[技术]Arizona眼睛模型 [复制链接]

简介 W]5USFan  
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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。 GO^_=EMR[  
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模型 =hMY2D  
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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。 [!U?}1YQ  
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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. rhb@FE)Mc  
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光源 ,.qMEMm  
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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。 $n^gmhp  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 1rDqa(7  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 6%VV,$p  
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视网膜的散射 U8G%YGMG.4  
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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。 6l4mS~/  
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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。 ._+J_ts  
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脚本 ($~RoQ=0S  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 +r<0zh,n.  
余下的脚本计算与屈光度有关的所有参数。 V}zEK0n(6  
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分析 I'@Ydt2  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 e~"f
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脚本代码 A2nqf^b{#  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. UAyC.$!  
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Dim entity As T_ENTITY &RTX6%'KY  
Dim op As T_OPERATION =k oSUVO0  
Dim mat As T_MODELMATERIAL DK oN}c  
Dim A As Double SC- $B  
Dim pupilDiam As Double eBJUv]o %  
Dim eID As Long 5P'p2x#U  
Dim parID As Long cDI [PJ9  
Dim count As Integer ru7RcYRq  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double _Dwqy(  
Dim tlens As Double, nlens As Double @GvztVYo  
Dim curv As Double, conic As Double >X51$wBL  
Dim ok As Long WsDM{1c  
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Sub Main =?-ye!w  
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    '用户输入对话框 XduV+$03  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 [S@}T zE  
        TextBox 220,21,40,21,.TextBox1 'default: 0 }E7:ihy  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 a:_I
  
        OKButton 40,91,90,21 8Y#\xzod
 
        CancelButton 190,91,90,21 G!XIc>F*  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 "C*B
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        TextBox 220,49,40,21,.TextBox2 'default: 4 {$1J=JbE  
    End Dialog _kY#D;`:r  
    Dim dlg As UserDialog ,<Q~b%(
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    ok = Dialog (dlg) 3<=G?of  
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    If ok=0 Then    'cancel button was pressed &V)6!,rb  
        Print "Execution cancelled." 0n/gd"M  
        End 9Mgq1Z  
    End If NxLXm,  
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    'Assign accommodation and pupil diameter & use defaults if field left empty {vE
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    If dlg.TextBox1 = "" Then fkSwD(  
        A = 0           'Default accommodation vhb)2n  
    Else Gxax2o  
        A = CDbl(dlg.TextBox1) qSejLh6  
    End If dCFlM&(i  
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    If dlg.TextBox2 = "" Then c c  
        pupilDiam = 4   'Default pupil diameter NOS>8sy  
    Else w%zRHf8C  
        pupilDiam = CDbl(dlg.TextBox2) aSP4a+\*  
    End If |G/7_+J6  
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    Print " " 9TAj) {U%'  
    Print "Accommodation = " & A & " Diopters" {W\T"7H  
    Print "Pupil Diameter = " & pupilDiam & " mm" z7-k`(l4  
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    ' Calculate new parameters with accommodation T{}fHfM  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness WX4;l(PL=  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens %AW4.3()8  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens AE@NOM7u  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 4c+$%pq5  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens /Ky__l
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    tlens = 3.767 + 0.04*A                  'Lens thickness /xJqJ_70X  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ,Os? f:Y6  
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    'Adjust parameters to account for accommodation HWm#t./  
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    '************************************************************************* b|5w]<?'  
    'Aqueous thickness (Position of Lens) U,Mx@KdV  
    '************************************************************************* rbZ[!LA  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) aV1lJ;0  
    GetCustomElement eID, entity p#K
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    parID = FindFullName( "Geometry.Arizona Eye" ) 90xk$3(
 
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    ' Delete any shift(s) in z Z
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    count = 0 q:8_]Qt  
    While GetOperationCount(eID)>count \b*X:3g*  
        GetOperation eID, count, op m%#`y\]I  
        If op.Type="ShiftZ" Then ir3VTqz  
            DeleteOperation eID,count >`jU`bR@  
            count=count-1 0qFH s  
        End If 6> {r6ixs1  
        count=count+1 t_ur&.^SB  
    Wend 4Tct  
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    'Set new shift in =iHiPvP0  
    op.Type = "ShiftZ" W@\ (nfD2  
    op.val1 = taq Jg$xO@.  
    op.parent = parID q|)Q9+6$+  
    AddOperation eID, op n+1y  
    Print "Set aqueous humor thickness = " & taq-0.55 X%9*O[6{  
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    '************************************************************************* 3_5XHOdE  
    'Radius and conic constant of anterior lens  StYzGJ  
    '************************************************************************* fMf&?`V  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) P6U%=xaC  
    GetConic eID, entity, curv, conic [XlB<P=|>  
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    SetConic eID, entity, 1/Rant, CCant <EO<x D=:  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant k6\^p;!Y  
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    '************************************************************************* =sOo:s
 
