[技术]Arizona眼睛模型 [复制链接]

简介 89l{h8R  
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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。 ;0Mg\~T~'  
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模型 `dm}|
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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。 #RVN7-x  
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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. ;`}b .S=n  
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光源 '/Ag3R  
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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。 /]hE?cmj  
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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。 XZ1WY(  
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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。 YfUUbV  
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视网膜的散射 V0a)9\x(\  
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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。 7?EC kuSv  
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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。 )Qixde>]p  
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脚本 5$Aiez~tBq  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： xH/Pw?^  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 X/-u$c  
余下的脚本计算与屈光度有关的所有参数。 BuIly&qbm<  
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分析 HE>sZ;  
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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。 _ ZC[h~9H  
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脚本代码 v|K<3@J  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. @N,I}_9-  
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Dim entity As T_ENTITY _/%,Z
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Dim op As T_OPERATION 'q9='TOk  
Dim mat As T_MODELMATERIAL ECF \/12  
Dim A As Double >Vv
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Dim pupilDiam As Double ^lCQHz  
Dim eID As Long %?~`'vYoi  
Dim parID As Long 1X$hwkof  
Dim count As Integer #I|j
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ]f~mR_E  
Dim tlens As Double, nlens As Double ZJeTx.Gi6  
Dim curv As Double, conic As Double b+qdl`Vd  
Dim ok As Long sU}.2k  
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Sub Main 8!q$8]M  
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    '用户输入对话框 ("$ ,FRTQ:  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 b&~s}IX
 
        TextBox 220,21,40,21,.TextBox1 'default: 0 f}U@e0Lsb  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 1=.+!Tg  
        OKButton 40,91,90,21 A/+bwCDP  
        CancelButton 190,91,90,21 >:yU bo)  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 69>N xr~k  
        TextBox 220,49,40,21,.TextBox2 'default: 4 =fZMute  
    End Dialog uY'77,G_J  
    Dim dlg As UserDialog 39zwPoN>  
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    ok = Dialog (dlg) /"*eMe!=  
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    If ok=0 Then    'cancel button was pressed @p}"B9h*^  
        Print "Execution cancelled." Z}*{4V`R  
        End %Yi^{ZrM  
    End If x!@P|c1nKC  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 16N+  
    If dlg.TextBox1 = "" Then zjVQ\L  
        A = 0           'Default accommodation K@UQ O  
    Else C
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        A = CDbl(dlg.TextBox1) mtQ
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    End If C0bOPn  
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    If dlg.TextBox2 = "" Then Zg#VZg1 2  
        pupilDiam = 4   'Default pupil diameter 3.^Tm+ C  
    Else ?U;KwS]%  
        pupilDiam = CDbl(dlg.TextBox2) (T]<  
    End If |`50Tf\J  
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    Print " " cii]-%J}c  
    Print "Accommodation = " & A & " Diopters" rIg5Wcd  
    Print "Pupil Diameter = " & pupilDiam & " mm" 8A3pYW-  
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    ' Calculate new parameters with accommodation Q5:8$ C}+  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness t@(`24  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [`eqma  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens  c>(`X@KL  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens @\|W#,~  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ,GH;jw)P  
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    tlens = 3.767 + 0.04*A                  'Lens thickness WLe9m02r  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ]$VYzE2e  
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    'Adjust parameters to account for accommodation foOwJ}JU  
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    '************************************************************************* [4_JK  
    'Aqueous thickness (Position of Lens) 7oK7f=*Q  
    '************************************************************************* ;GgW&*|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) wCwJ#-z.=  
    GetCustomElement eID, entity @@O=a  
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    parID = FindFullName( "Geometry.Arizona Eye" ) L`M.Htm8  
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    ' Delete any shift(s) in z ~baVS-v  
    count = 0 M,ObzgW  
    While GetOperationCount(eID)>count {4@+ 2)l  
        GetOperation eID, count, op O"<W<l7Q  
        If op.Type="ShiftZ" Then 4%3R}-'mh  
            DeleteOperation eID,count  >Mzk;TM  
            count=count-1 opKk#40  
        End If EPZ^I)  
        count=count+1 qXH\e|  
    Wend @4'bI)  
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    'Set new shift in *r&q;ER  
    op.Type = "ShiftZ" ygvX}q  
    op.val1 = taq W
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    op.parent = parID nS53mLU)  
    AddOperation eID, op #ZPU.NNT?  
