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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 # [0>wEq  
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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。 0y"Ra%Y  
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    模型 3]iBX`Ni  
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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。 }8W5m(Zq9n  
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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. 'z=QV{ni  
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    光源 lR9~LNK?  
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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。 C(^IX"9 #  
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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。 )$Erfu  
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 (RL5L=,u  
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    图2. 字母F光源的设定方法光 km]RrjRp  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 KV!!D{VS`@  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 E_aDkNT  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 jtMN)TM  
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    图5. 视网膜重点采样规格设定
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    脚本 Gj.u /l  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: BtSl%(w  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 y8$TU;  
    余下的脚本计算与屈光度有关的所有参数。 7,sslf2%K  
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    分析 Wm5/>Cu,  
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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。 pN[G?A  
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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 }NQ {S3JW  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ;t.LLd  
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    Dim entity As T_ENTITY D3^Yc:[_@  
    Dim op As T_OPERATION o*OaYF'8  
    Dim mat As T_MODELMATERIAL SWX;sM  
    Dim A As Double !,#42TY*X  
    Dim pupilDiam As Double '$]u?m  
    Dim eID As Long ![wV}. }  
    Dim parID As Long "]%.%$  
    Dim count As Integer "Q:m0P xb  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double d$uh .?F5  
    Dim tlens As Double, nlens As Double ?(cbZ#( o  
    Dim curv As Double, conic As Double DQ{Yr>J  
    Dim ok As Long A=7  [^I2  
    7 I/  
    Sub Main ?jywW$   
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        '用户输入对话框 edt(Zzk@3-  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 !<wM?Q:  
            TextBox 220,21,40,21,.TextBox1 'default: 0 \BT8-}  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 R "S,&  
            OKButton 40,91,90,21 $J>J@4  
            CancelButton 190,91,90,21 s2*^ PG  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 NR8YVO)5$  
            TextBox 220,49,40,21,.TextBox2 'default: 4 dF$Fd{\4^  
        End Dialog :V>M{vd  
        Dim dlg As UserDialog e}u# :ysj  
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        ok = Dialog (dlg) ncEOz1u  
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        If ok=0 Then    'cancel button was pressed k%iZ..  
            Print "Execution cancelled." l@ +]XyLj  
            End DwXzmp[qWH  
        End If w<?v78sT  
    #]ZOi`;  
        'Assign accommodation and pupil diameter & use defaults if field left empty gDP\u<2!  
        If dlg.TextBox1 = "" Then CU3[{a  
            A = 0           'Default accommodation O`nrXC{  
        Else `!?SA<a:  
            A = CDbl(dlg.TextBox1) $V$|"KRcs  
        End If nRpZ;X)'.  
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        If dlg.TextBox2 = "" Then 3YyB0BMW  
            pupilDiam = 4   'Default pupil diameter #P,mZ}G\  
        Else xm@vx}O:  
            pupilDiam = CDbl(dlg.TextBox2) o#X|4bES  
        End If >gAq/'.Q  
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        Print " " $:I~y| !1  
        Print "Accommodation = " & A & " Diopters" .6Swc?  
        Print "Pupil Diameter = " & pupilDiam & " mm" |k~\E|^  
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        ' Calculate new parameters with accommodation GdFTKOq  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness &j}\ZD  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens Hcw@24ic  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens $O*rxQ}  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Z~}=q  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens c?i=6C dD'  
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        tlens = 3.767 + 0.04*A                  'Lens thickness -(FVTWi0  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction #/'5N|?  
