[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 P".rm0@R  
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。 ?/Z5%?6  
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模型 Br"K{g?  
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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。 _(:bGI'.m  
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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. qjLFgsd  
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光源 l~GcD  
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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。 ')j@OO3  
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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。 rs:a^W5t  
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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。 v,,Dz8!Ty  
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视网膜的散射 Vw b6QIs  
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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。 hdx"/.s  
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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\]_?r  
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脚本 :LBRyBV  
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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： `'M}.q,k~  
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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。 jsnk*>j  
余下的脚本计算与屈光度有关的所有参数。 W\JwEb9Y  
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分析 8iwqy0<  
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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。 tu0agSpU  
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脚本代码 qx<h rC0Z&  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used.
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Dim entity As T_ENTITY \1b!I)T9  
Dim op As T_OPERATION tgB\;nbB  
Dim mat As T_MODELMATERIAL ;33LuD<h.  
Dim A As Double \w\{x0u  
Dim pupilDiam As Double o&b1-=MC2  
Dim eID As Long x7l3&;yDv  
Dim parID As Long 1Ydym2  
Dim count As Integer Y1Qg|U o  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double h#!u"'JW  
Dim tlens As Double, nlens As Double O+Qt8,  
Dim curv As Double, conic As Double LU4k/  
Dim ok As Long Auz.wes  
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Sub Main KZ;Q71  
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    '用户输入对话框 7BDRA},o  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 jLu`DKB  
        TextBox 220,21,40,21,.TextBox1 'default: 0 4
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ME%W,B.|"s  
        OKButton 40,91,90,21 `$odxo+  
        CancelButton 190,91,90,21 uNSbAw3  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ,3tcti~sZ  
        TextBox 220,49,40,21,.TextBox2 'default: 4 DHlCus=ic  
    End Dialog 9dFSppM  
    Dim dlg As UserDialog qFD#D_O6  
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    ok = Dialog (dlg) *.]M1  
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    If ok=0 Then    'cancel button was pressed 1JI\e6]I  
        Print "Execution cancelled." g:
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        End tuF hPqe {  
    End If -0/5!  
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    'Assign accommodation and pupil diameter & use defaults if field left empty v9qgfdBS5  
    If dlg.TextBox1 = "" Then r-
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        A = 0           'Default accommodation TsB"<6@!AA  
    Else |_^A$Hv  
        A = CDbl(dlg.TextBox1) 6eNo}Tos9  
    End If ,@1.&!F4it  
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    If dlg.TextBox2 = "" Then 0*F{=X~L  
        pupilDiam = 4   'Default pupil diameter SCZ6:P"$qX  
    Else t<|S7EqIL  
        pupilDiam = CDbl(dlg.TextBox2) 23AMrDF=N  
    End If [o0Z;}fU  
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    Print " " ,r-l^I3<  
    Print "Accommodation = " & A & " Diopters" } :@s  
    Print "Pupil Diameter = " & pupilDiam & " mm" 5B lptC  
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    ' Calculate new parameters with accommodation ^/<0r]=  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness c3>#.NP_  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens `T gwa  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ^" EsBt  

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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens mrzrQ@sN  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens .9< i  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 8d90B9  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction wap@q6fz<  
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    'Adjust parameters to account for accommodation B|~tW21  
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    '************************************************************************* }CiB+  
    'Aqueous thickness (Position of Lens) /WlpRf%  
    '************************************************************************* UUf-G0/P  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) V?a+u7*U&  
    GetCustomElement eID, entity l.#iMi(@p~  
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    parID = FindFullName( "Geometry.Arizona Eye" ) xMAfa>]{n  
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    ' Delete any shift(s) in z hpxqL%r  
    count = 0 f#s /Ycp+  
    While GetOperationCount(eID)>count $rAHtr  
        GetOperation eID, count, op #sn2Vmi  
        If op.Type="ShiftZ" Then x2|YrkGv  
            DeleteOperation eID,count '8Q:}{  
            count=count-1 f xWW"B*A  
        End If 1mLd_]F'F  
        count=count+1 Kd?TIeFE  
    Wend dU7+rc2,CU  
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    'Set new shift in ;^q@w  
    op.Type = "ShiftZ" fgs){Ng`  
    op.val1 = taq TV~<1vj  
    op.parent = parID 1e8J-Nkj  
    AddOperation eID, op g:l5,j.K  
    Print "Set aqueous humor thickness = " & taq-0.55 /B$9B  
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    '************************************************************************* #}/YnVk  
    'Radius and conic constant of anterior lens Xndgs}zz  
    '************************************************************************* p[Pa(a,B7  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ionFP
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    GetConic eID, entity, curv, conic wj-=#gyAoo  
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    SetConic eID, entity, 1/Rant, CCant He#5d!cf:M  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 7QXA*.' F  
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    '************************************************************************* Y:GSjq  
    'Radius and conic constant of posterior lens )ZU)$dJ>V  
    '************************************************************************* "|{3V:e>a  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ~FnB!Mh}?  
