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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 lJ/6-dP  
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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。 r#h {$iW  
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    模型 b :\D\X  
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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。 OhWC}s  
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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. 7>je6*(K  
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    光源 h%b hrkD  
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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[ #6-T &  
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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。 EVz9WY  
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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。 -uR{X G. D  
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    图2. 字母F光源的设定方法光 Ru7L>(Njs  
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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 &q>h *w4O  
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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。 XARSGAuw  
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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。 (-2R{! A  
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    图5. 视网膜重点采样规格设定
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    脚本 bw;iz ,Z  
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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: onh?/3l  
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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。 Nh :JU?h  
    余下的脚本计算与屈光度有关的所有参数。 +9~ZA3DiP  
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    分析 uXP- 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。 bXm :]?  
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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 xOgq-@`  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ?:JdRnH\  
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    Dim entity As T_ENTITY 0O^r.&{j>  
    Dim op As T_OPERATION !xJFr6G~8  
    Dim mat As T_MODELMATERIAL [BE:+ ID3  
    Dim A As Double ndB@J*Imu  
    Dim pupilDiam As Double Lqq*Nr  
    Dim eID As Long - YAO3  
    Dim parID As Long %N1T{   
    Dim count As Integer l]/> `62  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double W=M< c@  
    Dim tlens As Double, nlens As Double i 63?"  
    Dim curv As Double, conic As Double IwnYJp:9v  
    Dim ok As Long &LwJ'h +nd  
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    Sub Main =^"~$[z(  
    'H FwP\HX  
        '用户输入对话框 h#;?9DP  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 >Ziy1Dp  
            TextBox 220,21,40,21,.TextBox1 'default: 0 )*+u\x_Hx  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 =cknE=  
            OKButton 40,91,90,21 mn Qal>0~  
            CancelButton 190,91,90,21 ?<g|.HY/  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 '|J)ds  
            TextBox 220,49,40,21,.TextBox2 'default: 4 7kOE/>P?  
        End Dialog #Xj;f^}/  
        Dim dlg As UserDialog y K=S!7p\  
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        ok = Dialog (dlg) EOofa6f&l  
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        If ok=0 Then    'cancel button was pressed :R{x]sv  
            Print "Execution cancelled." es{cn=\ s  
            End 55(J&q  
        End If ]kzv8#  
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        'Assign accommodation and pupil diameter & use defaults if field left empty VoWA tNU  
        If dlg.TextBox1 = "" Then *c!;^Qyp&  
            A = 0           'Default accommodation 4;",@}  
        Else ZKZl>dDuh  
            A = CDbl(dlg.TextBox1) ;sm"\.jF  
        End If b "`ru~]  
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        If dlg.TextBox2 = "" Then t@l(xnsV  
            pupilDiam = 4   'Default pupil diameter Cca~Cq[%*(  
        Else Ax :3}  
            pupilDiam = CDbl(dlg.TextBox2) 5~v(AB(x  
        End If rDK;6H:u{  
    Omp i~  
        Print " " (9Fabo\SH  
        Print "Accommodation = " & A & " Diopters" L?AM&w-cg9  
        Print "Pupil Diameter = " & pupilDiam & " mm" aslU`#"  
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        ' Calculate new parameters with accommodation Fc34Y0_A  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness LuQ"E4;nY%  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens uEc0/ a :.  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens /8 e2dw: \  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens V=G b>_d  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens fho=<|-  
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        tlens = 3.767 + 0.04*A                  'Lens thickness !C9ps]6  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction z }FiU[Hs  
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        'Adjust parameters to account for accommodation qAS70XjOF  
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        '************************************************************************* ] P:NnKgK  
        'Aqueous thickness (Position of Lens) 8MYLXW6  
        '************************************************************************* ^&f{beU9  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) P5yJO97  
        GetCustomElement eID, entity f}Ne8]U/Hc  
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        parID = FindFullName( "Geometry.Arizona Eye" ) c,3'wnui  
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        ' Delete any shift(s) in z ]%cHm4#m3  
        count = 0 Fi?U)T+%+  
