        AddOperation eID, op q%S8\bt  
    I?M@5u  
        Print "Set pupil diameter = " & pupilDiam J"&y |; G  
    N^J*!]|  
        'Update AZ Eye subassembly Description &t6Tcy  
        eID = FindFullName( "Geometry.Arizona Eye" ) ";dU-\3M  
        GetEntity eID, entity fU ={a2  
        entity.Description = "Accommodation = " & A & "D" oMc1:=EG  
        SetEntity eID, entity W ~NYU  
    4B$bj `h  
        Update 38wq (  
        Print "DONE!" H,|YLKg-|  
         g1V)$s 7  
    End Sub +^gO/ 0  
    %wW'!p-<  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: ^PQM;"  
    or.\)(m#(  
    Accommodation = 4 Diopters z2~87fv+  
    Pupil Diameter = 4 mm -tyaE  
    Set aqueous humor thickness = 2.81 ]M\q0>HoJ  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 e5OVq ,  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 s<VJ`Ur  
    Set lens thickness = 3.927 \Tkp  
    Set lens index of refraction = 1.42672 e& Rb  
    Set pupil diameter = 4 FmI;lVF0j  
    DONE! $5L(gn[  
    L[. <o{  
    (文章来源:讯技光电)
     
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