[技术]Arizona眼睛模型 [复制链接]

简介 PglSQ2P  
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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。 ;J@U){R  
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模型 ;AG&QdTMh  
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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。 vbD""  
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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. D6dliU?k  
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光源 zv7)JH7EV&  
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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。 ~.tl7wKkR/  
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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。 +7Uv|LZ~@  
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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。 !kG|BJ$j  
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视网膜的散射 S"VO@
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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。 !F:mDZeY  
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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。 pw&k0?K#  
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脚本 I94-#*~I  
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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： HOx+umjxW  
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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。 M}j[{wW3  
余下的脚本计算与屈光度有关的所有参数。 Yi]`"\  
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分析 =W;e9 6#  
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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。 c
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脚本代码 fJP *RVz  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. [!>9K}z,=  
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Dim entity As T_ENTITY {n&n^`Em  
Dim op As T_OPERATION A|,qjiEJCc  
Dim mat As T_MODELMATERIAL W"*2,R[}%  
Dim A As Double $hHV Ie]+  
Dim pupilDiam As Double CPL,QVO9  
Dim eID As Long aNs8T`  
Dim parID As Long MD*dq  
Dim count As Integer ZPY&q&R  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ]kXWeY<  
Dim tlens As Double, nlens As Double 1hlU 6=Y  
Dim curv As Double, conic As Double k$ T  
Dim ok As Long _Rb2jq(&0  
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Sub Main *7-rm  
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    '用户输入对话框
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 0{uaSR  
        TextBox 220,21,40,21,.TextBox1 'default: 0 o<iU;15  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 !yVY[  
        OKButton 40,91,90,21 5~/EAK`  
        CancelButton 190,91,90,21 )[cuYH>  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 a??8)=0|}  
        TextBox 220,49,40,21,.TextBox2 'default: 4 P[-do  
    End Dialog _~MX~M3MB  
    Dim dlg As UserDialog v-SXPL]_^  

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    ok = Dialog (dlg) y3o3G  
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    If ok=0 Then    'cancel button was pressed ?]D))_|G  
        Print "Execution cancelled." +}M3O]?4  
        End 9PACXW0  
    End If a;^lOU|L{  
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    'Assign accommodation and pupil diameter & use defaults if field left empty W7b m}JHn  
    If dlg.TextBox1 = "" Then :fwtPvLo  
        A = 0           'Default accommodation |dbKK\ X9  
    Else \o/eF&  
        A = CDbl(dlg.TextBox1) ;Vc|3  
    End If uDXV@;6<  
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    If dlg.TextBox2 = "" Then oQ,<Yx%E3  
        pupilDiam = 4   'Default pupil diameter H8[A*uYL  
    Else 4oH ,_sr  
        pupilDiam = CDbl(dlg.TextBox2) })P!7t  
    End If F[$cE  
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    Print " " c?EvrtND  
    Print "Accommodation = " & A & " Diopters" 9]w?mHslE  
    Print "Pupil Diameter = " & pupilDiam & " mm" #=S^i[K/  
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    ' Calculate new parameters with accommodation hmd3W`8D  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness |idw?qCn  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens |%F,n2  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens A]5];c  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens HnKgD:  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Wh| T3&  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ;m#4Q6k)V?  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction @`C'tfG/4  

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    'Adjust parameters to account for accommodation bTrusSAl  
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    '************************************************************************* j|wN7@Zc  
    'Aqueous thickness (Position of Lens) $.,B2}'  
    '************************************************************************* @-Ql6k  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) (@5`beEd  
    GetCustomElement eID, entity SU4i'o  
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    parID = FindFullName( "Geometry.Arizona Eye" ) S<Gm*$[7  

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    ' Delete any shift(s) in z
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    count = 0 ERIMz,  
    While GetOperationCount(eID)>count !|xB>d q?  
        GetOperation eID, count, op [UZr|F  
        If op.Type="ShiftZ" Then 0jlM~H  
            DeleteOperation eID,count X1`3KqK<9  
            count=count-1 o>,r<
  