    'Radius and conic constant of posterior lens @o
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    '************************************************************************* f*xpE`&  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) (!?K7<Jv  
    GetConic eID, entity, curv, conic >P. 'CU  
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    SetConic eID, entity, 1/Rpost, CCpost 5c-N0@\  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost sNU}n<J-  
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    '************************************************************************* >adV(V<  
    'Lens thickness (Position of posterior lens surface) eR!G[Cw-  
    '************************************************************************* XT@Mzo49z\  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 'i>xf ^  
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    ' Delete any z-shift(s) +iF 1sC_  
    count = 0 D>wZ0p b-  
    While GetOperationCount(eID)>count ^O%9yEo
  
        GetOperation eID, count, op q9}m!*8e  
        If op.Type="ShiftZ" Then v@u<Ww;=@  
            DeleteOperation eID,count 3 EYiQ`  
            count=count-1 S-Ai3)t6  
        End If ^i_Iqph=  
        count=count+1 qs=tJ^<<o  
    Wend So4nJ><p  
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    'Set new z-shift E(L<L1:"  
    op.Type = "ShiftZ" '
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    op.val1 = tlens S]2 {ZDP  
    op.parent = parID ,-rB=|w  
    AddOperation eID, op =3ADT$YHd  
    Print "Set lens thickness = " & tlens b1!@v+  
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    '************************************************************************* #s+X+fe  
    'Lens index of refraction E`@43Nz  
    '************************************************************************* V,LVB_6  
    eID = FindMaterial( "Lens" ) F!8=FTb  
    GetModelMaterial eID, mat :):zNn_>`  
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    mat.Nd = nlens fA8ozL T  
    SetModelMaterial eID, mat dbO#  
    Print "Set lens index of refraction = " & nlens Jyu`-=It  
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    '************************************************************************* ,d 7
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    'Pupil diameter 3ps,uozj  
    '************************************************************************* V-vlTgemwc  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) G :4;y7  
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    'Adjust pupil diameter (trimming volume inner hole) SFO&=P:U  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" vR]mSX3)?  
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    ' Adjust pupil location to just in front of the lens fS./y=j(X  
    parID = FindFullName( "Geometry.Arizona Eye" ) #%cR%Z  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 5G?.T?  
    count = 0 6q%ed UED  
    While GetOperationCount(eID)>count Fp:3#Bh  
        GetOperation eID, count, op #?m{YT{P  
        If op.Type="ShiftZ" Then 0>Fqx{!heq  
            DeleteOperation eID,count sx-F8:Qa  
            count=count-1 2z-$zB<vyw  
        End If QGPR.<D)B  
        count=count+1 },6*Y*?{  
    Wend 37KU~9-A  
    op.Type = "ShiftZ" v*L '{3f  
    op.val1 = taq-0.01 pF='jj51  
    op.parent = parID _$(GRNRYK  
    AddOperation eID, op =>YvA>izE  
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    Print "Set pupil diameter = " & pupilDiam X,Zd=
 
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    'Update AZ Eye subassembly Description (C~dkR?  
    eID = FindFullName( "Geometry.Arizona Eye" ) <|V'pim  
    GetEntity eID, entity "%kGRHq  
    entity.Description = "Accommodation = " & A & "D" s]bPV,"p  
    SetEntity eID, entity y
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    Update %Qd3BZ  
    Print "DONE!" Bbs5f@E  
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End Sub cUC17z2D  
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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： X X&K=<,Ja  
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Accommodation = 4 Diopters Y^5"qd|`  
Pupil Diameter = 4 mm }s6G!v^2""  
Set aqueous humor thickness = 2.81 H%~Q?4  
Set anterior lens radius = 10.4 and conic constant = -2.375869 &oc_a1R  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Mz}i[|U\  
Set lens thickness = 3.927 1t%<5O;R  
Set lens index of refraction = 1.42672 gA"<MI'y  
Set pupil diameter = 4 \6LcVik  
DONE! CLktNR(45