[技术]Arizona眼睛模型 [复制链接]

简介 )IcSdS0@M  
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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。 oH w!~c7  
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模型 !-`L1D_hy  
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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。 /
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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. 0 8)f  
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光源 bRu9*4t  
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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。 w=XIpWl  
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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。 ~T;:Tg*  
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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。 B]tj0FB`-*  
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视网膜的散射 nnn\  
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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。 C"kfxpCi  
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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。 /4(HVua  
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脚本 SLEOcOAmD  
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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： ynw(wSH=  
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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。
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余下的脚本计算与屈光度有关的所有参数。 '1DY5`i{  
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分析 ?ja%*0 R  
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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。 5{(4%  
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脚本代码 itNuY<"  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used.  d;>G  
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Dim entity As T_ENTITY b4wT3  
Dim op As T_OPERATION Psf'^42(v  
Dim mat As T_MODELMATERIAL #C }+  
Dim A As Double 3:Nc`tM_  
Dim pupilDiam As Double Y7+c/co  
Dim eID As Long ftMlm_u  
Dim parID As Long g"" 1\rc=  
Dim count As Integer 8nBYP+t,e  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double %
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Dim tlens As Double, nlens As Double I(7GVYM  
Dim curv As Double, conic As Double <_8bAO8\  
Dim ok As Long o5J6Xi
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Sub Main Q\s+w){f%  
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    '用户输入对话框 ?ch?q~e)  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 oUsfO-dET^  
        TextBox 220,21,40,21,.TextBox1 'default: 0 MR,I`9Pe  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 423%K$710  
        OKButton 40,91,90,21 [2xu`HT02  
        CancelButton 190,91,90,21
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 SrNc  
        TextBox 220,49,40,21,.TextBox2 'default: 4 u~*A-X[  
    End Dialog Y$XzZ>VW  
    Dim dlg As UserDialog 9=$pV==  
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    ok = Dialog (dlg) o|d:rp!^  
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    If ok=0 Then    'cancel button was pressed [)}P{y [&  
        Print "Execution cancelled." m{ani/bt  
        End *=B<S/0  
    End If @su<_m6'  
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    'Assign accommodation and pupil diameter & use defaults if field left empty IT=y+  
    If dlg.TextBox1 = "" Then ShVR{gIs  
        A = 0           'Default accommodation Y?1T XsvF  
    Else esZhX)dS  
        A = CDbl(dlg.TextBox1) JE{cZ<NNH  
    End If b=BNbmX  
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    If dlg.TextBox2 = "" Then 5"40{3  
        pupilDiam = 4   'Default pupil diameter [4C_iaE  
    Else HfH+U&  
        pupilDiam = CDbl(dlg.TextBox2) yuC$S&Y>!  
    End If 6oQ7u90z*  
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    Print " " 7;@YR
 
