[技术]Arizona眼睛模型 [复制链接]

简介 tHZ"o!(S  
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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。 zIjfxK  
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模型 x5BS|3W$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。 jYRSV7d  
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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. =2Yt[8';  
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光源 +KIz#uqF8Z  
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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。 A#T"4'#?<  
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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。 k1f<(@*`  
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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。 0P9\;!Y  
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视网膜的散射 A+* lV*@0  
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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。 Yr_B(n  
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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。 !~~KM?g  
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脚本 A'z]?xQR  
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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： y1%OH#:duD  
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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。 ;P)oKx
 
余下的脚本计算与屈光度有关的所有参数。 rCDt9o>  
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分析 2[+.*Ef  
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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。 'sUOi7U  
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脚本代码 ";rXCH.  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. m_/Ut  
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Dim entity As T_ENTITY L.'61ZU  
Dim op As T_OPERATION zFm`e:td  
Dim mat As T_MODELMATERIAL k37?NoT  
Dim A As Double ^t4^gcoZ4Z  
Dim pupilDiam As Double wz`% (\  
Dim eID As Long
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Dim parID As Long 1cOR?=G~  
Dim count As Integer DfAF-Yhut  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double tJ;q
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Dim tlens As Double, nlens As Double SzMh  
Dim curv As Double, conic As Double 5`p9Xo>)yW  
Dim ok As Long j_sos%-  
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Sub Main J"AR3b@,$?  
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    '用户输入对话框 rt*x[5<  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Bu=1-8@=qs  
        TextBox 220,21,40,21,.TextBox1 'default: 0 xS1n,gTA  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 )v;O2z  
        OKButton 40,91,90,21 I+kAy;2  
        CancelButton 190,91,90,21 K-k!':K:  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ulsU~WW7r  
        TextBox 220,49,40,21,.TextBox2 'default: 4 % vUU Fub  
    End Dialog 3!p`5hJd  
    Dim dlg As UserDialog 3F|p8zPS  
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    ok = Dialog (dlg) \bdKLcKI,  
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    If ok=0 Then    'cancel button was pressed c_vGr55  
        Print "Execution cancelled." jyIIE7.I"  
        End 9Q,>I6`l  
    End If ?]D&D:Z?I  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 4O-LLH  
    If dlg.TextBox1 = "" Then 5oG~Fc  
        A = 0           'Default accommodation Uwkxc  
    Else /.e7#-+?  
        A = CDbl(dlg.TextBox1) @!OXLM   
    End If D{JjSky  
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    If dlg.TextBox2 = "" Then o~XK*f=(  
        pupilDiam = 4   'Default pupil diameter D-{*3?x  
    Else 4ekwmw(ox  
        pupilDiam = CDbl(dlg.TextBox2) ZJ%NZAxy  
    End If 
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    Print " " 0~U%csPHt  
    Print "Accommodation = " & A & " Diopters" W2X`%Tx
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    Print "Pupil Diameter = " & pupilDiam & " mm" 'zm5wqrkAd  
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    ' Calculate new parameters with accommodation 7vZO;FGtG  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Dazm8_x  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens v Z]j%c@  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens f%EHzm/V  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens @Pcgm"H<  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 1J9p1_d5  
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    tlens = 3.767 + 0.04*A                  'Lens thickness TXi|  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction %/I:r7UR{  
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    'Adjust parameters to account for accommodation LA;f,CQ  
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    '************************************************************************* AI3x,rk#  
    'Aqueous thickness (Position of Lens) 7_oUuNw  
    '************************************************************************* ({rcH.:  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) j.]]VA  
    GetCustomElement eID, entity sPQjB[  
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    parID = FindFullName( "Geometry.Arizona Eye" ) w?_8OJ  
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    ' Delete any shift(s) in z z` 6$p1U  
    count = 0 :N<Qk  
    While GetOperationCount(eID)>count ~v(c9I)  
        GetOperation eID, count, op X(/fE?%;  
        If op.Type="ShiftZ" Then 6V$ )ym*F  
            DeleteOperation eID,count nmiJ2edx  
            count=count-1 .pPuBJL]<  
        End If 2 %fcDEG/  
        count=count+1 p7> 9 m  
    Wend +#wVe  
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    'Set new shift in Kkq-x'gt^  
    op.Type = "ShiftZ" 3\RD%[}  
    op.val1 = taq 7HW:;2dL  
    op.parent = parID (.=Y_g
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    AddOperation eID, op v CsE|eMP  
    Print "Set aqueous humor thickness = " & taq-0.55 y2+f)Xp_.C  
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    '************************************************************************* O$,
 
