[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 U#x`u|L&6  
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。 :IO"' b  
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模型 z57q|  
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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。 e= XC$Jv  
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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. (&=3Y8  
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光源 ?
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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。 Rzyaicj^
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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。 S\ K[l/  
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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。 , {}S<^?]  
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视网膜的散射 v+i==vxg  
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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。 #<@_mbQ@|K  
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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。 S#
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脚本 ZftucD|ZY/  
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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： DG=_E\"#  
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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。 "Z"`X3,-z  
余下的脚本计算与屈光度有关的所有参数。 Of nN  
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分析 ;`
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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。 h2aO-y>K  
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脚本代码 (#Xgfb"S3  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. #b1/2=PA  
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Dim entity As T_ENTITY 'l1cuAP!+  
Dim op As T_OPERATION <2\QY  
Dim mat As T_MODELMATERIAL I^O`#SA(  
Dim A As Double j[w5#]&%  
Dim pupilDiam As Double ^56#{~%^?  
Dim eID As Long )IuwI#pm  
Dim parID As Long +H_
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Dim count As Integer %Gjjl*`E  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double I -XkxDw  
Dim tlens As Double, nlens As Double } d7o-  
Dim curv As Double, conic As Double ~gEd(  
Dim ok As Long XE|"n  
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Sub Main P1ynCe  
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    '用户输入对话框 rzKn5
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 B 3eNvUFZg  
        TextBox 220,21,40,21,.TextBox1 'default: 0 jAD{?/RB}  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 M-5zsN  
        OKButton 40,91,90,21 Lw{'mtm  
        CancelButton 190,91,90,21 <-|g>  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 L;'v,s  
        TextBox 220,49,40,21,.TextBox2 'default: 4 gjy:o5{vA*  
    End Dialog Y;8.(0r/  
    Dim dlg As UserDialog 1<f,>BQ+  
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    ok = Dialog (dlg) ACH!Gw~  
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    If ok=0 Then    'cancel button was pressed ptpu u=3"  
        Print "Execution cancelled." oz?6$oE(bt  
        End 5?MKx!%  
    End If ,:3Di (  
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    'Assign accommodation and pupil diameter & use defaults if field left empty o n?8l?iQ  
    If dlg.TextBox1 = "" Then 8KS9!*.iZ  
        A = 0           'Default accommodation qo0]7m7|  
    Else ?;Ge/~QU5  
        A = CDbl(dlg.TextBox1) Ks^EGy+O:-  
    End If Z65]|  
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    If dlg.TextBox2 = "" Then 51x)fZQ  
        pupilDiam = 4   'Default pupil diameter ,9ZN k@q  
    Else rKWkT"  
        pupilDiam = CDbl(dlg.TextBox2) ,xIWyI.  
    End If 31}kNc}n  
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    Print " " Qtn%h:i S~  
    Print "Accommodation = " & A & " Diopters" J9/}ZD^  
    Print "Pupil Diameter = " & pupilDiam & " mm" W RVm^  
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    ' Calculate new parameters with accommodation $v

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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness i9k/X&V  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens k M' :.QT  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens D.R 7#^.  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 8_F5c@7  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 3.s.&^  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 7q[a8rUdh  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction eo&nAr  
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    'Adjust parameters to account for accommodation o Kfm=TbY  
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    '************************************************************************* m`Ver:{  
    'Aqueous thickness (Position of Lens) cfd7)(6  
    '************************************************************************* $,~D-~-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) W{(q7>g  
    GetCustomElement eID, entity .0>2j(  
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    parID = FindFullName( "Geometry.Arizona Eye" ) -(]s!,  
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    ' Delete any shift(s) in z 3ud_d>  
    count = 0 lUd;u*A  
    While GetOperationCount(eID)>count 
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        GetOperation eID, count, op P6ztP$M(  
        If op.Type="ShiftZ" Then t\$P*_  
            DeleteOperation eID,count .`3O4]N[  
            count=count-1 mew,S)dq!  
        End If TZk.?@s5  
        count=count+1 ]l WEdf+  
    Wend sox0:9Oqnf  
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    'Set new shift in JXIxk"m  
    op.Type = "ShiftZ" lef,-{X-  
    op.val1 = taq _3YuPMaN  
    op.parent = parID S3iXG @  
    AddOperation eID, op j%m9y_rg}  
    Print "Set aqueous humor thickness = " & taq-0.55 :q0TS>l  
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    '************************************************************************* K*_5M  
    'Radius and conic constant of anterior lens eiV[y^?  
    '************************************************************************* F5|6*K  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Is $I;`  
    GetConic eID, entity, curv, conic 8i=c|k,GL.  
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    SetConic eID, entity, 1/Rant, CCant %&RF;qa2xu  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant (HW!!xM  
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    '************************************************************************* N:]71+  
    'Radius and conic constant of posterior lens dp3>G2Yq  
    '************************************************************************* <:mV^tK  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) W'BB FG  
    GetConic eID, entity, curv, conic F?wfh7q  
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    SetConic eID, entity, 1/Rpost, CCpost Cz%tk}2  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost G>/Gw90E  

