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    [技术]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 2(5wFc  
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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。  n1y#gC  
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    模型 [k@D}p x  
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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。 @-kzSm  
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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. =XQ3sk6U  
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    光源 3y r{B Xn  
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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。 V F6OC4 K  
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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。 1^}() H62}  
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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。 _AI2\e  
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    图2. 字母F光源的设定方法光 V/"0'H\"1  
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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 W E|L{  
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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。 .{5)$w>  
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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。 +]I;C  
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    图5. 视网膜重点采样规格设定
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    脚本 H",yVD  
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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: O4 \GL  
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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。 ?tqTG2!(  
    余下的脚本计算与屈光度有关的所有参数。 Jc`LUJT  
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    分析 kVkV~  
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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。 ukS@8/eJ  
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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 kL*Q})  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. (}4tj4d  
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    Dim entity As T_ENTITY [p}J=1S  
    Dim op As T_OPERATION 8@6:UR.)  
    Dim mat As T_MODELMATERIAL zoC/Hm  
    Dim A As Double yHr/i) c  
    Dim pupilDiam As Double b'M g  
    Dim eID As Long W>wE8? _,  
    Dim parID As Long ;]Y.2 J  
    Dim count As Integer Ywr^uy1V,/  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double zhHQJcQ.  
    Dim tlens As Double, nlens As Double g@MTKqs  
    Dim curv As Double, conic As Double >W.Pg`'D  
    Dim ok As Long pL-p  
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    Sub Main >/1.VT\E  
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        '用户输入对话框 9y.C])(2  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 1@CI7j  
            TextBox 220,21,40,21,.TextBox1 'default: 0 !rTh+F*  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 cQ*:U@  
            OKButton 40,91,90,21 L)8;96  
            CancelButton 190,91,90,21 Wf0ui1@  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :#d$[:r#  
            TextBox 220,49,40,21,.TextBox2 'default: 4 6dC!&leNi  
        End Dialog ^tc@bsUF  
        Dim dlg As UserDialog !x;T2l  
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        ok = Dialog (dlg) 8* >6+"w  
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        If ok=0 Then    'cancel button was pressed A-ir   
            Print "Execution cancelled." FT`y3 ~  
            End +r4US or  
        End If [rqq*_eB  
    (zk'i13#6  
        'Assign accommodation and pupil diameter & use defaults if field left empty <wj2:Z0  
        If dlg.TextBox1 = "" Then jY87N Hg  
            A = 0           'Default accommodation KkJcH U  
        Else q Z`@Ro  
            A = CDbl(dlg.TextBox1) 6M+~{9(S  
        End If J>!p^|S{  
    '(^p$=3|@D  
        If dlg.TextBox2 = "" Then `j_R ?mY  
            pupilDiam = 4   'Default pupil diameter =2J+}ac  
        Else ?P{C=Td2z  
            pupilDiam = CDbl(dlg.TextBox2) #vLDNR  
        End If X*$ 7g;  
    Tk.MtIs)V}  
        Print " " *v l_3S5_  
        Print "Accommodation = " & A & " Diopters" t(p  
        Print "Pupil Diameter = " & pupilDiam & " mm" =Q3Go8b4HJ  
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        ' Calculate new parameters with accommodation +vDT^|2SF  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness gqZ7Pro.  
    FE/&<g0,:  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens F[RhuNa&'W  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens -Ah\a0z  
    \ {"8(ELX  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 7D9R^\K  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens if#$wm%  
    I?bL4u$\  
        tlens = 3.767 + 0.04*A                  'Lens thickness f=} u;^  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction <0v'IHlZ8  
    =E4nNL?  
        'Adjust parameters to account for accommodation gJ vc<]W8!  
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        '************************************************************************* rUx%2O|qu  
        'Aqueous thickness (Position of Lens) 3i35F.=X,  
        '************************************************************************* cf0em!  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) c{||l+B  
        GetCustomElement eID, entity {'>X6:  
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        parID = FindFullName( "Geometry.Arizona Eye" ) ~;bwfp_  
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        ' Delete any shift(s) in z 1D=My1B  
        count = 0 Q6Jb]>g\H  
        While GetOperationCount(eID)>count LT'#0dCC  
            GetOperation eID, count, op IQ2<Pinv  
            If op.Type="ShiftZ" Then Pvbw>k;  
                DeleteOperation eID,count .!)7x3|$[  
                count=count-1 HV>|f'45  
            End If  "thfd"-  
            count=count+1 Z;WqKIM#  
        Wend 1(On.Y=   
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        'Set new shift in P 3lN ns3  
        op.Type = "ShiftZ" 2eyvY|:Q>  
        op.val1 = taq "GZhr[AW  
        op.parent = parID Z(xn-  
        AddOperation eID, op Eptsxyz{  
        Print "Set aqueous humor thickness = " & taq-0.55 Ix1ec^?f  
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        '************************************************************************* W=F?+Kg L  
        'Radius and conic constant of anterior lens ]*):2%f  
        '************************************************************************* ?;^_%XSQ*  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) gK#a C [  
        GetConic eID, entity, curv, conic )o9CFhFB  
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        SetConic eID, entity, 1/Rant, CCant w :^b3@gd  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant G V0q?  