        End If qc @cdi  
        count=count+1 ?@$xLUHR4  
    Wend =X7kADRq  
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    'Set new shift in <n]PD;.4  
    op.Type = "ShiftZ" b;UDgq8v  
    op.val1 = taq zU~ Ff"<  
    op.parent = parID 7GsKD=bl]  
    AddOperation eID, op }#H,oy;Dz  
    Print "Set aqueous humor thickness = " & taq-0.55 px K&aY8  
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    '************************************************************************* zT78FliY6  
    'Radius and conic constant of anterior lens 77O$^fG2  
    '************************************************************************* =b:XL#VA  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) )8W! |  
    GetConic eID, entity, curv, conic 8(\}\4
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    SetConic eID, entity, 1/Rant, CCant 1l#46?]~  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant bp:`m>4<  
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    '************************************************************************* ylZQwICk  
    'Radius and conic constant of posterior lens %T]^,y$n  
    '************************************************************************* N:| :L:<1  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ]5f;Kz)  
    GetConic eID, entity, curv, conic 37zBX~  
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    SetConic eID, entity, 1/Rpost, CCpost r9_ ON|  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ]E<Z5G1HD  
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    '************************************************************************* W"vLCHTh  
    'Lens thickness (Position of posterior lens surface) G9Uc }z  
    '************************************************************************* *{w0=J[15  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) +112{v=!i  
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    ' Delete any z-shift(s) Mc@9ivwL#  
    count = 0 ZDFq=)0C  
    While GetOperationCount(eID)>count |?^<=%  
        GetOperation eID, count, op JKM(fX+  
        If op.Type="ShiftZ" Then gA(npsUHI  
            DeleteOperation eID,count R|\eBnfI  
            count=count-1 "i;.>  
        End If bN. G%1  
        count=count+1 ^~[7])}g6  
    Wend 5Z!$?J4Rl  
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    'Set new z-shift Qt+D ,X  
    op.Type = "ShiftZ" )sm9%|.&  
    op.val1 = tlens _Rii19k  
    op.parent = parID LBy`N_@  
    AddOperation eID, op Zt3sU_  
    Print "Set lens thickness = " & tlens M#'7hm6  

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    '************************************************************************* ['}|#
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    'Lens index of refraction <J;O$S  
    '************************************************************************* |:R\j0t  
    eID = FindMaterial( "Lens" ) :.+w'SEn4M  
    GetModelMaterial eID, mat TRi#  
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    mat.Nd = nlens tw$EwNI[  
    SetModelMaterial eID, mat 9xK>fM&u  
    Print "Set lens index of refraction = " & nlens 5?>4I"ne  
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    '************************************************************************* 0(y*EJA$  
    'Pupil diameter r*`e%`HU   
    '************************************************************************* qIZ+%ZOu  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ,zoHmV1Wd+  
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    'Adjust pupil diameter (trimming volume inner hole) $vXY"-k  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"  ImhkU%  
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    ' Adjust pupil location to just in front of the lens }h;Z_XF&  
    parID = FindFullName( "Geometry.Arizona Eye" ) s=jmvvs_V}  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) W]D YfR,  
    count = 0 :g|.x
  
    While GetOperationCount(eID)>count 6-wpR  
        GetOperation eID, count, op 8`*5[ L~~/  
        If op.Type="ShiftZ" Then 1-p#}VX  
            DeleteOperation eID,count #a}w&O";  
            count=count-1 -KGJr  
        End If $=plAi  
        count=count+1 *,X)tZ6VX  
    Wend E^rBs2;9
  
    op.Type = "ShiftZ" _E?tVx.6  
    op.val1 = taq-0.01 R9A:"sJ  
    op.parent = parID @JlT*:Dz  
    AddOperation eID, op ELwXp|L  
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    Print "Set pupil diameter = " & pupilDiam Vl1.]'p_  
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    'Update AZ Eye subassembly Description Zl3l=x h  
    eID = FindFullName( "Geometry.Arizona Eye" ) L8D=F7  
    GetEntity eID, entity VDnrm*  
    entity.Description = "Accommodation = " & A & "D" J0IKI,X.  
    SetEntity eID, entity DL,R~  
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    Update N#M>2b<A/T  
    Print "DONE!" : _Y^o  
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End Sub qY-aR;  
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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： zKP[]S-  
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Accommodation = 4 Diopters 9mvy+XD  
Pupil Diameter = 4 mm s>G6/TTH6  
Set aqueous humor thickness = 2.81 ;0WAfu}#H  
Set anterior lens radius = 10.4 and conic constant = -2.375869 "-S!^h/v  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 "#wAGlH6>  
Set lens thickness = 3.927 Ut~YvWc9  
Set lens index of refraction = 1.42672 GThGV"  
Set pupil diameter = 4 Q3ZGN1aX<  
DONE! `P\H{