[技术]Arizona眼睛模型 [复制链接]

简介 er&uC4Y]a  
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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。 |Ba4 G`
 
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模型 Z'7 c^c7_  
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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。 XLkL#&Ir  
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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. i{Y=!r5r  
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光源 Q `J,dzY  
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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。 T%M1[<"Q  
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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。 -o=P85V  
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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。 8:3oH!n  
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视网膜的散射 [[Jv)?jm  
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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。 ECmHy@(  
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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。 ZNL;8sI?>  
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脚本 }`+^|1  
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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： [9YlLL@  
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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。 cpr{b8Xb8&  
余下的脚本计算与屈光度有关的所有参数。 n]6}yJJo  
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分析 aPY>fy^8D  
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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。 %%-U.   
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脚本代码 x3Dg%=R  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. pjmGzK  
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Dim entity As T_ENTITY r0hta)xa  
Dim op As T_OPERATION }jyS\drJ  
Dim mat As T_MODELMATERIAL Im' :sJ31  
Dim A As Double f!uA$uLc  
Dim pupilDiam As Double E{+c*sz  
Dim eID As Long %1 VNP(E  
Dim parID As Long O0=,&=i  
Dim count As Integer **w*hd]

 
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double cc2oFn  
Dim tlens As Double, nlens As Double ?-.Ep0/  
Dim curv As Double, conic As Double cciAMQhA  
Dim ok As Long +qSr=Y:+  
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Sub Main qqz,~EhC  
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    '用户输入对话框 @dT:
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 yTq(x4]  
        TextBox 220,21,40,21,.TextBox1 'default: 0 }G,SqpcG  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 {Y@-*pL]  
        OKButton 40,91,90,21 :)+@qxTy  
        CancelButton 190,91,90,21 :UJUh/U  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 nX.sh  
        TextBox 220,49,40,21,.TextBox2 'default: 4 4MF}FS2)  
    End Dialog oX:1 qJ
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    Dim dlg As UserDialog Z,8+@  
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    ok = Dialog (dlg) tE9_dR^K  
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    If ok=0 Then    'cancel button was pressed ad3z]dUZ9  
        Print "Execution cancelled." .'NO~  
        End C$..w80/1  
    End If bh;b` 5  
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    'Assign accommodation and pupil diameter & use defaults if field left empty qY~$wVY(  
    If dlg.TextBox1 = "" Then SFk11  
        A = 0           'Default accommodation .5[LQR  
    Else ,TfI  
        A = CDbl(dlg.TextBox1) Y4~wNs6  
    End If yY@s(:  
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    If dlg.TextBox2 = "" Then 
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        pupilDiam = 4   'Default pupil diameter G}?P r4Gj  
    Else }2!5#/^~  
        pupilDiam = CDbl(dlg.TextBox2) vA7jZw  
    End If p`l[cVQ<  
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    Print " " '__3[D  
    Print "Accommodation = " & A & " Diopters" tx1m36a"  
    Print "Pupil Diameter = " & pupilDiam & " mm" "JUQ)> !?  
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    ' Calculate new parameters with accommodation zs]/Y2  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness :Z]+Z_9p  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens MCrO]N($b  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens }$k`[ivBx(  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ";Ig%]  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Qpv}N*v^  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ^B6i6]Pd=9  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction R#Nd|f<  
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    'Adjust parameters to account for accommodation :mtw}H 'F8  
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    '************************************************************************* Gv+
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    'Aqueous thickness (Position of Lens) vyx\N{  
    '************************************************************************* 53+rpU_  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) DGfQo5#  
    GetCustomElement eID, entity qpwh #^2  
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    parID = FindFullName( "Geometry.Arizona Eye" ) IweK!,:>dN  
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    ' Delete any shift(s) in z SnF[mN'  
    count = 0 674oL,  
    While GetOperationCount(eID)>count ch8w'  
        GetOperation eID, count, op jUR#  
        If op.Type="ShiftZ" Then Qx,$)|_  
            DeleteOperation eID,count 3;l>x/amk  
            count=count-1 gWv+i/,  
        End If \/4%[Q2QDm  
        count=count+1 ,JBw$C  
    Wend oY6|h3T=Q$  
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    'Set new shift in |%cO"d^ri  
    op.Type = "ShiftZ" MbFe1U]B  
    op.val1 = taq ]%Yis=v  
    op.parent = parID i7FR78^  
    AddOperation eID, op ].f,3itg&  
    Print "Set aqueous humor thickness = " & taq-0.55 t-x"(  
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    '************************************************************************* `"b7y(M  
    'Radius and conic constant of anterior lens Z *
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    '************************************************************************* m^x\@!N:(  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) jhbH6=f4]^  
    GetConic eID, entity, curv, conic >h( rd1  
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    SetConic eID, entity, 1/Rant, CCant yz$1qEII`q  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant #!&R7/ KdD  
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    '************************************************************************* 'U{: zBh  
    'Radius and conic constant of posterior lens SF7b1jr  
    '************************************************************************* 32|L $o  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @ h`Zn1;  
    GetConic eID, entity, curv, conic qe"6#@b *|  
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    SetConic eID, entity, 1/Rpost, CCpost vMdhNOU  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ^W[`##,{Od  
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    '************************************************************************* 7Z~szD  
    'Lens thickness (Position of posterior lens surface) kDP^[V P+  
    '************************************************************************* la{uJ9Iw@}  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) _7"W\gn:9  
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    ' Delete any z-shift(s) d#:J\2V"R  
    count = 0 p}|wO&4h  
    While GetOperationCount(eID)>count 4x?u5L 9o  
        GetOperation eID, count, op UkbQ'P+oS  
        If op.Type="ShiftZ" Then H1qw1[%0y
 
