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infotek 2021-10-22 09:55

Arizona眼睛模型

简介 "7`<~>9t.  
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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。 92-I~ !d  
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模型 ^C%<l( b  
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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。 I 2DpRMy  
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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. L=h'Qgk%  
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光源 BORA(,  
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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。 YoE3<[KD(  
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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。 6zn5UW#q  
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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。 tI{_y  
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图2. 字母F光源的设定方法光  LIdF 0  
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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 9C i-v/M]  
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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。 q,6DEz  
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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。 iyog`s c  
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图5. 视网膜重点采样规格设定
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脚本 ]s748+  
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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: hpJ-r  
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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。 fxIf|9Qi`  
余下的脚本计算与屈光度有关的所有参数。 w`=\5Oa.G  
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分析 yCX?!E;La  
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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。 qjc4.,/  
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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 YgoBHE0#  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. T,tdL N-  
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Dim entity As T_ENTITY C'X!\}f.b/  
Dim op As T_OPERATION BF<ikilR  
Dim mat As T_MODELMATERIAL MqUH',\3  
Dim A As Double &! ?eL  
Dim pupilDiam As Double ` ~`k_7t.  
Dim eID As Long ofv)SCjd  
Dim parID As Long = 9]~ yt  
Dim count As Integer J)C/u{o  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double #C3.Jef  
Dim tlens As Double, nlens As Double +?!(G}5  
Dim curv As Double, conic As Double ?I@W:#>o  
Dim ok As Long r0gJpttDl  
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Sub Main _ORvo{[:  
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    '用户输入对话框 !GGkdg*-*9  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 &JI8]JmU)  
        TextBox 220,21,40,21,.TextBox1 'default: 0 .VzT:4-<Q"  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 :4%k9BGAj"  
        OKButton 40,91,90,21 Ez=Olbk  
        CancelButton 190,91,90,21 8*T=Xei8  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ^ovR7+V  
        TextBox 220,49,40,21,.TextBox2 'default: 4 aAA U{EWW  
    End Dialog ( ICd}  
    Dim dlg As UserDialog 'X2POay1  
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    ok = Dialog (dlg) }!C)}.L<  
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    If ok=0 Then    'cancel button was pressed J6aef ^>  
        Print "Execution cancelled." N' `A?&2ru  
        End ;BIY^6,7e  
    End If Hg$lXtn]  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 5N&?KA-  
    If dlg.TextBox1 = "" Then ~La>?:g <+  
        A = 0           'Default accommodation "!%l/_p?  
    Else fx>4  
        A = CDbl(dlg.TextBox1) 'y3!fN =h  
    End If X(-4<B  
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    If dlg.TextBox2 = "" Then <<R*2b  
        pupilDiam = 4   'Default pupil diameter 7{I0s;R  
    Else KNIn:K^/  
        pupilDiam = CDbl(dlg.TextBox2) QW(Mz Hg  
    End If }d}Ke_Q0  
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    Print " " eM?I$ePTN  
    Print "Accommodation = " & A & " Diopters" d,n 'n  
    Print "Pupil Diameter = " & pupilDiam & " mm" wT8DSq  
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    ' Calculate new parameters with accommodation DX K?Cv71z  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ByNn  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens &AbNWtCV+G  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens hp-<2i^"!  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens wyO4Y  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens |Uh  
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    tlens = 3.767 + 0.04*A                  'Lens thickness o]M5b;1  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction [;) ,\\u,d  
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    'Adjust parameters to account for accommodation XG{zlOD+  
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    '************************************************************************* \$T(t/$9  
    'Aqueous thickness (Position of Lens) lB vR+9Qw  
    '************************************************************************* V7fq4O^:  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Cl8Cg~2  
    GetCustomElement eID, entity A1>OY^p3%  
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    parID = FindFullName( "Geometry.Arizona Eye" ) !0LWa"  
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    ' Delete any shift(s) in z =Qj{T  
    count = 0 %oa-WmWm  
    While GetOperationCount(eID)>count 62o:,IcoG  