    'Radius and conic constant of anterior lens F#|y,<}<  
    '************************************************************************* TP#Ncqh  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) g8E5"jpXx3  
    GetConic eID, entity, curv, conic pBe1:  
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    SetConic eID, entity, 1/Rant, CCant `scW.Vem  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant sT1k]duT  
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    '************************************************************************* nmn/4>  
    'Radius and conic constant of posterior lens {f/]K GGk  
    '************************************************************************* #akJhy@m$  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @$kO7k0{g  
    GetConic eID, entity, curv, conic T"htWo{v>  
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    SetConic eID, entity, 1/Rpost, CCpost [ p,]/ ^ N  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ??e|ec2%  
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    '************************************************************************* 8Y8bFWuc  
    'Lens thickness (Position of posterior lens surface) )
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    '************************************************************************* #f(tzPD  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~6t<`&f  
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    ' Delete any z-shift(s) H.iCYD_=  
    count = 0  g4q{ ]  
    While GetOperationCount(eID)>count vbJdhaf  
        GetOperation eID, count, op #QsJr_=  
        If op.Type="ShiftZ" Then xKBi".wA  
            DeleteOperation eID,count o% Q7 el$f  
            count=count-1 R%r25_8  
        End If v(Kj6'  
        count=count+1 M^\`~{*T  
    Wend Q1*_l  
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    'Set new z-shift lFf>z}eLy  
    op.Type = "ShiftZ" LsI@_,XW<  
    op.val1 = tlens 9[\do@  
    op.parent = parID ';\norx;  
    AddOperation eID, op =/j!S|P  
    Print "Set lens thickness = " & tlens g:~q&b[q6  
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    '************************************************************************* &Oz  
    'Lens index of refraction @VHstjos^V  
    '************************************************************************* 6K7lQ!#}Q  
    eID = FindMaterial( "Lens" ) sa<\nH$_X  
    GetModelMaterial eID, mat #l
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    mat.Nd = nlens ?/T=Gk  
    SetModelMaterial eID, mat zk3\v "  
    Print "Set lens index of refraction = " & nlens oH4zW5  
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    '************************************************************************* Ha]vG@?+  
    'Pupil diameter ~G8l1dD  
    '************************************************************************* /m>SEo\{C  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ?`Mk$Y%my  
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    'Adjust pupil diameter (trimming volume inner hole) \2~\c#-k  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ~C>;0a;<:  
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    ' Adjust pupil location to just in front of the lens <]z4;~/&  
    parID = FindFullName( "Geometry.Arizona Eye" ) *qL'WrB1  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) dm_Pz\*  
    count = 0 4W
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    While GetOperationCount(eID)>count v1+.-hO  
        GetOperation eID, count, op )mAD<y+  
        If op.Type="ShiftZ" Then [oBRH]9cq  
            DeleteOperation eID,count mHW%^R=  
            count=count-1 F5H*z\/={  
        End If T>*G1-J#  
        count=count+1 5cM%PYU4:v  
    Wend GNwFB)?j  
    op.Type = "ShiftZ" sqF.,A,  
    op.val1 = taq-0.01 %*<Wf4P"  
    op.parent = parID OcpvY~"Pr  
    AddOperation eID, op &xUCXj2-z  
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    Print "Set pupil diameter = " & pupilDiam je#LD  
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    'Update AZ Eye subassembly Description ]X7_ji(l,  
    eID = FindFullName( "Geometry.Arizona Eye" ) QTF1~A\  
    GetEntity eID, entity *'-C/  
    entity.Description = "Accommodation = " & A & "D" $z)egh(z  
    SetEntity eID, entity 3qu?qD  
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    Update < fe.  
    Print "DONE!" Ed;!A(64r  
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End Sub 6 3PV R"  
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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： n/BoK6g  
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Accommodation = 4 Diopters H,EZ% Gl  
Pupil Diameter = 4 mm pwSkwJ]  
Set aqueous humor thickness = 2.81 )eSQce7H  
Set anterior lens radius = 10.4 and conic constant = -2.375869 2RqV\Ji
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 mo4F\$2N  
Set lens thickness = 3.927 S}Z@g  
Set lens index of refraction = 1.42672 RvU'8Y?>w  
Set pupil diameter = 4 .bV^u  
DONE! i
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