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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 o_1N "o%  
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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。 Mf2F LrAh  
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    模型 ^v `naA(  
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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。 hrm<!uKn  
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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. lYTQg~aPm  
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    光源 m8=n`XI  
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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。  vTgx7gP  
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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。 [ /YuI@C,@  
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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。 )S 7+y6f&*  
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    图2. 字母F光源的设定方法光 c} +*$DeT  
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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 PJcfiRa'jQ  
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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。 hbOXR.0z  
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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。 'S1u@p,q  
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    图5. 视网膜重点采样规格设定
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    脚本 +rJ6DZ  
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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:  #D4  
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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。 >;^/B R=  
    余下的脚本计算与屈光度有关的所有参数。 Y@`uBB[  
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    分析 V D~5]TQ  
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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。 {YgU23;q  
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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 a(|6)w-  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. \y5lYb,*c_  
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    Dim entity As T_ENTITY Z^ :_,aJ?  
    Dim op As T_OPERATION $G-<kC}8:  
    Dim mat As T_MODELMATERIAL :YI5O/gsk?  
    Dim A As Double dMH_:jb  
    Dim pupilDiam As Double |gA@WV-%  
    Dim eID As Long Zp> v  
    Dim parID As Long 1o`1W4Q  
    Dim count As Integer z.Ic?Wz7  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double B;r_[^  
    Dim tlens As Double, nlens As Double J5G<Y*q  
    Dim curv As Double, conic As Double 68XJ`/d  
    Dim ok As Long :$$~$P  
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    Sub Main nwU],{(Hgr  
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        '用户输入对话框 -K'UXoU1  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 1ysfpX{=  
            TextBox 220,21,40,21,.TextBox1 'default: 0 XI\Slq  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 fAgeF$9@  
            OKButton 40,91,90,21 $6a9<&LP_  
            CancelButton 190,91,90,21 HG;;M6  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Q>,&@  
            TextBox 220,49,40,21,.TextBox2 'default: 4 XM`GK>*aC(  
        End Dialog =&z+7Pe[  
        Dim dlg As UserDialog 7GOBb|  
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        ok = Dialog (dlg) bzFac5n)Q  
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        If ok=0 Then    'cancel button was pressed >qo!#vJc a  
            Print "Execution cancelled." -qc'J<*^4  
            End t`Kpbfk  
        End If uge r:cD  
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        'Assign accommodation and pupil diameter & use defaults if field left empty l+9RPJD/:  
        If dlg.TextBox1 = "" Then ubM1Qr  
            A = 0           'Default accommodation `;j1H<L  
        Else k24I1DlR8  
            A = CDbl(dlg.TextBox1) !T,<p    
        End If )#m{"rk[x,  
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        If dlg.TextBox2 = "" Then ] 0X|_bU  
            pupilDiam = 4   'Default pupil diameter ,D;8~l lM  
        Else /x??J4r0  
            pupilDiam = CDbl(dlg.TextBox2) C}h(WOcr`X  
        End If K1 "HJsj  
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        Print " " 46=E- Tq  
        Print "Accommodation = " & A & " Diopters" 9<u&27.  
        Print "Pupil Diameter = " & pupilDiam & " mm" .V hU:_u  
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        ' Calculate new parameters with accommodation |8'}mjs.Q  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness e3ZRL91c  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens @rYZ0`E9  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens M2Nh3ijr  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens jlBsm'M<m  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens @@D/&}#F  
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        tlens = 3.767 + 0.04*A                  'Lens thickness zIF1A*UH  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 6]1RxrAV  
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        'Adjust parameters to account for accommodation ]Ozz"4Z  
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        '************************************************************************* XZOBK^,5^B  
        'Aqueous thickness (Position of Lens) >)WE3PT/O"  
        '************************************************************************* }ekNZNcuM  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z?eTjkNS#  
        GetCustomElement eID, entity 4BMu0["6|s  
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        parID = FindFullName( "Geometry.Arizona Eye" ) K}cZK  
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        ' Delete any shift(s) in z . V!5Ui<  
        count = 0 fQ9af)d  
        While GetOperationCount(eID)>count < dE7+w  
            GetOperation eID, count, op GG#-x$jK  
            If op.Type="ShiftZ" Then ^6 l5@#)w  
                DeleteOperation eID,count MEI&]qI  
                count=count-1 D\G 8p;  
            End If \;-Yz  
            count=count+1 C/!P&`<6  
        Wend cUug}/!I  
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        'Set new shift in Jj ]<SWh  
        op.Type = "ShiftZ" 4M"'B A<  
        op.val1 = taq q}_8iDO6  
        op.parent = parID yFAUD ro  
        AddOperation eID, op W _[9  
        Print "Set aqueous humor thickness = " & taq-0.55 (1=@.srAzK  
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        '************************************************************************* "I=Lbh-`  
        'Radius and conic constant of anterior lens I_B%F#X)  
        '************************************************************************* ~Xx}:@Ld  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) t]sk[  
        GetConic eID, entity, curv, conic `V/kM0A5  
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        SetConic eID, entity, 1/Rant, CCant 6<z#*`U1  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant <1vogUDW  
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        '************************************************************************* lGet)/w;c  
        'Radius and conic constant of posterior lens -wUT@a  
        '************************************************************************* Oh}52=  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) WDnNVE  
        GetConic eID, entity, curv, conic ZXhNn<  
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        SetConic eID, entity, 1/Rpost, CCpost + $M<ck?Bo  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost qW3XA$g|j'  
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        '************************************************************************* 9|jMN j]vo  
        'Lens thickness (Position of posterior lens surface) 6oWFjeZ0  
        '************************************************************************* A/zAB3  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) *k\ ;G?  
