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    [分享]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: 2020-12-09
    简介 (Q%'N3gk  
     -QOw8vm  
    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。 _7IKzUn9g[  
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    模型 zXv3:uRp.  
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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。 bA\<.d  
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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. 6fd+Q  /  
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    光源 vJ\pR~?  
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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。 70f Klp  
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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。 <@}I0  
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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。 A3B56K  
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    图2. 字母F光源的设定方法光 ?_"+^R z  
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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=LP"bqlI  
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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。 2>86oP&  
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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。 6&bY}i^K  
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    图5. 视网膜重点采样规格设定
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    脚本 AZa 6 C w  
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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: SV v;q?jZ  
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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。 ]%BWIqbr  
    余下的脚本计算与屈光度有关的所有参数。 J9\a{c;.  
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    分析 @J5Jpt*IE  
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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。 4'-|UPhx  
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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 4m*M,#mV  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ,WvY$_#xW%  
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    Dim entity As T_ENTITY )//I'V  
    Dim op As T_OPERATION oS7(s  
    Dim mat As T_MODELMATERIAL 9lGOWRxR)  
    Dim A As Double \MjJ9u `8  
    Dim pupilDiam As Double 1Wm)rXW[x  
    Dim eID As Long AJSx%?h:6  
    Dim parID As Long y`$Q \}fS  
    Dim count As Integer ,Z{d.[$  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double INkD=tX  
    Dim tlens As Double, nlens As Double x_c7R;C  
    Dim curv As Double, conic As Double 94 e): jS  
    Dim ok As Long [5uRS}!  
    [@Q_(LQ-U  
    Sub Main 7zHh@ B:]  
    ]S(%[|  
        '用户输入对话框 -i4&v7"  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 H}H7lO  
            TextBox 220,21,40,21,.TextBox1 'default: 0 yv\#8I:qh  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Ux#x#N  
            OKButton 40,91,90,21 e|&6$A>4]  
            CancelButton 190,91,90,21 ]~6_WE8L  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 C_4)=#@GU  
            TextBox 220,49,40,21,.TextBox2 'default: 4 @BrMl%gV  
        End Dialog T"&)&"W*U  
        Dim dlg As UserDialog :.?gHF.?  
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        ok = Dialog (dlg) E@-KGsdhK  
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        If ok=0 Then    'cancel button was pressed IBQ@{QB  
            Print "Execution cancelled." XuD=E  
            End \EKU*5\Hp>  
        End If B9T!j]'  
    ,oNOC3 U  
        'Assign accommodation and pupil diameter & use defaults if field left empty /;tPNp{!dw  
        If dlg.TextBox1 = "" Then FJ %  
            A = 0           'Default accommodation p|Q*5TO  
        Else fm(e3]  
            A = CDbl(dlg.TextBox1) vk>b#%1{  
        End If fx@j?*Qb  
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        If dlg.TextBox2 = "" Then 2MATpV#BT  
            pupilDiam = 4   'Default pupil diameter ?x+Z)`w_  
        Else 6<N5_1  
            pupilDiam = CDbl(dlg.TextBox2) w,O,W[C  
        End If u5~Ns&o&N  
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        Print " " N<Q jdD&  
        Print "Accommodation = " & A & " Diopters" E;d7ch  
        Print "Pupil Diameter = " & pupilDiam & " mm" >@ YtDl8R  
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        ' Calculate new parameters with accommodation 6<'rG''  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness e#,~,W.H  
    #U*_1P0h  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens Wm H~m k"  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens _{Sm k [  
    / }Rz=&  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Cn>ADWpT&  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens $5v0m#[^  
    ]c&<zeX,  
        tlens = 3.767 + 0.04*A                  'Lens thickness N`E-+9L)  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction !r`,=jK"  
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        'Adjust parameters to account for accommodation 50 A^bbid  
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        '************************************************************************* ]r3Kg12Mi  
        'Aqueous thickness (Position of Lens) O:{U^K:*  
        '************************************************************************* (mtoA#X1:h  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) >6oOZbUY0  
        GetCustomElement eID, entity p-%|P ]&  
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        parID = FindFullName( "Geometry.Arizona Eye" ) _BFOc>0  
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        ' Delete any shift(s) in z p~.8\bI=  
        count = 0  e(NLX`  
        While GetOperationCount(eID)>count x+]!m/  
            GetOperation eID, count, op S!PzLTc  
            If op.Type="ShiftZ" Then AW#<i_Ybf  
                DeleteOperation eID,count %+ FG,d  
                count=count-1 8vuCc=  
            End If /)xlJUq  
            count=count+1 66#"  
        Wend \m=?xb8 f  
    En&5)c+js4  
        'Set new shift in zZiJ 9 e  
        op.Type = "ShiftZ" &20P,8@  
        op.val1 = taq cEe? *\G  
        op.parent = parID *jMk/9oa<N  
        AddOperation eID, op K^rIG6  
        Print "Set aqueous humor thickness = " & taq-0.55 ^ FZ^6*  
    >a1{397Y}  
        '************************************************************************* =<@\,xN>C  
        'Radius and conic constant of anterior lens W5/0`[4  
        '************************************************************************* m^_6:Q0F!8  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ubu?S%`  
        GetConic eID, entity, curv, conic 'a^{=+  
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        SetConic eID, entity, 1/Rant, CCant BZb]SoAL  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 83cW=?UgA  
    "xAWG$b  
        '************************************************************************* CSV;+,Vv  
        'Radius and conic constant of posterior lens p"*y58  
        '************************************************************************* @<M*qK1h  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Qp2I[Ioz3  
        GetConic eID, entity, curv, conic #k<":O  
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        SetConic eID, entity, 1/Rpost, CCpost ^). )  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost dY" }\v6  
    +>7$4`Nb2  
        '************************************************************************* tn|,O.t  
        'Lens thickness (Position of posterior lens surface) 4yaxl\2  
        '************************************************************************* )' xETA  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) pium$4l2#  
    x'Pi5NRE  
        ' Delete any z-shift(s) kCUT ^  
        count = 0 19(Dj&x  
        While GetOperationCount(eID)>count u@p?  
