[技术]Arizona眼睛模型 [复制链接]

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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。 *9e T#dH  
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模型 Z'dY,<@  
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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。 o>#<c @  
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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. ^zkTV_,cRp  
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光源 -H~g+i*J  
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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。 SPW @TF1  
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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。 W+PAlsOC  
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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。 Pa2HFy2  
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视网膜的散射 USu/Y29  
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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。 Ou/@!Y1  
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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。 #/sKb2eQ  
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脚本 >=^g%K$L6J  
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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： @]tFRV  
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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。 wRf_IBhCd  
余下的脚本计算与屈光度有关的所有参数。 $=iz&{9  
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分析 ^te9f%>$l  
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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。 %Z&[wU~  
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脚本代码 FB@c +*1  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. }txHuq1Q.  
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Dim entity As T_ENTITY oe`oUnN  
Dim op As T_OPERATION 2i', e  
Dim mat As T_MODELMATERIAL O<S*bN>BF  
Dim A As Double S4s\tA<  
Dim pupilDiam As Double gm8L5c V  
Dim eID As Long ItQIM#  
Dim parID As Long nlHH}K  
Dim count As Integer Lcplc"C  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double )!3XM  
Dim tlens As Double, nlens As Double /4RKA!W  
Dim curv As Double, conic As Double fS-#dJC";`  
Dim ok As Long eznw05U  
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Sub Main Ia)wlA02S  
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    '用户输入对话框 sBS\S  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ckP&N:tC  
        TextBox 220,21,40,21,.TextBox1 'default: 0 g
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 p}uL%:Vr  
        OKButton 40,91,90,21 tbAN{pX  
        CancelButton 190,91,90,21 u%5B_<90V  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 v;el= D  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ")ow,r^"  
    End Dialog Sl^HMO  
    Dim dlg As UserDialog cG?RisSZ  
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    ok = Dialog (dlg) KmZUDU%R  
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    If ok=0 Then    'cancel button was pressed 8
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        Print "Execution cancelled." 9XF+? x  
        End !-x^b.${B  
    End If \`{ YqOT  
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    'Assign accommodation and pupil diameter & use defaults if field left empty '68{dyFZL  
    If dlg.TextBox1 = "" Then + R])u5c'  
        A = 0           'Default accommodation \PU|<Ru.  
    Else 9g J`H'  
        A = CDbl(dlg.TextBox1) 2 'xT%  
    End If 8iK>bp  
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    If dlg.TextBox2 = "" Then :2 ?dl:l  
        pupilDiam = 4   'Default pupil diameter `"I^nD^t>Y  
    Else 2aW&d=!ZV  
        pupilDiam = CDbl(dlg.TextBox2) Eo)Q> AM  
    End If [>;U1Wt  
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    Print " " Wxb/|?,  
    Print "Accommodation = " & A & " Diopters" O]m,zk  
    Print "Pupil Diameter = " & pupilDiam & " mm" -}9ZZ#K  
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    ' Calculate new parameters with accommodation Jnb>u*7,  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness _(<[!c!@0  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens u_e}m>[S  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens #]:yCiA  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens :v Pzw!  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ~(-B%Az  
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    tlens = 3.767 + 0.04*A                  'Lens thickness |6"zIHvtc  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction q,^^c
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    'Adjust parameters to account for accommodation 4B-v\3Ff  
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    '************************************************************************* 9FX'Uws  
    'Aqueous thickness (Position of Lens) u <%,Ql  
    '************************************************************************* (3%NudkwT  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) fwf]1@#  
    GetCustomElement eID, entity "[BuQ0(g  
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    parID = FindFullName( "Geometry.Arizona Eye" ) M!,$i  
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    ' Delete any shift(s) in z .AWRe1?  
