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infotek 2021-10-22 09:55

Arizona眼睛模型

简介 ==OUd6e}  
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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。 UDh \%?j  
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模型 |Dn Zk3M,  
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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。 UZI:st   
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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. $6a9<&LP_  
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光源  y:RW:D&  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 gx.\H3y  
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图1. 光源和提示信息使用
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 ,c&u\W=p  
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在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 pi?/]}:  
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图2. 字母F光源的设定方法光 N4vcd=uG#  
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图3. 字母F在视网膜上位置点列图
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视网膜的散射 ^2~ZOP$A  
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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。 &<N8d(  
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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。 kG /1  
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图5. 视网膜重点采样规格设定
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脚本 yMNJHiE/  
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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: uppa`addK  
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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。 a51(ySC}<s  
余下的脚本计算与屈光度有关的所有参数。 cg8/v:B  
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分析 OkciL]  
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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。 =Fz mifTc  
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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 ".>#Qp%  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. [)I^v3]U  
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Dim entity As T_ENTITY ec!e  
Dim op As T_OPERATION Z;uKnJh  
Dim mat As T_MODELMATERIAL %$&eC  
Dim A As Double K6->{!8]k  
Dim pupilDiam As Double vFe=AY<Rt|  
Dim eID As Long MGF !ZZ\  
Dim parID As Long &}u_e`A  
Dim count As Integer 4BMu0["6|s  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double &u:U"j  
Dim tlens As Double, nlens As Double X?haHM#]  
Dim curv As Double, conic As Double U<=TAWZ@  
Dim ok As Long ;l;jTb^l  
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Sub Main OAkqPG&w  
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    '用户输入对话框 usc/DQ1  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 9BakxmAc  
        TextBox 220,21,40,21,.TextBox1 'default: 0 r.?dT |A  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Ov(k:"N  
        OKButton 40,91,90,21 570ja7C:  
        CancelButton 190,91,90,21 t XzuP_0  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Jj ]<SWh  
        TextBox 220,49,40,21,.TextBox2 'default: 4 F7}yt  
    End Dialog D!* SA  
    Dim dlg As UserDialog `m'RvUc  
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    ok = Dialog (dlg) bzG vnaTt  
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    If ok=0 Then    'cancel button was pressed Z84w9y7O<  
        Print "Execution cancelled." -d?<t}a  
        End IYe[IHny1  
    End If HHx5 VI  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 67/@J)z0%  
    If dlg.TextBox1 = "" Then {v!w2p@  
        A = 0           'Default accommodation c*owP  
    Else R UCUEo63  
        A = CDbl(dlg.TextBox1) qi@Nz=t#HJ  
    End If -wUT@a  
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    If dlg.TextBox2 = "" Then tG]W!\C'h  
        pupilDiam = 4   'Default pupil diameter xz`0V}dPl  
    Else #F/W_G7v  
        pupilDiam = CDbl(dlg.TextBox2) $m)eO8S+  
    End If ~&,S xQT  
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    Print " " zq5N@d F  
    Print "Accommodation = " & A & " Diopters" #+i5'p(4  
    Print "Pupil Diameter = " & pupilDiam & " mm" * r4FOA%P  
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    ' Calculate new parameters with accommodation JiqhCt\  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness rXSw@pqZ&  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ?RE"<L  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ^!m%:r7Dr  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens "Ml#,kU<T  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens P/S,dhs(  
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    tlens = 3.767 + 0.04*A                  'Lens thickness VaonG]Ues  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction "SuG6!k3  
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    'Adjust parameters to account for accommodation ^K<!`B  
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    '************************************************************************* )REegFN@  
    'Aqueous thickness (Position of Lens) iqF|IVPoi  
    '************************************************************************* 7#HSe#0J  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) n1x3q/~  
    GetCustomElement eID, entity i1{)\/f3  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 8VpmcGvc3  
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    ' Delete any shift(s) in z jJ RaY3  
    count = 0 D3tcwjXoW_  
    While GetOperationCount(eID)>count c r18`xU  
        GetOperation eID, count, op p=[I;U-#H  