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        ' Delete any z-shift(s) Eb,M+c?  
        count = 0 k'v+/6 Y  
        While GetOperationCount(eID)>count f3;[ZS  
            GetOperation eID, count, op =m|<~t  
            If op.Type="ShiftZ" Then Z%sTj6Th  
                DeleteOperation eID,count MHE/#G  
                count=count-1 Y;\@ 5TgQ,  
            End If u$qasII  
            count=count+1 >d;U>P5.  
        Wend >xRUw5jN  
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        'Set new z-shift r{* Qsaw  
        op.Type = "ShiftZ" #.FhN x  
        op.val1 = tlens {#t7lV'4  
        op.parent = parID a'q&[08  
        AddOperation eID, op iqF|IVPoi  
        Print "Set lens thickness = " & tlens 7#HSe#0J  
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        '************************************************************************* 0#5&*  
        'Lens index of refraction [+@T"2h2b  
        '************************************************************************* zl, Vj%d  
        eID = FindMaterial( "Lens" ) 0W 1bZPM  
        GetModelMaterial eID, mat ]:#W$9,WL  
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        mat.Nd = nlens aYtW!+#  
        SetModelMaterial eID, mat IUWJi\,  
        Print "Set lens index of refraction = " & nlens Eb'M< ZY  
    [$]-W$j+  
        '************************************************************************* D3O)Tj@:}(  
        'Pupil diameter {iQ4jJ`n  
        '************************************************************************* B$q5/L$}  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) m8l!+8  
    ?>R(;B|ER  
        'Adjust pupil diameter (trimming volume inner hole) Q*f0YjH!  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" DEPsud;  
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        ' Adjust pupil location to just in front of the lens $|@-u0sv  
        parID = FindFullName( "Geometry.Arizona Eye" ) t ,EMyZ  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ErQGVE;zk  
        count = 0 ;+3@S`2r  
        While GetOperationCount(eID)>count P#:nXc$  
            GetOperation eID, count, op iII%!f?{[  
            If op.Type="ShiftZ" Then *aYuuRx  
                DeleteOperation eID,count &j"_hFhv  
                count=count-1 H-% B<7  
            End If  ;t/KF"  
            count=count+1 |41~U\  
        Wend 8yswi[  
        op.Type = "ShiftZ" i"^ y y+  
        op.val1 = taq-0.01 n&Q0V.  
        op.parent = parID ] < ;y_  
        AddOperation eID, op dA#'HMh@  
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        Print "Set pupil diameter = " & pupilDiam :@Ml-ZE  
    ayg^js2,  
        'Update AZ Eye subassembly Description gP!k[E ,Q8  
        eID = FindFullName( "Geometry.Arizona Eye" ) Jg&f.  
        GetEntity eID, entity 5p7i9"tgn  
        entity.Description = "Accommodation = " & A & "D" :c:}_t{%  
        SetEntity eID, entity R,l*@3Q  
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        Update ;|,*zD  
        Print "DONE!" =+4om*  
         ; Yt'$D*CP  
    End Sub _Q*,~ z~  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: *"V) h I5  
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    Accommodation = 4 Diopters <. V*]g/;  
    Pupil Diameter = 4 mm S:c d'68D  
    Set aqueous humor thickness = 2.81 *b`1+~p_2  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 wk2Ff*&  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 4=njM`8Y'  
    Set lens thickness = 3.927 8wCB}qC  
    Set lens index of refraction = 1.42672 ddlF4L_  
    Set pupil diameter = 4 }?6gj%$c  
    DONE! p3IhK>  
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    QQ:2987619807 !3ji]q;uF  
     
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