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    [技术]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: 2021-10-22
    简介 0y3<Ho,+$  
    +L$,jZqS  
    人眼光学模型可用来设计眼科用设备,光学系统注定了要与人眼一起使用。本文演示了这样一个模型:Arizona眼睛模型,在Jim Schwiegerling教授的书中有详细描述:《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源,并包括一个基于想要的屈光度来调整模型的内嵌脚本。 QF fKEMN  
    M5Twulz/w  
    模型 f @cs<x  
    DB>Y#2j4h  
    模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 dTV:/QM  
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    Table 1. AZ眼睛模型的定义
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    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. +HK)A%QI  
    hR$lX8  
    光源 dLSnhZ  
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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。 Y)@PGxjz  
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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。 '1}rQqZ  
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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。 1x07ua@(v  
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    图2. 字母F光源的设定方法光 1@ j>2>i  
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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 I@=h|GM  
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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。 !j(KbAhWZ  
    )r2$/QF9  
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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。 oPNYCE  
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    图5. 视网膜重点采样规格设定
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    脚本 K]bS:[34 R  
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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: zJMKgw,i*  
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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。 9ok|]d P  
    余下的脚本计算与屈光度有关的所有参数。 HHZ!mYr  
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    分析 K74oRKv  
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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。 dW7dMx  
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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 6\,^MI  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 0iX qAa  
    MatC2-aV1  
    Dim entity As T_ENTITY p8"(z@T  
    Dim op As T_OPERATION 8{+~3@T  
    Dim mat As T_MODELMATERIAL fnnwe2aso  
    Dim A As Double 1|w,Z+/  
    Dim pupilDiam As Double 73~Mq7~8  
    Dim eID As Long :,q3?l6  
    Dim parID As Long nu0bJ:0aLd  
    Dim count As Integer 6sy%KO*A  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double [/uKo13  
    Dim tlens As Double, nlens As Double b+p!{  
    Dim curv As Double, conic As Double 8 (^2  
    Dim ok As Long ;D8Nya>%  
    \N#)e1.0P  
    Sub Main e+R.0E  
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        '用户输入对话框 <Awx:lw.  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 jX&&@zMq  
            TextBox 220,21,40,21,.TextBox1 'default: 0 Y0B*.H Ae  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 g&0GO:F`  
            OKButton 40,91,90,21 8)POEY4  
            CancelButton 190,91,90,21 N~>?w#?J  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9jPb-I-   
            TextBox 220,49,40,21,.TextBox2 'default: 4 b$R>GQ?#  
        End Dialog deTbvl  
        Dim dlg As UserDialog 9_>4~!x`  
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        ok = Dialog (dlg) wCt+{Y3T  
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        If ok=0 Then    'cancel button was pressed y]jh*KD[  
            Print "Execution cancelled." Ee|+uQ981>  
            End aY:(0en]&  
        End If Gm2rjpZeq  
    e4)g F*  
        'Assign accommodation and pupil diameter & use defaults if field left empty 'c$9[|x  
        If dlg.TextBox1 = "" Then rFy9K4D  
            A = 0           'Default accommodation <dYk|5AdLF  
        Else Fcr@Un'  
            A = CDbl(dlg.TextBox1) c&Zm>Qo[  
        End If =-VV`  
    Z],"<[E  
        If dlg.TextBox2 = "" Then Fo G<$9  
            pupilDiam = 4   'Default pupil diameter `X^e}EGWu  
        Else \34|9#*z-  
            pupilDiam = CDbl(dlg.TextBox2) )(L&+DDy  
        End If Mc}x]j`f  
    #wjBMR%  
        Print " " M<p)@p  
        Print "Accommodation = " & A & " Diopters" Y+jKP*ri  
        Print "Pupil Diameter = " & pupilDiam & " mm" kTk?[BK  
    | fI%L9  
        ' Calculate new parameters with accommodation Ksp;bfe  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness iE Oyc59  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens Y@4vQm+  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens >@L HJ61C  
    Ur-^X(nL  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens V0AX1?H~w  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens  XGoy#h  
    {;}8Z$  
        tlens = 3.767 + 0.04*A                  'Lens thickness $($SQZK&  
    ~+np7  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \S<5b&G  
    aOD"z7}U  
        'Adjust parameters to account for accommodation y%,BDyK  
    P8VU&b\  
        '************************************************************************* Qm.kXlsDI  
        'Aqueous thickness (Position of Lens) 1}uDgz^  
        '************************************************************************* %pp+V1FH  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ( 7?%Hg  
        GetCustomElement eID, entity op-#Ig$#  
    o/zCXZnw#  
        parID = FindFullName( "Geometry.Arizona Eye" ) 0hkuBQb\  
    ,![=_d  
        ' Delete any shift(s) in z ;9PM?Iy[  
        count = 0 UH.cn|R  
        While GetOperationCount(eID)>count O$H150,Q  
            GetOperation eID, count, op dvD<>{U,8  
            If op.Type="ShiftZ" Then SHk[X ]Uo  
                DeleteOperation eID,count (6BCFl:/Q<  
                count=count-1  +o  
            End If |u{QI3#'  
            count=count+1  mb/[2y<  
        Wend ! -c*lb  
    eC$v0Gtq  
        'Set new shift in {Pb^Lf >  
        op.Type = "ShiftZ" K|G $s  
        op.val1 = taq C' ._}\nX  
        op.parent = parID i-?zwVmn  
        AddOperation eID, op lz(,;I'x  
        Print "Set aqueous humor thickness = " & taq-0.55 jEsTw_  
    ]CZLaID~  
        '************************************************************************* V</T$V$  
        'Radius and conic constant of anterior lens 0'hxw3#  
        '************************************************************************* T]|O/  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) I{zE73  
        GetConic eID, entity, curv, conic i'wF>EBz  
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        SetConic eID, entity, 1/Rant, CCant C.E> )  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant k Ml<  
    wP/9z(US  
        '************************************************************************* u mlZ(??.  
