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infotek 2022-02-25 09:52

Arizona眼睛模型

简介 `a:@[0r0U  
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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。 xpFu$2T6P.  
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模型 .)})8csl.d  
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模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 ix^:qw;  
Table 1. AZ眼睛模型的定义
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在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. J~ v<Z/gm  
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光源 /.05rTpp  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 x:;8U i"&B  
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图1. 光源和提示信息使用
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 lZ^XZjwoM  
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在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 n5S$Dl  
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图2. 字母F光源的设定方法光 \R&`bAdk  
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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 } 5OlX  
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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。 }'kk}2ej`  
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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。 !bH-(K{S6  
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图5. 视网膜重点采样规格设定
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脚本 M%&`&{  
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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: _PNU*E%s<  
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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。 jE2ziK  
余下的脚本计算与屈光度有关的所有参数。 s.zH.q,  
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分析 J>hl&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。 @!%<JZEz3  
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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 vU{ZB^+&6o  
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  1. Option Explicit     'Remove this to enable non-dimensioned variables to be used. 1Lj\"+.  
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    Dim entity As T_ENTITY Ks7s2vK^  
    Dim op As T_OPERATION qf24l&}  
    Dim mat As T_MODELMATERIAL q;kM eE*  
    Dim A As Double 4 D\_[(P  
    Dim pupilDiam As Double *#UDMoz<  
    Dim eID As Long |C>Yd*E,C  
    Dim parID As Long 0pkU1t~9  
    Dim count As Integer cO(|>&tJ  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double rX;(48Y  
    Dim tlens As Double, nlens As Double y0(k7D|\  
    Dim curv As Double, conic As Double 8{?Oi'-|0  
    Dim ok As Long %HYC-TF#  
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    Sub Main Zls4@/\Q  
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        '用户输入对话框 !7%L%~z^  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 qY14LdC}~  
            TextBox 220,21,40,21,.TextBox1 'default: 0 CUxSmN2[  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 7;|6g8=  
            OKButton 40,91,90,21 S'3l<sY  
            CancelButton 190,91,90,21 ;Kkn7&'F  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 {_(;&\5  
            TextBox 220,49,40,21,.TextBox2 'default: 4 ?`FI!3j  
        End Dialog /tt  
        Dim dlg As UserDialog %j^=  
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        ok = Dialog (dlg)  ZfvFs  
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        If ok=0 Then    'cancel button was pressed zhN'@Wj'_  
            Print "Execution cancelled." MHxv@1)K|Y  
            End [xI@)5Xk  
        End If l'3NiIX  
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        'Assign accommodation and pupil diameter & use defaults if field left empty [HNGTde&  
        If dlg.TextBox1 = "" Then L}:u9$w  
            A = 0           'Default accommodation kv (N/G  
        Else _|6{(  
            A = CDbl(dlg.TextBox1) G e~&Ble  
        End If |n6nRE wW  
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        If dlg.TextBox2 = "" Then $orhY D3gv  
            pupilDiam = 4   'Default pupil diameter 25YJH1x  
        Else 37lmB '~  
            pupilDiam = CDbl(dlg.TextBox2) u[d8)+VX  
        End If X0U{9zP  
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        Print " " t5eux&C  
        Print "Accommodation = " & A & " Diopters" vn,L),"=  
        Print "Pupil Diameter = " & pupilDiam & " mm" @ @# G.  
