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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 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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    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. v#FJ+  
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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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    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。 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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    图2. 字母F光源的设定方法光 +l[Z2mW  
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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 ?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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    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。 \ pe[V~F  
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    图5. 视网膜重点采样规格设定
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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: )$lSG}WD  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 c*M)DO`y;h  
    余下的脚本计算与屈光度有关的所有参数。 %(dV|,|v  
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    分析 /`j  K  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 R.T?ZF  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 )=,9`+Zta  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. Fb\2df{@  
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    Dim entity As T_ENTITY [# tT o;q  
    Dim op As T_OPERATION @LkW_  
    Dim mat As T_MODELMATERIAL  ycAi(K  
    Dim A As Double [6/%V>EM  
    Dim pupilDiam As Double &ls!IN  
    Dim eID As Long yaYIgG  
    Dim parID As Long {%+3D,$)  
    Dim count As Integer 1=o(sIeA  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double  2U+z~  
    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/v37%p7  
            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 4,T  
            Print "Execution cancelled." b09#+CH?  
            End <x%my4M  
        End If EJ &ZZg  
    as!|8JE`  
        '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  
    +iDz+3v(  
        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/(s  
        '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  
    T//+&Sk[  
        '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  
    !LSWg:Ev+  
        '************************************************************************* 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 ZlGQ6  
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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  
    *\5H\s9<  
        '************************************************************************* \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  
    D'=`O6pK  
        ' Delete any z-shift(s) (bXp1*0 ;  
        count = 0 F= lj$?4{  
        While GetOperationCount(eID)>count Q 7?4GxMj  
            GetOperation eID, count, op uATRZMai  
            If op.Type="ShiftZ" Then 6H9]]Unju  
                DeleteOperation eID,count .h } D%Qa  
                count=count-1 <0MUn#7'  
            End If 1&WFs6  
            count=count+1 /FXfu  
        Wend 4iPg_+  
    ucO]&'hu:  
        'Set new z-shift =z dti'2{4  
        op.Type = "ShiftZ" e1a%Rj~  
        op.val1 = tlens (6aZQ`H  
        op.parent = parID 4WnxJ]5`  
        AddOperation eID, op n*|-"'j  
        Print "Set lens thickness = " & tlens F:U_gW?  
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        '************************************************************************* 2Ki/K(  
        'Lens index of refraction r#}%sof  
        '************************************************************************* m/h0J03'T  
        eID = FindMaterial( "Lens" ) ~-zC8._w3r  
        GetModelMaterial eID, mat ZaV@}=Rd8  
    )HHzvGsL)  
        mat.Nd = nlens "*WXr$  
        SetModelMaterial eID, mat T9.gs}B0  
        Print "Set lens index of refraction = " & nlens W6>uLMUa  
    _E 8SX v  
        '************************************************************************* >TJ$Z3  
        'Pupil diameter Sn,z$-;h;  
        '************************************************************************* @ vudeaup  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) G 0 yt%qHE  
    sa ?;D  
        'Adjust pupil diameter (trimming volume inner hole) djp(s$:{4  
    &0TheY;srf  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" K a jyQ"j  
    C?J%^?v  
        ' Adjust pupil location to just in front of the lens YG|T;/-  
        parID = FindFullName( "Geometry.Arizona Eye" ) 'r0gqtB  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) _X/`4 G  
        count = 0 c`Cn9bX  
        While GetOperationCount(eID)>count .j.=|5nVo4  
            GetOperation eID, count, op |szfup~5es  
            If op.Type="ShiftZ" Then NI)nf;C  
                DeleteOperation eID,count F'!}$oT"  
                count=count-1 "/=x u|  
            End If x(~l[hT  
            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  
    9|,AhyhO  
        Print "Set pupil diameter = " & pupilDiam `pr,lL  
    J)_ 42Z  
        'Update AZ Eye subassembly Description NgKNT}JDv  
        eID = FindFullName( "Geometry.Arizona Eye" ) .#}R$}e+  
        GetEntity eID, entity 'UKB pm/  
        entity.Description = "Accommodation = " & A & "D" a6C ~!{'nW  
        SetEntity eID, entity t/ w>t! q  
    (A_9;uL^_  
        Update jC=_>\<|X*  
        Print "DONE!" R<U <Y'Y  
         Qpc>5p![3  
    End Sub $I%]jAh6  
    &M0v/!%L  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: SV >EB;<  
    f QdQ[  
    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  
     
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