            GetOperation eID, count, op hNXBVIL<&  
            If op.Type="ShiftZ" Then NZu)j["  
                DeleteOperation eID,count %~j2 ('Y  
                count=count-1 <DH*~tLp2  
            End If  n i  
            count=count+1 IMQ]1uq0$  
        Wend JNWg|Qt  
    A>NsKWf{  
        'Set new z-shift ^D@b;EyK  
        op.Type = "ShiftZ" I\\QS.2  
        op.val1 = tlens &X`u9 V  
        op.parent = parID f>$h@/-*  
        AddOperation eID, op gQ~5M'#  
        Print "Set lens thickness = " & tlens IfDx@?OB  
    8_d -81Dd  
        '************************************************************************* nzX@:7g  
        'Lens index of refraction Uz%Z&K  
        '************************************************************************* ? 8 1X  
        eID = FindMaterial( "Lens" ) lEPAP|~uw  
        GetModelMaterial eID, mat [O-sVYB  
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        mat.Nd = nlens vMSW$Bx ;  
        SetModelMaterial eID, mat pz_e=xr  
        Print "Set lens index of refraction = " & nlens ^_p%Yv  
    A1cb"N^  
        '************************************************************************* ly4Qg\l  
        'Pupil diameter V'Qn sI  
        '************************************************************************* o%M<-l"!/  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) AB.(CS=i  
    v7trr W}  
        'Adjust pupil diameter (trimming volume inner hole) <c,~aq#W'  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" daZQz"PP  
    f?Bj _z  
        ' Adjust pupil location to just in front of the lens K2'O]#  
        parID = FindFullName( "Geometry.Arizona Eye" ) IGj`_a  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) :ipoD%@  
        count = 0 Q^eJ4{Ya:  
        While GetOperationCount(eID)>count 3$M3Q]z  
            GetOperation eID, count, op !)NidG  
            If op.Type="ShiftZ" Then Aq#/2t  
                DeleteOperation eID,count dc0@Y  
                count=count-1 H!IDV }dn  
            End If d<o.o?Vc  
            count=count+1 ^E>CGGS4  
        Wend d-!<C7O}  
        op.Type = "ShiftZ" ]]iO- }  
        op.val1 = taq-0.01 {^q)^<#JT  
        op.parent = parID Ar, 9U9  
        AddOperation eID, op 0x)dnq\  
    2BB<mv K4  
        Print "Set pupil diameter = " & pupilDiam !FG%2L4?,5  
    t Y1Et0  
        'Update AZ Eye subassembly Description Mpx/S<Z  
        eID = FindFullName( "Geometry.Arizona Eye" ) 'Am-vhpm  
        GetEntity eID, entity x%BF {Sw  
        entity.Description = "Accommodation = " & A & "D" : iY$82wQ  
        SetEntity eID, entity 6`nR5fh  
    k{Lv37H  
        Update s_wUM)!  
        Print "DONE!" eG] a zt  
         R"6;NPeo  
    End Sub 8<PKKDgbfd  
    Z>A{i?#m  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: 2:v<qX  
    |KG&HN fP-  
    Accommodation = 4 Diopters 66ohmP@04Z  
    Pupil Diameter = 4 mm |'hLa  
    Set aqueous humor thickness = 2.81 FRyPeZR  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 oNRG25  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 *v #/Y9}  
    Set lens thickness = 3.927 ]W9B6G_  
    Set lens index of refraction = 1.42672 ]A:( L9  
    Set pupil diameter = 4 Pern*x9$  
    DONE! o'UHStk  
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    QQ:2987619807 |XcH]7Ai"  
     
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