[技术]Arizona眼睛模型 [复制链接]

简介 TPJuS)TU9  
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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。 f`}u9!jVR  
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模型 |r*y63\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。 1\jj3Y'i'  
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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. tjZS:@3 Z  
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光源 r*7J#M /  
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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。 2V @ pt  
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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。 * se),CP!s  
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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。 *@ \LS!N  
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视网膜的散射 o>M&C X+j$  
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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。 ZYl*-i&~?  
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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。 S?H qrf7<  
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脚本 ]T<RC\o  
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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： uQkFFWS  
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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。 v3/G.B@=  
余下的脚本计算与屈光度有关的所有参数。 
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分析 _`]YWvh  
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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。 b;e*`f8T3c  
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脚本代码 Y&b JKX  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. !vSj1w  
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Dim entity As T_ENTITY #F >R5 D  
Dim op As T_OPERATION I_h&35^t  
Dim mat As T_MODELMATERIAL :'gX//b):  
Dim A As Double ~LN {5zg  
Dim pupilDiam As Double .{#J2}+[_}  
Dim eID As Long TqXB2`
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Dim parID As Long Oc?]L&ap  
Dim count As Integer +,ZQ( ZW  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double QK/~lN  
Dim tlens As Double, nlens As Double ^{fA:N=  
Dim curv As Double, conic As Double uyWt{>$  
Dim ok As Long ||kUi=5  
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Sub Main ~Wj. 4b*  
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    '用户输入对话框 _QOZ`st  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ZC:7N{a  
        TextBox 220,21,40,21,.TextBox1 'default: 0 +(| ,Ke  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 f+W%X  
        OKButton 40,91,90,21 <@2g.+9  
        CancelButton 190,91,90,21 ^NiS7)FX  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 wtnC^d$  
        TextBox 220,49,40,21,.TextBox2 'default: 4 /jv4#9  
    End Dialog 'e06QMp@  
    Dim dlg As UserDialog ).1F0T  
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    ok = Dialog (dlg) pbePxOG  
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    If ok=0 Then    'cancel button was pressed S U$U  
        Print "Execution cancelled." %oE3q>S$en  
        End -mK;f$X  
    End If CQm(N  
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    'Assign accommodation and pupil diameter & use defaults if field left empty K.K=\ Y2  
    If dlg.TextBox1 = "" Then aqzIMOAf  
        A = 0           'Default accommodation u3ns-e  
    Else e2l!L*[g  
        A = CDbl(dlg.TextBox1) E;AOCbV*$  
    End If yJAz#~PO/  
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    If dlg.TextBox2 = "" Then jou741  
        pupilDiam = 4   'Default pupil diameter v46 5Z  
    Else 
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        pupilDiam = CDbl(dlg.TextBox2) 7[?{wbq  
    End If E1-BB  
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    Print " " %d#h<e|,.  
    Print "Accommodation = " & A & " Diopters" 05gdVa,  
    Print "Pupil Diameter = " & pupilDiam & " mm" (W4H
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    ' Calculate new parameters with accommodation Doj>Irj?7  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness (TJ )Y7E  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens rsgTd\b  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens =9AX\2w*H;  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens "MNI_C#{  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens nkn4VA?"  
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    tlens = 3.767 + 0.04*A                  'Lens thickness (6#, $Ze   
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 5b5Hc Inu
 
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    'Adjust parameters to account for accommodation lqoJ2JMy  
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    '************************************************************************* \hr2#!  
    'Aqueous thickness (Position of Lens) E+!A0!1  
    '************************************************************************* 70BLd(?  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) n3Q Rn^  
    GetCustomElement eID, entity o1zKns?  
