[技术]Arizona眼睛模型 [复制链接]

简介 <}x_F)E[t  
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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。 @KRr$k  
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模型 ],{b&\  
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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。 G/ToiUY  
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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. g2;!AI5f  
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光源 kd^CZ;O  
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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。 W9>q1  
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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。 )`5kfj  
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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。 z/zUb``  
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视网膜的散射 9AQMB1D*v4  
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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。 KICy! "af  
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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。 #4uuT
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脚本 rXR=fj= 2  
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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： VNKtJmt  
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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。 (6##\}L&9  
余下的脚本计算与屈光度有关的所有参数。 YCJcDab  
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分析 EXt?xiha?  
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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。 w
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脚本代码 9X<o8^V  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. b[}f]pB@n  
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Dim entity As T_ENTITY C(o]3):?  
Dim op As T_OPERATION Y`$dtg {  
Dim mat As T_MODELMATERIAL <Z^P8nu  
Dim A As Double ID+o6/V8  
Dim pupilDiam As Double NCm>iEeY  
Dim eID As Long Rw8l"`  
Dim parID As Long b|7c]l  
Dim count As Integer v/dyu  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double d1MY>zq  
Dim tlens As Double, nlens As Double >,JLYz|</  
Dim curv As Double, conic As Double '9O4$s1  
Dim ok As Long R+}x#  
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Sub Main rof&
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    '用户输入对话框 (N63k1M  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 IB~`Ht8 b  
        TextBox 220,21,40,21,.TextBox1 'default: 0
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ci]IH]x  
        OKButton 40,91,90,21 6g\SJO-;N  
        CancelButton 190,91,90,21 +C`h*%BW  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 6]`XW0{C  
        TextBox 220,49,40,21,.TextBox2 'default: 4 -Ucj|9+(a  
    End Dialog 'FVh/};Y.D  
    Dim dlg As UserDialog )"Ef* /+  
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    ok = Dialog (dlg) )C \ %R  
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    If ok=0 Then    'cancel button was pressed !Db0r/_:G  
        Print "Execution cancelled." 2L=+z1%I  
        End 4}mp~AXy;z  
    End If 9wR-0E )  
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    'Assign accommodation and pupil diameter & use defaults if field left empty EVovx7dr  
    If dlg.TextBox1 = "" Then 8&q|*/2  
        A = 0           'Default accommodation (wxdT6RVm\  
    Else j,7NLb9M  
        A = CDbl(dlg.TextBox1) ?`& l Y  
    End If {Pi+VuLE  
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    If dlg.TextBox2 = "" Then ,mpvGvAI  
        pupilDiam = 4   'Default pupil diameter >0#WkmRY  
    Else eh`sfH  
        pupilDiam = CDbl(dlg.TextBox2) }zA kUt  
    End If l`#XB:#U  
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    Print " " ;4E.Yr*  
    Print "Accommodation = " & A & " Diopters" NF/@'QRT  
    Print "Pupil Diameter = " & pupilDiam & " mm" qU ESN!  
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    ' Calculate new parameters with accommodation +4[L_  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness >.P/fnvJ  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens -}2'P)Xp  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens z]P=>w  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens MS`wd  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ?]JTrv"zp  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ]{tnNr>mv  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction %Se@8d8  
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    'Adjust parameters to account for accommodation 1M%'Xe7  
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    '************************************************************************* T]&% KQ  
    'Aqueous thickness (Position of Lens) )3
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    '************************************************************************* Fpz)@0K;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) *pu ,|  
    GetCustomElement eID, entity -2)6QKh~D  
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    parID = FindFullName( "Geometry.Arizona Eye" ) O<A$,<67  
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    ' Delete any shift(s) in z ;0)|c}n+.5  
    count = 0 }|MPQy  
    While GetOperationCount(eID)>count *$  
        GetOperation eID, count, op )qgcz<p?W  
        If op.Type="ShiftZ" Then '\vmm>  
            DeleteOperation eID,count 'X()|{  
            count=count-1 \KBE+yj  
        End If ^jY'Hj.Bs  
        count=count+1 ck=x_HB1  
    Wend 4#pn]  
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    'Set new shift in %Tc P[<  
    op.Type = "ShiftZ"
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    op.val1 = taq 5PaOa8=2f  
    op.parent = parID @O&<_&  
    AddOperation eID, op {8'f>YP  
    Print "Set aqueous humor thickness = " & taq-0.55 `v]|x,l+C  
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    '************************************************************************* PP2>v|  
    'Radius and conic constant of anterior lens
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    '************************************************************************* X:aLed_{f  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) z.NJu q  
    GetConic eID, entity, curv, conic Bh'_@PHP  
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    SetConic eID, entity, 1/Rant, CCant #:^aE|s  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 17-D\ +}  
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    '************************************************************************* -i,=sZXB  
    'Radius and conic constant of posterior lens H$M#+EfL  
    '*************************************************************************  j-H2h  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) q%G"P*g$(  
    GetConic eID, entity, curv, conic MF7q*f  
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    SetConic eID, entity, 1/Rpost, CCpost 'U9l   
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 7P&O{tl(  
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    '************************************************************************* |OgtAI9  
    'Lens thickness (Position of posterior lens surface) ,YEwz3$5u  
    '************************************************************************* cO&(&*J r  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) nUp, %z[  
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    ' Delete any z-shift(s) Thlqe?  
