[技术]Arizona眼睛模型 [复制链接]

简介 [)M%cyQ   
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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。  :D6 ON"6  
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模型 p!7FpxZY  
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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。 KNvZm;Q6  
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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. >}8j+t&T  
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光源 -`kW&I0  
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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。 wedbx00o  
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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。 !Vn\
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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。 qFCOUl  
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视网膜的散射 3tIVXtUCUk  
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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。 /tx]5`#@7]  
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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。 A5I)^B<(  
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脚本 !&y8@MD15  
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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： u"cV%(#  
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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。 T= y}y  
余下的脚本计算与屈光度有关的所有参数。 Cx@);4arj  
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分析 )Pa'UGY  
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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。 r"3=44St  
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脚本代码 shy-Gu&  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. wY{-BuXv  
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Dim entity As T_ENTITY TTX5EDCrC  
Dim op As T_OPERATION Q2w_X8  
Dim mat As T_MODELMATERIAL KEo,m  
Dim A As Double 7UKh688  
Dim pupilDiam As Double
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Dim eID As Long 7?!d^$B  
Dim parID As Long ?DS@e@lx  
Dim count As Integer "yy5F>0Wt  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double bivuqKA  
Dim tlens As Double, nlens As Double Drgv`z  
Dim curv As Double, conic As Double 'A=^Se`=  
Dim ok As Long ,GhS[VJjR  
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Sub Main 9IdA%RM~mH  
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    '用户输入对话框 Fc)@,/R"v  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 HT
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        TextBox 220,21,40,21,.TextBox1 'default: 0 }z'8Bu  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ~k-y &<UR  
        OKButton 40,91,90,21 p}z<Fdu0  
        CancelButton 190,91,90,21 b4%??"&<Y  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Ws3)gvpPA  
        TextBox 220,49,40,21,.TextBox2 'default: 4 xf\C|@i  
    End Dialog }1L4"}L.  
    Dim dlg As UserDialog cN-?l7  
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    ok = Dialog (dlg) &T?RZ2  
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    If ok=0 Then    'cancel button was pressed c)6m$5]  
        Print "Execution cancelled." Gt8M&S-;  
        End :%_LpZ
 
    End If RtkEGxw*^  
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    'Assign accommodation and pupil diameter & use defaults if field left empty G/y5H;<9M  
    If dlg.TextBox1 = "" Then P[G)sA_"  
        A = 0           'Default accommodation "b~+;<}Q  
    Else ^&9zw\x;z  
        A = CDbl(dlg.TextBox1) #X+JHl  
    End If n$A9_cHF7  
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    If dlg.TextBox2 = "" Then Di,^%  
        pupilDiam = 4   'Default pupil diameter GLH0 ]  
    Else hIYNhZv  
        pupilDiam = CDbl(dlg.TextBox2) y;m|  
    End If H
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    Print " " a Yg6H2Un  
    Print "Accommodation = " & A & " Diopters" Si4!R+
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    Print "Pupil Diameter = " & pupilDiam & " mm" 9R!atPz9  
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    ' Calculate new parameters with accommodation T= 80,  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness X~bX5b[P  

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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens W
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens hk;5w{t}}  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens JMCKcZ%N  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens '0;l]/i.  
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    tlens = 3.767 + 0.04*A                  'Lens thickness rET\n(AJ  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction F>Ah0U0  
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    'Adjust parameters to account for accommodation i]c!~`  
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    '************************************************************************* ~Py`P'+  
    'Aqueous thickness (Position of Lens) B6+khuG(  
    '************************************************************************* GhAlx/K  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~f2z]JLr:  
    GetCustomElement eID, entity V5@:#BIs  
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    parID = FindFullName( "Geometry.Arizona Eye" ) RXMISt3+{y  
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    ' Delete any shift(s) in z DaQ?\uq  
    count = 0 {S]}.7`l9(  
    While GetOperationCount(eID)>count nAAs{  
        GetOperation eID, count, op )N{Pw$l_  
        If op.Type="ShiftZ" Then /s&9SYF  
            DeleteOperation eID,count %@J.{@>  
            count=count-1 6D;Sgc5"  
        End If vQG5*pR*w  
        count=count+1 UkwP  
    Wend 3)wN))VBX  
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    'Set new shift in 94`7a<&ZNL  
    op.Type = "ShiftZ" )bL'[h
 
