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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 Pme`UcE3H  
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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。 wf8vKl#Kfw  
    `iQyKZS/+  
    模型 rj<%_d'Z`  
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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。 ~Bj-n6QDE  
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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. oPre$YT}h  
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    光源 0~n= |3*P  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 ;~/  
    ^$rt|]  
    #4d 0/28b  
    图1. 光源和提示信息使用
    #T !YFMh;  
    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。 )"j_ NlO  
    1a#wUd3  
    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。 Hhfqb"2on  
    3tOnALv  
    图2. 字母F光源的设定方法光 c#U x{^ZE  
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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 C5;"mo-  
    }Y<(1w  
    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。 PT>,:zY  
    R,6?1Z:J  
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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。 S }fIZ1  
    )[%#HT  
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    图5. 视网膜重点采样规格设定
    !cWKY \lpv  
    脚本 _3kAN .g  
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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: ))306*X\  
    |%b'L.$4  
    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
    !aIIjWz]  
    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。 #?8'Z/1 )  
    余下的脚本计算与屈光度有关的所有参数。 Pm" ,7  
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    分析 Lo9+#ITyx  
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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。 =]etw  
    7\5 [lM  
    图7. 字母F在视网膜上颜色分析
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    脚本代码 Hyc19|  
    CX\# |Q8q  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. $yc&f(Tv  
    |bB..b  
    Dim entity As T_ENTITY |A0kbC.  
    Dim op As T_OPERATION qj=12;  
    Dim mat As T_MODELMATERIAL IvH0sS`F  
    Dim A As Double IsnC_"f  
    Dim pupilDiam As Double >&Bg F*mm  
    Dim eID As Long O+z-6:`  
    Dim parID As Long |)GE7y0Q  
    Dim count As Integer <R_3; 5J%  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ><^A4s  
    Dim tlens As Double, nlens As Double HLTz|P0JZ  
    Dim curv As Double, conic As Double QeU>%qKT  
    Dim ok As Long [Zgy,j\ \  
    }2JSa8  
    Sub Main h:j-Xd$H+  
    q$U;\Mg)  
        '用户输入对话框 K;S&91V)=  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 zBqr15  
            TextBox 220,21,40,21,.TextBox1 'default: 0 [=..#y!U  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 [wIyW/+  
            OKButton 40,91,90,21 1 5rE|m^  
            CancelButton 190,91,90,21 _mFb+8C  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 .6  
            TextBox 220,49,40,21,.TextBox2 'default: 4 D~8f6Ko"m  
        End Dialog N b(se*Y#  
        Dim dlg As UserDialog aD0w82s]J  
    o$Hc5W([Z  
        ok = Dialog (dlg) kA\;h|Y3  
    2lXsD;[  
        If ok=0 Then    'cancel button was pressed sOVaQ&+y  
            Print "Execution cancelled." kD"dZQx  
            End A\k-OP]  
        End If $"x(:  
    gy~M]u{  
        'Assign accommodation and pupil diameter & use defaults if field left empty M> 1V3 sM  
        If dlg.TextBox1 = "" Then .DCp)&m l;  
            A = 0           'Default accommodation 9l OUE  
        Else )M^;6S  
            A = CDbl(dlg.TextBox1) #`}g?6VHo  
        End If %xWmzdn  
    o3}12i S  
        If dlg.TextBox2 = "" Then YQe @C  
            pupilDiam = 4   'Default pupil diameter @AVx4,!>[  
        Else d|DIq T~{W  
            pupilDiam = CDbl(dlg.TextBox2) Zw"6-h4  
        End If bncK8SK  
    }{E//o:Ta  
        Print " " zXZy:SD  
        Print "Accommodation = " & A & " Diopters" )mwY] !  
        Print "Pupil Diameter = " & pupilDiam & " mm" rA{h/T"  
    kZF\V7k  
        ' Calculate new parameters with accommodation u%v^(9z  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness v }P~g  
    xAz gQ  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ^<sX^V+{  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ,gD30Pylz  
    cF,u)+2b|6  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens [o|]>(tk  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Ya\G/R  
    t41\nTZr  
        tlens = 3.767 + 0.04*A                  'Lens thickness x-Xb4?{  
    (;Lz `r'  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L{ .r8wSrI  
    Ia>qVM0  
        'Adjust parameters to account for accommodation BAqu@F\):  
    I~4 `NV0  
        '************************************************************************* bYG}CO  
        'Aqueous thickness (Position of Lens) F KL}6W:  
        '************************************************************************* %'^m6^g;  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) RTF{<,E.UX  
        GetCustomElement eID, entity REFisH-  
    l  4~'CLi  
        parID = FindFullName( "Geometry.Arizona Eye" ) zA( 2+e 7  
    V@cRJ3ZF  
        ' Delete any shift(s) in z S,Tm=} wj  
        count = 0 a$;+-Y  
        While GetOperationCount(eID)>count LnR3C:NO k  
            GetOperation eID, count, op t*Lo;]P  
            If op.Type="ShiftZ" Then !.3 MtXr  
                DeleteOperation eID,count S2j7(T;~YB  
                count=count-1 X ,T^(p  
            End If uiHlaMf  
            count=count+1 ?9=yo5M}  
        Wend 7W}~c/%  
    ( B50~it  
        'Set new shift in @,zBZNX y  
        op.Type = "ShiftZ" j-yD;N  
        op.val1 = taq a$9UUH-|  
        op.parent = parID ,9W0fm \t  
        AddOperation eID, op G)b]uX  
        Print "Set aqueous humor thickness = " & taq-0.55 S5bk<8aPP  
    ;O5NZa!.73  
        '************************************************************************* = ng\  
        'Radius and conic constant of anterior lens QC ]z--wu  
        '************************************************************************* E*RP8  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ;Oe6SNquT  
        GetConic eID, entity, curv, conic PB }$.8  
    h"ZF,g;a  
        SetConic eID, entity, 1/Rant, CCant ?8vjHEE  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant :Z1_;`>CT  
    '7_'s1  
        '************************************************************************* Prjl ;[I}  
        'Radius and conic constant of posterior lens )%#hpP M^  
        '************************************************************************* s,` n=#  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 6p1TI1(  
        GetConic eID, entity, curv, conic X Phw0aV  
    GI6 EZ}.MZ  
        SetConic eID, entity, 1/Rpost, CCpost zRf]SZ(t O  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 5!y3=.j  
    D(Xv shQ  
        '************************************************************************* M~ *E!  