        While GetOperationCount(eID)>count sw3:HNG=  
            GetOperation eID, count, op M~d+HE   
            If op.Type="ShiftZ" Then A{DIp+  
                DeleteOperation eID,count Z`SWZ<  
                count=count-1 Fy4<  
            End If t  z +  
            count=count+1 w /Bn2bD  
        Wend 2|T|K?R^  
    $ uz1  
        'Set new shift in )V9Mcr*Ce6  
        op.Type = "ShiftZ" :Ul'(@  
        op.val1 = taq >q} !>k$B  
        op.parent = parID ! 4qps$p{  
        AddOperation eID, op s/W!6JX4  
        Print "Set aqueous humor thickness = " & taq-0.55 !%Z)eO~Z  
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        '************************************************************************* onWYT}c{  
        'Radius and conic constant of anterior lens LP0;n\  
        '************************************************************************* M[`w{A  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6\)8mK  
        GetConic eID, entity, curv, conic lzr>WbM{{p  
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        SetConic eID, entity, 1/Rant, CCant )$9C`d[  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant U 3wsWSO  
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        '************************************************************************* HiS,q0  
        'Radius and conic constant of posterior lens 8a":[Q[  
        '************************************************************************* : e0R7sj  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Yq)YS]  
        GetConic eID, entity, curv, conic `/gEKrhL-  
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        SetConic eID, entity, 1/Rpost, CCpost ?}1JL6mF{  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost YP .%CD(K  
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        '************************************************************************* mhJOR'2  
        'Lens thickness (Position of posterior lens surface) "I}'C^gP  
        '************************************************************************* =@ L5  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Qn'r+X5t  
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        ' Delete any z-shift(s) x jP" 'yU  
        count = 0 9`gGsC  
        While GetOperationCount(eID)>count 0%&fUz36E6  
            GetOperation eID, count, op %xbz&'W,  
            If op.Type="ShiftZ" Then S7#^u`'Q_^  
                DeleteOperation eID,count 63y':g  
                count=count-1 a dz;N;rIY  
            End If ?O.6r"  
            count=count+1 A Eyr_!G,  
        Wend nkCRe  
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        'Set new z-shift YiI:uG!|D  
        op.Type = "ShiftZ" [pC-{~  
        op.val1 = tlens (8m\#[T+R  
        op.parent = parID jQK2<-HZ3  
        AddOperation eID, op aP6%OI  
        Print "Set lens thickness = " & tlens *C:q _/  
    d]O_E4X*  
        '************************************************************************* QvG56:M3  
        'Lens index of refraction 3bbp>7V!  
        '************************************************************************* NCowt|#t  
        eID = FindMaterial( "Lens" ) 3W7;f!  
        GetModelMaterial eID, mat Kcscz,  
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        mat.Nd = nlens ~_DF06G  
        SetModelMaterial eID, mat 1A7%0/K-]  
        Print "Set lens index of refraction = " & nlens G$?|S@I,  
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        '************************************************************************* ^%\)Xi  
        'Pupil diameter Xt</ -`  
        '************************************************************************* <^,o$b  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) U}tl_5%)  
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        'Adjust pupil diameter (trimming volume inner hole) kZV^F*7  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" A[u)wX^`f^  
    1%$d D2  
        ' Adjust pupil location to just in front of the lens Zu\p;!e  
        parID = FindFullName( "Geometry.Arizona Eye" ) k sB  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]]el|  
        count = 0 1a7!4)\  
        While GetOperationCount(eID)>count mgi,b2  
            GetOperation eID, count, op iBG`43;  
            If op.Type="ShiftZ" Then 5h_<R!jA  
                DeleteOperation eID,count <lC]>L  
                count=count-1 "KMLk  
            End If 6eOrs-ty  
            count=count+1 cU7rq j_  
        Wend Hze-Ob8  
        op.Type = "ShiftZ" Z} c'Bm(  
        op.val1 = taq-0.01 2{Wo-B,wt~  
        op.parent = parID `d75@0:  
        AddOperation eID, op 285_|!.Y  
    +O)]^"TG  
        Print "Set pupil diameter = " & pupilDiam @@'nit  
    T#\p%w9d  
        'Update AZ Eye subassembly Description oS~}TR:}  
        eID = FindFullName( "Geometry.Arizona Eye" ) ao)Ck3]  
        GetEntity eID, entity +p13xc?#j  
        entity.Description = "Accommodation = " & A & "D" M6J/mOVx5  
        SetEntity eID, entity  ;KZrl`  
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        Update q.-y)C) ;  
        Print "DONE!" A:kkCG!~Nf  
         G7 1U7  
    End Sub }ppVR$7]0  
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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: RXBb:f  
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    Accommodation = 4 Diopters 3AK(dC[ri  
    Pupil Diameter = 4 mm c\M#5+1j  
    Set aqueous humor thickness = 2.81 , Hn7(^t  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 6MuWlCKF8  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 3=Z<wD s  
    Set lens thickness = 3.927 Yy]T J  
    Set lens index of refraction = 1.42672 \@i=)dA  
    Set pupil diameter = 4 x ;Gz6|  
    DONE! "LOnDa7E^  
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