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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 l) iv\j  
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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。 z-)*Q  
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    模型 oEPNN'~3  
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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。 o>$|SU!a  
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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. S].Ft/+H  
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    光源 XzlIW&"uC  
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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。 1uY3[Z9S  
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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。 s?~8O|Mu'  
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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。 ,?t}NZY&  
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    图2. 字母F光源的设定方法光  =05iW  
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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 okVp\RC  
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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。 tu7+LwF7  
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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。 kf}F}Ad:%  
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    图5. 视网膜重点采样规格设定
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    脚本 Bmi:2} j  
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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: 'MSEki67  
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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。 T-hU+(+hg  
    余下的脚本计算与屈光度有关的所有参数。 d'x<- l9  
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    分析 v&k>0lV, ^  
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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。 rSM$E  
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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 9k714bnMLX  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. i#CaKS  
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    Dim entity As T_ENTITY L"Qh_+   
    Dim op As T_OPERATION E1$Hu{  
    Dim mat As T_MODELMATERIAL ; ,Of\Efc|  
    Dim A As Double ~ >&I^4  
    Dim pupilDiam As Double # q0Ub-  
    Dim eID As Long MLkL.1eGSb  
    Dim parID As Long  #a|6Q 8  
    Dim count As Integer TBoM{s=.  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double +a7EsR  
    Dim tlens As Double, nlens As Double B"pFJ"XR  
    Dim curv As Double, conic As Double 4iYgs-,  
    Dim ok As Long Bf D,z  
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    Sub Main v_?s1+w  
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        '用户输入对话框 $[HcHnf  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Yio>ft&g]  
            TextBox 220,21,40,21,.TextBox1 'default: 0 V6DBKq  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 GnSgO-$"  
            OKButton 40,91,90,21 4jC4X*  
            CancelButton 190,91,90,21 .g6PrhzFbk  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 2eZk3_w  
            TextBox 220,49,40,21,.TextBox2 'default: 4 ]7XkijNb  
        End Dialog h|(Z XCH  
        Dim dlg As UserDialog ?.rH;:9To  
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        ok = Dialog (dlg) fPh}l  
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        If ok=0 Then    'cancel button was pressed 2uJNc!&  
            Print "Execution cancelled." y(aAp.S>  
            End X/- W8  
        End If wW6mYgPN%  
    dy2_@/T7  
        'Assign accommodation and pupil diameter & use defaults if field left empty Y|GJp h  
        If dlg.TextBox1 = "" Then FqT,4SIR  
            A = 0           'Default accommodation  #{)r*"%  
        Else 2$j Ot}  
            A = CDbl(dlg.TextBox1) E3FW*UNg[y  
        End If .-O@UQx.I  
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        If dlg.TextBox2 = "" Then ? $)x$nS`  
            pupilDiam = 4   'Default pupil diameter Xh7~MU~X  
        Else %-1BA *J`|  
            pupilDiam = CDbl(dlg.TextBox2) y(bt56 | z  
        End If /el["l  
    a=:{{\1o  
        Print " " ]<\;d B  
        Print "Accommodation = " & A & " Diopters" #x4h_K Y  
        Print "Pupil Diameter = " & pupilDiam & " mm" > hDsm;,/  
    Z uFV tW@  
        ' Calculate new parameters with accommodation &.+n L  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness jE?\Yv3  
    QKUBh-QFK  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens V#-qKV  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens /A[oj2un  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens pjKl)q  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens .%J?T5D  
    +s/N@]5nW  
        tlens = 3.767 + 0.04*A                  'Lens thickness %X0NHta ~@  
    },Re5W nl  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction "&~?Hzm  
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        'Adjust parameters to account for accommodation  ^ :  
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        '************************************************************************* t=E|RYC(k  
        'Aqueous thickness (Position of Lens) c:@OX[##  
        '************************************************************************* >^a"Z[s[  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) R+kZLOE  
        GetCustomElement eID, entity |=^#d\?]j  
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        parID = FindFullName( "Geometry.Arizona Eye" ) N?2 #YTjR  
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        ' Delete any shift(s) in z MWn L#!  
