[技术]Arizona眼睛模型 [复制链接]

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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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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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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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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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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脚本 Gj.u
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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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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$TU;  
余下的脚本计算与屈光度有关的所有参数。 7,sslf2%K  
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分析 Wm5/>Cu,  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 pN[G?A  
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脚本代码 }NQ{S3JW  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ;t.LLd  
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Dim entity As T_ENTITY D3^Yc:[_@  
Dim op As T_OPERATION o*OaYF'8  
Dim mat As T_MODELMATERIAL SWX;sM  
Dim A As Double !,#42TY*X  
Dim pupilDiam As Double '$]
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Dim eID As Long ![wV}.}  
Dim parID As Long "]%.%
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Dim count As Integer "Q:m0P xb  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double d$uh.?F5  
Dim tlens As Double, nlens As Double ?(cbZ#( o  
Dim curv As Double, conic As Double DQ{Yr>
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Dim ok As Long A=7  [^I2  
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Sub Main ?jywW$   
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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  
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    '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" .6Sw
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    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=6CdD'  
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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 $MVgX  
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    ' Delete any shift(s) in z Ob+L|FbnN  
    count = 0 `X8AM=  
    While GetOperationCount(eID)>count 3
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        GetOperation eID, count, op 8M m,a  
        If op.Type="ShiftZ" Then lgTavs  
            DeleteOperation eID,count B@ZedXi  
            count=count-1 0R~{|RHM  
        End If :_YpSw<Q  
        count=count+1 T69'ta32V  
    Wend hPt(7E2ke~  
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    'Set new shift in K1O0/2O  
    op.Type = "ShiftZ" d_BO&k<+I  
    op.val1 = taq E 5PefD\m  
    op.parent = parID ]Lq9Ompf(t  
    AddOperation eID, op V2kNJwwk  
    Print "Set aqueous humor thickness = " & taq-0.55 _|.q?;C]$  
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    '*************************************************************************  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,;-[s
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    '************************************************************************* )}\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
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    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:8iJA  
        End If u$d T^c
 
        count=count+1 I?@9;0R  
    Wend 4Y8/>uL  
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    '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 K1a$ m2  
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    '************************************************************************* g|8G!7O  
    'Lens index of refraction hrPm$`  
    '************************************************************************* !\.x7N<)0  
    eID = FindMaterial( "Lens" ) lpLjfHr  
    GetModelMaterial eID, mat 
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    mat.Nd = nlens Dsc{- <v  
    SetModelMaterial eID, mat 8W Mhe=[  
    Print "Set lens index of refraction = " & nlens |]sh*<:?,  
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    '************************************************************************* LC)-aw>-  
    'Pupil diameter _U;z@  
    '************************************************************************* eS9uKb5n(  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Q1? !,a  
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    '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-  
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    ' 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<,  
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    Print "Set pupil diameter = " & pupilDiam 6jT+kq)  
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    '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" i
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    SetEntity eID, entity R,?
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    Update N9 yL(2  
    Print "DONE!" 4sOo>.<x  
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End Sub rkOLTi[$  
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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： #wn`choT'  
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Accommodation = 4 Diopters w4w[q
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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%kir  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 jt9fcw  
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