[技术]Arizona眼睛模型 [复制链接]

简介 $F@ ,,*  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 i&L!?6 5-f  
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模型 LKM;T-  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 EuKkIr/(  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 76cT}l&.h8  
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光源 v+DXs!O{  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 XrGP]k6.^  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 pE{Ecrc3|  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 CS;4ysNf  
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视网膜的散射 (~?p`g+I.P  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ,-SWrp
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 5jsZJpk$  
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脚本 1;~|[C  
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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： "Ve9\$_s  
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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。 lLS7K8;4W  
余下的脚本计算与屈光度有关的所有参数。 nNh5f]]  
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分析 (P-$tHt  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 *$@u`nM  
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脚本代码 H4<Q}([w  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. m"wP]OQH*+  
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Dim entity As T_ENTITY _IWLC{%V  
Dim op As T_OPERATION ^95njE`>t`  
Dim mat As T_MODELMATERIAL =X7_!vSv  
Dim A As Double -L!lJ  
Dim pupilDiam As Double 1o?uf,H7O  
Dim eID As Long "6Z(0 iu:{  
Dim parID As Long E@4/<;eKK  
Dim count As Integer e/}4Pt  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 9T0g%&  
Dim tlens As Double, nlens As Double \r"gqv)^  
Dim curv As Double, conic As Double zpZfsn!  
Dim ok As Long %a!gN  
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Sub Main wZWAx  
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    '用户输入对话框 Rx?ze(  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ER0B{b  
        TextBox 220,21,40,21,.TextBox1 'default: 0 W:K'2j  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Zpz3?VM(  
        OKButton 40,91,90,21 <,D*m+BWn  
        CancelButton 190,91,90,21 3cF8DNh  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 `@#rAW D  
        TextBox 220,49,40,21,.TextBox2 'default: 4 =nqHVRA  
    End Dialog UqNUX?(  
    Dim dlg As UserDialog Y(R.<LtY  
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    ok = Dialog (dlg) ?$l|];m)-  
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    If ok=0 Then    'cancel button was pressed 1xInU_SPf  
        Print "Execution cancelled." tS-gaT`T  
        End x,ZF+vE  
    End If 'xEK0~awD  
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    'Assign accommodation and pupil diameter & use defaults if field left empty $lq.*UQ;0  
    If dlg.TextBox1 = "" Then c3r`T{Kf  
        A = 0           'Default accommodation r-.>3J  
    Else 7VL|\^Y`q  
        A = CDbl(dlg.TextBox1) ]sJC%/  
    End If dT[JVl+3=  
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    If dlg.TextBox2 = "" Then gtePo[ZH.P  
        pupilDiam = 4   'Default pupil diameter _,/~P)  
    Else
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        pupilDiam = CDbl(dlg.TextBox2) _ j`tR:  
    End If dqs~K7O^E  
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    Print " " gd*2*o$g(  
    Print "Accommodation = " & A & " Diopters" eW;
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    Print "Pupil Diameter = " & pupilDiam & " mm" [FLR&=.(  
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    ' Calculate new parameters with accommodation is~2{
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness K6sXw[VC[  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ~clX2U8u`  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 6?;z\AP&  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens O1bW, n(  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens AI`k }sA~  
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    tlens = 3.767 + 0.04*A                  'Lens thickness B(ktIy  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction }>d  
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    'Adjust parameters to account for accommodation I]E 3&gnC  
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    '************************************************************************* `j(._`8%a  
    'Aqueous thickness (Position of Lens) CS~_>bn  
    '************************************************************************* -%@ah:iJ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) o+7)cI  
    GetCustomElement eID, entity y^ |u'
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    parID = FindFullName( "Geometry.Arizona Eye" ) 6dV )pJd  
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    ' Delete any shift(s) in z _OyQ:>M6P  
    count = 0 8-Y*b89  
    While GetOperationCount(eID)>count U||GeEd  
        GetOperation eID, count, op Kk6=61}A  
        If op.Type="ShiftZ" Then &J
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            DeleteOperation eID,count ;RRw-|/Wm  
            count=count-1 gXJBb+P   
        End If V~ORb1  
        count=count+1 1l"2 ~k  
    Wend hlB\Xt  
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    'Set new shift in 0o"aSCq8
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    op.Type = "ShiftZ" KE@+I.x  
    op.val1 = taq N)GHQlgH  
    op.parent = parID ao"2kqa)r  
    AddOperation eID, op U/^#nU.,  
    Print "Set aqueous humor thickness = " & taq-0.55
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    '************************************************************************* tP7<WGHd/  
    'Radius and conic constant of anterior lens PPr Pj^%z=  
    '************************************************************************* #Uu,yHMv:;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) L_RVHvA=M/  
    GetConic eID, entity, curv, conic bo/9k 4N3  
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    SetConic eID, entity, 1/Rant, CCant {0Y6jk>I  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Q_|}~4_+  
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    '************************************************************************* d#a/J.Z$A  
    'Radius and conic constant of posterior lens )q-NE)  
    '************************************************************************* XPO-u]<W  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) q.`<q  
    GetConic eID, entity, curv, conic ~TEn +  
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    SetConic eID, entity, 1/Rpost, CCpost |HD>m'e  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 3HpqMz  
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    '************************************************************************* LhbdvJAk@  
    'Lens thickness (Position of posterior lens surface) Sv{n?BYq  
    '************************************************************************* J<QZ)<T,&  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 1>j,v+  
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    ' Delete any z-shift(s) Y~g{9 <!  
