[技术]Arizona眼睛模型 [复制链接]

简介 ~\jP+[>M'  
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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。 =GPXuo  
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模型 'z(Y9%+a  
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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。 O -1O@:}c  
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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. :ZV|8xI  
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光源 o$sD9x
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 6]?mjG6  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 E EDFyZ  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 OlOOg  
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视网膜的散射 QxYm3x5  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 V`^*Z}d9  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 {dpC;jsW1  
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脚本 >^s2$@J?p  
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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： fEHFlgN3Ap  
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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。 ;llPM`)  
余下的脚本计算与屈光度有关的所有参数。 atTR6%!6  
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分析 *7xcwjeP  
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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。 pU7;!u:c4%  
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脚本代码 5Z>a}s_i  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. |?T=4~b  
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Dim entity As T_ENTITY g0B] ;Y>(  
Dim op As T_OPERATION Hr?lRaV  
Dim mat As T_MODELMATERIAL @+b$43^  
Dim A As Double zZCl]cql  
Dim pupilDiam As Double ET}Z>vU}+  
Dim eID As Long 4z<c8 E8  
Dim parID As Long 9O;Sn+  
Dim count As Integer ?'> .>  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double !85bpQ.  
Dim tlens As Double, nlens As Double @z1QoZ^w  
Dim curv As Double, conic As Double A6z,6v6  
Dim ok As Long $${I[2R)  
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Sub Main !Cr3>tA  
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    '用户输入对话框 N~!, S;w  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 W.j^L;  
        TextBox 220,21,40,21,.TextBox1 'default: 0 h4`8C]  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 #[prG  
        OKButton 40,91,90,21 dA)T>  
        CancelButton 190,91,90,21 \?n6l7*t>  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ;M~,S^U  
        TextBox 220,49,40,21,.TextBox2 'default: 4 `+,?%W)  
    End Dialog <x}wy+SG  
    Dim dlg As UserDialog `etw[#~N  
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    ok = Dialog (dlg) 8_%GH}{  
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    If ok=0 Then    'cancel button was pressed '[$KG  
        Print "Execution cancelled." Lf9hOMHx  
        End rI$NNk'A  
    End If y0xBNhev  
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    'Assign accommodation and pupil diameter & use defaults if field left empty wkp2A18n  
    If dlg.TextBox1 = "" Then U"G
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        A = 0           'Default accommodation h@ lz  
    Else %0Ur3  
        A = CDbl(dlg.TextBox1) $Tbsre\MJ  
    End If u> {aF{  
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    If dlg.TextBox2 = "" Then &wQ;J)13  
        pupilDiam = 4   'Default pupil diameter fu!T4{2  
    Else rUKg<]&@  
        pupilDiam = CDbl(dlg.TextBox2) |+Wn5iT  
    End If 9`f@"%h  
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    Print " " l#[Z$+!09  
    Print "Accommodation = " & A & " Diopters" Tt
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    Print "Pupil Diameter = " & pupilDiam & " mm"
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    ' Calculate new parameters with accommodation xNIrmqm5]  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness <+*0{8?0  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Jr5S8c|"  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens m1W) PUy  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens a"@f< wU~  
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    tlens = 3.767 + 0.04*A                  'Lens thickness gKb,Vrt  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Ek<Qz5)  
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    'Adjust parameters to account for accommodation *O[/KR%  
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    '************************************************************************* ^SpQtW118  
    'Aqueous thickness (Position of Lens) gXI-{R7Me  
    '************************************************************************* {Zc8,jm  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) y]Nk^ga:U6  
    GetCustomElement eID, entity JMB#KzvN[  
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    parID = FindFullName( "Geometry.Arizona Eye" )  bUcp8
 
