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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 ss/h[4h4h  
    ]NbX`'  
    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。 AS`2=w  
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    模型 h-Tsi:%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。 C:rRK*  
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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. 3fm;r5  
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    光源 U~oBNsU"  
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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。 $*YC7f  
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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。 g8LT7  
    /&*m1EN#o  
    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。 c"sj)-_  
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    图2. 字母F光源的设定方法光 z\e>DdS  
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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 O|HIO&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。 ov?.:M  
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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。 n33JTqX  
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    图5. 视网膜重点采样规格设定
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    脚本 n^* >a  
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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: j5PaSk&o=  
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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。 cYZwWMzp  
    余下的脚本计算与屈光度有关的所有参数。 70'} f  
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    分析 "}S9`-Wd|  
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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。 WpXODkQL  
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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 UiJ^~rn  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ExN j|*  
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    Dim entity As T_ENTITY "WF( 6z#  
    Dim op As T_OPERATION skk-.9  
    Dim mat As T_MODELMATERIAL n%83jep9  
    Dim A As Double @?<N +qdH>  
    Dim pupilDiam As Double /W"Bf  
    Dim eID As Long hg[l{)Q  
    Dim parID As Long xaGVu0q  
    Dim count As Integer r4;5b s6wm  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double MILIu;[{#r  
    Dim tlens As Double, nlens As Double ddUjs8VvJ  
    Dim curv As Double, conic As Double pieU|?fQ  
    Dim ok As Long ke3HK9P;  
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    Sub Main 7sQ]w   
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        '用户输入对话框 p{mxk)A  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 zznPD%#Sc  
            TextBox 220,21,40,21,.TextBox1 'default: 0 *k3 d^9o#  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 '+ o:,6  
            OKButton 40,91,90,21 /E`l:&89)  
            CancelButton 190,91,90,21 zCKy`u .  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 p/\$P=  
            TextBox 220,49,40,21,.TextBox2 'default: 4 6 . +[ z  
        End Dialog dD/29b(  
        Dim dlg As UserDialog c8k6(#\  
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        ok = Dialog (dlg) 2x<Qt2"  
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        If ok=0 Then    'cancel button was pressed gFWEodx,9  
            Print "Execution cancelled." 9B!im\]O  
            End >wg9YZ~8  
        End If ^DW#  
    <|KKv5[  
        'Assign accommodation and pupil diameter & use defaults if field left empty &;6|nl9;  
        If dlg.TextBox1 = "" Then r 85Xa'hh  
            A = 0           'Default accommodation YLA557~  
        Else %=NM_5a}]  
            A = CDbl(dlg.TextBox1) a@5xz)  
        End If 8!o{W=m^4  
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        If dlg.TextBox2 = "" Then U}RS*7`  
            pupilDiam = 4   'Default pupil diameter WuP([8  
        Else e' /  
            pupilDiam = CDbl(dlg.TextBox2) 0@sr NuW  
        End If /XWPN(JC?  
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        Print " " WTV3p,;6a  
        Print "Accommodation = " & A & " Diopters"  Vq .!(x  
        Print "Pupil Diameter = " & pupilDiam & " mm" *!r\GGb  
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        ' Calculate new parameters with accommodation Wvut)T  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness "W_jdE6v  
    .WL\:{G8;  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens eB<V%,%N#  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens BDRYip[Sa  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens n3l"L|W^(<  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens <\}Y@g8  
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        tlens = 3.767 + 0.04*A                  'Lens thickness N#pl mPrZ  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction }l]3m=)  
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        'Adjust parameters to account for accommodation 6PzN>+t^y  
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        '************************************************************************* @Q$ /eL  
        'Aqueous thickness (Position of Lens) 9?g]qy,1)  
        '************************************************************************* MUCJ/GF*  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z5*(W;;  
        GetCustomElement eID, entity 7?Qt2tr  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 48~m=mI  
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        ' Delete any shift(s) in z k[r./xEv+t  
        count = 0 O)U$Ef  
        While GetOperationCount(eID)>count RXx?/\~yd;  
            GetOperation eID, count, op B(en5|  
            If op.Type="ShiftZ" Then 9p[W :)P4d  
                DeleteOperation eID,count 6wpND|cT  
                count=count-1 ?G>5 D`V  
            End If *xv/b=  
            count=count+1 p+`*~6Jj/  
        Wend px [1#*  
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        'Set new shift in zNsL^;uT  
        op.Type = "ShiftZ" DX%8. @  
        op.val1 = taq Ghq'k:K,  
        op.parent = parID a_pCjG89  
        AddOperation eID, op !7ZfT?&  
        Print "Set aqueous humor thickness = " & taq-0.55 Ltic_cjYd?  
