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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 w)Q0_2p.  
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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。 -F<Wd/Xse  
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    模型 vJ'2@f$  
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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。 6"~P/\jP  
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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. k~jP'aD  
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    光源 xO&eRy?%  
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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。 ;*:Pw?'  
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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。 =5kY6%E7c  
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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。 w-Da~[J  
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    图2. 字母F光源的设定方法光 pKit~A,Q  
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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 =Ur}~w&H8  
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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。 `/EGyN6X  
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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。 %F-ZN^R  
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    图5. 视网膜重点采样规格设定
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    脚本 K':K{ee>  
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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: i`dC G[  
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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。 il:$sd  
    余下的脚本计算与屈光度有关的所有参数。 (^u1~1E 5  
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    分析 L1Iz<>  
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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。 v?& -xH-S  
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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 H\qC["  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ^(|vsFzn  
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    Dim entity As T_ENTITY W!?7D0q  
    Dim op As T_OPERATION #m{UrTC  
    Dim mat As T_MODELMATERIAL rld67'KcE  
    Dim A As Double b0Kc^uj5  
    Dim pupilDiam As Double +YqZ ((  
    Dim eID As Long 11<KpxKpk  
    Dim parID As Long {`K m_<Te!  
    Dim count As Integer DsT>3  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ~ ; -! n;  
    Dim tlens As Double, nlens As Double YEj8S5"Su\  
    Dim curv As Double, conic As Double }RwSp!}C  
    Dim ok As Long V??dYB(  
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    Sub Main yjhf   
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        '用户输入对话框 rfNm&!K  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 IuNiEtKx  
            TextBox 220,21,40,21,.TextBox1 'default: 0 UmQ?rS8d  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 /4 vG3  
            OKButton 40,91,90,21 *g[^.Sg  
            CancelButton 190,91,90,21 +eX@U;J,g  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 _c, '>aH=  
            TextBox 220,49,40,21,.TextBox2 'default: 4 o9F/y=.r=  
        End Dialog [BT/~6ovrZ  
        Dim dlg As UserDialog /ew Ukc8,  
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        ok = Dialog (dlg) z&{5;A}Q@  
    'rr^2d]`ST  
        If ok=0 Then    'cancel button was pressed []A%<EI7  
            Print "Execution cancelled." OnK~3j  
            End !kE-_dY6)  
        End If /yZQ\{=  
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        'Assign accommodation and pupil diameter & use defaults if field left empty _ h": >  
        If dlg.TextBox1 = "" Then }b0; 0j  
            A = 0           'Default accommodation \l.-eu'O  
        Else %"af748!+D  
            A = CDbl(dlg.TextBox1) U )l,'y2  
        End If R8T] 2?Q1  
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        If dlg.TextBox2 = "" Then cdG |m[  
            pupilDiam = 4   'Default pupil diameter ##EYH1P]  
        Else $pFo Rv  
            pupilDiam = CDbl(dlg.TextBox2) 7g(F#T?;'  
        End If ODC8D>ZYl  
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        Print " " Ldl 5zc  
        Print "Accommodation = " & A & " Diopters" Ns[ym>x#2  
        Print "Pupil Diameter = " & pupilDiam & " mm" [fKUyIY_  
    +{L<? "  
        ' Calculate new parameters with accommodation 'I /aboDB  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness N1}={yF.fQ  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens Jte#ZnP  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens =n' 4?W@  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens }-o{ASC#  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens BYo/57&:  
    ;x8k[p~2  
        tlens = 3.767 + 0.04*A                  'Lens thickness ^+m+zd_  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction I~9hx*!%%  
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        'Adjust parameters to account for accommodation NM6Teu_  
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        '************************************************************************* y T#{UA^  
        'Aqueous thickness (Position of Lens) v !FMs<  
        '************************************************************************* = pzn u+,  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) S9>0t0  
        GetCustomElement eID, entity zWb4([P;  
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        parID = FindFullName( "Geometry.Arizona Eye" ) sqS=qC  
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        ' Delete any shift(s) in z |-CnT:|o  
        count = 0 ?l$Nf@-  
        While GetOperationCount(eID)>count /g$G_}  
            GetOperation eID, count, op CCX8>09  
            If op.Type="ShiftZ" Then j $TwL;  
                DeleteOperation eID,count W5'3$,X9  
                count=count-1 8B#GbS K  
            End If !QT'L,_  
            count=count+1 `r_m+]  
        Wend ??i4z[0M  
    v (2GX  
        'Set new shift in h#hxOVl%x  
        op.Type = "ShiftZ" %Jf<l&K .`  
        op.val1 = taq ?^EXTU85`"  
        op.parent = parID mnID3=JF  
        AddOperation eID, op Cb_oS4vM  
        Print "Set aqueous humor thickness = " & taq-0.55 \^V`ds*.  