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    ' Delete any shift(s) in z .2%t3ul[  
    count = 0 ]$2 yV&V&  
    While GetOperationCount(eID)>count &5y  
        GetOperation eID, count, op 1J[$f>%n]  
        If op.Type="ShiftZ" Then 1%_RXQVG  
            DeleteOperation eID,count $.D)Llcq  
            count=count-1 cAN!5?D\  
        End If 4`8s]X  
        count=count+1 "mQp#d/'  
    Wend }-fHS;/  
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    'Set new shift in T+L=GnYl  
    op.Type = "ShiftZ" )h@PRDI_  
    op.val1 = taq ~HIj+kN  
    op.parent = parID aV$kxzEc  
    AddOperation eID, op }.o.*N  
    Print "Set aqueous humor thickness = " & taq-0.55 t"B3?<?]  
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    '************************************************************************* _.9 5>`  
    'Radius and conic constant of anterior lens +q pW"0[  
    '************************************************************************* '9!_:3[d\]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 4~Qnhv7  
    GetConic eID, entity, curv, conic yP7b))AW9  
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    SetConic eID, entity, 1/Rant, CCant z%E(o%l8  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 'd2 :a2C]  
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    '************************************************************************* sUlf4<_zW  
    'Radius and conic constant of posterior lens 6CFnE7TQf  
    '************************************************************************* ^mLX}E]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 7G+!9^  
    GetConic eID, entity, curv, conic 
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    SetConic eID, entity, 1/Rpost, CCpost
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost `<g]p-=":  
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    '************************************************************************* )(,O~w  
    'Lens thickness (Position of posterior lens surface) bit|L7*14  
    '************************************************************************* 9}QIqH\p  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) cD]H~D}M  
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    ' Delete any z-shift(s) {Fwvuk  
    count = 0 se.HA  
    While GetOperationCount(eID)>count oh-EEo4,  
        GetOperation eID, count, op }vh <x6  
        If op.Type="ShiftZ" Then Y-bTKSn  
            DeleteOperation eID,count Dh4Lffy  
            count=count-1 bVz<8b6h'-  
        End If ~qZ6I
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        count=count+1 @&G}'6vF!  
    Wend 8SU0q9X.  
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    'Set new z-shift kxKb}>=  
    op.Type = "ShiftZ" *` mxv0w~(  
    op.val1 = tlens NxF:s,a6  
    op.parent = parID >TglX t+  
    AddOperation eID, op !D F~]&  
    Print "Set lens thickness = " & tlens d;<'28A  
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    '************************************************************************* +@]k[9  
    'Lens index of refraction [;Ih I  
    '************************************************************************* 5/Qu5/  
    eID = FindMaterial( "Lens" ) AS]8rH  
    GetModelMaterial eID, mat "8%$,rG1&  
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    mat.Nd = nlens sSfP.R  
    SetModelMaterial eID, mat 7vXP|8j  
    Print "Set lens index of refraction = " & nlens J-/w{T8:  
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    '************************************************************************* H ~3.F  
    'Pupil diameter cWo>DuW&  
    '************************************************************************* qqo#H O  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) mxZ+r#|di  
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    'Adjust pupil diameter (trimming volume inner hole) lusUmFm'*  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" E[#VWM I  
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    ' Adjust pupil location to just in front of the lens mS[``$Z\!  
    parID = FindFullName( "Geometry.Arizona Eye" ) Wu* 4r0  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) fZpi+I  
    count = 0 g%T
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    While GetOperationCount(eID)>count Mi#i 3y(  
        GetOperation eID, count, op tl /i  
        If op.Type="ShiftZ" Then OvQzMXU^I  
            DeleteOperation eID,count lx4pTw1  
            count=count-1 0?oL zw&  
        End If @;Jv/N6@  
        count=count+1 _cJ)v/]  
    Wend !&Q?ASJH  
    op.Type = "ShiftZ" =PY{Elf  
    op.val1 = taq-0.01 E9mu:T  
    op.parent = parID kh#QT_y  
    AddOperation eID, op PX/Y?DP  
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    Print "Set pupil diameter = " & pupilDiam N$e mS  
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    'Update AZ Eye subassembly Description w>cqsTq  
    eID = FindFullName( "Geometry.Arizona Eye" ) #8M?y*<I  
    GetEntity eID, entity hDTC~~J/  
    entity.Description = "Accommodation = " & A & "D" x#3*C|A  
    SetEntity eID, entity z/"*-+j  
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    Update UFT JobU  
    Print "DONE!" RtR@wZ2\s  
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End Sub +kd1q  
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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： Q<u?BA/  

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Accommodation = 4 Diopters $adZ|Q\  
Pupil Diameter = 4 mm czIAx1R9  
Set aqueous humor thickness = 2.81 E"VFBKB  
Set anterior lens radius = 10.4 and conic constant = -2.375869 wH!$TAZ:Yw  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 *GoTN  
Set lens thickness = 3.927 w>9d^kU'  
Set lens index of refraction = 1.42672 5b/ ~]v  
Set pupil diameter = 4 =K0%bI  
DONE! iii|;v]+