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    [分享]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2020-12-09
    简介 ]3y5b9DuW  
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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。 g*c\'~f;  
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    模型 @SG="L  
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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。 Y&!]I84]  
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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. &b6@_C9  
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    光源 u`Qcw|R+  
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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。 '=5_u  
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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。 m"7R 4O  
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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。 N3c)ce7[  
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    图2. 字母F光源的设定方法光 rJQ|Oi&1i  
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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 S!!\!w>N  
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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。 aq\TO?  
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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。 j~f 7WJ  
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    图5. 视网膜重点采样规格设定
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    脚本 ?!j/wV_H  
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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: 'yRv~BA  
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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。 U105u.#7  
    余下的脚本计算与屈光度有关的所有参数。 [Q_| 6Di  
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    分析 !;C(pnE  
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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。 Wc;D{p?Lb  
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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 &:f'{>3z  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. =V]i?31[  
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    Dim entity As T_ENTITY pYUkd!K"  
    Dim op As T_OPERATION 3Il/3\  
    Dim mat As T_MODELMATERIAL XXmu|h  
    Dim A As Double HwMsP$`q  
    Dim pupilDiam As Double g@f/OsR76  
    Dim eID As Long K2`WcEe  
    Dim parID As Long :!15>ML;-  
    Dim count As Integer %)ov,p |  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double -+@~*$ d  
    Dim tlens As Double, nlens As Double ~0GX~{;r  
    Dim curv As Double, conic As Double Z@O e}\.$  
    Dim ok As Long l^?A8jG  
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    Sub Main ! -nm7Q  
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        '用户输入对话框 <%uZwk>#  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 r9*H-V$  
            TextBox 220,21,40,21,.TextBox1 'default: 0 T sW6w  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 .h^Ld,Chj  
            OKButton 40,91,90,21 n8aiGnd=v  
            CancelButton 190,91,90,21 bO3KaOC8N  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 -vAG5x/,  
            TextBox 220,49,40,21,.TextBox2 'default: 4 }mZ*f y0t  
        End Dialog jt?%03iuk  
        Dim dlg As UserDialog _!1c.[ \T  
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        ok = Dialog (dlg) D ,^ U%<`  
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        If ok=0 Then    'cancel button was pressed urjp&L&  
            Print "Execution cancelled." g]JI}O*5  
            End 5z]KkPQ  
        End If )X$n'E  
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        'Assign accommodation and pupil diameter & use defaults if field left empty Z i&X ,K~  
        If dlg.TextBox1 = "" Then yE{UV>ry  
            A = 0           'Default accommodation i.,B 0s] Z  
        Else O4mWsr  
            A = CDbl(dlg.TextBox1) iPNs EQ0We  
        End If vu >@_hv  
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        If dlg.TextBox2 = "" Then )@M|YM1+  
            pupilDiam = 4   'Default pupil diameter czi!q1<vg  
        Else OZ9j3Q;a$  
            pupilDiam = CDbl(dlg.TextBox2) ')~HOCBSE  
        End If hmk5 1  
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        Print " " 1nG"\I5N}  
        Print "Accommodation = " & A & " Diopters" (XWs4R.mkb  
        Print "Pupil Diameter = " & pupilDiam & " mm" 8Wp1L0$B  
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        ' Calculate new parameters with accommodation m':m`,c!  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness sM[c\Z]  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens WG4|Jf Y  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens +Q&@2 oY"  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Ut@)<N  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ^T>.04";x  
    :7*\|2zA  
        tlens = 3.767 + 0.04*A                  'Lens thickness Q&{5.}L  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Vdyx74xX  
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        'Adjust parameters to account for accommodation i?9Lf  
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        '************************************************************************* $% t  
        'Aqueous thickness (Position of Lens) 6h8NrjX  
        '************************************************************************* #}?$mxME*  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) tJ3s#q6  
        GetCustomElement eID, entity qpCi61lTDJ  
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        parID = FindFullName( "Geometry.Arizona Eye" ) #y%Ao\~kG  
    ,oe4*b}O=.  