    8l"O(B'#Z  
        '************************************************************************* $L2%u8}8:  
        'Radius and conic constant of anterior lens .<K iMh  
        '************************************************************************* ]D!k&j~P  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) wHem5E  
        GetConic eID, entity, curv, conic PccB]  
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        SetConic eID, entity, 1/Rant, CCant hHPs&EA.p  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant NcAp_q? 4  
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        '************************************************************************* thqS*I'#g  
        'Radius and conic constant of posterior lens @Fpb-Qd"  
        '************************************************************************* :~ A%#  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) DS -fjH\  
        GetConic eID, entity, curv, conic 3F#+~^2  
    4A3nO<o MF  
        SetConic eID, entity, 1/Rpost, CCpost Dr9 ?2  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 1H,g=Y4f%  
    q,2]5 '  
        '************************************************************************* /n4pXT  
        'Lens thickness (Position of posterior lens surface) >z`,ch6~  
        '************************************************************************* cFagz* !  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) lI/0:|l  
    4"vaMa  
        ' Delete any z-shift(s) gs W0  
        count = 0 )){xlFA}  
        While GetOperationCount(eID)>count &VBd~4|p  
            GetOperation eID, count, op -[Qvg49jy  
            If op.Type="ShiftZ" Then {R^'=(YFy  
                DeleteOperation eID,count o_Si mJFK  
                count=count-1 2 /y}a#s  
            End If 8:.nEo'  
            count=count+1 . /p|?pu  
        Wend rz(0:vxwA  
    ZE `lr+_Y  
        'Set new z-shift e0;  
        op.Type = "ShiftZ" 'lS `s(  
        op.val1 = tlens <g9"Cr`  
        op.parent = parID b%t+,0s|  
        AddOperation eID, op [ "xn5l E  
        Print "Set lens thickness = " & tlens .]|Zf!>}s  
    7rHS^8'H&  
        '************************************************************************* V5D`eX9  
        'Lens index of refraction 5=KF!?  
        '************************************************************************* wG8Wez%  
        eID = FindMaterial( "Lens" ) *wV[TKaN  
        GetModelMaterial eID, mat L "<B;u5pM  
    $A$@|]}p  
        mat.Nd = nlens (H?ZSeWx  
        SetModelMaterial eID, mat IB|]fzy  
        Print "Set lens index of refraction = " & nlens OSzjK7:  
    _B,_4}  
        '************************************************************************* E-1"+p  
        'Pupil diameter (}:C+p 'I  
        '************************************************************************* X;!D};;M  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) xiyxr R;  
    <SVmOmJ-K  
        'Adjust pupil diameter (trimming volume inner hole) x "(9II*  
    K<v:-TjQZ:  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" e(1k0W4B  
    ?G? gy2  
        ' Adjust pupil location to just in front of the lens m h;X~.98  
        parID = FindFullName( "Geometry.Arizona Eye" ) XtBMp=7Oa  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) iS@\ =CK  
        count = 0 e@F|NCQ.9  
        While GetOperationCount(eID)>count 5eX59:vtl  
            GetOperation eID, count, op tL0`Rvl  
            If op.Type="ShiftZ" Then S)%_weLW7  
                DeleteOperation eID,count =z:U~D  
                count=count-1 :k46S<RE  
            End If AH.9A_dG  
            count=count+1 eSl-9 ^  
        Wend p-GT`D  
        op.Type = "ShiftZ" jnoL2JR[=-  
        op.val1 = taq-0.01 !;>(i e\  
        op.parent = parID #  nfI%  
        AddOperation eID, op ^ua12f  
    @XOi62(  
        Print "Set pupil diameter = " & pupilDiam X9~m8c){z  
    S=gW(c2'  
        'Update AZ Eye subassembly Description FQf #*  
        eID = FindFullName( "Geometry.Arizona Eye" ) bdV3v`  
        GetEntity eID, entity [V@yRWI  
        entity.Description = "Accommodation = " & A & "D" dDKqq(9(`  
        SetEntity eID, entity Rq7p29w  
    #Y[H8TW  
        Update 0^]t"z5f0  
        Print "DONE!" 0 15Owi  
         a ]1i/3/  
    End Sub ;mO,3dV  
    7unA"9=[4V  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: qmmv7==  
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    Accommodation = 4 Diopters q|q:: q*  
    Pupil Diameter = 4 mm da*9(!OV  
    Set aqueous humor thickness = 2.81 '7nJb6V,0l  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 FU@uH U5fd  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 &]nd!N  
    Set lens thickness = 3.927 a'[)9:  
    Set lens index of refraction = 1.42672 L? ;/cO^  
    Set pupil diameter = 4 \; bW h  
    DONE! B- Y+F  
     
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