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        '************************************************************************* t7!>5e)C}  
        'Radius and conic constant of anterior lens ktw!T{  
        '************************************************************************* #a'x)$2;R|  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) >Rki[SNb-b  
        GetConic eID, entity, curv, conic MR)KLM0  
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        SetConic eID, entity, 1/Rant, CCant ,I2re G  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant z[lRb]:i[  
    5>1Y="B  
        '************************************************************************* :LIKp;  
        'Radius and conic constant of posterior lens rt@-Pw!B  
        '************************************************************************* y`B!6p 5j  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Z'EO   
        GetConic eID, entity, curv, conic )(ZPSg$/F  
    >nIcF m  
        SetConic eID, entity, 1/Rpost, CCpost 8v)~J}[Bz  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ^pQ;0[9Y0  
    "PX3%II  
        '************************************************************************* SG|i/K|7  
        'Lens thickness (Position of posterior lens surface) (y+5d00  
        '************************************************************************* kkE)zF   
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) eVCkPv *  
    : 7DVc&0  
        ' Delete any z-shift(s) h$ETH1Ue  
        count = 0 dVmAMQk.g  
        While GetOperationCount(eID)>count eR* ]<0=  
            GetOperation eID, count, op #g`cih=QL  
            If op.Type="ShiftZ" Then ]g-qWSKU  
                DeleteOperation eID,count w7t"&=pF7  
                count=count-1 W'2-3J  
            End If }rMpp[  
            count=count+1 u.L8tR:(  
        Wend }b ]y 0"  
    iJaNP%N  
        'Set new z-shift ! ?U^+)^$  
        op.Type = "ShiftZ" i;'X}KW  
        op.val1 = tlens @#--dOWYR  
        op.parent = parID '3_B1iAv  
        AddOperation eID, op Q0"F> %Cn  
        Print "Set lens thickness = " & tlens zS"zb  
    :V-}Sde  
        '************************************************************************* p|9ECdU>;  
        'Lens index of refraction =|5bhwU]  
        '************************************************************************* E=_B@VJknW  
        eID = FindMaterial( "Lens" ) d7K17KiC  
        GetModelMaterial eID, mat d>"$^${  
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        mat.Nd = nlens !lN a`  
        SetModelMaterial eID, mat g d}TTe  
        Print "Set lens index of refraction = " & nlens >A(?Pn{|a  
    6!Ji>h.Ak  
        '************************************************************************* .' 2gJ"?,  
        'Pupil diameter ;!Z7-OZX  
        '************************************************************************* fJ"~XTN}T  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) NF\^'W@N  
    E~@HC5.M  
        'Adjust pupil diameter (trimming volume inner hole) H.mQbD`X  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" `# M.t);^  
    Q.E^9giC  
        ' Adjust pupil location to just in front of the lens F-7b`cF9[r  
        parID = FindFullName( "Geometry.Arizona Eye" ) FQ~ead36C  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) "O1*uwm  
        count = 0 dpn&)?f  
        While GetOperationCount(eID)>count `"=L  
            GetOperation eID, count, op (xSi6EZ6;  
            If op.Type="ShiftZ" Then 8J?`_  
                DeleteOperation eID,count L\?g/l+k  
                count=count-1 nIKT w  
            End If >iWf7-:  
            count=count+1 f{5| }PL  
        Wend Sfa m=.l  
        op.Type = "ShiftZ" 2c`=S5  
        op.val1 = taq-0.01 #.L0]Uqcp  
        op.parent = parID <9.7gwzE  
        AddOperation eID, op O+Lb***b"  
    }~~^ZtJ\  
        Print "Set pupil diameter = " & pupilDiam MG5Sn*(C  
    I)%jPH:ua  
        'Update AZ Eye subassembly Description c^)E:J/  
        eID = FindFullName( "Geometry.Arizona Eye" ) % ih7Jt  
        GetEntity eID, entity ="[](X^ l  
        entity.Description = "Accommodation = " & A & "D" ne24QZ~}  
        SetEntity eID, entity nC{rs+P  
    ~+iJpW  
        Update =2)$|KC  
        Print "DONE!" z.Kq}r^  
         >rS<!e%  
    End Sub Y~SlipY_  
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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: ;)pV[3[  
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    Accommodation = 4 Diopters ~Q 9)Q  
    Pupil Diameter = 4 mm MkGq%AE`Y  
    Set aqueous humor thickness = 2.81 R9-JjG2v  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 N\e@$1  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 2bxMIr  
    Set lens thickness = 3.927 T9<nD"=:  
    Set lens index of refraction = 1.42672 2m_M9e\  
    Set pupil diameter = 4 ^(JbJ@m/  
    DONE! y-q?pqt  
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