[技术]Arizona眼睛模型 [复制链接]

简介 /aB9pD+%  
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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。 ,FPgbs  
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模型 XDJQO /qN  
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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。 1`_i%R^  
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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. Yg#)@L  
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光源 U)p P^:|  
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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。 I -obfyije  
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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。 .j4IW3)  
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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。 :LFwJ  
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视网膜的散射 *#;rp~  
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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。 3Pp*ID  
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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。 Bd"7F{H  
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脚本 %2oLND}?z  
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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： fp4d?3G  
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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。 +.\JYH=yEr  
余下的脚本计算与屈光度有关的所有参数。 b)w3 G%Xx  
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分析 !,\9,lc  
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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。 jO:<"l^+u  
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脚本代码 rmQGzQnun  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. o`j%$K4?5  
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Dim entity As T_ENTITY ~w[zX4@  
Dim op As T_OPERATION :@b>,{*4zS  
Dim mat As T_MODELMATERIAL 9f,HjR
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Dim A As Double ,%nmCetD@  
Dim pupilDiam As Double 'Dk(jpYB  
Dim eID As Long -R7f/a8  
Dim parID As Long ~?b(2gn  
Dim count As Integer 9y]$c1  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double //Tr=!TQu  
Dim tlens As Double, nlens As Double /e{Oqhf[n  
Dim curv As Double, conic As Double R!pV`N  
Dim ok As Long 9CBB,  
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Sub Main V`fh,(:  
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    '用户输入对话框 ^<|If:|  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 RXx +rdF0  
        TextBox 220,21,40,21,.TextBox1 'default: 0 5K6_#g4"  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ^ACp
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        OKButton 40,91,90,21 =C3l:pGMB;  
        CancelButton 190,91,90,21 .=@M>TZM  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 (c[h,>`@:  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Y?%6af+  
    End Dialog 3?5 ~KxOE(  
    Dim dlg As UserDialog 3UN Jj&-`  
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    ok = Dialog (dlg) #sqD
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    If ok=0 Then    'cancel button was pressed HZK0Ldf  
        Print "Execution cancelled." P^h2w%6'  
        End <RhKlCP  
    End If G0]n4"~+?  
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    'Assign accommodation and pupil diameter & use defaults if field left empty .ySesN: C~  
    If dlg.TextBox1 = "" Then -O_UpjR;  
        A = 0           'Default accommodation dU&.gFw1  
    Else m1[QD26  
        A = CDbl(dlg.TextBox1) v"F0$c
 
    End If IYCKF/2o  
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    If dlg.TextBox2 = "" Then /d{L]*v)]  
        pupilDiam = 4   'Default pupil diameter xwRnrWd^6  
    Else +tV(8h4  
        pupilDiam = CDbl(dlg.TextBox2) q]r!5&Z  
    End If lMm-K%(2  
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    Print " " h |lQTT  
    Print "Accommodation = " & A & " Diopters" _ma4  
    Print "Pupil Diameter = " & pupilDiam & " mm" 3x=F  
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    ' Calculate new parameters with accommodation wl{p,[
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness `riv`+J{s  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens V.-?aXQ*  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens no/]Me!j=  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens <HzAh<_@F  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens "FXS;Jf  
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    tlens = 3.767 + 0.04*A                  'Lens thickness hx2C<;s4  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction fN4pG*D  
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    'Adjust parameters to account for accommodation kK1qFe?]  
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    '************************************************************************* (jm.vL&5j  
    'Aqueous thickness (Position of Lens) Z~,.l  
    '************************************************************************* G4{qWa/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) v]BQIE?R /  
    GetCustomElement eID, entity K?;p:  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Z*TW;h0ZQ3  
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    ' Delete any shift(s) in z z1FbW&V  
    count = 0 dI 5sqM:  
    While GetOperationCount(eID)>count bMUIe\/v[  
        GetOperation eID, count, op (O-)uC  
        If op.Type="ShiftZ" Then Vd/S81/  
            DeleteOperation eID,count (En\odbvt  
            count=count-1 `HS4(2+C  
        End If y[zA[H:  
        count=count+1 a?Y1G3U'  
    Wend `
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    'Set new shift in cyhD%sB[D9  
    op.Type = "ShiftZ" pNqf2CnnT  
    op.val1 = taq YT5>pM-%  
    op.parent = parID AslH V@K  
    AddOperation eID, op B@;)$1-UT  
    Print "Set aqueous humor thickness = " & taq-0.55 -PnC^r0L$  
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    '************************************************************************* ,Mhe:^3  
    'Radius and conic constant of anterior lens @gqw]
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    '************************************************************************* S[a5k;8GL  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) g&"(- :  
    GetConic eID, entity, curv, conic (v`;ym  
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    SetConic eID, entity, 1/Rant, CCant }m9LyT=~$  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant R2$U K  
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    '************************************************************************* )RYnRC#O  
    'Radius and conic constant of posterior lens nFfCw%T?  