    Print "Set aqueous humor thickness = " & taq-0.55 =ca<..yh[d  
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    '************************************************************************* hSO(s  
    'Radius and conic constant of anterior lens UA{tmIC\  
    '************************************************************************* qJQ!e
  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) g@va@*|~d  
    GetConic eID, entity, curv, conic x1$:u6YD22  
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    SetConic eID, entity, 1/Rant, CCant B4<W%lm  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant cNX0.7Ls  
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    '************************************************************************* Q UQ"2oC  
    'Radius and conic constant of posterior lens Ls<.&3X2  
    '************************************************************************* ZwV`} 2{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) *6-fvqCv  
    GetConic eID, entity, curv, conic ),<E-Ub  
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    SetConic eID, entity, 1/Rpost, CCpost 0{8^)apII  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [BH^SvE  
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    '************************************************************************* j=%^CRum  
    'Lens thickness (Position of posterior lens surface) #q06K2  
    '************************************************************************* c\n&Z'vK  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?HP54G<{xz  
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    ' Delete any z-shift(s) #SHmAB  
    count = 0 rcC}4mNe  
    While GetOperationCount(eID)>count O:=%{/6&D  
        GetOperation eID, count, op N(%%bHi#V  
        If op.Type="ShiftZ" Then ,+u.FQv~  
            DeleteOperation eID,count
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            count=count-1 6N%fJ  
        End If (6aSDx Sc  
        count=count+1 Y7vTs
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    Wend & *^FBJEa.  
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    'Set new z-shift +@'{  
    op.Type = "ShiftZ" U5 `
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    op.val1 = tlens ]%{.zl!  
    op.parent = parID RG'Ft]l92N  
    AddOperation eID, op RGeM.  
    Print "Set lens thickness = " & tlens X#qmwcF  
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    '*************************************************************************
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    'Lens index of refraction "Ih>>|r  
    '************************************************************************* K+0&~XU  
    eID = FindMaterial( "Lens" ) h6*&1r  
    GetModelMaterial eID, mat hmA$gR_  
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    mat.Nd = nlens -xJ_5  
    SetModelMaterial eID, mat B?Vr9H7n  
    Print "Set lens index of refraction = " & nlens *h<= (Y%   
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    '************************************************************************* s`j QX\{  
    'Pupil diameter P87!+pB(  
    '************************************************************************* fn%Gu s~  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) A@8Ot-t:\2  
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    'Adjust pupil diameter (trimming volume inner hole) CQf<En|1  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" m;=wQYFr{I  
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    ' Adjust pupil location to just in front of the lens Ywj=6 +;  
    parID = FindFullName( "Geometry.Arizona Eye" ) b`NXe7A  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) hX-([
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    count = 0 DCJmk6p%0  
    While GetOperationCount(eID)>count z (N3oBW  
        GetOperation eID, count, op E8TJ*ZU  
        If op.Type="ShiftZ" Then +`EF0sux  
            DeleteOperation eID,count !]%M  
            count=count-1 IETdL{`~  
        End If o/EN3J  
        count=count+1 L<kIzB !  
    Wend Kn9O=?Xh;  
    op.Type = "ShiftZ" zW`Zmt\T2  
    op.val1 = taq-0.01 W\(u1>lj  
    op.parent = parID 49)A.Bh&!  
    AddOperation eID, op f8ap+][  
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    Print "Set pupil diameter = " & pupilDiam b-/ztZ@u  
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    'Update AZ Eye subassembly Description T6X%.tR>`  
    eID = FindFullName( "Geometry.Arizona Eye" ) j3Ng] @N  
    GetEntity eID, entity CaX0Jlk*  
    entity.Description = "Accommodation = " & A & "D" %5N;SRtv  
    SetEntity eID, entity Rw]4/  
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    Update z*Y4t?+  
    Print "DONE!" .g CC$  
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End Sub CYr2~0<g  
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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： |{#=#3X  
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Accommodation = 4 Diopters &*G+-cF  
Pupil Diameter = 4 mm
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Set aqueous humor thickness = 2.81 89I[Dg;"u  
Set anterior lens radius = 10.4 and conic constant = -2.375869 2gn*B$a  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 vYh_<Rp5  
Set lens thickness = 3.927 O1/U3/2/d  
Set lens index of refraction = 1.42672 \
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Set pupil diameter = 4 moQ><>/  
DONE! O|#N$a&_N