    Print "Accommodation = " & A & " Diopters" 0sSBwG  
    Print "Pupil Diameter = " & pupilDiam & " mm" -*[)CR-{  
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    ' Calculate new parameters with accommodation QqF*SaO>  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness i@6g9\x+  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens @I
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens xe6V7Wi/Tt  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens K)x6F15r  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens -">Tvi4  
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    tlens = 3.767 + 0.04*A                  'Lens thickness f%_$RdU  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^y ', l  
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    'Adjust parameters to account for accommodation .$d:c61X  
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    '************************************************************************* ?$;&DoE  
    'Aqueous thickness (Position of Lens) %r6_['T  
    '************************************************************************* q2|z \  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) OY|9V  
    GetCustomElement eID, entity o6 NmDv5  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ;7E"@b,tPN  
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    ' Delete any shift(s) in z He4q-\ht  
    count = 0 $B>L_~cS  
    While GetOperationCount(eID)>count .AX%6+o  
        GetOperation eID, count, op d72( g$F  
        If op.Type="ShiftZ" Then \QSD*  
            DeleteOperation eID,count S]T71W<i  
            count=count-1 h$~$a;2cR  
        End If liB~vdqj  
        count=count+1 GRL42xp'*D  
    Wend /L$q8+  
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    'Set new shift in n|=yw6aV'  
    op.Type = "ShiftZ" *WzPxQ_  
    op.val1 = taq ZFX}=?+  
    op.parent = parID j _E(h.  
    AddOperation eID, op >4>. Ycp  
    Print "Set aqueous humor thickness = " & taq-0.55 ?OO
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    '************************************************************************* <;b  
    'Radius and conic constant of anterior lens gi@&Mr)fS  
    '************************************************************************* WV|9d}5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) yYk?K<ou  
    GetConic eID, entity, curv, conic $1Z3yb^  
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    SetConic eID, entity, 1/Rant, CCant bDw\;bnG  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant [sPLu)q2  
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    '************************************************************************* |SJ%Myy  
    'Radius and conic constant of posterior lens Y'6P ~C;v  
    '************************************************************************* ONcS
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 2qj0iRH#N<  
    GetConic eID, entity, curv, conic JKXIxw>q  
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    SetConic eID, entity, 1/Rpost, CCpost HwMe^
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost =o"sBVj  
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    '************************************************************************* #eI`l`}  
    'Lens thickness (Position of posterior lens surface) lQ.3_{"s  
    '************************************************************************* [nsTO5G$u  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) TlQ5'0&I  
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    ' Delete any z-shift(s) 1-4*Y
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    count = 0 7,9zj1<  
    While GetOperationCount(eID)>count \w{fq+G  
        GetOperation eID, count, op b{e|~v6&  
        If op.Type="ShiftZ" Then C\[g>_J  
            DeleteOperation eID,count g
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            count=count-1 )i.\q  
        End If TU8K\;l]  
        count=count+1 N;,N6&veK/  
    Wend xaSiG  
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    'Set new z-shift @)@hzXQ  
    op.Type = "ShiftZ" <_Po/a!c3  
    op.val1 = tlens f
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    op.parent = parID bzMs\rj\  
    AddOperation eID, op b(g?X (&  
    Print "Set lens thickness = " & tlens ;%i.@@:IQ  
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    '************************************************************************* f['pHR%l2$  
    'Lens index of refraction 1Yv#4t  
    '************************************************************************* pK2n'4 C  
    eID = FindMaterial( "Lens" ) ?K?v64[  
    GetModelMaterial eID, mat }"c
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    mat.Nd = nlens POUD*(DqNK  
    SetModelMaterial eID, mat _RzcMX  
    Print "Set lens index of refraction = " & nlens N`rOlEk  
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    '************************************************************************* [W,maTM"  
    'Pupil diameter 9ev"BO  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Mj@ 0F 2hy  
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    'Adjust pupil diameter (trimming volume inner hole) thSo,uGlW  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" AJH-V 6  
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    ' Adjust pupil location to just in front of the lens }h)[>I(  
    parID = FindFullName( "Geometry.Arizona Eye" ) ]hkway  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Aa/lKiiz  
    count = 0 R'r^v  
    While GetOperationCount(eID)>count vN4g#,<  
        GetOperation eID, count, op f9 b=Zm'  
        If op.Type="ShiftZ" Then wKAc ;!  
            DeleteOperation eID,count %sLij*  
            count=count-1 A,qWg0A]nt  
        End If #nh;KlI0  
        count=count+1 @v,qfT*k7  
    Wend G?6[K&w  
    op.Type = "ShiftZ" rx#\Dc}  
    op.val1 = taq-0.01 /\9X0a2h|E  
    op.parent = parID VXAgp6  
    AddOperation eID, op /TgG^|  
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    Print "Set pupil diameter = " & pupilDiam 4RqOg1  
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    'Update AZ Eye subassembly Description x~tG[Y2F?  
    eID = FindFullName( "Geometry.Arizona Eye" ) OC]_b36v  
    GetEntity eID, entity ^25[%aJI  
    entity.Description = "Accommodation = " & A & "D" ~T[m{8uh  
    SetEntity eID, entity [ Q6v#I  
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    Update b|*A%?m  
    Print "DONE!" BI]%$rq  
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End Sub g.N~81A
 
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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： F+S;u=CKx  
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Accommodation = 4 Diopters pFg9-xd%  
Pupil Diameter = 4 mm XoaBX2  
Set aqueous humor thickness = 2.81 xla9:*pPn  
Set anterior lens radius = 10.4 and conic constant = -2.375869 )nS;]7pB@  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 bd2"k;H<o  
Set lens thickness = 3.927 /tf}8d  
Set lens index of refraction = 1.42672 f,Sybf/uHh  
Set pupil diameter = 4 |T9p#) ec2  
DONE! iCIu]6