    count = 0 9$)TAI&P  
    While GetOperationCount(eID)>count &( b\jyf  
        GetOperation eID, count, op ,l#V eC  
        If op.Type="ShiftZ" Then C*/d%eHD  
            DeleteOperation eID,count [|<|a3']|  
            count=count-1 @;G}bYq^(I  
        End If P
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        count=count+1 w~;1R\?|  
    Wend !HY+6!hk  
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    'Set new shift in ]GJIrtS4  
    op.Type = "ShiftZ" 0{@E=}}h  
    op.val1 = taq My5h;N@C  
    op.parent = parID (Y)$+9  
    AddOperation eID, op yg5Ik{  
    Print "Set aqueous humor thickness = " & taq-0.55 s0E:hn:  
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    '************************************************************************* -SlLX\>p  
    'Radius and conic constant of anterior lens e#0R9+"Ba  
    '************************************************************************* rKg5?.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Z<0M_q9?MO  
    GetConic eID, entity, curv, conic bEMD2ABm  
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    SetConic eID, entity, 1/Rant, CCant egYJ.ZzF0  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant E/Q[J.$o  
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    '************************************************************************* aHXd1\6m  
    'Radius and conic constant of posterior lens @@# ^G8+l  
    '************************************************************************* >IJH#>i  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) H .JA)*b-  
    GetConic eID, entity, curv, conic Zyu4!  
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    SetConic eID, entity, 1/Rpost, CCpost ?N~rms e  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost h&{9 &D1t  
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    '************************************************************************* q#xoM1  
    'Lens thickness (Position of posterior lens surface) ^I5k+cL  
    '************************************************************************* cE$<6&0  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,@;

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    ' Delete any z-shift(s) ]L"jt8E  
    count = 0 jav7V"$  
    While GetOperationCount(eID)>count ==RYf*d  
        GetOperation eID, count, op }:])1!a  
        If op.Type="ShiftZ" Then MD1n+FgTu  
            DeleteOperation eID,count }G]6Rip3  
            count=count-1 U6t>UE6k  
        End If Ovxs+mQ  
        count=count+1 "iMuA  
    Wend sy.FMy+  
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    'Set new z-shift DJdW$S7  
    op.Type = "ShiftZ" }u5/  
    op.val1 = tlens 1aP3oXLL  
    op.parent = parID D{x'k2=  
    AddOperation eID, op w<!F& kQB  
    Print "Set lens thickness = " & tlens V`fp%7W  
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    '************************************************************************* z\]]d?d?;  
    'Lens index of refraction bJ4})P&  
    '************************************************************************* $nUhM|It  
    eID = FindMaterial( "Lens" ) UMILAoR  
    GetModelMaterial eID, mat )"/.2
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    mat.Nd = nlens "oz : & #+  
    SetModelMaterial eID, mat ]0p] u d&  
    Print "Set lens index of refraction = " & nlens V^
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    '************************************************************************* J&CA#Bg:w  
    'Pupil diameter e{EKM4  
    '************************************************************************* 2w_[c.  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) R.@I}>  
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    'Adjust pupil diameter (trimming volume inner hole) hfE5[  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" >o9tlO)  
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    ' Adjust pupil location to just in front of the lens />Kd w  
    parID = FindFullName( "Geometry.Arizona Eye" ) o-a\T  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 1Bp?HyCR  
    count = 0 fUx;_GX?  
    While GetOperationCount(eID)>count .;}vp*  
        GetOperation eID, count, op NXo$rf:  
        If op.Type="ShiftZ" Then 0`UI^
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            DeleteOperation eID,count QiC}hj$  
            count=count-1 l7 Pn5c  
        End If {P')$f)  
        count=count+1 $$F iCMI  
    Wend cZC%W!pT  
    op.Type = "ShiftZ" ]Y111<Ja  
    op.val1 = taq-0.01 xs,,)jF(u  
    op.parent = parID g]&7c:/  
    AddOperation eID, op
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    Print "Set pupil diameter = " & pupilDiam hhWIwR  
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    'Update AZ Eye subassembly Description $0 ]xeD0X  
    eID = FindFullName( "Geometry.Arizona Eye" ) |?A:[C#X  
    GetEntity eID, entity n=Ze p{^  
    entity.Description = "Accommodation = " & A & "D" FxU a5n  
    SetEntity eID, entity X'FDQoH  
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    Update 4N6JKS  
    Print "DONE!" Rax]svc  
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End Sub (;VlK#rnC  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： | KtI:n4d  
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Accommodation = 4 Diopters %9vl  
Pupil Diameter = 4 mm Jlp nR#@  
Set aqueous humor thickness = 2.81 IC"Z.'Ph  
Set anterior lens radius = 10.4 and conic constant = -2.375869 VOJA}$  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ;n,xu0/  
Set lens thickness = 3.927 w1Txz4JqB  
Set lens index of refraction = 1.42672 iq^F?$gFk  
Set pupil diameter = 4 Ef @  
DONE! z@I'Ryalyc