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    [分享]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: 2020-12-09
    简介 e0D;]  
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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。 AIE)q]'Q  
    A81kb  
    模型 X \h]N  
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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。 4[6A~iC_  
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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. MZ{)`7acR\  
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    光源 X1+Wb9P  
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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。 ?J>^X-z  
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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。 b2Ct^`|M5  
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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。 Q i?   
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    图2. 字母F光源的设定方法光 Gs-'  
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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 0BD3~Lv  
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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。 & K7+V  
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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。 B&tl6?7h  
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    图5. 视网膜重点采样规格设定
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    脚本 e\/Lcng  
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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: NK d8XQ=%  
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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。 :U?Kwv8s  
    余下的脚本计算与屈光度有关的所有参数。 '*W/Bett  
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    分析 ]{dg"J  
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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。 1C:lXx$|  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 K47W7zR  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ~GMlnA]6  
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    Dim entity As T_ENTITY 3<?#*z4]_  
    Dim op As T_OPERATION eFbr1IV  
    Dim mat As T_MODELMATERIAL Zs)HzOP)9  
    Dim A As Double i9W@$I,f  
    Dim pupilDiam As Double jiz"`,-},O  
    Dim eID As Long AOhsat;O`  
    Dim parID As Long s4t>/.;x  
    Dim count As Integer jF{zcYU  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Hb IRE  
    Dim tlens As Double, nlens As Double l[.RnM[v  
    Dim curv As Double, conic As Double H<g- Bhv  
    Dim ok As Long b=.Ikt+y  
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    Sub Main b?qtTce  
    9 *Q/3|   
        '用户输入对话框 IC37f[Q  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 r6QNs1f~.  
            TextBox 220,21,40,21,.TextBox1 'default: 0 ho;Km  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ?< mSEgvu  
            OKButton 40,91,90,21 3\G&fb|?}R  
            CancelButton 190,91,90,21 @~xNax&^  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 (Z;-u+ }.  
            TextBox 220,49,40,21,.TextBox2 'default: 4 5q}680s9+  
        End Dialog 1]m]b4]  
        Dim dlg As UserDialog h )fi9  
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        ok = Dialog (dlg) "\U$aaF  
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        If ok=0 Then    'cancel button was pressed MW6d-  
            Print "Execution cancelled." rx CSs  
            End 2/x+7F}w5  
        End If s=#3f3  
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        'Assign accommodation and pupil diameter & use defaults if field left empty mn)kd  
        If dlg.TextBox1 = "" Then C1Slx !}  
            A = 0           'Default accommodation vn9_tL&  
        Else &AG,]#  
            A = CDbl(dlg.TextBox1) sTU`@}}  
        End If 7ae8nZ3&  
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        If dlg.TextBox2 = "" Then -tlRe12  
            pupilDiam = 4   'Default pupil diameter EQET:a:g  
        Else :"#EQq]ct  
            pupilDiam = CDbl(dlg.TextBox2) hqmKUlo  
        End If ~8o's`  
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        Print " " !g-|@W  
        Print "Accommodation = " & A & " Diopters" @YHB>rNf(7  
        Print "Pupil Diameter = " & pupilDiam & " mm" c~K^ooS-  
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        ' Calculate new parameters with accommodation +'Ec)7m  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness DP6M4  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens qCi6kEr  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 3.Oc8(N^}  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens @2yi%_ ]h  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens JBo/<W#|  
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        tlens = 3.767 + 0.04*A                  'Lens thickness ,W;\6"Iwx'  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction >jD,%yG  
    }SR}ET&z  
        'Adjust parameters to account for accommodation C: @T5m  
    . T6fPEb  
        '************************************************************************* @kw#\%Uz  
        'Aqueous thickness (Position of Lens) ],YIEOx6  
        '************************************************************************* /f@VRME  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^Qt4}V=  
        GetCustomElement eID, entity 7{e0^V,\k  
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        parID = FindFullName( "Geometry.Arizona Eye" ) E5(\/;[*`  
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        ' Delete any shift(s) in z po~V{>fUm  
        count = 0 i/N4uq}'A<  
        While GetOperationCount(eID)>count vtM!?#  
            GetOperation eID, count, op ~3< Li}W  
            If op.Type="ShiftZ" Then { K'QE0'x  
                DeleteOperation eID,count |r[yMI|VR  
                count=count-1 t84(kzcC  
            End If :_E q(r  
            count=count+1 _C$JO   
        Wend -`x$a&}  
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        'Set new shift in @5+ JXD  
        op.Type = "ShiftZ" !VUxy  
        op.val1 = taq fmC)]O%q  
        op.parent = parID ;O5p>o  
        AddOperation eID, op ">PpC]Y1  
        Print "Set aqueous humor thickness = " & taq-0.55 (F@.o1No%  
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        '************************************************************************* P{v>o,a.  