            DeleteOperation eID,count C{,] 1X
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            count=count-1 JU \J   
        End If ZV4' |q  
        count=count+1 (ai-n,y  
    Wend vk+%#w  
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    'Set new z-shift /~huTKA}  
    op.Type = "ShiftZ" il%tu<E#J~  
    op.val1 = tlens '<D}5u72  
    op.parent = parID cE>/iZc  
    AddOperation eID, op gL"Q.ybA  
    Print "Set lens thickness = " & tlens 9QZwUQ  
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    '************************************************************************* WzbN=& C]h  
    'Lens index of refraction M]TVaN$v#  
    '************************************************************************* PlRs-%d  
    eID = FindMaterial( "Lens" ) [\n.[4gq"  
    GetModelMaterial eID, mat |F{E4mg(o  
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    mat.Nd = nlens uN0fWj]  
    SetModelMaterial eID, mat }4]x"DfIg  
    Print "Set lens index of refraction = " & nlens [y;ZbfMP|o  
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    '************************************************************************* x)Kh_G  
    'Pupil diameter T\CQ  
    '************************************************************************* Awf=yE:  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) @_ZW
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    'Adjust pupil diameter (trimming volume inner hole) >Mw =}g@P  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" :Zo2@8@7  
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    ' Adjust pupil location to just in front of the lens rWKLxK4oU  
    parID = FindFullName( "Geometry.Arizona Eye" ) l<_mag/j9o  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) _?LI0iIFx  
    count = 0 u`,R0=<
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    While GetOperationCount(eID)>count "dOY_@kg  
        GetOperation eID, count, op zb,`K*Z{  
        If op.Type="ShiftZ" Then !O_^Rn+<2  
            DeleteOperation eID,count ~M1%,]  
            count=count-1 Yx c >+mx  
        End If Xb 1^Oj  
        count=count+1 m?G+#k;K  
    Wend t1s@Ub5);I  
    op.Type = "ShiftZ" 2DdLqZY#  
    op.val1 = taq-0.01 9gayu<J  
    op.parent = parID t
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    AddOperation eID, op 5j5t?G;d,  
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    Print "Set pupil diameter = " & pupilDiam qZ1PC
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    'Update AZ Eye subassembly Description :u93yH6~8  
    eID = FindFullName( "Geometry.Arizona Eye" ) c4W"CD;D  
    GetEntity eID, entity PP|xIAc  
    entity.Description = "Accommodation = " & A & "D" j'cCX[i  
    SetEntity eID, entity :8T@96]P  
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    Update S]@iS[|?  
    Print "DONE!" {'aqOlw3<j  
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End Sub 8#-}3~l[  
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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： oC>~r1.j  
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Accommodation = 4 Diopters m':m`,c
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Pupil Diameter = 4 mm <-7Ha_#  
Set aqueous humor thickness = 2.81 .AS,]*?Zn%  
Set anterior lens radius = 10.4 and conic constant = -2.375869 )A;<'{t #L  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 =J\7(0Dz4t  
Set lens thickness = 3.927 -W vAmi  
Set lens index of refraction = 1.42672 U?yXTMD  
Set pupil diameter = 4 za
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DONE! P~>nlm82]