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        '************************************************************************* Yng9_w9Y  
        'Radius and conic constant of posterior lens $R7d*\(G  
        '************************************************************************* DPy"FQYZb  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) %9Ulgs8=  
        GetConic eID, entity, curv, conic .bL{fBTT~  
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        SetConic eID, entity, 1/Rpost, CCpost .lTGFeJqZ4  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ?P"ht  
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        '************************************************************************* o Q{gh$6*  
        'Lens thickness (Position of posterior lens surface) VZ_ 4B *D  
        '************************************************************************* Y*J`Wf(w  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) wW!*"z  
    rl4daV&,U  
        ' Delete any z-shift(s) (qB$I\  
        count = 0 173/A=]  
        While GetOperationCount(eID)>count p1X lni%=  
            GetOperation eID, count, op , JVD ;u  
            If op.Type="ShiftZ" Then >@ge[MuS  
                DeleteOperation eID,count <V>vDno\  
                count=count-1 n %"s_W'E  
            End If W P.6ea7k  
            count=count+1 of{wZU\J+9  
        Wend rBgLj,/`U/  
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        'Set new z-shift nM}X1^PiK"  
        op.Type = "ShiftZ" |? r,W ~9`  
        op.val1 = tlens UN,@K9  
        op.parent = parID 2psLX  
        AddOperation eID, op V=E9*$b]  
        Print "Set lens thickness = " & tlens z,DEBRT+  
     /H!I90  
        '************************************************************************* .&}}ro48  
        'Lens index of refraction 7CwG(c/5  
        '************************************************************************* -V4@BKI8  
        eID = FindMaterial( "Lens" ) >rYP}k  
        GetModelMaterial eID, mat UyK|KL  
    w6#hsRq[C  
        mat.Nd = nlens ;QgJw2G  
        SetModelMaterial eID, mat Is?0q@  
        Print "Set lens index of refraction = " & nlens i~l0XjQbs  
    WW==  
        '************************************************************************* Kw-E%7gh4c  
        'Pupil diameter t0}3QGf;c  
        '************************************************************************* >@y5R^B`  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) N,Y<mX  
    Y.Gr(]tk  
        'Adjust pupil diameter (trimming volume inner hole) $&lS7}  
    -?'u"*#1,  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" f4X?\eGT  
    +s_@964  
        ' Adjust pupil location to just in front of the lens ?~u"w OH'  
        parID = FindFullName( "Geometry.Arizona Eye" )  '+'  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) P9Rq'u  
        count = 0 my*UN_]  
        While GetOperationCount(eID)>count m 0un=>{  
            GetOperation eID, count, op *"1]NAz+  
            If op.Type="ShiftZ" Then l'-iIbKX  
                DeleteOperation eID,count =%$ _)=}J  
                count=count-1 N}\$i&Vi  
            End If VA2%2g2n{  
            count=count+1 F(@|p]3*  
        Wend >JC.qjA  
        op.Type = "ShiftZ" 2eb :(D7Cq  
        op.val1 = taq-0.01 t{84ioJ"$  
        op.parent = parID ^qV*W1|0  
        AddOperation eID, op d [K56wbpx  
    pm<<!`w"  
        Print "Set pupil diameter = " & pupilDiam IVEvu3  
    VbA#D4;  
        'Update AZ Eye subassembly Description 1z[WJ}$u  
        eID = FindFullName( "Geometry.Arizona Eye" ) T<p>:$vo  
        GetEntity eID, entity Zf(ucAhL  
        entity.Description = "Accommodation = " & A & "D" Ig5J_Z^]b  
        SetEntity eID, entity D~2,0K  
    n6ud;jN|  
        Update O^sgUT1O  
        Print "DONE!" N}.h_~6  
         gKS^-X{x  
    End Sub ) `;?%N\  
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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: SU H^]4>  
    8!:4m"Y  
    Accommodation = 4 Diopters YZ/mTQn_D  
    Pupil Diameter = 4 mm e|Lh~sVq  
    Set aqueous humor thickness = 2.81 ~_^nWT*BV  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 5_=&U-? H  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 _Se>X=  
    Set lens thickness = 3.927 EeL~`$f  
    Set lens index of refraction = 1.42672 e2/[`k=7-  
    Set pupil diameter = 4 w3,QT}WvY  
    DONE! kiqq_`66  
     
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