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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 9F##F-%x  
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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。 ;hDa@3|]34  
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    模型 r o\1]`6  
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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。 m&Yi!7@(  
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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. #@f[bP}a  
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    光源 #1/}3+=5B  
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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。 z@U} ~TvP  
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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。 mY-hN|  
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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。 Akk 3 Qx  
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    图2. 字母F光源的设定方法光 SaDA`JmO  
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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 ~(X(&  
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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。 wS XVyg{  
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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。 KtN&,C )lJ  
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    图5. 视网膜重点采样规格设定
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    脚本 \=e8%.#@J  
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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: WNX5iwm  
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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。 ][@F  
    余下的脚本计算与屈光度有关的所有参数。 &X>7n~@0  
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    分析  Lc2QXeo8  
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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。 ]7YNIS  
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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 R)8s  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. F2I 5q C/  
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    Dim entity As T_ENTITY PGn);Baq  
    Dim op As T_OPERATION nHOr AD|&  
    Dim mat As T_MODELMATERIAL =t0tK}Y+4  
    Dim A As Double y-aRXF=W  
    Dim pupilDiam As Double ?A*Kg;IU  
    Dim eID As Long oOU1{[  
    Dim parID As Long J ++v@4Z  
    Dim count As Integer al^!,ykc  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double /pH(WHT+/H  
    Dim tlens As Double, nlens As Double b~Y%gC)FR  
    Dim curv As Double, conic As Double ,J =P,](  
    Dim ok As Long |L3X_Me  
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    Sub Main F iAY\4  
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        '用户输入对话框 ii|? ;  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 8/%6@Y"Y*  
            TextBox 220,21,40,21,.TextBox1 'default: 0 1} m3 ;  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ?8V UO x  
            OKButton 40,91,90,21 z}4L=KR\v  
            CancelButton 190,91,90,21 8 ;gXg  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 +b$S~0n   
            TextBox 220,49,40,21,.TextBox2 'default: 4 Gpj* V|J  
        End Dialog @E9" Zv-$  
        Dim dlg As UserDialog mqtg[~dNc  
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        ok = Dialog (dlg) U]6&b  
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        If ok=0 Then    'cancel button was pressed fC-P.:F#I  
            Print "Execution cancelled." LO%!Z,}   
            End HM[klH]s=  
        End If {=:#S+^ER  
    wD \ZOn_J  
        'Assign accommodation and pupil diameter & use defaults if field left empty Y g|lq9gD  
        If dlg.TextBox1 = "" Then 3\$wdUFr  
            A = 0           'Default accommodation *s4\\Wb=  
        Else TV59(bG.2  
            A = CDbl(dlg.TextBox1) >7Jr^o#|_x  
        End If q ?j|K|%   
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        If dlg.TextBox2 = "" Then 5N7H{vT_  
            pupilDiam = 4   'Default pupil diameter Qt>>$3]!!  
        Else MHj,<|8Q  
            pupilDiam = CDbl(dlg.TextBox2) n`7f"'/:  
        End If u eb-2[=  
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        Print " " ;\;M =&{}  
        Print "Accommodation = " & A & " Diopters" g(x9S'H3l  
        Print "Pupil Diameter = " & pupilDiam & " mm"  \[:/CxP  
    n]Li->1  
        ' Calculate new parameters with accommodation /*)Tl   
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ( <*e  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens `_X;.U.Mv  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens /s:fW+C  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens {MdLX.ycc)  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens !]` #JAL7  
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        tlens = 3.767 + 0.04*A                  'Lens thickness Q%S9fq,q  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction nR;D#"p%  
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        'Adjust parameters to account for accommodation >ezi3Zx^  
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        '************************************************************************* K*-@Q0"KM{  
        'Aqueous thickness (Position of Lens) Y]|:?G7l]  
        '************************************************************************* E-5_{sc  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) xw^.bz|  
        GetCustomElement eID, entity P$GjF-!:  
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        parID = FindFullName( "Geometry.Arizona Eye" ) Y.#:HRtgW  
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        ' Delete any shift(s) in z 6vKS".4C  
        count = 0 , "0)6=AE  
        While GetOperationCount(eID)>count #K\?E.9h  
            GetOperation eID, count, op FCj{AD  
            If op.Type="ShiftZ" Then ti5HrKIw  
                DeleteOperation eID,count @F*wg  
                count=count-1 |R/.r_x,V?  