    count = 0 )|xu5.F  
    While GetOperationCount(eID)>count ,<t.Iz%  
        GetOperation eID, count, op z7bJV/f  
        If op.Type="ShiftZ" Then 9 A ?{}c  
            DeleteOperation eID,count Ne1Oz}  
            count=count-1 EGUlLqP6e  
        End If LJ/He[r|[  
        count=count+1 .iRKuBM/  
    Wend IDH~nMz  
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    'Set new z-shift r6Yd"~
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    op.Type = "ShiftZ" (4
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    op.val1 = tlens $lJcC |*  
    op.parent = parID )bOfs*S  
    AddOperation eID, op 9f( X7kt  
    Print "Set lens thickness = " & tlens [g/D<g5O  
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    '************************************************************************* Wn(!6yid  
    'Lens index of refraction 5p[}<I{  
    '************************************************************************* z}!g2
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    eID = FindMaterial( "Lens" ) V2Vr7v=Y"  
    GetModelMaterial eID, mat #XDgvX >  
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    mat.Nd = nlens +M0pmK!  
    SetModelMaterial eID, mat eut2x7Z(c  
    Print "Set lens index of refraction = " & nlens <#C,66k  
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    '************************************************************************* UPuoIfuqI  
    'Pupil diameter 3}fOb  
    '************************************************************************* mZR3Hl$  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) fZo#
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    'Adjust pupil diameter (trimming volume inner hole) XGx[Ny_A2  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" (SBhU:^h  
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    ' Adjust pupil location to just in front of the lens &
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    parID = FindFullName( "Geometry.Arizona Eye" ) {|?^@  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) .xsfq*3e5  
    count = 0 Jp=fLo 9  
    While GetOperationCount(eID)>count e?]5q ez  
        GetOperation eID, count, op *U[y
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        If op.Type="ShiftZ" Then  rL{R=0  
            DeleteOperation eID,count t5-O-AI[b{  
            count=count-1 UY< PiP  
        End If k7CKl;Fck  
        count=count+1 F^u12R)  
    Wend |sZqqgZ-  
    op.Type = "ShiftZ" H$h#n~W~  
    op.val1 = taq-0.01 P1-eDHYw  
    op.parent = parID (I>Ch)'  
    AddOperation eID, op XIdh9)]^}  
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    Print "Set pupil diameter = " & pupilDiam &zEQbHK
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    'Update AZ Eye subassembly Description nq M7Is  
    eID = FindFullName( "Geometry.Arizona Eye" ) 3v8LzS3@  
    GetEntity eID, entity DzAZv/h76  
    entity.Description = "Accommodation = " & A & "D" ?_NKyiu95  
    SetEntity eID, entity dJ"M#
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    Update v-1}&K  
    Print "DONE!" BO[:=x`  
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End Sub QKG3>lU  
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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： hYW9a`Ht/  
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Accommodation = 4 Diopters 'C[tPP  
Pupil Diameter = 4 mm ^m qEKy<
 
Set aqueous humor thickness = 2.81 oW3"J6,S  
Set anterior lens radius = 10.4 and conic constant = -2.375869 w' 7sh5  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 |b  
Set lens thickness = 3.927 Pxlc RF  
Set lens index of refraction = 1.42672 9bM\ (s/  
Set pupil diameter = 4 VXeO}>2S  
DONE! dHnCSOM<