    op.val1 = taq R{`(c/%8  
    op.parent = parID h%na>G  
    AddOperation eID, op W\$`w  
    Print "Set aqueous humor thickness = " & taq-0.55 FW;?s+Uyx  
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    '************************************************************************* VOsRAn/N  
    'Radius and conic constant of anterior lens Wx%H%FeK  
    '************************************************************************* ;3coP{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ah$b[\#C  
    GetConic eID, entity, curv, conic .&iawz  
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    SetConic eID, entity, 1/Rant, CCant (62"8iD
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant |)DGkOtd  
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    '************************************************************************* \[i1JG  
    'Radius and conic constant of posterior lens .[KrlfI  
    '************************************************************************* 5X$jl;6  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) tmYz R%i  
    GetConic eID, entity, curv, conic ;W )Y OT  
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    SetConic eID, entity, 1/Rpost, CCpost QD&`^(X1p  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ~8Fk(E_  
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    '*************************************************************************  :A_@,Q  
    'Lens thickness (Position of posterior lens surface) =_*Zn(>t`  
    '************************************************************************* ?3`UbN:  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Xf]d. :  
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    ' Delete any z-shift(s) :uS\3toj  
    count = 0 CI0C1/:@  
    While GetOperationCount(eID)>count |$Sedzj'  
        GetOperation eID, count, op Yx%Hs5}8  
        If op.Type="ShiftZ" Then V#$RR!X'  
            DeleteOperation eID,count h 0Q5-EA  
            count=count-1 '3tCH)s  
        End If ibk6|pp  
        count=count+1 7hcYD!DS  
    Wend f|c{5$N!  
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    'Set new z-shift ,AFu C<  
    op.Type = "ShiftZ" g}{aZ$sta  
    op.val1 = tlens :J@gmY:C  
    op.parent = parID R4cM%l_#W  
    AddOperation eID, op c ( C%Hld  
    Print "Set lens thickness = " & tlens =z69e%.  
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    '************************************************************************* 6,"Q=9k4[  
    'Lens index of refraction :Yh+>c}N  
    '************************************************************************* L|xbR#v  
    eID = FindMaterial( "Lens" ) g-bK|6?yz  
    GetModelMaterial eID, mat I3I/bofz  
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    mat.Nd = nlens 7(8;to6(  
    SetModelMaterial eID, mat 5c0 ZRV#  
    Print "Set lens index of refraction = " & nlens O
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    '************************************************************************* Ya"a`ozq  
    'Pupil diameter zu{P#~21  
    '************************************************************************* J=I:CD%  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) >*_$]E  
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    'Adjust pupil diameter (trimming volume inner hole) AjMh,@  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ,T$U'&;  
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    ' Adjust pupil location to just in front of the lens Id .nu/  
    parID = FindFullName( "Geometry.Arizona Eye" ) WiR(;m<g  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) NP3
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    count = 0 vMH  
    While GetOperationCount(eID)>count b9HtR-iR;  
        GetOperation eID, count, op %_W)~Pv{+  
        If op.Type="ShiftZ" Then f+,qNvBY/  
            DeleteOperation eID,count _op}1   
            count=count-1 )_S(UVI5  
        End If Fj3a.'  
        count=count+1 )U:m:cr<  
    Wend l4YJ c  
    op.Type = "ShiftZ" !ons]^km  
    op.val1 = taq-0.01 k2tF}  
    op.parent = parID 7WS p($  
    AddOperation eID, op 6}Ci>_i4#  
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    Print "Set pupil diameter = " & pupilDiam ?X<eV1a   
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    'Update AZ Eye subassembly Description 04P}-L,  
    eID = FindFullName( "Geometry.Arizona Eye" ) e\zm7_+i{  
    GetEntity eID, entity CxW>~O:  
    entity.Description = "Accommodation = " & A & "D" j-}O0~Jz  
    SetEntity eID, entity plstZ,#j  

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    Update V5>B])yQ  
    Print "DONE!" 0 ZKx<]!  
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End Sub  |TH\`U  
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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： 4p;`C  
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Accommodation = 4 Diopters vr6w^&[c^  
Pupil Diameter = 4 mm \V
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Set aqueous humor thickness = 2.81 >@_^fw)  
Set anterior lens radius = 10.4 and conic constant = -2.375869 *P=VFP  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 2eY_%Y0  
Set lens thickness = 3.927 jLm ;ty2;  
Set lens index of refraction = 1.42672 <<5(0#y#  
Set pupil diameter = 4 N5 6g+,w%)  
DONE! iz PDd{[