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    [技术]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: 2021-10-22
    简介 nc&Jmo7  
    Ok*Z  
    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。 <ZVZ$ZW~D  
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    模型 0E1=W 6UZ  
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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。 R:f7LRF/\  
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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. M J\r 4n  
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    光源 as#J qE  
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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。 ZV( w  
    9~~UM<66W  
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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。 "xn|zB  
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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。 r[!(?%>j  
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    图2. 字母F光源的设定方法光 ="3,}qR  
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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 @RVOXkVo  
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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。 +v-LL*fa  
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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。 %Rarr  
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    图5. 视网膜重点采样规格设定
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    脚本 K'Spbn!nC  
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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: sUc iFAb  
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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。 YxyG\J\|,  
    余下的脚本计算与屈光度有关的所有参数。 De]^&qw(  
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    分析 <\ETPL,<  
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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。 Ux_<d?p  
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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 rS,j;8D-  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. Z"D W 2k  
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    Dim entity As T_ENTITY kwF]TO S  
    Dim op As T_OPERATION Pgev)rh[  
    Dim mat As T_MODELMATERIAL G/(*foT8SE  
    Dim A As Double T.2ZBG ~|[  
    Dim pupilDiam As Double 5p )IV>G  
    Dim eID As Long =qX*]  
    Dim parID As Long !sG"n&uZq  
    Dim count As Integer Fx5ZwT t  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 4|F#gK5E  
    Dim tlens As Double, nlens As Double lM+ xU;  
    Dim curv As Double, conic As Double PI63RH8e  
    Dim ok As Long xE1rxPuq)d  
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    Sub Main DB~MYOX~  
    C$K+=jT  
        '用户输入对话框 (H1lqlVWV#  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 zp#:EZ  
            TextBox 220,21,40,21,.TextBox1 'default: 0 0\wiam-  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 H+R7X71{  
            OKButton 40,91,90,21 1I \tu  
            CancelButton 190,91,90,21 \gd6Yx^[  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ?} X}#  
            TextBox 220,49,40,21,.TextBox2 'default: 4 J&_3VKrN  
        End Dialog )Oe`s(O@[I  
        Dim dlg As UserDialog V&R$8tpz  
    )2]a8JVf  
        ok = Dialog (dlg) A!4VjE>  
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        If ok=0 Then    'cancel button was pressed /yp/9r@T0  
            Print "Execution cancelled." f)U6p  
            End #!L%J<MX  
        End If Oa1'oYIHg  
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        'Assign accommodation and pupil diameter & use defaults if field left empty -)6;0  
        If dlg.TextBox1 = "" Then j9>TTgy@  
            A = 0           'Default accommodation !pl_Ao~(  
        Else tJz^DXqAc  
            A = CDbl(dlg.TextBox1) m\?\6W k  
        End If F:,#?  
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        If dlg.TextBox2 = "" Then 5v+L';wx[T  
            pupilDiam = 4   'Default pupil diameter Pfk{=y  
        Else IW mHp]  
            pupilDiam = CDbl(dlg.TextBox2) _<3r'Y,  
        End If hRLKb}  
    4M7^ [G  
        Print " " HGb.656r  
        Print "Accommodation = " & A & " Diopters" -aT=f9u  
        Print "Pupil Diameter = " & pupilDiam & " mm" .X^43 q  
    Bqp&2zg)@  
        ' Calculate new parameters with accommodation $^ubo5%  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness <0>[c<{V<  
    m3B \)2B  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens C-&#r."L  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens P.!;Uf}32  
    4V1|jy3  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens [C2kK *JZ  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens y6\ [1nZ  
    EL"4E',  
        tlens = 3.767 + 0.04*A                  'Lens thickness 0T=jR{j!o  
    ea>[BB3#  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction BJ"Ay@D*  
    "AV1..mu  
        'Adjust parameters to account for accommodation H8( C>w-'  
    > e;]mU`,  
        '************************************************************************* q;KshpfRMD  
        'Aqueous thickness (Position of Lens) rpx 0|{m  
        '************************************************************************* 1O|RIv7F[/  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) p FXd4*  
        GetCustomElement eID, entity r,QJG$ Jo  
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        parID = FindFullName( "Geometry.Arizona Eye" ) a pKa4nI  
    tnA_!$Y a  
        ' Delete any shift(s) in z :jl u  
        count = 0 x_]",2 W'  
        While GetOperationCount(eID)>count }k4`  
            GetOperation eID, count, op #/\pUK~km  
            If op.Type="ShiftZ" Then 5?D1][  
                DeleteOperation eID,count k\Yu5)  
                count=count-1 uPM8GIvZX.  
