[技术]Arizona眼睛模型 [复制链接]

简介 }2X"  
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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。 BY&+fKae  
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模型 >U2[]fu  
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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。 QEb ^'y  
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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. B0&W wa:  
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光源 XXe?@w2{  
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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。 fzhCV  
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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。 !-OPzfHrI  
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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。 |oL}c!0vs  
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视网膜的散射 pod=
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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。 p3N/"t&>  
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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。 js~?y|e8k  
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脚本 -#e3aXe  
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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： 82z\^a  
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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。 ^@"EI|fsP  
余下的脚本计算与屈光度有关的所有参数。 :zWI"  

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分析 <x^Ab#K"  
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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。 J2ryYdo>  
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脚本代码 zlw+=NX  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. `ecIy_O3P&  
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Dim entity As T_ENTITY ZYi."^l  
Dim op As T_OPERATION tE~OWjL  
Dim mat As T_MODELMATERIAL W'B=H1  
Dim A As Double p#yq'kY  
Dim pupilDiam As Double sFvu@Wm'7W  
Dim eID As Long PU"C('AP  
Dim parID As Long R;6$lO8C&  
Dim count As Integer 5Q9nJC{'NN  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double KTQy pv  
Dim tlens As Double, nlens As Double 8H%-/2NW  
Dim curv As Double, conic As Double h !yu. v  
Dim ok As Long dE`a1H%  
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Sub Main nNN~Z'bG  
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    '用户输入对话框 A$H;2T5N  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 b#17N2xkT  
        TextBox 220,21,40,21,.TextBox1 'default: 0 !sJ*0  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 z;#DX15Rj  
        OKButton 40,91,90,21 ++HHUM  
        CancelButton 190,91,90,21 sghQ!ux  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 sb]{05:  
        TextBox 220,49,40,21,.TextBox2 'default: 4 $CXMeY{tOo  
    End Dialog qt.G_fOz  
    Dim dlg As UserDialog \$iU#Z  
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    ok = Dialog (dlg) s.zfiJ
 
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    If ok=0 Then    'cancel button was pressed hhqSfafUX  
        Print "Execution cancelled." EGY'a*]cU  
        End ~$
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    End If 2
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    'Assign accommodation and pupil diameter & use defaults if field left empty |\ZsoA  
    If dlg.TextBox1 = "" Then I|`/#BYbW  
        A = 0           'Default accommodation -Tzp;o  
    Else Ji#"PE/Pt  
        A = CDbl(dlg.TextBox1) "L(4 EcO@  
    End If }
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    If dlg.TextBox2 = "" Then e1EFZ,EcaO  
        pupilDiam = 4   'Default pupil diameter {1<XOp#b  
    Else CSA.6uIT  
        pupilDiam = CDbl(dlg.TextBox2) 5*q!:$ W  
    End If 5)T=^"IHXi  
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    Print " " +# 38  
    Print "Accommodation = " & A & " Diopters" o~_wx  
    Print "Pupil Diameter = " & pupilDiam & " mm" cEP
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    ' Calculate new parameters with accommodation 0L ^WTq  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness {hXIP`  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 9(\eL9^  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens "<#-#j  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens |>Q]q  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens R>r@I_  
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    tlens = 3.767 + 0.04*A                  'Lens thickness qHGwD20 ~  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction !vaS fL*]  
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    'Adjust parameters to account for accommodation \NiW(!Z}  
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    '************************************************************************* $,mljJSQv  
    'Aqueous thickness (Position of Lens) zKY 9'y  
    '************************************************************************* #[Z1W8e  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) eaG_)y  
    GetCustomElement eID, entity ke+3J\;>  
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    parID = FindFullName( "Geometry.Arizona Eye" ) U#u=9%'  
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    ' Delete any shift(s) in z P0Q]Ds|  
    count = 0 ,n}h_ct  
    While GetOperationCount(eID)>count (O&R-5m  
        GetOperation eID, count, op 4TPAD)C  
        If op.Type="ShiftZ" Then rx
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            DeleteOperation eID,count B7*^rbI:X  
            count=count-1 5i<E AKL  
        End If ![>j`i  
        count=count+1 Q^B !^_M  
    Wend _gLj(<^9  
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    'Set new shift in prdlV)LTpY  
    op.Type = "ShiftZ" VssD  
    op.val1 = taq *om
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    op.parent = parID P2j"L#%  
    AddOperation eID, op dR^7d _!  
    Print "Set aqueous humor thickness = " & taq-0.55 \\Z{[{OZ  

