[技术]Arizona眼睛模型 [复制链接]

简介 y8|?J\eRy  
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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。 WZ]f \S  
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模型 csNB \  
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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。 w]
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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. OPP^n-iPr  
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光源 `R+I(Cb  
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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。 ]31UA>/TI  
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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。 #FQkwX'g  
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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。 n%Df6zQ<@s  
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视网膜的散射 xJS
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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。 XwNJHOaF  
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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。 ,9@JBV%_  
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脚本 |1[3RnGS  
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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： 4`M7 3k0  
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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。 ccPTJ/%$  
余下的脚本计算与屈光度有关的所有参数。 jFr[T  
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分析 Or9"T]z  
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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。 k(bDj[0q^  
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脚本代码 B2/d%B  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 
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Dim entity As T_ENTITY ?Xq"Q^o4#e  
Dim op As T_OPERATION xxS>O%  
Dim mat As T_MODELMATERIAL CNkI9>L=W`  
Dim A As Double Vhi4_~W3j]  
Dim pupilDiam As Double )A1u uW (  
Dim eID As Long )4tOTi[  
Dim parID As Long G3wkqd
 
Dim count As Integer Nm.G,6<J  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double aF!Im}  
Dim tlens As Double, nlens As Double &Fg|52  
Dim curv As Double, conic As Double wdo(K.m  
Dim ok As Long ZCC T  
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Sub Main {IgLH`@  
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    '用户输入对话框 [0M`uf/u  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 92 oUQ EK  
        TextBox 220,21,40,21,.TextBox1 'default: 0 y`Nprwb  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 CAT{)*xc  
        OKButton 40,91,90,21 JV`"kk/  
        CancelButton 190,91,90,21 FD[o94`%  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ,%X"Caz  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Zb4+zps^-  
    End Dialog ]p-xds#d  
    Dim dlg As UserDialog >.o<}!FW  
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    ok = Dialog (dlg) o^8Z cN>  
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    If ok=0 Then    'cancel button was pressed ^(+@uuBx  
        Print "Execution cancelled." B{hV|2  
        End 3n3$?oV  
    End If Z(Z$>P&4  
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    'Assign accommodation and pupil diameter & use defaults if field left empty N#<X"&-_#  
    If dlg.TextBox1 = "" Then F"| ;  
        A = 0           'Default accommodation Qu_=K_W  
    Else 0 H0U%x8  
        A = CDbl(dlg.TextBox1) 9cXL4  
    End If K0'= O  
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    If dlg.TextBox2 = "" Then 
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        pupilDiam = 4   'Default pupil diameter $g&_7SJ@  
    Else ZU68\cL  
        pupilDiam = CDbl(dlg.TextBox2) <0btw
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    End If vtw97G  
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    Print " " @>q4hYF  
    Print "Accommodation = " & A & " Diopters" .Mxt F\  
    Print "Pupil Diameter = " & pupilDiam & " mm" 8'-E>+L   
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    ' Calculate new parameters with accommodation =:=s  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness :/\KVz'fw}  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens )u=46EU_  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens '>:%n  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ;-quK%VO!  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 4&<zkAMR  
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    tlens = 3.767 + 0.04*A                  'Lens thickness $VJE&b  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction p?' F$Wz  
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    'Adjust parameters to account for accommodation ZK`x(h{p)  
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    '************************************************************************* 1[]V @P^  
    'Aqueous thickness (Position of Lens) M
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    '************************************************************************* S #C;"se  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ')Qb,#/,%  
    GetCustomElement eID, entity 5|g#>sx>`q  
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    parID = FindFullName( "Geometry.Arizona Eye" ) GXwQ )P5]  
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    ' Delete any shift(s) in z fiQ/ &]|5  
    count = 0 $%zM Z  
    While GetOperationCount(eID)>count 2#Y5*r's\  
        GetOperation eID, count, op X<uH [  
        If op.Type="ShiftZ" Then uz@lz +  
            DeleteOperation eID,count 7 aN}lQM  
            count=count-1 bJB*
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        End If oRHWb_$"  