        'Lens thickness (Position of posterior lens surface) sH+]lTSX6{  
        '************************************************************************* QuF%m^aE  
    #Oe=G:+A  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) U/jJ@8  
    LM*9b  
        ' Delete any z-shift(s) gs0,-)  
        count = 0 }m0Lr:vq<r  
        While GetOperationCount(eID)>count wBeOMA  
            GetOperation eID, count, op %M'"%Yn@(y  
            If op.Type="ShiftZ" Then Kz^aW  
                DeleteOperation eID,count w8@MUz}/#  
                count=count-1 M_*w)<  
            End If ` qt4~rD  
            count=count+1 u6B (f;  
        Wend 0*tEuJ7  
    ~r>WnI:vg  
        'Set new z-shift (<8T*Xo  
        op.Type = "ShiftZ" ?w<x_Lo  
        op.val1 = tlens U ][.ioc  
        op.parent = parID @ ?e;Jp9  
        AddOperation eID, op IXz ad  
        Print "Set lens thickness = " & tlens q)@.f.  
    ,pAMQ5  
        '************************************************************************* 4&`66\p;  
        'Lens index of refraction zb;2xTH+  
        '************************************************************************* dB_\,%vAd  
        eID = FindMaterial( "Lens" ) 7Y#b7H  
        GetModelMaterial eID, mat YW/<. 0rI  
    BE3~f6 `  
        mat.Nd = nlens e3(0L I  
        SetModelMaterial eID, mat Q jQJ "  
        Print "Set lens index of refraction = " & nlens B]]M?pS  
    &Kjqdp  
        '************************************************************************* T-<^mX[}  
        'Pupil diameter %|-Rh^H[JK  
        '************************************************************************* TOBAh.1  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Ex@#!fz{%  
    VfZ/SByh7p  
        'Adjust pupil diameter (trimming volume inner hole) TFM}P  
    2etlR  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" oh:t ex<  
    Nwu#,f=X  
        ' Adjust pupil location to just in front of the lens +vYm:  
        parID = FindFullName( "Geometry.Arizona Eye" ) m{V @Om  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) )<3WVvB  
        count = 0 # ^%'*/z  
        While GetOperationCount(eID)>count VQ}=7oe%q  
            GetOperation eID, count, op :uI}"Bp  
            If op.Type="ShiftZ" Then j l7e6#zu  
                DeleteOperation eID,count [{Y$]3?}  
                count=count-1 yGN<.IP75  
            End If `qfVgT=2  
            count=count+1 'fg`td  
        Wend BJ&>'rc  
        op.Type = "ShiftZ" 67n1s  
        op.val1 = taq-0.01 if `/LJsa  
        op.parent = parID qv,|7yw{  
        AddOperation eID, op S++}kR);  
    3$y]#L  
        Print "Set pupil diameter = " & pupilDiam 4!monaB"e  
    3mBr nq]j>  
        'Update AZ Eye subassembly Description lhxhAe  
        eID = FindFullName( "Geometry.Arizona Eye" ) 0~FX!1;  
        GetEntity eID, entity ?rv+ydR/q  
        entity.Description = "Accommodation = " & A & "D" G=b`w;oL:  
        SetEntity eID, entity mBnC]$<R  
    aV>w($tdd  
        Update _ -?)-L&g  
        Print "DONE!" \(;5YCCE  
         63k8j[$  
    End Sub vn kktD'n  
    ?j $z[_K  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: @c{Z?>dUc#  
    yJKezIL\z  
    Accommodation = 4 Diopters 9VP|a-  
    Pupil Diameter = 4 mm NIYAcLa@n8  
    Set aqueous humor thickness = 2.81 *^NC5=A(d  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 S&R~*  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 qed; UyN  
    Set lens thickness = 3.927 )Wc#?K  
    Set lens index of refraction = 1.42672 ~ xXB !K~C  
    Set pupil diameter = 4 Xbap' /t  
    DONE! l+T\DZ  
     
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