        ' Delete any shift(s) in z IC~D?c0H:  
        count = 0 qxh\umm+2  
        While GetOperationCount(eID)>count ><^@1z.J  
            GetOperation eID, count, op cMAfW3j: ;  
            If op.Type="ShiftZ" Then )qe o`4+y  
                DeleteOperation eID,count >dY"B$A>  
                count=count-1 lN" rhZ  
            End If :#;?dMkTY  
            count=count+1 7#QH4$@1P  
        Wend h#9)M  
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        'Set new shift in Zx0c6d!B  
        op.Type = "ShiftZ" 9G9lSj5>  
        op.val1 = taq aleIy}"  
        op.parent = parID 9X~^w_cdk  
        AddOperation eID, op #'oKkrl  
        Print "Set aqueous humor thickness = " & taq-0.55 ;?9~^,l  
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        '************************************************************************* Zup?nP2GkT  
        'Radius and conic constant of anterior lens !j@ 8:j0WY  
        '************************************************************************* x&wUPo{  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) . b"e`Bw_=  
        GetConic eID, entity, curv, conic g(Nf.hko  
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        SetConic eID, entity, 1/Rant, CCant ;RI,zQ  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant gS ]'^Sr  
    }, H,ky  
        '************************************************************************* 49 D*U5o  
        'Radius and conic constant of posterior lens 2}A V_]]  
        '************************************************************************* {iv=KF_S_  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) B#}RMFIj  
        GetConic eID, entity, curv, conic AJ /_l;  
    '7^_$M3$\  
        SetConic eID, entity, 1/Rpost, CCpost A(B2XBS!?  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost CpXv?uU   
    7E'C o|  
        '************************************************************************* \<%a`IA!*  
        'Lens thickness (Position of posterior lens surface) KpL82  
        '************************************************************************* 5+r#]^eQY-  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) &wfM:a/c  
    STMcMm3  
        ' Delete any z-shift(s) {+MMqJCa  
        count = 0 :?TV6M  
        While GetOperationCount(eID)>count K+Qg=vGY  
            GetOperation eID, count, op FP$]D~DMo  
            If op.Type="ShiftZ" Then qJ !xhf1  
                DeleteOperation eID,count q b'ka+X  
                count=count-1 ]pt @  
            End If Onl:eG;@  
            count=count+1 03xQ%"TU<  
        Wend Kh>^;`h  
     2r[,w]  
        'Set new z-shift = FQH  
        op.Type = "ShiftZ" bm^ou#]|  
        op.val1 = tlens l"Css~^  
        op.parent = parID *\>7@r[%5  
        AddOperation eID, op A-<qr6q  
        Print "Set lens thickness = " & tlens ``={FaV~m  
    +MEWAW[}^  
        '************************************************************************* [|3 %~s|Sv  
        'Lens index of refraction wo/H:3^N  
        '************************************************************************* ,[x'S>N  
        eID = FindMaterial( "Lens" ) B:l(`G  
        GetModelMaterial eID, mat 1\BECP+  
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        mat.Nd = nlens opBv x>S  
        SetModelMaterial eID, mat "371`!%  
        Print "Set lens index of refraction = " & nlens #f[yp=uI:  
    czj[U|eB}=  
        '************************************************************************* Z?~7#F~Z`  
        'Pupil diameter g+f{I'j  
        '************************************************************************* jE{z4en  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) A;kB"Tx  
    :%Bo)0a9  
        'Adjust pupil diameter (trimming volume inner hole) OIN]u{S  
    #2}S83 k  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" niFjsTA.Z  
    + }^  
        ' Adjust pupil location to just in front of the lens &B) F_EI  
        parID = FindFullName( "Geometry.Arizona Eye" ) EV9m\'=j  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) }MoCUN)I  
        count = 0 te1lUQ  
        While GetOperationCount(eID)>count pDu~84!])  
            GetOperation eID, count, op '  _N >  
            If op.Type="ShiftZ" Then 2 `#|;x^<  
                DeleteOperation eID,count zdY`c  
                count=count-1 Th-zMQ4  
            End If sg3%n0Ms.W  
            count=count+1 7JujU.&{6  
        Wend '+`CwB2  
        op.Type = "ShiftZ" @x)z" )>  
        op.val1 = taq-0.01 1 @/+ c  
        op.parent = parID > vgqf>)kk  
        AddOperation eID, op |/q*Fg[f  
    1j}o. 0\  
        Print "Set pupil diameter = " & pupilDiam VRD2e ,K  
    $u>^A<TBN  
        'Update AZ Eye subassembly Description iJ~p X\FKO  
        eID = FindFullName( "Geometry.Arizona Eye" ) &fW;;>  
        GetEntity eID, entity )xi|BqQz  
        entity.Description = "Accommodation = " & A & "D" $BG9<:p  
        SetEntity eID, entity B-o"Y'iXs  
    ~ejHA~QC  
        Update hj-M #a  
        Print "DONE!" /H\ZCIu/7  
         Am- JB  
    End Sub L-Z1Xs  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: }UX>O  
    [3j]r{0I  
    Accommodation = 4 Diopters Uq"RyvkpP  
    Pupil Diameter = 4 mm !j\  yt  
    Set aqueous humor thickness = 2.81 nPKf~|\1{  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 o8bV z2E  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 +W-sb5)  
    Set lens thickness = 3.927 u'}DG#@-  
    Set lens index of refraction = 1.42672 .NZ_dz$c  
    Set pupil diameter = 4 D`Fl*Wc4H  
    DONE! G3KiU($V  
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    QQ:2987619807 GX(p7ZgB2  
     
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