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    '************************************************************************* pu:Ie#xTDf  
    'Lens thickness (Position of posterior lens surface) Pd<s#  
    '************************************************************************* 3 ?1qI'5  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) SM;*vkwz~  
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    ' Delete any z-shift(s) o"te7nBI  
    count = 0 "B~c/%#PH  
    While GetOperationCount(eID)>count ADTx _tE  
        GetOperation eID, count, op Nq`@ >Ml  
        If op.Type="ShiftZ" Then PgeC\#;9  
            DeleteOperation eID,count "0Wi-52=V  
            count=count-1 M7O5uW`  
        End If CWP),]#n  
        count=count+1 EqN<""2  
    Wend JumZ>\'p(  
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    'Set new z-shift u?(@hUV.  
    op.Type = "ShiftZ" jT~PwDSFt3  
    op.val1 = tlens M.|cl#  
    op.parent = parID RObo4  
    AddOperation eID, op iYqZBLf{S  
    Print "Set lens thickness = " & tlens  I~'%
 
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    '************************************************************************* iP7 Cku}l  
    'Lens index of refraction #H'j;=]:  
    '************************************************************************* {t.5cX"[  
    eID = FindMaterial( "Lens" ) fgiOYvIS2m  
    GetModelMaterial eID, mat i`m&X6)\j  
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    mat.Nd = nlens n(i Uc1Y  
    SetModelMaterial eID, mat FeW}tKH  
    Print "Set lens index of refraction = " & nlens y$ L@!r/s  
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    '************************************************************************* ^#|Sl D]  
    'Pupil diameter f<14-R=  
    '************************************************************************* uPVM>xf>w  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) skd3E4  
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    'Adjust pupil diameter (trimming volume inner hole) `-R-O@X|  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" }ZQ)]Mr  
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    ' Adjust pupil location to just in front of the lens B]KR*  
    parID = FindFullName( "Geometry.Arizona Eye" ) }Y}f73-|  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) b^*9m PP  
    count = 0 fH-fEMyW  
    While GetOperationCount(eID)>count prHM}n{0  
        GetOperation eID, count, op s6q6)RD"  
        If op.Type="ShiftZ" Then %DK0s(*w0  
            DeleteOperation eID,count [@VM'@
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            count=count-1 jW,b"[  
        End If /C[Q?  
        count=count+1 K nl`[Nl  
    Wend VjI=5)+~  
    op.Type = "ShiftZ" S55h}5Y  
    op.val1 = taq-0.01 og`rsl  
    op.parent = parID i\zVP.c])*  
    AddOperation eID, op AiP#wK;  
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    Print "Set pupil diameter = " & pupilDiam V-{3)6I$hG  
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    'Update AZ Eye subassembly Description Wbq0K6X  
    eID = FindFullName( "Geometry.Arizona Eye" ) URd0|?t9^L  
    GetEntity eID, entity w)rd--9f  
    entity.Description = "Accommodation = " & A & "D" ]<3n;*8k?  
    SetEntity eID, entity W\c1QY$E  
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    Update 7C&J88|\  
    Print "DONE!" V0l"tr@  
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End Sub n5DS  
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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： dwpE(G y6c  
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Accommodation = 4 Diopters hCOCX_  
Pupil Diameter = 4 mm  [HEljEv  
Set aqueous humor thickness = 2.81 q4EOI  
Set anterior lens radius = 10.4 and conic constant = -2.375869 @*9c2\"k  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ;!+-fn4C  
Set lens thickness = 3.927 w+wg)$i  
Set lens index of refraction = 1.42672 fTOGW`s^  
Set pupil diameter = 4 8.!+Hm4  
DONE! \ xJ_)r  
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