        count=count+1 \ocC'FmE  
    Wend S~\u]j^%y  
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    'Set new shift in 7!q.MOYm  
    op.Type = "ShiftZ" mU;\,96#  
    op.val1 = taq `r+`vJ$  
    op.parent = parID e$4l[&kH_  
    AddOperation eID, op Z`yW2ON$'  
    Print "Set aqueous humor thickness = " & taq-0.55 ;|.IUXEgcF  
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    '************************************************************************* [p96H)8YU  
    'Radius and conic constant of anterior lens =%0r_#F%=  
    '************************************************************************* Ombvp;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 2^fSC`!  
    GetConic eID, entity, curv, conic ~c|{PZ9U  
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    SetConic eID, entity, 1/Rant, CCant c59l/qoz  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant p} i5z_tS  
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    '************************************************************************* )5l9!1j  
    'Radius and conic constant of posterior lens \"Aw ATQ  
    '************************************************************************* bEl)/z*gy/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ?q hme   
    GetConic eID, entity, curv, conic (\ Gs7  
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    SetConic eID, entity, 1/Rpost, CCpost Q);^gV  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 22"/|S  
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    '************************************************************************* X-J<gI(Y  
    'Lens thickness (Position of posterior lens surface) QiQO>r  
    '************************************************************************* Z{ b($po  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) zP#%ya:I  
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    ' Delete any z-shift(s) )Tj\ym-Vl  
    count = 0 @(s"5
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    While GetOperationCount(eID)>count ,XmyC7y<  
        GetOperation eID, count, op a[Oi  
        If op.Type="ShiftZ" Then H8?Kgaj~vf  
            DeleteOperation eID,count :EZ"D#>y~  
            count=count-1 }|4dEao\  
        End If CD
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        count=count+1 Qh@A7N/L  
    Wend J(
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    'Set new z-shift \k)(:[^FY  
    op.Type = "ShiftZ" XV*uu "F  
    op.val1 = tlens b+ J)  
    op.parent = parID mqb6MnK -  
    AddOperation eID, op V-%Am  
    Print "Set lens thickness = " & tlens 
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    '************************************************************************* cQldBc  
    'Lens index of refraction i-_ * 5%A  
    '************************************************************************* XhxCOpO  
    eID = FindMaterial( "Lens" ) RE}$(T=  
    GetModelMaterial eID, mat 'hl4cHk14  
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    mat.Nd = nlens 1b-_![&]1  
    SetModelMaterial eID, mat #jNN?,ZK  
    Print "Set lens index of refraction = " & nlens `+O7IyTMA  
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    '************************************************************************* o$-!E(p  
    'Pupil diameter L.) 0!1  
    '************************************************************************* ]:vo"{*C  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 
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    'Adjust pupil diameter (trimming volume inner hole) p!xCNZ(m  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" +>wBGVvS  
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    ' Adjust pupil location to just in front of the lens =vZF/r  
    parID = FindFullName( "Geometry.Arizona Eye" ) ~i y]X:U  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) X,"(G}KUA  
    count = 0 x[5uz))  
    While GetOperationCount(eID)>count &KS*rHgt?  
        GetOperation eID, count, op u+Q<>>lU  
        If op.Type="ShiftZ" Then eAD
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            DeleteOperation eID,count @fSBW+  
            count=count-1 7r4|>F  
        End If mE}@}@(  
        count=count+1 d`+@ _)ea  
    Wend ^*=.Vuqy  
    op.Type = "ShiftZ" 1||\3
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    op.val1 = taq-0.01 lEe<!B$d"  
    op.parent = parID wjeuZNYf  
    AddOperation eID, op x<es1A'u6  
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    Print "Set pupil diameter = " & pupilDiam gLL8-T[9
 
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    'Update AZ Eye subassembly Description zZax![Z  
    eID = FindFullName( "Geometry.Arizona Eye" ) [R~`6  
    GetEntity eID, entity Btgxzf  
    entity.Description = "Accommodation = " & A & "D" %!X|X
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    SetEntity eID, entity L d;))e  
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    Update iYk4=l  
    Print "DONE!" Lm{qFu  
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End Sub :ENdF `nC  
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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： WQ1~9#  
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Accommodation = 4 Diopters ,p\:Z3{ZH  
Pupil Diameter = 4 mm [,)G\  
Set aqueous humor thickness = 2.81
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Set anterior lens radius = 10.4 and conic constant = -2.375869 d~F4  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ;"K;D@xzh]  
Set lens thickness = 3.927 i
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Set lens index of refraction = 1.42672 hE|W%~Jx  
Set pupil diameter = 4 3\B28m  
DONE! -0>gq$/N=^