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    '************************************************************************* PsV1btq]  
    'Radius and conic constant of anterior lens 5>S<9A|Q  
    '************************************************************************* !U6 x_  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Y`U[Y Hx  
    GetConic eID, entity, curv, conic >" z$p@7  
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    SetConic eID, entity, 1/Rant, CCant ^L,Uz:[J  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant vi4lmkyh^  
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    '************************************************************************* S260h,(,  
    'Radius and conic constant of posterior lens 5Nt40)E}sN  
    '************************************************************************* 68!W~%?pR  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 0-=PP@W  
    GetConic eID, entity, curv, conic ?k}"g$JFn  
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    SetConic eID, entity, 1/Rpost, CCpost wqZ*$M  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost e2}5< 7  
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    '************************************************************************* |})7\o  
    'Lens thickness (Position of posterior lens surface) HRG2sv T4t  
    '************************************************************************* >k)zd-  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /}ADV2sF  
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    ' Delete any z-shift(s) >$g+Gx\v4  
    count = 0 /Cl=;^)  
    While GetOperationCount(eID)>count ag7(nn0!  
        GetOperation eID, count, op &|LP>'H;  
        If op.Type="ShiftZ" Then 0wA?.~ L  
            DeleteOperation eID,count )[Bl3+'  
            count=count-1 x=7qC#+)  
        End If <*vWcCS1  
        count=count+1 *oW^P~m/  
    Wend #cF ?a5  
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    'Set new z-shift G'dN_6ho3  
    op.Type = "ShiftZ" s^QXCmb$8  
    op.val1 = tlens s4&JBm(33N  
    op.parent = parID 1pDL()t  
    AddOperation eID, op :mI[fQ  
    Print "Set lens thickness = " & tlens Xh[02iL-  
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    '************************************************************************* jx?"m=`s:  
    'Lens index of refraction NmH:/xU?^  
    '************************************************************************* Wb;x eG  
    eID = FindMaterial( "Lens" ) ]6*+i$  
    GetModelMaterial eID, mat Y
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    mat.Nd = nlens ,iy;L_N  
    SetModelMaterial eID, mat FL/395 <:  
    Print "Set lens index of refraction = " & nlens 1%^d<%,]  
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    '************************************************************************* P
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    'Pupil diameter 4_i6qu(4  
    '************************************************************************* zNo(|;19  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ]CnqPLqL  
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    'Adjust pupil diameter (trimming volume inner hole) ,RYahu  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Bt?.8H6Y  
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    ' Adjust pupil location to just in front of the lens fN
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    parID = FindFullName( "Geometry.Arizona Eye" ) q]}1/JZS  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Qt VZ)777
 
    count = 0 W4ygJL7 6  
    While GetOperationCount(eID)>count UomO^P  
        GetOperation eID, count, op gT=RJB  
        If op.Type="ShiftZ" Then L>PPAI  
            DeleteOperation eID,count ~=#jr0IZ  
            count=count-1 3v
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        End If n#fc=L1U  
        count=count+1 mz<wYV*  
    Wend }w
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    op.Type = "ShiftZ" E{#Y=  
    op.val1 = taq-0.01 (F.vVldBy  
    op.parent = parID B*,Qw_3dG  
    AddOperation eID, op #ozQF~
 
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    Print "Set pupil diameter = " & pupilDiam ;<~lzfs
 
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    'Update AZ Eye subassembly Description !arTR.b\  
    eID = FindFullName( "Geometry.Arizona Eye" ) ;=ci7IT'  
    GetEntity eID, entity rjJ-ZRs\  
    entity.Description = "Accommodation = " & A & "D" +P//p$pE
 
    SetEntity eID, entity e|~s'{3  
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    Update 1$^=M[v  
    Print "DONE!" M,f|.p{,Y  
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End Sub $S(q;Y  
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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： VJ'bS9/T  
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Accommodation = 4 Diopters Pp9nilb_(  
Pupil Diameter = 4 mm Pqc+pE  
Set aqueous humor thickness = 2.81 |vLlEN/S  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Wt8=j1>  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 iI.d8}A  
Set lens thickness = 3.927 G._E9  
Set lens index of refraction = 1.42672 ^1 P@BRh  
Set pupil diameter = 4 s/=.a2\  
DONE! MGGc