        'Radius and conic constant of posterior lens 9@Sb! 9h  
        '************************************************************************* 3~</lAm;  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) V@:=}*E  
        GetConic eID, entity, curv, conic 9yo[T(8  
    <88}+j  
        SetConic eID, entity, 1/Rpost, CCpost P$/A!r  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost yl<$yd0Zdu  
    W<91m*  
        '************************************************************************* (eG]Cp@  
        'Lens thickness (Position of posterior lens surface) |/^aL j^u  
        '************************************************************************* `U_>{p&x  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?gwbg*  
    ~e<'t4  
        ' Delete any z-shift(s) #}7m'F  
        count = 0 eBTedSM?t  
        While GetOperationCount(eID)>count 2{kfbm-89t  
            GetOperation eID, count, op *rz(}(r  
            If op.Type="ShiftZ" Then $lAb6e$n  
                DeleteOperation eID,count \G=R hx f  
                count=count-1 jfPJ5]Z  
            End If ICbdKgLz  
            count=count+1 /B@% pq  
        Wend qb> r\bc  
    qm8n7Z/  
        'Set new z-shift ]a!; `m$  
        op.Type = "ShiftZ" dU>R<jl!$  
        op.val1 = tlens J s<MJ4r>/  
        op.parent = parID g~hk-nXL.  
        AddOperation eID, op /Np"J  
        Print "Set lens thickness = " & tlens `J#xyDL6?  
    FR,#s^kF  
        '************************************************************************* 6a]f&={E  
        'Lens index of refraction K: o|kd  
        '************************************************************************* qVD!/;l  
        eID = FindMaterial( "Lens" ) =R;1vUio  
        GetModelMaterial eID, mat P tQ#  
    @EP{VV  
        mat.Nd = nlens QjjJtKz  
        SetModelMaterial eID, mat XBWSO@M'  
        Print "Set lens index of refraction = " & nlens '"]>`=R  
    PP[)h,ZL*  
        '************************************************************************* JeTrMa2  
        'Pupil diameter 5@>4)dk\  
        '************************************************************************* B,vHn2W  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &Wv`AoV  
    D*T$ v   
        'Adjust pupil diameter (trimming volume inner hole) ,gL)~6!A  
    E}b> 7L&w  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" &>zy_)  
    qe6C|W~n  
        ' Adjust pupil location to just in front of the lens E0)mI)RW.  
        parID = FindFullName( "Geometry.Arizona Eye" ) `k{ff  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) FQ|LA[~  
        count = 0 Hu9-<upc&  
        While GetOperationCount(eID)>count !OoaE* s  
            GetOperation eID, count, op GkGC4*n  
            If op.Type="ShiftZ" Then snTJe[^d  
                DeleteOperation eID,count K!- &Zv  
                count=count-1 :S99}pgY  
            End If OZC/+"\,  
            count=count+1 X\p`pw$  
        Wend JM+sHHs  
        op.Type = "ShiftZ" uU[[[LQq  
        op.val1 = taq-0.01 |Y8Mk2,s  
        op.parent = parID i_9Cc$Qh<  
        AddOperation eID, op zN)|g  
    'x45E.wYw  
        Print "Set pupil diameter = " & pupilDiam /[nZ#zj!3  
    DNm7z[ t{  
        'Update AZ Eye subassembly Description LN~N Fjs  
        eID = FindFullName( "Geometry.Arizona Eye" ) C;)Xwm>e  
        GetEntity eID, entity 9-a2L JI  
        entity.Description = "Accommodation = " & A & "D" ,p*ntj{  
        SetEntity eID, entity VO @ 4A6  
    xu"94y+  
        Update x<{;1F,k3  
        Print "DONE!" ek(kY6x:  
         D,GPn%Wqi  
    End Sub h$aew63  
    k67i`f=  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: :_fjml/  
    _ r^90  
    Accommodation = 4 Diopters gf3u0' $  
    Pupil Diameter = 4 mm +9 16ZPk  
    Set aqueous humor thickness = 2.81 `u p-m=zA  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 - 5o<Q'(  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 _Qm7x>NT4  
    Set lens thickness = 3.927 `uNvFlP  
    Set lens index of refraction = 1.42672 y?*[}S  
    Set pupil diameter = 4 _>jrlIfc  
    DONE! %2Xus9;k#  
     
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