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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 8u!"#S#>a  
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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。 6%Be36<  
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    模型 >J u]2++lx  
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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。 <L&m4O#|  
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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. P,sjo u^  
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    光源 .'a&3 3J  
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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。 ~^+0  
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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}xdTP  
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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。 s|y:UgD  
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    图2. 字母F光源的设定方法光 JJRK7\~$  
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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 T)\"Xj  
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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。 U?.9D  
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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。 $H$j-)\D  
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    图5. 视网膜重点采样规格设定
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    脚本  JMdPwI  
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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: z#F.xVg'  
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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。 fqu}Le  
    余下的脚本计算与屈光度有关的所有参数。 [=%TnT+^9  
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    分析 `>o?CIdp  
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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。 z6py"J@  
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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 yz2Ci0Dwy  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. M,}|tsL  
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    Dim entity As T_ENTITY !`bio cA  
    Dim op As T_OPERATION Z0De!?ALV\  
    Dim mat As T_MODELMATERIAL sE{pzPq!  
    Dim A As Double 5'a3huRtV  
    Dim pupilDiam As Double #P#-xz  
    Dim eID As Long &Z?ut *%S  
    Dim parID As Long a?YCn!  
    Dim count As Integer m?HZ;  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double U:F/ iXz  
    Dim tlens As Double, nlens As Double #0 6-:  
    Dim curv As Double, conic As Double m*X[ Jtr  
    Dim ok As Long .WQ<jZt>  
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    Sub Main {YUIMd!Y  
     'Pvm8t  
        '用户输入对话框 @Mvd'.r<;  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 fJZp?e"  
            TextBox 220,21,40,21,.TextBox1 'default: 0 fIF<g@s  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 e4FM} z[  
            OKButton 40,91,90,21 `]Bxn) b(  
            CancelButton 190,91,90,21 Il.Ed-&62  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 rw)kAe31  
            TextBox 220,49,40,21,.TextBox2 'default: 4 y$81Z q  
        End Dialog #}^-C&~  
        Dim dlg As UserDialog | nJZie8m  
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        ok = Dialog (dlg) 1+`l7'F  
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        If ok=0 Then    'cancel button was pressed .lhn;*Yi  
            Print "Execution cancelled." _if|TFw;h  
            End LflFe@2  
        End If yk2!8  
    >\ST-7[^L  
        'Assign accommodation and pupil diameter & use defaults if field left empty :ug4g6;#H0  
        If dlg.TextBox1 = "" Then p1c3Q$>i  
            A = 0           'Default accommodation FZiW|G  
        Else c.\O/N   
            A = CDbl(dlg.TextBox1) i~J;G#b  
        End If *=Z26  
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        If dlg.TextBox2 = "" Then W\f9jfD  
            pupilDiam = 4   'Default pupil diameter (SVWdgb  
        Else (eCFWmO  
            pupilDiam = CDbl(dlg.TextBox2) SvvUkQ#1w  
        End If a'\By?V]  
    n3MWs);5  
        Print " " t]1ubt2W  
        Print "Accommodation = " & A & " Diopters" U-wLt(Y<  
        Print "Pupil Diameter = " & pupilDiam & " mm" H(0q6~|  
    4\.V   
        ' Calculate new parameters with accommodation ,~zj=F  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness `nR%Cav,U  
    ?j7vZ}iRi  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens cD1o"bq  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens &@"]+33  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Uh.Zi3X6}6  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 1gO2C $  
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        tlens = 3.767 + 0.04*A                  'Lens thickness "%8A :^1  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 2}}?'PwwT  
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        'Adjust parameters to account for accommodation XC15K@K  
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        '************************************************************************* z1 i &Ge  
        'Aqueous thickness (Position of Lens)  'k&?DZ!  
