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infotek 2022-02-25 09:52

Arizona眼睛模型

简介 W7.O(s,32  
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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。  v'i"Q  
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模型 c'OJodpa  
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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。 W!q 'wrIx(  
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. k| 0Fa}Z[  
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光源 .B*Yg<j  
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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。 z"o;|T:  
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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。 YM{Q)115  
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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。 GDw4=0u-  
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图2. 字母F光源的设定方法光 C0/s/p'  
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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 'KpCPOhfR  
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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。 8~RUYsg  
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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;Cr92  
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图5. 视网膜重点采样规格设定
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脚本 gXI_S9 z  
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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:  s=#IoNh  
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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。 OzBo *X/p  
余下的脚本计算与屈光度有关的所有参数。 a1ZGMQq!  
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分析 FMY r6/I  
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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。 9;dP7o  
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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 rsBF\(3b~  
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  1. Option Explicit     'Remove this to enable non-dimensioned variables to be used. z%ljEI"<C  
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    Dim entity As T_ENTITY RUf,)]Vvk  
    Dim op As T_OPERATION ./kmI#gaV  
    Dim mat As T_MODELMATERIAL ]=9%fA  
    Dim A As Double @SPmb o  
    Dim pupilDiam As Double W#e:rz8=  
    Dim eID As Long L3Ry#uw  
    Dim parID As Long d(, -13  
    Dim count As Integer OW)8Z 60  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 8 /b_4!5c  
    Dim tlens As Double, nlens As Double i3: sV5  
    Dim curv As Double, conic As Double r!Eo8C  
    Dim ok As Long @U;-5KYYi  
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    Sub Main St|sUtj<r  
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        '用户输入对话框 qTqvEa^X`  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ~/3cQN^  
            TextBox 220,21,40,21,.TextBox1 'default: 0 #` z!f0 P  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 v{H23Cfh:  
            OKButton 40,91,90,21 tl;?/  
            CancelButton 190,91,90,21 /qI80KVnN  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 N$Gx$u3Cd  
            TextBox 220,49,40,21,.TextBox2 'default: 4 G2a fHL<  
        End Dialog "4g1I<  
        Dim dlg As UserDialog RfN5X}&A  
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        ok = Dialog (dlg) A6iyJFm D  
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        If ok=0 Then    'cancel button was pressed 5 F^,7A4I0  
            Print "Execution cancelled." 5 1 x^gX|  
            End 4 CX*,7LZ  
        End If ih+kh7J-  
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        'Assign accommodation and pupil diameter & use defaults if field left empty D:n0d fPU  
        If dlg.TextBox1 = "" Then wk9tJ#}  
            A = 0           'Default accommodation ?N11R?8  
        Else lS?f?n^  
            A = CDbl(dlg.TextBox1) = 1}-]ctVn  
        End If /f%u_ 8pV%  
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        If dlg.TextBox2 = "" Then &~E=T3  
            pupilDiam = 4   'Default pupil diameter {GWcw<g.B  
        Else sE/9~L  
            pupilDiam = CDbl(dlg.TextBox2) iZSj T"l^  
        End If c |C12b[  
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        Print " " <V6#)^Or  
        Print "Accommodation = " & A & " Diopters" +nJ}+|@K  
        Print "Pupil Diameter = " & pupilDiam & " mm" w_U5w  
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        ' Calculate new parameters with accommodation B.Xm*adBT  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness U4N S.`V  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens VwC, +B  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 8L=QfKr  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens k*M{?4  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens k*!J,/=k  
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        tlens = 3.767 + 0.04*A                  'Lens thickness m   
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction PTePSj1N  
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        'Adjust parameters to account for accommodation fA 3  
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        '************************************************************************* 3c9[FZ@ya  
        'Aqueous thickness (Position of Lens) U-lN_?  