            End If I`(l*U  
            count=count+1 `Mj}md;O"  
        Wend '\#EIG  
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        'Set new shift in +k<w!B*  
        op.Type = "ShiftZ" ~ (On|h  
        op.val1 = taq `Pn[tuIO  
        op.parent = parID `Hx~UH)  
        AddOperation eID, op q"qo.TPh|$  
        Print "Set aqueous humor thickness = " & taq-0.55 tMx}*l|]  
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        '************************************************************************* #:x4DvDkR  
        'Radius and conic constant of anterior lens -5l6&Y   
        '************************************************************************* f$HH:^#  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) qo6y %[  
        GetConic eID, entity, curv, conic .9[45][FK  
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        SetConic eID, entity, 1/Rant, CCant wd@aw/  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant m(iR|Zx  
    6 9y;`15  
        '************************************************************************* A=zPL q{Sb  
        'Radius and conic constant of posterior lens M]v=-  
        '************************************************************************* x"P);su  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) |WryBzZ>on  
        GetConic eID, entity, curv, conic DHC+C4  
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        SetConic eID, entity, 1/Rpost, CCpost X6+qpp  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost _M[,! {C  
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        '************************************************************************* ^-CINt{O  
        'Lens thickness (Position of posterior lens surface) cV{%^0? D  
        '************************************************************************* J/!cGr( B~  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) q-ES6R  
    J~B 7PW  
        ' Delete any z-shift(s) spofLu.  
        count = 0 ;!< Znw  
        While GetOperationCount(eID)>count D<i[LZd  
            GetOperation eID, count, op BElJB&I  
            If op.Type="ShiftZ" Then >gKh  
                DeleteOperation eID,count # {fTgq  
                count=count-1 8.=\GV  
            End If hd V1nS$  
            count=count+1 e}VBRvr  
        Wend t2" (2  
    w6dFb6~R  
        'Set new z-shift -F"Q EL#  
        op.Type = "ShiftZ" yV3^Qtb!  
        op.val1 = tlens (R~]|?:wt  
        op.parent = parID 9mc!bj^811  
        AddOperation eID, op >>Ts??  
        Print "Set lens thickness = " & tlens 3cS2gxF  
    o'~5pS(wq  
        '************************************************************************* gG%V 9eOQ  
        'Lens index of refraction Ch()P.n?  
        '************************************************************************* $GQ`clj<  
        eID = FindMaterial( "Lens" ) [a o U5;7  
        GetModelMaterial eID, mat h0oMTiA  
    ?;YC'bF  
        mat.Nd = nlens "1q>At  
        SetModelMaterial eID, mat B<8N96fx  
        Print "Set lens index of refraction = " & nlens '$As<LOEd/  
    qzw'zV  
        '************************************************************************* GhY1k";  
        'Pupil diameter }ZSQ>8a  
        '************************************************************************* -5>-%13  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 6<,dRn  
    n 26Y]7N  
        'Adjust pupil diameter (trimming volume inner hole) 6J~12TU,  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" X.K<4N0A9J  
    ?.c;oS|  
        ' Adjust pupil location to just in front of the lens WD;Y~|  
        parID = FindFullName( "Geometry.Arizona Eye" ) ._wkj  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) c(co\A.]:6  
        count = 0 Bx"7%[  
        While GetOperationCount(eID)>count Nfe>3uQK  
            GetOperation eID, count, op SYeadsvF  
            If op.Type="ShiftZ" Then 2>-S-;i  
                DeleteOperation eID,count vB37M@wm  
                count=count-1 fl Jp4-nx  
            End If {Y}dv`G#Iu  
            count=count+1 wi8Yl1p]!z  
        Wend =Cv/Y%DN  
        op.Type = "ShiftZ" :0K8h  
        op.val1 = taq-0.01 q1y/x@  
        op.parent = parID }pkj:NT  
        AddOperation eID, op vhvdKD  
    {:c]|^w6  
        Print "Set pupil diameter = " & pupilDiam zL5d0_E9  
     `G1&Z]z  
        'Update AZ Eye subassembly Description 04J}UE]Ww  
        eID = FindFullName( "Geometry.Arizona Eye" ) 2RF^s.W  
        GetEntity eID, entity (3[z%@I  
        entity.Description = "Accommodation = " & A & "D" (qn2xrV  
        SetEntity eID, entity s%iOUL2/  
    Nf3.\eR  
        Update mD:IO  
        Print "DONE!" &2-L. Xb  
         <?D[9Mk$  
    End Sub ]maYUKqv}'  
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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: =5D nR  
    =S[yE]v^  
    Accommodation = 4 Diopters !$A37j6  
    Pupil Diameter = 4 mm {Z;jhR,  
    Set aqueous humor thickness = 2.81 #jpoHvt h  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 6b8;}],|  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 %or,{mmiM:  
    Set lens thickness = 3.927 #{r#;+  
    Set lens index of refraction = 1.42672 k^$+n_  
    Set pupil diameter = 4 uUE9g  
    DONE! Q@e[5RA +]  
    D7]# Xk2  
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    QQ:2987619807 gIR^ )m  
     
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