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    parID = FindFullName( "Geometry.Arizona Eye" ) nkAS]sC  
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    ' Delete any shift(s) in z (AI 4a+  
    count = 0 ev"f@y9Do  
    While GetOperationCount(eID)>count rCp'O\@S  
        GetOperation eID, count, op cA8A^Iv:0  
        If op.Type="ShiftZ" Then 0c6Ea>S[  
            DeleteOperation eID,count yT<,0~F9  
            count=count-1 y8arFG  
        End If g/f^|:  
        count=count+1 !xxdC  
    Wend n/Fx2QC{  
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    'Set new shift in O; #qG/b1  
    op.Type = "ShiftZ" WAqH*LB  
    op.val1 = taq V|W[>/  
    op.parent = parID  :qe.*\ c  
    AddOperation eID, op 3F ]30  
    Print "Set aqueous humor thickness = " & taq-0.55 BDiN*.w5  
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    '************************************************************************* NA;OT7X[  
    'Radius and conic constant of anterior lens u]uZc~T  
    '************************************************************************* +Cg[!6[#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) V+Y;  
    GetConic eID, entity, curv, conic J[7Sf^r  
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    SetConic eID, entity, 1/Rant, CCant .TpM3b#r  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant o<8SiVC2  
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    '************************************************************************* H05xt
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    'Radius and conic constant of posterior lens VteMsL/H  
    '************************************************************************* ~lH_d[  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) mP[ZlS~"  
    GetConic eID, entity, curv, conic GMW,+  
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    SetConic eID, entity, 1/Rpost, CCpost *aaK_=w  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost `m+o^!SGe  
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    '************************************************************************* l:- <CbG  
    'Lens thickness (Position of posterior lens surface) ZXH{9hxd  
    '************************************************************************* *pj
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) s)9d\{  
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    ' Delete any z-shift(s) X-k$6}D  
    count = 0 'gv~M_  
    While GetOperationCount(eID)>count gEISnMH  
        GetOperation eID, count, op +Jw+rjnP  
        If op.Type="ShiftZ" Then ![Ll$Lr  
            DeleteOperation eID,count 'Hv=\p4$1  
            count=count-1 AXT(D@sI=  
        End If fb|%)A=  
        count=count+1 GMOnp$@H^s  
    Wend ,0\Pr  
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    'Set new z-shift + C'<*  
    op.Type = "ShiftZ" *Eg[@5;QA  
    op.val1 = tlens Q|7l!YTzVu  
    op.parent = parID ]o2jSD  
    AddOperation eID, op JrNqS[c/  
    Print "Set lens thickness = " & tlens |{ TVW  
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    '************************************************************************* P={8qln,X  
    'Lens index of refraction =QS%D*.|D  
    '************************************************************************* f=paa/k0  
    eID = FindMaterial( "Lens" ) O 4C}]E  
    GetModelMaterial eID, mat mTgsvC  
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    mat.Nd = nlens +[Bl@RHe^  
    SetModelMaterial eID, mat ~sMEfY,p  
    Print "Set lens index of refraction = " & nlens R4g;-Ci->  
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    '************************************************************************* y#v<V1b]  
    'Pupil diameter :R1F\FT*  
    '************************************************************************* yt[*4gF4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) <*[D30<  
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    'Adjust pupil diameter (trimming volume inner hole) 0x,NMS  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" [ XBVES8  
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    ' Adjust pupil location to just in front of the lens \'.|7{Xu  
    parID = FindFullName( "Geometry.Arizona Eye" ) GZzBATx  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]=vRjw  
    count = 0 wu~?P`  
    While GetOperationCount(eID)>count 3A!Qu$r9  
        GetOperation eID, count, op jg\FD51$  
        If op.Type="ShiftZ" Then /pQUu(~h_  
            DeleteOperation eID,count ;5&=I|xqe  
            count=count-1 "@(Sw>*o  
        End If b*TQKYT  
        count=count+1 ('1]f?:M  
    Wend Ci$?Hm9n  
    op.Type = "ShiftZ" jX&/ e'B  
    op.val1 = taq-0.01 bx:j`5Uj`  
    op.parent = parID ,w%hD*  
    AddOperation eID, op su0q 2.  
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    Print "Set pupil diameter = " & pupilDiam v{;^>"5o  
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    'Update AZ Eye subassembly Description &\e8c g  
    eID = FindFullName( "Geometry.Arizona Eye" ) se*!OiOt  
    GetEntity eID, entity EI8KKo *  
    entity.Description = "Accommodation = " & A & "D" l5FKw;=K}:  
    SetEntity eID, entity % 8P8h%%Z  
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    Update SYA0Hiw7P  
    Print "DONE!" R 6 -RH7.  
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End Sub B3Daw/G  
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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： |-`-zo4z  
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Accommodation = 4 Diopters )St`}qu;  
Pupil Diameter = 4 mm k{J\)z  
Set aqueous humor thickness = 2.81 iC4rzgq  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Bmv5yc+;  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 'J8Ga<s7C  
Set lens thickness = 3.927 'Esz#@R  
Set lens index of refraction = 1.42672 ( 9(NP_s  
Set pupil diameter = 4 "{x+ \Z\  
DONE! {sF;R.P&r