        '************************************************************************* +=}% 7o  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ]a:kP,  
        GetCustomElement eID, entity lA]u8+gXd  
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        parID = FindFullName( "Geometry.Arizona Eye" ) oO UVU}H  
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        ' Delete any shift(s) in z  (K?[gI  
        count = 0 CZa9hsM  
        While GetOperationCount(eID)>count huq6rA/i  
            GetOperation eID, count, op N{q'wep  
            If op.Type="ShiftZ" Then g{D&|qWj  
                DeleteOperation eID,count u8W*_;%:  
                count=count-1 72{kig9c  
            End If K^w9@&g6  
            count=count+1 qC 6Q5F  
        Wend ;^*^ :L  
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        'Set new shift in u>(Q& 25  
        op.Type = "ShiftZ" }j:ae \(  
        op.val1 = taq NeK:[Q@je  
        op.parent = parID jkdNisq37  
        AddOperation eID, op m+u>%Ys`  
        Print "Set aqueous humor thickness = " & taq-0.55 Tbwq_3f K  
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        '************************************************************************* E"" /dC:B  
        'Radius and conic constant of anterior lens #m M&CscE  
        '************************************************************************* FVD}9ia  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) [7Kn$OfP  
        GetConic eID, entity, curv, conic Ke/P [fo  
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        SetConic eID, entity, 1/Rant, CCant +<q^[<pS  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Sm1bDa\!=  
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        '************************************************************************* g9 yCd(2<5  
        'Radius and conic constant of posterior lens lZua"Ju  
        '************************************************************************* -s)2b ;  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) T4#knSIlh  
        GetConic eID, entity, curv, conic Bdg*XfXXk  
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        SetConic eID, entity, 1/Rpost, CCpost + zrwz\  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ~XxD[T5  
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        '************************************************************************* cp2fDn  
        'Lens thickness (Position of posterior lens surface) zk/!#5JtK  
        '************************************************************************* #0P<#S^7  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) %F4Q|  
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        ' Delete any z-shift(s) 8qc %{8  
        count = 0 3Mcz9exY  
        While GetOperationCount(eID)>count lxmS.C  
            GetOperation eID, count, op * c%@f<R~  
            If op.Type="ShiftZ" Then kg61Dgu  
                DeleteOperation eID,count Pz)QOrrG~  
                count=count-1 #wd \&  
            End If 395o[YZx*  
            count=count+1 O}`01A!u;  
        Wend ChW0vIL`  
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        'Set new z-shift <F3sQAe  
        op.Type = "ShiftZ" p%ZiTrA1&D  
        op.val1 = tlens 'H'+6   
        op.parent = parID MU e 'xK  
        AddOperation eID, op 1h#k&r#*3  
        Print "Set lens thickness = " & tlens _l,Z38  
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        '************************************************************************* 4GfLS.Ip  
        'Lens index of refraction &`Di cfD  
        '************************************************************************* "[?/I3 {E  
        eID = FindMaterial( "Lens" ) n>0dz#  
        GetModelMaterial eID, mat y;Zfz~z  
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        mat.Nd = nlens ) e2IT*7  
        SetModelMaterial eID, mat PJYA5"}W  
        Print "Set lens index of refraction = " & nlens Yz,!#ob$  
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        '************************************************************************* 5p|@)  
        'Pupil diameter -Wn.@bz6B  
        '************************************************************************* 3.0c/v5Go  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" )  b:QFD|  
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        'Adjust pupil diameter (trimming volume inner hole) UjDF  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" uBTT {GGQ  
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        ' Adjust pupil location to just in front of the lens 4 ufLP DH  
        parID = FindFullName( "Geometry.Arizona Eye" ) u,akEvH~a  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) y9L#@   
        count = 0 _o?(t\B9{  
        While GetOperationCount(eID)>count Y+ Z9IiS7  
            GetOperation eID, count, op ~0-764%  
            If op.Type="ShiftZ" Then ]k: m2$le  
                DeleteOperation eID,count &7T H V  
                count=count-1 bVeTseAG  
            End If rH9}nL  
            count=count+1 hcgc =$^  
        Wend D'`"_  
        op.Type = "ShiftZ" LZ)m](+M  
        op.val1 = taq-0.01 w;EXjl;X O  
        op.parent = parID (`]*Y(/2G  
        AddOperation eID, op K~8tN ,~&  
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        Print "Set pupil diameter = " & pupilDiam daIL> c"  
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        'Update AZ Eye subassembly Description S9NN.dKu  
        eID = FindFullName( "Geometry.Arizona Eye" ) ING_:XpnJ  
        GetEntity eID, entity =_=Z;#`cXk  
        entity.Description = "Accommodation = " & A & "D" WQ}!]$<"y  
        SetEntity eID, entity FMd LkyK;  
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        Update )SX6)__  
        Print "DONE!" vif8 {S  
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    End Sub B`B%:#  
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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: N+M&d3H`  
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    Accommodation = 4 Diopters 6#)Jl  
    Pupil Diameter = 4 mm MpA;cw]cI/  
    Set aqueous humor thickness = 2.81 uUz`=4%A  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 %Lp7@  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 uR ;-eK  
    Set lens thickness = 3.927 ~$4.Mf,u  
    Set lens index of refraction = 1.42672 em1cc,  
    Set pupil diameter = 4 P$3=i`X!nw  
    DONE!
silence唯爱 2022-02-25 13:53
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