    count = 0 ;x]CaG)f  
    While GetOperationCount(eID)>count GmjTxNU@  
        GetOperation eID, count, op ?h7,q*rxk  
        If op.Type="ShiftZ" Then m$ubxI)  
            DeleteOperation eID,count E46+B2_~zk  
            count=count-1 jrF#DDH?I  
        End If riy@n<Z4  
        count=count+1 m2i'$
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    Wend z0yPBt1W  
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    'Set new z-shift r5k{mV+  
    op.Type = "ShiftZ" _LYI#D  
    op.val1 = tlens VL[}  
    op.parent = parID &jbZL5  
    AddOperation eID, op X(YR).a~  
    Print "Set lens thickness = " & tlens lhp.zl  
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    '************************************************************************* ;5ANw"Dq  
    'Lens index of refraction lR
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    '************************************************************************* vXq2="+  
    eID = FindMaterial( "Lens" ) j9voeV|7  
    GetModelMaterial eID, mat %^zGM^PD  
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    mat.Nd = nlens j\/Rjn+:[  
    SetModelMaterial eID, mat >j%4U*  
    Print "Set lens index of refraction = " & nlens %o4d(C B  
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    '************************************************************************* L/39<&W  
    'Pupil diameter 0@BhRf5  
    '************************************************************************* a7Xa3 vlpO  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) h#e((j3-2Z  
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    'Adjust pupil diameter (trimming volume inner hole) <kc9KE  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 8c1ma  
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    ' Adjust pupil location to just in front of the lens /'g/yBY  
    parID = FindFullName( "Geometry.Arizona Eye" ) )C1ihm!7\  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) v 7g?  
    count = 0 P {8d.  
    While GetOperationCount(eID)>count *# 7 1aZ  
        GetOperation eID, count, op uhf% zG  
        If op.Type="ShiftZ" Then axpn*
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            DeleteOperation eID,count %]KOxaf_z  
            count=count-1 It@1!_tO2  
        End If x&['g*[L0  
        count=count+1  4u.v7r  
    Wend 5 `Mos  
    op.Type = "ShiftZ" !#b8QER  
    op.val1 = taq-0.01 W
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    op.parent = parID an<loLW  
    AddOperation eID, op F?3zw4Vt~  
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    Print "Set pupil diameter = " & pupilDiam sf(2~BMQI  
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    'Update AZ Eye subassembly Description V\=QAN^  
    eID = FindFullName( "Geometry.Arizona Eye" ) V=+wsc  
    GetEntity eID, entity v;_k*y[VV$  
    entity.Description = "Accommodation = " & A & "D" BT3X7Cx  
    SetEntity eID, entity |PY*"Ul  
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    Update =]Vrl-a`^  
    Print "DONE!" '(.vB~m7*+  
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End Sub uJg|  
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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： &1(PS)s  
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Accommodation = 4 Diopters 4w)aAXK  
Pupil Diameter = 4 mm C3#mmiL-  
Set aqueous humor thickness = 2.81 1#OM~v6B  
Set anterior lens radius = 10.4 and conic constant = -2.375869 <aVfgVS  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 rO;Vr},3\%  
Set lens thickness = 3.927 :}[RDF?  
Set lens index of refraction = 1.42672 5m(V(@a3  
Set pupil diameter = 4 ?A\[EI^  
DONE! fMSB