        If op.Type="ShiftZ" Then [pt U}  
            DeleteOperation eID,count ZP:+'\&J  
            count=count-1 ocS}4.a@  
        End If \^cXmyQ<%  
        count=count+1 iYW<qgz  
    Wend -lfbn =3  
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    'Set new shift in (j%"iQD  
    op.Type = "ShiftZ" DEPsud;  
    op.val1 = taq jlyuu  
    op.parent = parID H ~<.2b  
    AddOperation eID, op qus%?B{b}  
    Print "Set aqueous humor thickness = " & taq-0.55 : t D`e<  
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    '************************************************************************* :VR% I;g;  
    'Radius and conic constant of anterior lens dM -<aq  
    '************************************************************************* X=jD^"-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6 ZXRb  
    GetConic eID, entity, curv, conic 1O2V!?P  
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    SetConic eID, entity, 1/Rant, CCant $F/xv&t  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant MHCwjo"  
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    '************************************************************************* j3R}]F'C*  
    'Radius and conic constant of posterior lens n482?Wp  
    '************************************************************************* \Jwc[R&x  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) p8iKZI]g  
    GetConic eID, entity, curv, conic (F#2z\$;  
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    SetConic eID, entity, 1/Rpost, CCpost |lIgvHgg  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost kb\\F:w(W  
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    '************************************************************************* Eh *u6K)Z  
    'Lens thickness (Position of posterior lens surface) yx<-M  
    '************************************************************************* 5^{2 g^jH6  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~'Korxa  
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    ' Delete any z-shift(s) ]0")iY_  
    count = 0 7Xh ;dJAF3  
    While GetOperationCount(eID)>count {P==6/<2o  
        GetOperation eID, count, op $%1oZ{&M  
        If op.Type="ShiftZ" Then K;R!>p}t  
            DeleteOperation eID,count S;u 2B_/  
            count=count-1 &<(&u`S  
        End If %y+v0.aWH+  
        count=count+1 =|V#~p*  
    Wend CSzu $Hnq  
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    'Set new z-shift H96|{q=  
    op.Type = "ShiftZ" A4)TJY 3g  
    op.val1 = tlens @f#6Nu  
    op.parent = parID #_'^oGz`  
    AddOperation eID, op .aC/ g?U  
    Print "Set lens thickness = " & tlens 4@jX{{^6%  
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    '************************************************************************* Xz'o<S  
    'Lens index of refraction 7! /+[G  
    '************************************************************************* rL/H{.@$`  
    eID = FindMaterial( "Lens" ) dlDO?T  
    GetModelMaterial eID, mat xeRoif\4c  
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    mat.Nd = nlens xE6hE'rh.O  
    SetModelMaterial eID, mat .bNG:y>  
    Print "Set lens index of refraction = " & nlens C:vVFU|4  
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    '************************************************************************* 5C5OLAl v  
    'Pupil diameter C!|Yz=e  
    '************************************************************************* }Rq{9j,%  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) \[]4rXZN0  
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    'Adjust pupil diameter (trimming volume inner hole) eY`o=xN  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" rotu#?B  
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    ' Adjust pupil location to just in front of the lens V17!~  
    parID = FindFullName( "Geometry.Arizona Eye" ) .|KBQMI  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) $OaxetPH  
    count = 0 Wfsd$kN6{  
    While GetOperationCount(eID)>count d*LW32B@  
        GetOperation eID, count, op ]}9[ys  
        If op.Type="ShiftZ" Then n"Wlfd0  
            DeleteOperation eID,count m(^nG_eX  
            count=count-1 AK&=/[U>  
        End If 8-x)8B  
        count=count+1 kK.[v'[>&  
    Wend && b;Wr  
    op.Type = "ShiftZ" yg82a7D  
    op.val1 = taq-0.01 z6 .^a-sU5  
    op.parent = parID M AL;XcRR  
    AddOperation eID, op JD]uDuE  
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    Print "Set pupil diameter = " & pupilDiam aqv'c j>  
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    'Update AZ Eye subassembly Description E^m;Ab=  
    eID = FindFullName( "Geometry.Arizona Eye" ) L fZF  
    GetEntity eID, entity M[QQi2:&  
    entity.Description = "Accommodation = " & A & "D" sA oxLI  
    SetEntity eID, entity *rA]q' jM  
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    Update No*[@D]g  
    Print "DONE!" 8"o@$;C  
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End Sub V+t's*9o3  
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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: k +Cwnp  
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Accommodation = 4 Diopters TrBW0Bn>p  
Pupil Diameter = 4 mm gKtgW&PYm  
Set aqueous humor thickness = 2.81 W"&,=wvg2  
Set anterior lens radius = 10.4 and conic constant = -2.375869 LX#gc.c  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 }ldpudU  
Set lens thickness = 3.927 D THWL  
Set lens index of refraction = 1.42672 }l Gui>/D  
Set pupil diameter = 4 M[(pLYq:  
DONE! S:1g(f*85  
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