    '************************************************************************* @:7gHRJ!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +^J-'7Vt  
    GetConic eID, entity, curv, conic 99!{[gOv  
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    SetConic eID, entity, 1/Rpost, CCpost O8r"M8  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 9 <KtI7  
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    '************************************************************************* 7rSUSra  
    'Lens thickness (Position of posterior lens surface) CJ?gjV6  
    '************************************************************************* r}\h\ {  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) z}1xy+  
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    ' Delete any z-shift(s) ]|N4 #4  
    count = 0 X[Ek'=}  
    While GetOperationCount(eID)>count
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        GetOperation eID, count, op ^V}R(gDu}s  
        If op.Type="ShiftZ" Then u-
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            DeleteOperation eID,count tHtV[We.:  
            count=count-1 #Q3PzDfj  
        End If VK'T[5e  
        count=count+1 e(#IewKp  
    Wend qd+[ShrhqZ  
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    'Set new z-shift Zva  
    op.Type = "ShiftZ" HJ qQlEq  
    op.val1 = tlens b#g {`E  
    op.parent = parID }[z<iij4  
    AddOperation eID, op 8},<e>q  
    Print "Set lens thickness = " & tlens U+;>S$  
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    '************************************************************************* g?~Tguv  
    'Lens index of refraction n`)7Y`hBhP  
    '************************************************************************* (
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    eID = FindMaterial( "Lens" ) g6g$nY@Jm  
    GetModelMaterial eID, mat 90T%T2K  
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    mat.Nd = nlens 9U)t@b  
    SetModelMaterial eID, mat cVay=5].  
    Print "Set lens index of refraction = " & nlens _;:rkC fj  
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    '************************************************************************* CofH}-  
    'Pupil diameter ^5]uBOv  
    '************************************************************************* k\pDJ7wF^  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &G/|lv>j  
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    'Adjust pupil diameter (trimming volume inner hole)
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" BMNr<P2li  
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    ' Adjust pupil location to just in front of the lens C.>  
    parID = FindFullName( "Geometry.Arizona Eye" ) GVG!sMmnX  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) rKzlK 'U  
    count = 0 x=5P+_  
    While GetOperationCount(eID)>count !&`}]qQZ  
        GetOperation eID, count, op #%^\\|'z  
        If op.Type="ShiftZ" Then nlzW.OLM  
            DeleteOperation eID,count ejklpa ./  
            count=count-1 A)Qh  
        End If -\kXH"%  
        count=count+1 |mxNUo-  
    Wend 0||"r&:X  
    op.Type = "ShiftZ" EqnpMHF  
    op.val1 = taq-0.01 2QGMe}  
    op.parent = parID rLJ[FqS  
    AddOperation eID, op $;Vc@mYGW;  
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    Print "Set pupil diameter = " & pupilDiam j1YH9T#|D  
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    'Update AZ Eye subassembly Description
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    eID = FindFullName( "Geometry.Arizona Eye" ) )nwZ/&@  
    GetEntity eID, entity h2wN<dJCM  
    entity.Description = "Accommodation = " & A & "D" FaFp_P?  
    SetEntity eID, entity [$l"-*s4  
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    Update 5vTv$2@  
    Print "DONE!" d/{Q t  
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End Sub 1")FWN_K/T  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： MO[kr2T  
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Accommodation = 4 Diopters TbLe6x  
Pupil Diameter = 4 mm qy_%~c87  
Set aqueous humor thickness = 2.81 NZLXN  
Set anterior lens radius = 10.4 and conic constant = -2.375869 6b?`:$Cw3)  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 AnNPTi  
Set lens thickness = 3.927 :l+_ja&o  
Set lens index of refraction = 1.42672 ]gu1#  
Set pupil diameter = 4 )Zas x6`  
DONE! !?nu?