            End If i0i.sizu  
            count=count+1 8}ii3Py  
        Wend {yGZc3e1j  
    *2w_oKE'+5  
        'Set new shift in f0:EQYYZ  
        op.Type = "ShiftZ" 50}.Xm@,BO  
        op.val1 = taq @1/Q  
        op.parent = parID #L|JkBia  
        AddOperation eID, op wghFGHgw  
        Print "Set aqueous humor thickness = " & taq-0.55 dqIZ#;:g  
    buMiJzU  
        '************************************************************************* p,M3#^ q  
        'Radius and conic constant of anterior lens w0q?\qEX  
        '************************************************************************* ]1YYrgi7  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) M6@'9E]|>  
        GetConic eID, entity, curv, conic c,b`N0dOKL  
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        SetConic eID, entity, 1/Rant, CCant ?NL&x  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ~;!i)[-  
    9RCB$Ka6X  
        '************************************************************************* 0ECO/EuCg  
        'Radius and conic constant of posterior lens H4,.H,PZ  
        '************************************************************************* [[.&,6  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ^`hI00u(  
        GetConic eID, entity, curv, conic u"Hd55"&  
    3cV+A]i  
        SetConic eID, entity, 1/Rpost, CCpost ?%8})^Dd>4  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 0pZ.; /<{  
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        '************************************************************************* 4N%2w(,+8  
        'Lens thickness (Position of posterior lens surface) &K}(A{  
        '************************************************************************* W?4&lC^G  
    @wAr[.lZ  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) *x# &[>  
    [][:/~q!  
        ' Delete any z-shift(s) l/y Kc8^<  
        count = 0 ?Uy*6YS  
        While GetOperationCount(eID)>count U{za m  
            GetOperation eID, count, op bdsHA2r`s  
            If op.Type="ShiftZ" Then  t3yQ/  
                DeleteOperation eID,count V.P5v {  
                count=count-1 3 DO$^JJ.  
            End If B3g82dm  
            count=count+1 9B?t3:  
        Wend 1X!f!0=g+  
    c|;|%"Mk  
        'Set new z-shift bTy' 5"  
        op.Type = "ShiftZ" CrwcYzrRWl  
        op.val1 = tlens pb2{J#  
        op.parent = parID P20]>Hg  
        AddOperation eID, op l_q>(FoqA  
        Print "Set lens thickness = " & tlens ? /|@ #&  
    i&s=!`  
        '************************************************************************* w]5f3CIm  
        'Lens index of refraction ptcH>wM!  
        '************************************************************************* % OfDTs  
        eID = FindMaterial( "Lens" ) V]S06>P  
        GetModelMaterial eID, mat Z$m2rZ#  
    .T$9Q Ar5  
        mat.Nd = nlens :7PSZc:xE  
        SetModelMaterial eID, mat Fi3(glgd-  
        Print "Set lens index of refraction = " & nlens <+1w'-  
    \z2hXT@D  
        '************************************************************************* vJj j+:  
        'Pupil diameter JjO/u>A3;7  
        '************************************************************************* .2SIU4[P  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 4.kkxQR7r  
    @j8L{FGnN  
        'Adjust pupil diameter (trimming volume inner hole) qA_DQ):  
    G C#95  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" T+{'W  
      SrU   
        ' Adjust pupil location to just in front of the lens f'yd {ihFp  
        parID = FindFullName( "Geometry.Arizona Eye" ) 2iINQK$  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) +CHO0n  
        count = 0 ::b;4Q L  
        While GetOperationCount(eID)>count vlKKPS  
            GetOperation eID, count, op /(L1!BPP9m  
            If op.Type="ShiftZ" Then LZbHK.G=  
                DeleteOperation eID,count (#Kvm  
                count=count-1 /OtQk -E  
            End If tZ2iSc  
            count=count+1 b,V=B{(~  
        Wend w [x+2  
        op.Type = "ShiftZ" L ]'CA^N  
        op.val1 = taq-0.01 mZ&Mj.0+~  
        op.parent = parID yBjWPx?  
        AddOperation eID, op 'WgwLE_  
    -Af`AX  
        Print "Set pupil diameter = " & pupilDiam 1pr_d"#4  
    @G{DOxE*  
        'Update AZ Eye subassembly Description ,Yt&PE  
        eID = FindFullName( "Geometry.Arizona Eye" ) {v'Fg  
        GetEntity eID, entity 9r*T3=u.S  
        entity.Description = "Accommodation = " & A & "D" C&"2`ll  
        SetEntity eID, entity %NoZf^ ?  
    z,P7b]KVe  
        Update Nr+1N83S}  
        Print "DONE!" >#|Q,hVU5  
         #ms98pw%5  
    End Sub >k-poBw  
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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: 5!%/j,?  
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    Accommodation = 4 Diopters "MN'%"/  
    Pupil Diameter = 4 mm A*i_- ;W)  
    Set aqueous humor thickness = 2.81 Vs{sB*:  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 FX 3[U+  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 Cu7iHhY5  
    Set lens thickness = 3.927 > `M\xt  
    Set lens index of refraction = 1.42672 :gt wvM7/B  
    Set pupil diameter = 4 4v .6_ebL  
    DONE! 95&HsgdxJ  
     
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