[技术]Arizona眼睛模型 [复制链接]

简介 #zv&h`gY  
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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。 :t9
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模型 sSf;j,7V  
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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。 [,MaAB  
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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. *s#6e}  
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光源 <"K2t Tg.  
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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。 pP#D*hiP-g  
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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。 eIy:5/s  
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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。 xbxzB<yL  
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视网膜的散射 AOkG.u-k  
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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。 mZXtHFMu  
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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。 +=Q:g,kP  
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脚本 $&qLrKJ  
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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： e`U 6JzC  
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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。 r7].48D  
余下的脚本计算与屈光度有关的所有参数。 $=,pQ q  
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分析 /F9Dg<#a  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Ywv\9KL  
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脚本代码 livKiX`  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. fVgN8b|&'  
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Dim entity As T_ENTITY QZG<sZ0"  
Dim op As T_OPERATION nSh~mP  
Dim mat As T_MODELMATERIAL 9_d#F'#F  
Dim A As Double f8SO:ihXL  
Dim pupilDiam As Double ]" e'z  
Dim eID As Long :!Dm
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Dim parID As Long LC##em=Y  
Dim count As Integer T iL.py,  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double h,B4Tg'  
Dim tlens As Double, nlens As Double [ `1`E1X  
Dim curv As Double, conic As Double ab2Cn|F  
Dim ok As Long N8df1>mW  
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Sub Main Fbu4GRgJ3  
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    '用户输入对话框 @[?ZwzY:9  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 :j .:t  
        TextBox 220,21,40,21,.TextBox1 'default: 0 M*qE)dZjS  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ~]RfOpq^w  
        OKButton 40,91,90,21 `p9N| V  
        CancelButton 190,91,90,21 n{<}<SVY  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 8f[ztT0`g  
        TextBox 220,49,40,21,.TextBox2 'default: 4 [e ztu9  
    End Dialog X<.l(9$  
    Dim dlg As UserDialog ME0u|_dPjz  
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    ok = Dialog (dlg) 3Mm_xYDud  
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    If ok=0 Then    'cancel button was pressed *xpn-hCp<  
        Print "Execution cancelled." CJCx
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        End 0&fO)de96  
    End If o6;  
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    'Assign accommodation and pupil diameter & use defaults if field left empty fNu/>pN  
    If dlg.TextBox1 = "" Then Xe_djy'8  
        A = 0           'Default accommodation GTTEg{  
    Else u&c%L0)E&  
        A = CDbl(dlg.TextBox1) -6I*k |%8T  
    End If T30fp  
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    If dlg.TextBox2 = "" Then jUNt4  
        pupilDiam = 4   'Default pupil diameter %L]sQq,  
    Else Hcg7u7M{  
        pupilDiam = CDbl(dlg.TextBox2) *S.FM.r  
    End If ps:`rVQ7  
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    Print " " T]z(>{  
    Print "Accommodation = " & A & " Diopters"  )sdHJ  
    Print "Pupil Diameter = " & pupilDiam & " mm" gsEcvkj*  
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    ' Calculate new parameters with accommodation F1_,V?  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 5EVypw?]x  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens kiN,N]-V  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 7?uDh'utt  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens fU ;H  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ,q#SAZ/N  
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    tlens = 3.767 + 0.04*A                  'Lens thickness @{fwM;me]P  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction WxO+cB+?  
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    'Adjust parameters to account for accommodation x+za6e_k"  
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    '************************************************************************* ReM]I<WuY  
    'Aqueous thickness (Position of Lens) }za pN v  
    '************************************************************************* f&^"[S"\f  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) !idVF!xG  
    GetCustomElement eID, entity ;T0X7MNx  
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    parID = FindFullName( "Geometry.Arizona Eye" ) |y0k}ed  
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    ' Delete any shift(s) in z Dzu//_u  
    count = 0 s:xJ }Ll  
    While GetOperationCount(eID)>count GXD<X_[  
        GetOperation eID, count, op h x5M)8#+  
        If op.Type="ShiftZ" Then nt()UC`5  
            DeleteOperation eID,count V[*>}XQER  
            count=count-1 [Q
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        End If /*BU5  
        count=count+1 11#b%dT  
    Wend TW(X#T@Z6I  
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    'Set new shift in /({oN1X>i  
    op.Type = "ShiftZ" o^(I+<el  
    op.val1 = taq ]9w8[T:O  
    op.parent = parID `kvIw,c.  
    AddOperation eID, op $,/E"G`  
    Print "Set aqueous humor thickness = " & taq-0.55 cH5  
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    '************************************************************************* <>f;g"qS  
    'Radius and conic constant of anterior lens Xr8fmJtg'  
    '************************************************************************* t,/8U  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 2!W[ff@~7  
    GetConic eID, entity, curv, conic >\:GFD{z  
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    SetConic eID, entity, 1/Rant, CCant S!$S'{f<  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant (j@c946z""  
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    '************************************************************************* O"o|8 l}M/  
    'Radius and conic constant of posterior lens #*y.C[^5{  
    '************************************************************************* uZ3do|um  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) i4k [#x  
    GetConic eID, entity, curv, conic }{@y]DcdM4  
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    SetConic eID, entity, 1/Rpost, CCpost U"
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost "PN4{"`V  
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    '************************************************************************* D8~\*0->  
    'Lens thickness (Position of posterior lens surface) 4t%Lo2v!X%  
    '************************************************************************* GKF!GbGR@  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0iR?r+|  
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    ' Delete any z-shift(s) ,38M6yD  
    count = 0 ?
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    While GetOperationCount(eID)>count 7\yh(+kN  
        GetOperation eID, count, op - uO(qUa#  
        If op.Type="ShiftZ" Then 4B[pQlg  
            DeleteOperation eID,count 9-_Lc<  
            count=count-1 gq*W 0S  
        End If r 20!  
        count=count+1 +0*\q  
    Wend =a=:+q g  
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    'Set new z-shift K+M\E[1W  
    op.Type = "ShiftZ" II _CT=  
    op.val1 = tlens  gsi2  
    op.parent = parID H$^9#{  
    AddOperation eID, op f9Xa}*  
    Print "Set lens thickness = " & tlens H<ovIMd  
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    '************************************************************************* %1#|>^  
    'Lens index of refraction &#u\@Qze  
    '************************************************************************* 37?X@@Z=  
    eID = FindMaterial( "Lens" ) NPO!J^^  
    GetModelMaterial eID, mat `.pd %\  
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    mat.Nd = nlens %qeNC\6N  
    SetModelMaterial eID, mat V(LfFO{^>?  
    Print "Set lens index of refraction = " & nlens A@d 2Ukv  
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    '************************************************************************* AEWrrE
 