        'Radius and conic constant of anterior lens Xo]QV.n  
        '************************************************************************* 28J ; 9  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) <8nl}^d5  
        GetConic eID, entity, curv, conic STmn%&  
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        SetConic eID, entity, 1/Rant, CCant Ta^l1]9.*  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant N% /if  
    8@S7_x  
        '************************************************************************* b<o Uy  
        'Radius and conic constant of posterior lens }GX[N\$N  
        '************************************************************************* bkk1_X  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) *<?or"P  
        GetConic eID, entity, curv, conic :a3  +f5  
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        SetConic eID, entity, 1/Rpost, CCpost J`}5bnFP  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost <20rxOEnf  
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        '************************************************************************* +rse,b&U(  
        'Lens thickness (Position of posterior lens surface) 7 \)OWp  
        '************************************************************************* #Bq.'?c'~  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) kNqSBzg  
    oo sbf#V  
        ' Delete any z-shift(s) A;VjMfoB  
        count = 0 3~ITvH,`s  
        While GetOperationCount(eID)>count @*Sge LeL  
            GetOperation eID, count, op VbR /k,Co  
            If op.Type="ShiftZ" Then ue8Cpn^M  
                DeleteOperation eID,count Z'sAu#C  
                count=count-1 dm;H0v+Y'  
            End If &E|2-)  
            count=count+1 pUtd_8  
        Wend v_-S#(  
    \z"0lAv"  
        'Set new z-shift :.KN;+tP  
        op.Type = "ShiftZ" ^wesuW@=  
        op.val1 = tlens m>dZ n  
        op.parent = parID ?Ne@OMc  
        AddOperation eID, op +%vBDcf  
        Print "Set lens thickness = " & tlens YNV!(>\GE  
    xszGao'  
        '************************************************************************* Fl{:aq"3  
        'Lens index of refraction wcGI2aflD  
        '************************************************************************* jSa9UD  
        eID = FindMaterial( "Lens" ) Cw`8[)=}o  
        GetModelMaterial eID, mat l !VPk"s  
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        mat.Nd = nlens WmU5YZ(mAq  
        SetModelMaterial eID, mat -<rQOPH%  
        Print "Set lens index of refraction = " & nlens |X&.+RI  
    VA4>!t)  
        '************************************************************************* 2uonT,W  
        'Pupil diameter =@%;6`AVcp  
        '************************************************************************* N[e QT  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) s|iph~W!L  
    V=yRE  
        'Adjust pupil diameter (trimming volume inner hole) JNhHQvi\  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" +Kc1a;  
    4dy2m!  
        ' Adjust pupil location to just in front of the lens c2M-/ x-:  
        parID = FindFullName( "Geometry.Arizona Eye" ) {v&c5B~,\  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) @\-i3EhR  
        count = 0 zh5'oE&[yC  
        While GetOperationCount(eID)>count l5sBDiir%  
            GetOperation eID, count, op ]3.Un,F  
            If op.Type="ShiftZ" Then RQ?T~ASs  
                DeleteOperation eID,count OO%< ~H  
                count=count-1  LW?Zd=  
            End If 2+KOUd&jS  
            count=count+1 u`E24~  
        Wend $*)??uU  
        op.Type = "ShiftZ" Y|ONCc  
        op.val1 = taq-0.01 cd8ZZ 8L  
        op.parent = parID JTT"t@__  
        AddOperation eID, op  y!6+jrI  
    4%l @   
        Print "Set pupil diameter = " & pupilDiam O6rrv,+_L  
    |Ad1/>8i  
        'Update AZ Eye subassembly Description 1d4 9z9F  
        eID = FindFullName( "Geometry.Arizona Eye" ) yX:A?U  
        GetEntity eID, entity "=~P&Mi_  
        entity.Description = "Accommodation = " & A & "D" .ZSGnbJ  
        SetEntity eID, entity 3/ sKRU  
    k< b`v&G  
        Update JQVu&S  
        Print "DONE!" KX*Hev'K  
         HVb9YU+  
    End Sub S<n3wR"^  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: (nP 6Xq  
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    Accommodation = 4 Diopters V\axOz!  
    Pupil Diameter = 4 mm ibDMhW$n  
    Set aqueous humor thickness = 2.81 5j(3pV`_  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ]:* 8 Mb#  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 (W~jr-O^  
    Set lens thickness = 3.927 $YDZtS&h  
    Set lens index of refraction = 1.42672 /EY ^ui  
    Set pupil diameter = 4 b XcDsP$.  
    DONE! F?j;3@z[A  
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    QQ:2987619807 y^; =+Z  
     
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