        GetOperation eID, count, op hVAn>_(  
        If op.Type="ShiftZ" Then SdxDa  
            DeleteOperation eID,count W^LY'ypT  
            count=count-1 ,,Q O^j]4~  
        End If BdblLUGK#  
        count=count+1 V/ uP%'cd  
    Wend RF4vtQC=  
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    'Set new shift in x vl#w  
    op.Type = "ShiftZ" l=)xo@6  
    op.val1 = taq -g Sa_8R  
    op.parent = parID }1i`6`y1  
    AddOperation eID, op e+ BQww  
    Print "Set aqueous humor thickness = " & taq-0.55 {|_M # w~&  
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    '************************************************************************* V0.vQ/  
    'Radius and conic constant of anterior lens `WFw3TI  
    '************************************************************************* Pz|>"'  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) s6v ;  
    GetConic eID, entity, curv, conic QIvVcfM^  
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    SetConic eID, entity, 1/Rant, CCant )SRefW.v  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant bj0G5dc=  
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    '************************************************************************* Eog0TQ+*  
    'Radius and conic constant of posterior lens yyRiP|hJ  
    '************************************************************************* uHvp;]/0\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) >j(_[z|v3  
    GetConic eID, entity, curv, conic e~[/i\  
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    SetConic eID, entity, 1/Rpost, CCpost q#ClnG*  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost x_6[P2"PP  
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    '************************************************************************* xPk8$1meZM  
    'Lens thickness (Position of posterior lens surface) wb5baY9  
    '************************************************************************* q`H_M{26!y  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) w/S%YW3*  
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    ' Delete any z-shift(s) eH3JyzzP,  
    count = 0 H*&f:mfq  
    While GetOperationCount(eID)>count z/WE,R  
        GetOperation eID, count, op wh\}d4gN  
        If op.Type="ShiftZ" Then ]J}  
            DeleteOperation eID,count bv9i*]  
            count=count-1 (vPN5F  
        End If \y)rt )  
        count=count+1 '4Ixqb+  
    Wend :W:K:lk  
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    'Set new z-shift YpZ+n*&+  
    op.Type = "ShiftZ" DV+xg3\(>1  
    op.val1 = tlens $@Rxrx_@M  
    op.parent = parID c~$)UND^  
    AddOperation eID, op @+M /&  
    Print "Set lens thickness = " & tlens S)k*?dQ##R  
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    '************************************************************************* 3yY}04[9<  
    'Lens index of refraction D},>mfzF  
    '************************************************************************* }Qc@m9;bH  
    eID = FindMaterial( "Lens" ) w%VU/6~  
    GetModelMaterial eID, mat Z!#!Gu*V  
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    mat.Nd = nlens L9 \1+rq  
    SetModelMaterial eID, mat dh*ZKI^@(  
    Print "Set lens index of refraction = " & nlens 2d(e:r h]  
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    '************************************************************************* *{@Nq=fE  
    'Pupil diameter )uIe&B  
    '************************************************************************* Xy&A~F  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 5\sd3<:+  
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    'Adjust pupil diameter (trimming volume inner hole) ooL!TS GD  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" C'@i/+  
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    ' Adjust pupil location to just in front of the lens JEwa &  
    parID = FindFullName( "Geometry.Arizona Eye" ) ?|C2*?hZ+  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) #m<nAR  
    count = 0 | y# Jx  
    While GetOperationCount(eID)>count vnt%XU,,Y  
        GetOperation eID, count, op qu6D 5t  
        If op.Type="ShiftZ" Then cAqLE\h  
            DeleteOperation eID,count R'`qKc  
            count=count-1 ksqQM  
        End If C8:f_mJU  
        count=count+1 Lpz>>}  
    Wend c|B('3h  
    op.Type = "ShiftZ" Mj?`j_X  
    op.val1 = taq-0.01 g i-$Z FzB  
    op.parent = parID |`,2ri*5A  
    AddOperation eID, op :WS@=sZN  
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    Print "Set pupil diameter = " & pupilDiam VT`^W Hu  
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    'Update AZ Eye subassembly Description (sTpmQx,b  
    eID = FindFullName( "Geometry.Arizona Eye" ) UiP"Ixg6  
    GetEntity eID, entity xJvmhN/c  
    entity.Description = "Accommodation = " & A & "D" LTCb@L{^i  
    SetEntity eID, entity n)e 6>R ;  
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    Update #PW9:_BE  
    Print "DONE!" c(m<h+ 2VL  
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End Sub kGS;s B  
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如果屈光度是4,光瞳直径是4,则会输出如下数据: Al^d$FaF  
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Accommodation = 4 Diopters 0 [# 3;a  
Pupil Diameter = 4 mm 9Cp-qA%t  
Set aqueous humor thickness = 2.81 [z\$?VJspQ  
Set anterior lens radius = 10.4 and conic constant = -2.375869 q=m'^ ,gPS  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 M,,bf[p$  
Set lens thickness = 3.927 1~`fVg  
Set lens index of refraction = 1.42672 @6sqMw}  
Set pupil diameter = 4 P[ck84F/  
DONE! 7wqK>Y1a  
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