    'Pupil diameter go6;_  
    '************************************************************************* Oi~Dio_?  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) M e:l)8+  
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    'Adjust pupil diameter (trimming volume inner hole) T 8]*bw  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" e~># M$  
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    ' Adjust pupil location to just in front of the lens Vx5fQ mx  
    parID = FindFullName( "Geometry.Arizona Eye" ) GeB-4img  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) _*sd#  
    count = 0 RHvKWt  
    While GetOperationCount(eID)>count vg X7B4  
        GetOperation eID, count, op W:wSM*  
        If op.Type="ShiftZ" Then mrKIiaU<J  
            DeleteOperation eID,count 4T$jY}U  
            count=count-1 n++

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        End If N^F5J  
        count=count+1 kDRxu!/  
    Wend :~s*yznf  
    op.Type = "ShiftZ" YFj#{C.  
    op.val1 = taq-0.01 {H9
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    op.parent = parID <pG 4g  
    AddOperation eID, op d%q&[<'jf  
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    Print "Set pupil diameter = " & pupilDiam )`W|J%w+  
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    'Update AZ Eye subassembly Description } 21!b :a  
    eID = FindFullName( "Geometry.Arizona Eye" ) c;yp}k]\  
    GetEntity eID, entity pxyFM@Z](  
    entity.Description = "Accommodation = " & A & "D" Edcv>}PfE  
    SetEntity eID, entity w_QWTD0  
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    Update B'vIL'  
    Print "DONE!" td$RDtW[3  
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End Sub /a-s9<  
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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： &!'R'{/?X  
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Accommodation = 4 Diopters mL;oR4{  
Pupil Diameter = 4 mm j#p3<V S4  
Set aqueous humor thickness = 2.81 ]D2d=\  
Set anterior lens radius = 10.4 and conic constant = -2.375869 u-.nR}DM_  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ,CqGO %DY  
Set lens thickness = 3.927 dIQ3snG  
Set lens index of refraction = 1.42672 !@T~m1L eY  
Set pupil diameter = 4 z<yqQ[  
DONE! 7fT_]H8