[技术]Arizona眼睛模型 [复制链接]

简介 8@9hU`H8l  
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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。 (M+,wW[6  
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模型 +1E?He:iQ  
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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。 +0oyt?  
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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. v#F
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光源 9 AQ96  
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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。 M~d+HE  
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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。 c<JM1  
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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。 P;HVLflu  
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视网膜的散射 ?34EJ !  
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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。 Zh@4_Z9n!  
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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。 \ pe[V~F  
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脚本 gr[ "A  
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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： )$lSG}WD  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 c*M)DO`y;h  
余下的脚本计算与屈光度有关的所有参数。 %(dV|,|v  
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分析 /`j K  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 R.T?
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脚本代码 )=,9`+Zta  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Fb\2df{@  
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Dim entity As T_ENTITY [# tT o;q  
Dim op As T_OPERATION @LkW_  
Dim mat As T_MODELMATERIAL  ycAi(K  
Dim A As Double [6/%V>EM  
Dim pupilDiam As Double &ls
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Dim eID As Long yaYIgG  
Dim parID As Long {%+3D,$)  
Dim count As Integer 1=o(sIeA  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 2U
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Dim tlens As Double, nlens As Double c@ZkX]g  
Dim curv As Double, conic As Double =aCIaL&9Y  
Dim ok As Long *~t$k56  
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Sub Main ;2xXX,'R7  
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    '用户输入对话框 ]Xkc0E1  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 H
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        TextBox 220,21,40,21,.TextBox1 'default: 0 Y(G*Yi?;  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 -SC2Zgi)A  
        OKButton 40,91,90,21 }v(H E%~}  
        CancelButton 190,91,90,21 Cn./Naq  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Z+"E*  
        TextBox 220,49,40,21,.TextBox2 'default: 4 g:HbmXOBpj  
    End Dialog x"C93ft[  
    Dim dlg As UserDialog ezq q@t9  
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    ok = Dialog (dlg) ^) b7m  
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    If ok=0 Then    'cancel button was pressed y
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        Print "Execution cancelled." b09#+CH?  
        End <x%my4M  
    End If EJ &ZZg  
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    'Assign accommodation and pupil diameter & use defaults if field left empty $Bwvw)(%  
    If dlg.TextBox1 = "" Then yn ?U7`V  
        A = 0           'Default accommodation ~E:/oV:4 >  
    Else ['N#aDh.?  
        A = CDbl(dlg.TextBox1) .n|3A3:  
    End If Rp@}9qijb  
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    If dlg.TextBox2 = "" Then 0?4^.N n3  
        pupilDiam = 4   'Default pupil diameter !PP?2Ax  
    Else bl=*3qB  
        pupilDiam = CDbl(dlg.TextBox2) )dN,b(w9  
    End If s7)# NT2  
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    Print " " |sZ9/G7  
    Print "Accommodation = " & A & " Diopters" ])ZJ1QL1  
    Print "Pupil Diameter = " & pupilDiam & " mm" HIp {< M3  
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    ' Calculate new parameters with accommodation Sm I8&c  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness MvjwP?J]  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens W!9f'Yn  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Yr(f iI  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 93p9?4;n-  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens WE8L?55_Au  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 1nM?>j%k  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction l=OC?d*m  
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    'Adjust parameters to account for accommodation k}a!lI:  
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    '************************************************************************* 9lwo/(
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    'Aqueous thickness (Position of Lens) HBkQ`T  
    '************************************************************************* sAAIyPJts  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) %RF  
    GetCustomElement eID, entity !m.')\4<  
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    parID = FindFullName( "Geometry.Arizona Eye" ) <qj@waKw4  
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    ' Delete any shift(s) in z r3lr`s`  
    count = 0 5TW<1'u  
    While GetOperationCount(eID)>count #2t\>7]  
        GetOperation eID, count, op B!C32~[  
        If op.Type="ShiftZ" Then Qz90 mb  
            DeleteOperation eID,count |8?{JKsg  