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        'Adjust parameters to account for accommodation _5I" %E;S  
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        '************************************************************************* OM!CP'u#{  
        'Aqueous thickness (Position of Lens) Sr)rKc  
        '************************************************************************* y0vo-)E]-]  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) >#z*gCO5,  
        GetCustomElement eID, entity K8y/U(@|D  
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        parID = FindFullName( "Geometry.Arizona Eye" ) f $MVgX  
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        ' Delete any shift(s) in z Ob+L|FbnN  
        count = 0 `X8AM=  
        While GetOperationCount(eID)>count 3 }Z [d  
            GetOperation eID, count, op 8M m,a  
            If op.Type="ShiftZ" Then lgTavs  
                DeleteOperation eID,count B@Zed Xi  
                count=count-1 0R~{|RHM  
            End If :_YpS w<Q  
            count=count+1 T69'ta32V  
        Wend hPt(7E2ke~  
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        'Set new shift in K1O0/2O  
        op.Type = "ShiftZ" d_BO&k<+I  
        op.val1 = taq E 5PefD\m  
        op.parent = parID ]Lq9Ompf(t  
        AddOperation eID, op V2kNJwwk  
        Print "Set aqueous humor thickness = " & taq-0.55 _|.q?;C]$  
    (v*$ExF  
        '************************************************************************* c#+JG  
        'Radius and conic constant of anterior lens kBd #=J  
        '************************************************************************* 9aT#7B  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) jJ-j   
        GetConic eID, entity, curv, conic Hs<vCL \  
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        SetConic eID, entity, 1/Rant, CCant az3rK4g  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 6bCC6G  
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        '************************************************************************* rk W*C'2fz  
        'Radius and conic constant of posterior lens c,;-[sn  
        '************************************************************************* )}\T~#Q]y  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Q}ho Y  
        GetConic eID, entity, curv, conic %^}3:0G  
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        SetConic eID, entity, 1/Rpost, CCpost E7^r3#s  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 6JBE=9d-Q  
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        '************************************************************************* |) QE+|?P  
        'Lens thickness (Position of posterior lens surface) ,6?L.L  
        '************************************************************************* C#X|U2$  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) k0.|%0?K  
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        ' Delete any z-shift(s) -#= v~vE  
        count = 0 L !:}  
        While GetOperationCount(eID)>count Zuod1;qIh  
            GetOperation eID, count, op g9I2 e<;o  
            If op.Type="ShiftZ" Then qazM@  
                DeleteOperation eID,count 1QXv}36#3n  
                count=count-1 Yd:8i JA  
            End If u$d T^c  
            count=count+1 I?@9;0R  
        Wend 4Y8/>uL  
    /,A:HM>B  
        'Set new z-shift rWEJCFa  
        op.Type = "ShiftZ" EXUjdJs"  
        op.val1 = tlens iqURlI);P  
        op.parent = parID Js[dT|>.  
        AddOperation eID, op jI!}}K)d  
        Print "Set lens thickness = " & tlens K1 a$ m2  
    <zH24[  
        '************************************************************************* g|8G!7O  
        'Lens index of refraction hrPm$`  
        '************************************************************************* !\.x7N<)0  
        eID = FindMaterial( "Lens" ) lpLjfHr  
        GetModelMaterial eID, mat .p&4]6  
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        mat.Nd = nlens Dsc{- <v  
        SetModelMaterial eID, mat 8W Mhe=[  
        Print "Set lens index of refraction = " & nlens |]sh*<:?,  
    }6MHIr=o  
        '************************************************************************* LC)-aw>-  
        'Pupil diameter _U;z@  
        '************************************************************************* eS9uKb5n(  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Q1?  !,a  
    H->J.5~,K  
        'Adjust pupil diameter (trimming volume inner hole) Zoh[tO   
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ZW n j-  
    NL%5'8F>,  
        ' Adjust pupil location to just in front of the lens E'zLgU)r`  
        parID = FindFullName( "Geometry.Arizona Eye" ) XhjH68S(  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) #Q}`kFB`  
        count = 0 LO0<=4iN(  
        While GetOperationCount(eID)>count p =_K P9  
            GetOperation eID, count, op  2bwf(  
            If op.Type="ShiftZ" Then zts%oIgV  
                DeleteOperation eID,count <z+5+h|^  
                count=count-1 < TJzp  
            End If OI</o0Ca  
            count=count+1 Ub!MyXd{q  
        Wend Ge=+ 0W)&  
        op.Type = "ShiftZ" ;LM`B^Q]s  
        op.val1 = taq-0.01 v:kTZB  
        op.parent = parID "pGSz%i-  
        AddOperation eID, op o8c4h<,  
    [`^5Zb  
        Print "Set pupil diameter = " & pupilDiam 6jT+kq)  
    3:1 h:Yc<  
        'Update AZ Eye subassembly Description !2>MaV1,  
        eID = FindFullName( "Geometry.Arizona Eye" ) O+hN?/>v  
        GetEntity eID, entity QQ^P IQj  
        entity.Description = "Accommodation = " & A & "D" ibo{!>m  
        SetEntity eID, entity R,?7|x  
    v8Gm ;~  
        Update N9 yL(2  
        Print "DONE!" 4sOo>.<x  
         0w[#`  
    End Sub r kOLTi[$  
    YD1 :m3l!  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: #wn`choT'  
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    Accommodation = 4 Diopters w4w[qxV>  
    Pupil Diameter = 4 mm cC@B\Q  
    Set aqueous humor thickness = 2.81 CPGiKE  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 I[u%k ir  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 j t9fcw  
    Set lens thickness = 3.927 vqDd][n  
    Set lens index of refraction = 1.42672 CYD&#+o  
    Set pupil diameter = 4 ha_&U@w  
    DONE! T;jy2|mLo  
     
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