[技术]Arizona眼睛模型 [复制链接]

简介 <ldid]o #  
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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。 q1N4X7<_  
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模型 EsT0"{  
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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。 C$KaT3I  
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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. I?f"<5[0  
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光源 CMC?R,d  
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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。 f?2zLE>u  
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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。 |C~Sr#6)7  
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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。 @)  
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视网膜的散射 B#J{F  
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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。  UP\8w#~  
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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。 4#TnXxL  
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脚本 72`/d`  
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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： |d5ggf.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。 pMOD\J:l,  
余下的脚本计算与屈光度有关的所有参数。 >Ja0hS{*  
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分析 n1_ %Td  
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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。 $H4=QVj6  
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脚本代码 #U\$@4D  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. GX7VlI[  
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Dim entity As T_ENTITY e,^pMg~  
Dim op As T_OPERATION  /;+oz  
Dim mat As T_MODELMATERIAL v<j2L"bj  
Dim A As Double "@(58nk
  
Dim pupilDiam As Double O!o <P5X^  
Dim eID As Long sb'lZFSP~s  
Dim parID As Long -P2 @mx%  
Dim count As Integer E{<?l 7t  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double
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Dim tlens As Double, nlens As Double 8`a,D5U:  
Dim curv As Double, conic As Double *JwFD^<j  
Dim ok As Long U8E0~[y'  
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Sub Main r;9z5'  
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    '用户输入对话框 ZH% we  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Sq<3
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        TextBox 220,21,40,21,.TextBox1 'default: 0 |%-YuD  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 cFw3Iw"JJ  
        OKButton 40,91,90,21 :|=- (z  
        CancelButton 190,91,90,21 :u AjV  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9g96 d-  
        TextBox 220,49,40,21,.TextBox2 'default: 4 l4zw]AYk+X  
    End Dialog 5|5=Y/  
    Dim dlg As UserDialog \` &ej{  
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    ok = Dialog (dlg) )x)gHY8;  
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    If ok=0 Then    'cancel button was pressed CNq[4T'~A  
        Print "Execution cancelled." vpi l$Uq  
        End ]/a g*F  
    End If &h\7^=s.  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 2g0K76=Co:  
    If dlg.TextBox1 = "" Then XYMxG:  
        A = 0           'Default accommodation RFB(d=o5S  
    Else IOX:yxj  
        A = CDbl(dlg.TextBox1) o7J{+V  
    End If \d:h$  
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    If dlg.TextBox2 = "" Then ,2
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        pupilDiam = 4   'Default pupil diameter %iX/y  
    Else (xbIUz.  
        pupilDiam = CDbl(dlg.TextBox2) i]dz}=j'  
    End If ;|;iCaD a+  
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    Print " " 1EQvcw#  
    Print "Accommodation = " & A & " Diopters" Q4=|@|U0  
    Print "Pupil Diameter = " & pupilDiam & " mm" 9Eu #lV  
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    ' Calculate new parameters with accommodation ^:+Rg}]W^  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Rh[Ibm56  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens %/Bvy*X&  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ~x\Cmu9`  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens k},>^qE  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 6W$rY] h!  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction xb]odYGdW  
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    'Adjust parameters to account for accommodation + LS3T^  
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    '************************************************************************* r,Ds[s)B  
    'Aqueous thickness (Position of Lens) %2}C'MqS  
    '************************************************************************* \1]rlzXGUT  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) }s(C^0x  
    GetCustomElement eID, entity rpSr^slr  
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    parID = FindFullName( "Geometry.Arizona Eye" ) JdO)YlM-  
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    ' Delete any shift(s) in z ifvU"l  
    count = 0 .$P|^Zx,  
    While GetOperationCount(eID)>count =},{8fZ4  
        GetOperation eID, count, op 3(C :X1  
        If op.Type="ShiftZ" Then dHq#  
            DeleteOperation eID,count bs BZE  
            count=count-1 bQ"N ;d)e  
        End If K?[)E3  
        count=count+1 6{8/P'@/Zz  
    Wend "
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    'Set new shift in jWSb5#Pw  
    op.Type = "ShiftZ" yjFe'  
    op.val1 = taq BJgDo  
    op.parent = parID gJk[Ja  
    AddOperation eID, op 2kVp_=c  
    Print "Set aqueous humor thickness = " & taq-0.55 iE=P'"I  
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    '************************************************************************* 
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    'Radius and conic constant of anterior lens ^aHh{
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    '************************************************************************* QLn+R(r  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Je@kiE  
    GetConic eID, entity, curv, conic kZv*rWAm  
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    SetConic eID, entity, 1/Rant, CCant FQ!Oxlq,Q  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant n]v7V&mj\  
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    '************************************************************************* GG+5/hU  
    'Radius and conic constant of posterior lens Z\'wm'  
    '************************************************************************* {>h97}P  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" )
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    GetConic eID, entity, curv, conic :~D];m  
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    SetConic eID, entity, 1/Rpost, CCpost Hd374U<8]T  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost tt{`\1q  
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    '************************************************************************* a,cC!   
    'Lens thickness (Position of posterior lens surface) $_FZn'Db6  
    '************************************************************************* > H~6NBd5D  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) wVE:X3Ei  
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    ' Delete any z-shift(s) ) $#(ZL^m  
    count = 0 b2s~%}T  
    While GetOperationCount(eID)>count :".w{0l@  
        GetOperation eID, count, op +Vy_9I(4Z  
        If op.Type="ShiftZ" Then :XYy7xz<  
            DeleteOperation eID,count a:b^!H>#  
            count=count-1 aq ki
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        End If CV3DMA  
        count=count+1 ="3,}qR  
    Wend ^yJ:+m;6K  
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    'Set new z-shift n`.#59-Hx  
    op.Type = "ShiftZ" /AR]dcL@76  
    op.val1 = tlens ZF'H
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    op.parent = parID Q6x%  
    AddOperation eID, op $H;+}VQ  
    Print "Set lens thickness = " & tlens >)3VbO  
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    '************************************************************************* 2yxi= XWZ  
    'Lens index of refraction *Ru2:}?MpS  
    '************************************************************************* c{4R*|^  
    eID = FindMaterial( "Lens" ) "lrA%~3%[P  
    GetModelMaterial eID, mat HTR1)b  
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    mat.Nd = nlens .Q[yD<)Ubs  
    SetModelMaterial eID, mat R&Ci/  
    Print "Set lens index of refraction = " & nlens LwQH6 !;[  
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    '************************************************************************* jyQVSQs  
    'Pupil diameter m8AAp1=  
    '************************************************************************* O]ZC+]}/  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Ue!Q."  
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    'Adjust pupil diameter (trimming volume inner hole) FWY[=S  