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        ' Calculate new parameters with accommodation oPWvZI(\&  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness urog.Q  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens $f C=v  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens >#0yd7BST  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens x%x[5.CT  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 5RlJybN"o  
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        tlens = 3.767 + 0.04*A                  'Lens thickness wF38c]r`\<  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^QFjBQ-Hai  
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        'Adjust parameters to account for accommodation 1~5={eI  
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        '************************************************************************* 0Y"==g+ >f  
        'Aqueous thickness (Position of Lens) U15Hq*8Z  
        '************************************************************************* dmE-W S  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5IMh$!/uc  
        GetCustomElement eID, entity ^M?uv{354  
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        parID = FindFullName( "Geometry.Arizona Eye" ) <y`yKXzBUV  
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        ' Delete any shift(s) in z Ye(0'*-jyc  
        count = 0 Lw!@[;2  
        While GetOperationCount(eID)>count v3aiX  
            GetOperation eID, count, op ^. Pn)J  
            If op.Type="ShiftZ" Then  '5[L []A  
                DeleteOperation eID,count wmT3 >  
                count=count-1 !^\|r<2M  
            End If u2U@Qrs2  
            count=count+1 h!)(R<  
        Wend q .?D{[2  
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        'Set new shift in Dy8Go4  
        op.Type = "ShiftZ" w@oq.K  
        op.val1 = taq y8,es$  
        op.parent = parID &O!d!Pf  
        AddOperation eID, op %*r P d>*  
        Print "Set aqueous humor thickness = " & taq-0.55 @];Xbbw+c  
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        '************************************************************************* Vxk0oI k`  
        'Radius and conic constant of anterior lens H[6d@m- Z  
        '************************************************************************* +  ^~n09  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) W6jB!W  
        GetConic eID, entity, curv, conic {O!fV<Vx 9  
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        SetConic eID, entity, 1/Rant, CCant & f!!UZMt)  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant dn5T7a~   
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        '************************************************************************* bg 7b!t1F  
        'Radius and conic constant of posterior lens Ya,>E@oc  
        '************************************************************************* ]n!pn#Q  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) guf+AVPno  
        GetConic eID, entity, curv, conic I@x*>  
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        SetConic eID, entity, 1/Rpost, CCpost NP|U |zn  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost l?#([(WM  
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        '************************************************************************* SUvHLOA  
        'Lens thickness (Position of posterior lens surface) 3 #jPQ[+  
        '************************************************************************* [ 9$>N  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) &Cdd  
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        ' Delete any z-shift(s) Ak4iG2  
        count = 0 W]reQ&<Z  
        While GetOperationCount(eID)>count KXR  
            GetOperation eID, count, op ;,9|;)U?u  
            If op.Type="ShiftZ" Then BeplS  
                DeleteOperation eID,count !m^WtF  
                count=count-1 WxIP~  
            End If &;C|=8eB  
            count=count+1 ^yBx.GrQc  
        Wend ,9q5jOnk  
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        'Set new z-shift ^>]p4Q3 6  
        op.Type = "ShiftZ" =k0l>)  
        op.val1 = tlens 0R *!o\y  
        op.parent = parID iUSs)[]H>  
        AddOperation eID, op Z/a]oR@  
        Print "Set lens thickness = " & tlens rsiG]o=8  
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        '************************************************************************* kbOo;<X9A  
        'Lens index of refraction v bh\uv&  
        '************************************************************************* T#h`BtET[  
        eID = FindMaterial( "Lens" ) *y.KD4@{  
        GetModelMaterial eID, mat ;:' A{&0N  
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        mat.Nd = nlens ucB<  
        SetModelMaterial eID, mat H?O*  
        Print "Set lens index of refraction = " & nlens |-Y,:sY:  
    , gz:2UY#  
        '************************************************************************* uv._N6mj  
        'Pupil diameter @'~v~3 $S  
        '************************************************************************* V =1Y&y  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) et)A$'Q  
    {wCQ#V  
        'Adjust pupil diameter (trimming volume inner hole) M-0BQs`N  
    *Q5/d9B8TN  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" cojuU=i  
    &e2") 4oh  
        ' Adjust pupil location to just in front of the lens &K|CH? D  
        parID = FindFullName( "Geometry.Arizona Eye" ) ~F DJKGK  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Z wIsEJz  
        count = 0 *`mwm:4  
        While GetOperationCount(eID)>count Fe`$mtPu.  
            GetOperation eID, count, op +=;F vb  
            If op.Type="ShiftZ" Then +d Ig&}Tr  
                DeleteOperation eID,count _[IN9ZC2G  
                count=count-1 5f}wQ  
            End If aq[kKS`  
            count=count+1 @K2q*d  
        Wend F&I^bkvh  
        op.Type = "ShiftZ" 8"RX~Igf  
        op.val1 = taq-0.01 LXfDXXF  
        op.parent = parID q=g;TAXZl  
        AddOperation eID, op :C>slxY  
    'TezUBRAz  
        Print "Set pupil diameter = " & pupilDiam q[7C,o>/  
    f~8Xue,l"  
        'Update AZ Eye subassembly Description $Jx] FZDQ  
        eID = FindFullName( "Geometry.Arizona Eye" ) BW z*!(   
        GetEntity eID, entity B-'Xk{  
        entity.Description = "Accommodation = " & A & "D" BTGPP@p4  
        SetEntity eID, entity @ L?7` VoE  
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        Update ,Cde5A{K  
        Print "DONE!" W 4~a`D7  
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    End Sub :J}L| `U9  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: ')+'m1N  
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    Accommodation = 4 Diopters jQ(qaX&  
    Pupil Diameter = 4 mm qeHb0G  
    Set aqueous humor thickness = 2.81 op/|&H'  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 U''/y\Z  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 qAHQZKk  
    Set lens thickness = 3.927 UC\CCDV#^  
    Set lens index of refraction = 1.42672 .$L'Jt2X  
    Set pupil diameter = 4 fg^$F9@  
    DONE!
silence唯爱 2022-02-25 13:53
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