            count=count-1 ?=o]Wx0(9  
        End If o\YdL2:X  
        count=count+1 4'eVFu+62  
    Wend "Q!{8 9Y  
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    'Set new shift in "+"dALX{3K  
    op.Type = "ShiftZ" ^\t">NJ^  
    op.val1 = taq GnHf9 JrR  
    op.parent = parID *m Tc4&*  
    AddOperation eID, op 4>eg@sN  
    Print "Set aqueous humor thickness = " & taq-0.55 AyXKhj#Ml  
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    '************************************************************************* 6E%k{ r  
    'Radius and conic constant of anterior lens TgG)btQ  
    '************************************************************************* jtCob'n8  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) E$fy*enON  
    GetConic eID, entity, curv, conic Z19y5?uR  
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    SetConic eID, entity, 1/Rant, CCant B ~bU7.Cd  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Ppn
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    '************************************************************************* G`K7P`m  
    'Radius and conic constant of posterior lens ,=yIfbFQ  
    '************************************************************************* J\},o|WI  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) b8Ad*f\  
    GetConic eID, entity, curv, conic T>?1+mruM  
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    SetConic eID, entity, 1/Rpost, CCpost E0'6!9y  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ^8t*WphZC  
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    '************************************************************************* \3UdC{~  
    'Lens thickness (Position of posterior lens surface) Xc<9[@  
    '************************************************************************* M#IR=|P]  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) #rC+13  
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    ' Delete any z-shift(s) (bXp1*0 ;  
    count = 0 F=lj$?4{  
    While GetOperationCount(eID)>count Q 7?4GxMj  
        GetOperation eID, count, op uATRZMai  
        If op.Type="ShiftZ" Then 6H9]]Unju  
            DeleteOperation eID,count .h }D%Qa  
            count=count-1 <0MUn#7'  
        End If 1&WFs6  
        count=count+1 /FXfu  
    Wend 4iPg_+  
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    'Set new z-shift =z dti'2{4  
    op.Type = "ShiftZ" e1a%Rj~  
    op.val1 = tlens (6aZQ`H  
    op.parent = parID 4WnxJ]5`  
    AddOperation eID, op n*|-"'j  
    Print "Set lens thickness = " & tlens F:U_gW?  
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    '************************************************************************* 2Ki/K(  
    'Lens index of refraction r#}%sof  
    '************************************************************************* m/h0J03'T  
    eID = FindMaterial( "Lens" ) ~-zC8._w3r  
    GetModelMaterial eID, mat ZaV@}=Rd8  
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    mat.Nd = nlens "*WXr$  
    SetModelMaterial eID, mat T9.gs}B0  
    Print "Set lens index of refraction = " & nlens W6>uLMUa  
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    '************************************************************************* >TJ$Z3
 
    'Pupil diameter Sn,z$-;h;  
    '************************************************************************* @ vudeaup  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) G 0 yt%qHE  
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    'Adjust pupil diameter (trimming volume inner hole) djp(s$:{4  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" K ajyQ"j  
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    ' Adjust pupil location to just in front of the lens YG|T;/-  
    parID = FindFullName( "Geometry.Arizona Eye" ) 'r0gqtB  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) _X/`4 G  
    count = 0 c`Cn9bX  
    While GetOperationCount(eID)>count .j.=|5nVo4  
        GetOperation eID, count, op |szfup~5es  
        If op.Type="ShiftZ" Then NI)nf;C  
            DeleteOperation eID,count F'!}$oT"  
            count=count-1 "/=xu|  
        End If x(~
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        count=count+1 Ws@s(5r  
    Wend TjdYCk]'  
    op.Type = "ShiftZ" Gz:a1-x  
    op.val1 = taq-0.01 j|9 2 g  
    op.parent = parID o\#e7Hqbh  
    AddOperation eID, op GKr L  
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    Print "Set pupil diameter = " & pupilDiam `pr,lL  
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    'Update AZ Eye subassembly Description NgKNT}JDv  
    eID = FindFullName( "Geometry.Arizona Eye" ) .#}R$}e+  
    GetEntity eID, entity 'UKB
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    entity.Description = "Accommodation = " & A & "D" a6C~!{'nW  
    SetEntity eID, entity t/w>t! q  
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    Update jC=_>\<|X*  
    Print "DONE!" R<U<Y'Y  
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End Sub $I%]jAh6  
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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： SV >EB;<  
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Accommodation = 4 Diopters |{(ynZ]R  
Pupil Diameter = 4 mm ,==lgM2V>  
Set aqueous humor thickness = 2.81 BH^q.p_#>X  
Set anterior lens radius = 10.4 and conic constant = -2.375869 t<-Iiq+tL  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 0FBifK  
Set lens thickness = 3.927 ZZUCwczI  
Set lens index of refraction = 1.42672 VlH9ap  
Set pupil diameter = 4 QQcJUOxT9  
DONE! <v?-$3YT