        '*************************************************************************  V[pvJ(  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) o?Sla_D   
        GetCustomElement eID, entity bAxTLIf  
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        parID = FindFullName( "Geometry.Arizona Eye" ) !a1i Un9  
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        ' Delete any shift(s) in z ( g :p5Rl  
        count = 0 4aZCFdc  
        While GetOperationCount(eID)>count ?3sT" r_d@  
            GetOperation eID, count, op $7I] `Jt  
            If op.Type="ShiftZ" Then Ni[4OR$-O  
                DeleteOperation eID,count "C%!8`K{a*  
                count=count-1 *.y'(tj[  
            End If IKvBf'%-  
            count=count+1 %IpSK 0<Sp  
        Wend D_|B2gdZY  
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        'Set new shift in Wf02$c0#K  
        op.Type = "ShiftZ" {7Cx#Ewd  
        op.val1 = taq  e/e0d<(1  
        op.parent = parID `!\ivIi^  
        AddOperation eID, op d+z[\i  
        Print "Set aqueous humor thickness = " & taq-0.55 ^[h2%c$  
    h\ ,5/ )Y  
        '************************************************************************* X<Za9  
        'Radius and conic constant of anterior lens ]>:^d%n,}  
        '************************************************************************* O{KB0"s>i  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ZcPUtun  
        GetConic eID, entity, curv, conic (b/d0HCND  
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        SetConic eID, entity, 1/Rant, CCant $CtCOwKZ  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant PN F4>)  
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        '************************************************************************* d5xxb _oE  
        'Radius and conic constant of posterior lens ]H2R  
        '************************************************************************* 993d/z|DX  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) }F{=#Kqn^  
        GetConic eID, entity, curv, conic vrcE]5(:s  
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        SetConic eID, entity, 1/Rpost, CCpost M1=_^f=&.  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 5]"BRn1*  
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        '************************************************************************* ./maY1>T  
        'Lens thickness (Position of posterior lens surface) ,zgNE*{Y"4  
        '************************************************************************* oW'PO Ar  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) l=Wd,$\  
    A|vP$zy  
        ' Delete any z-shift(s) *m_93J  
        count = 0 t!l%/$-  
        While GetOperationCount(eID)>count S!j^|!  
            GetOperation eID, count, op Fe= "EDh  
            If op.Type="ShiftZ" Then 4]6Qr  
                DeleteOperation eID,count !P|5#.eC  
                count=count-1 i>Iee^_(  
            End If ]t/f<jKN^  
            count=count+1 |QYZRz  
        Wend O<`R~  
    }K8Lm-.=  
        'Set new z-shift _^; ;i4VZ  
        op.Type = "ShiftZ" ('WY5Yps  
        op.val1 = tlens RWE~&w G}  
        op.parent = parID ##~!M(c  
        AddOperation eID, op a>b8- j=J  
        Print "Set lens thickness = " & tlens N$'>XtO  
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        '************************************************************************* `` -k{C#F  
        'Lens index of refraction G.ud1,S#  
        '************************************************************************* q z:]-A  
        eID = FindMaterial( "Lens" ) Iq,v  
        GetModelMaterial eID, mat } J;~P 9Y  
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        mat.Nd = nlens .}p|`3$P  
        SetModelMaterial eID, mat )VY10 R)$  
        Print "Set lens index of refraction = " & nlens !QTPWA  
    LVmY=d>  
        '************************************************************************* DQ5W6W  
        'Pupil diameter @ KJV1t`  
        '************************************************************************* &|z|SY]DL  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) #NJ<[Gew  
    ;Vo mFp L  
        'Adjust pupil diameter (trimming volume inner hole) e?vj+ZlS$f  
    \1{_lynD  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" PSEWL6=]N  
    V2QW\2@$  
        ' Adjust pupil location to just in front of the lens 86{ZFtv  
        parID = FindFullName( "Geometry.Arizona Eye" ) sS'{QIRC'  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) cKpQr7]ur  
        count = 0 /#IH -2N  
        While GetOperationCount(eID)>count paYz[Xq  
            GetOperation eID, count, op 82 .HH5Z{  
            If op.Type="ShiftZ" Then iPkT*Cl8  
                DeleteOperation eID,count ~ a >S#S  
                count=count-1 '8={ sMy  
            End If I9,8HtnA  
            count=count+1 9@etg4#]  
        Wend R25-/6_V>  
        op.Type = "ShiftZ" l]u7.~b  
        op.val1 = taq-0.01 hOn  
        op.parent = parID r"[L0Cbb  
        AddOperation eID, op "MTq{f2?  
    } Ab _o#Zy  
        Print "Set pupil diameter = " & pupilDiam .> ,Z k S  
    8'% +G  
        'Update AZ Eye subassembly Description :1NYpsd.i  
        eID = FindFullName( "Geometry.Arizona Eye" ) [[$Mh_MD  
        GetEntity eID, entity >E~~7Yal  
        entity.Description = "Accommodation = " & A & "D" .Map   
        SetEntity eID, entity hvL6zCi  
    qAbd xd[  
        Update (Otur  
        Print "DONE!" uAQg"j  
         0O^U{#*$I  
    End Sub XC2Q*Z  
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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: ]ci RiMkT(  
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    Accommodation = 4 Diopters E~qK&7+  
    Pupil Diameter = 4 mm [@zkv)D6  
    Set aqueous humor thickness = 2.81 Hj1k-Bs&'w  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ~(M*6b  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 78gob&p?  
    Set lens thickness = 3.927 -/1d&  
    Set lens index of refraction = 1.42672 r*>QT:sB  
    Set pupil diameter = 4 /T{mS7EpYc  
    DONE! %va[jJ  
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    QQ:2987619807 FmR\`yY_,  
     
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