        count = 0 f9 l<$l  
        While GetOperationCount(eID)>count "`W1yk5x  
            GetOperation eID, count, op q563,s  
            If op.Type="ShiftZ" Then aaf_3UH.B  
                DeleteOperation eID,count ,SJK  
                count=count-1 g+KzlS[6  
            End If yf#%)-7(  
            count=count+1 O)RzNfI^`N  
        Wend w /W Cj4`  
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        'Set new shift in O"J.k&C<,  
        op.Type = "ShiftZ" ELgae1  
        op.val1 = taq )QSt7g|OF  
        op.parent = parID QIMv9;  
        AddOperation eID, op <Z_wDK/UR  
        Print "Set aqueous humor thickness = " & taq-0.55 @)2V"FE4i  
    |B{$URu  
        '************************************************************************* |`(?<m  
        'Radius and conic constant of anterior lens Q~w G(0'8  
        '************************************************************************* #Z=)=  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) H-cBXp5z  
        GetConic eID, entity, curv, conic _E&vE5<-$  
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        SetConic eID, entity, 1/Rant, CCant 'd.@4 9  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ,^+R%7mv  
    l-^XW?CfL  
        '************************************************************************* PRk%C0`  
        'Radius and conic constant of posterior lens *liPJ29C[  
        '************************************************************************* !^w\$cw&  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +}-W.H%`0  
        GetConic eID, entity, curv, conic +&N&D"9A  
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        SetConic eID, entity, 1/Rpost, CCpost 0rm;)[SjF  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost syN b0LR  
    55\X\> 0C7  
        '************************************************************************* ;`of'9|  
        'Lens thickness (Position of posterior lens surface) 9;v"bc Q  
        '************************************************************************* h%w\O Z7  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) &9lc\Y4PY  
    hv:Z%D |S  
        ' Delete any z-shift(s) yxP?O@(  
        count = 0 K7O? {/  
        While GetOperationCount(eID)>count 4tTZkJc  
            GetOperation eID, count, op vYt:}$AE  
            If op.Type="ShiftZ" Then 8rG&CxI  
                DeleteOperation eID,count [ rQ(ae  
                count=count-1 TnU$L3k  
            End If o27`g\gDR,  
            count=count+1 e "adkV  
        Wend qp_ `Fj:  
    $}UJs <-F  
        'Set new z-shift YlcF-a  
        op.Type = "ShiftZ" N evvA(M  
        op.val1 = tlens 5Kw?SRFH/  
        op.parent = parID L{0OMyUA  
        AddOperation eID, op T17LYHIT  
        Print "Set lens thickness = " & tlens 8`~3MsE"  
    <[5${)  
        '************************************************************************* MJ"Mn^:/  
        'Lens index of refraction rU^ghF  
        '************************************************************************* W>|b98NPu  
        eID = FindMaterial( "Lens" ) iM/0Yp-v'>  
        GetModelMaterial eID, mat Isgk  
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        mat.Nd = nlens XK/@!ud"`  
        SetModelMaterial eID, mat K y4y  
        Print "Set lens index of refraction = " & nlens p;t!"I:`?  
    dDn4nwH  
        '************************************************************************* U?^|>cMr  
        'Pupil diameter 8'xnhV  
        '************************************************************************* 4qz{ D"M  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) OK J%M]<  
    x-#9i  
        'Adjust pupil diameter (trimming volume inner hole) kJeOlO[  
    5)v^ cR?&  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" K':pU1  
    f -nC+   
        ' Adjust pupil location to just in front of the lens %dU'$)  
        parID = FindFullName( "Geometry.Arizona Eye" ) KC-aLq/  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) D&m"~wI  
        count = 0 U(]5U^  
        While GetOperationCount(eID)>count }Z? [Ut  
            GetOperation eID, count, op 446hrzW>@  
            If op.Type="ShiftZ" Then .F3LA6se  
                DeleteOperation eID,count <r`Jn49  
                count=count-1 842+KLS  
            End If l<: E+lU  
            count=count+1 !X <n:J  
        Wend ~+nSI-L  
        op.Type = "ShiftZ" Iw |[*Nu-  
        op.val1 = taq-0.01 2^ZPO4|  
        op.parent = parID [=1?CD  
        AddOperation eID, op q<uLBaL_]r  
    7CMgvH)O  
        Print "Set pupil diameter = " & pupilDiam oNsx Fi:  
    ^k<$N  
        'Update AZ Eye subassembly Description p2vUt  
        eID = FindFullName( "Geometry.Arizona Eye" ) (a!,)  
        GetEntity eID, entity mT~>4xi0  
        entity.Description = "Accommodation = " & A & "D" #=#$b_6*  
        SetEntity eID, entity f4I9H0d;!  
    y" -{6{3  
        Update WA\f`SRF  
        Print "DONE!" i4r~eneP  
         @N{Ht)1r  
    End Sub DmPsltpzQ  
    6i9I 4*'  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: _-\{kJ  
    Du4#\OK  
    Accommodation = 4 Diopters h1o+7  
    Pupil Diameter = 4 mm B "zg85 e  
    Set aqueous humor thickness = 2.81 XRz6Yf(/  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 m8^2k2  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 %9Fg1LH42r  
    Set lens thickness = 3.927 1AV1W_"  
    Set lens index of refraction = 1.42672 6lAo`S\)eX  
    Set pupil diameter = 4 l>?vjy65  
    DONE! 1H 6Wrik  
     
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