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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Noz&noq  
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    ' Adjust pupil location to just in front of the lens |^iA6)Q  
    parID = FindFullName( "Geometry.Arizona Eye" ) _lT0Hu  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) h[Mdr  
    count = 0 DxfMqH[vs  
    While GetOperationCount(eID)>count 7Ud'd<  
        GetOperation eID, count, op ]]/lC  
        If op.Type="ShiftZ" Then }p{;^B  
            DeleteOperation eID,count c,$mWTC  
            count=count-1 e1uMR-Q  
        End If c[:Wf<%|  
        count=count+1 wko2M[  
    Wend '=#5(O%pp  
    op.Type = "ShiftZ" =YHt9fb$c  
    op.val1 = taq-0.01 Spo+@G  
    op.parent = parID xYwkFB$$*  
    AddOperation eID, op SUu >6'LN  
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    Print "Set pupil diameter = " & pupilDiam "
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    'Update AZ Eye subassembly Description y||@
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    eID = FindFullName( "Geometry.Arizona Eye" ) ?4sJw:  
    GetEntity eID, entity ohsH2]C  
    entity.Description = "Accommodation = " & A & "D" vgo{]:Aj{  
    SetEntity eID, entity ?K<ZkYw?  
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    Update kwF]TO S  
    Print "DONE!" ugxw!cj  
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End Sub PkJcd->  
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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： 50,Y  
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Accommodation = 4 Diopters nsl*Dm"*F  
Pupil Diameter = 4 mm 1J'pB;.]s  
Set aqueous humor thickness = 2.81 n^Vxi;F  
Set anterior lens radius = 10.4 and conic constant = -2.375869 :l`i4
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 ,R}Z=w#  
Set lens thickness = 3.927 |[ocyUsxX  
Set lens index of refraction = 1.42672 }P.K2ku  
Set pupil diameter = 4 0I^Eo|  
DONE! tN}
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