    GetConic eID, entity, curv, conic {s=n "*Qp)  
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    SetConic eID, entity, 1/Rpost, CCpost 5Ocd2T'  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 4NY00d/R  
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    '************************************************************************* mN5`Fct*A>  
    'Lens thickness (Position of posterior lens surface) Who7{|M\'  
    '************************************************************************* OQ[E-%v1 R  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) .~)[>  
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    ' Delete any z-shift(s) v35wlt^}  
    count = 0 0FA N9u2  
    While GetOperationCount(eID)>count ']nB_x7  
        GetOperation eID, count, op G#V}9l
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        If op.Type="ShiftZ" Then
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            DeleteOperation eID,count ]_cBd)3P}  
            count=count-1 'ZyHp=RN)  
        End If JfJUOaL  
        count=count+1 4)
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    Wend 0((3q'[ <  
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    'Set new z-shift 1!u}~E_  
    op.Type = "ShiftZ" r"yA=d'c  
    op.val1 = tlens )_*<uSl  
    op.parent = parID k=t\  
    AddOperation eID, op ' 0iXx   
    Print "Set lens thickness = " & tlens #St=%!  
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    '************************************************************************* $=>(7 =l_  
    'Lens index of refraction Y{].%xM5  
    '************************************************************************* ]=2wQ8  
    eID = FindMaterial( "Lens" ) E,6(/`0H*  
    GetModelMaterial eID, mat UQGOCP_  
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    mat.Nd = nlens 19 h7 M  
    SetModelMaterial eID, mat X#l]%
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    Print "Set lens index of refraction = " & nlens 8no_xFA  
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    '************************************************************************* t;P%&:"@M  
    'Pupil diameter m'Jk!eo  
    '************************************************************************* Yjv[rH5v  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) }-3| v<d  
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    'Adjust pupil diameter (trimming volume inner hole) 
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Da#|}m0>  
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    ' Adjust pupil location to just in front of the lens *9"
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    parID = FindFullName( "Geometry.Arizona Eye" ) 7aH E:Dnwp  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) eySV -f{  
    count = 0 0qXkWGB  
    While GetOperationCount(eID)>count L8<Yk`jx  
        GetOperation eID, count, op TNs0^h)  
        If op.Type="ShiftZ" Then az7<@vSXi  
            DeleteOperation eID,count EjsAV F [@  
            count=count-1 b6Jv|1w'  
        End If pWo`iM& F  
        count=count+1 
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    Wend ]=A=VH&  
    op.Type = "ShiftZ" JTcK\t8  
    op.val1 = taq-0.01 >G`=8Ku  
    op.parent = parID 6d~[My  
    AddOperation eID, op S>~QuCMY  
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    Print "Set pupil diameter = " & pupilDiam 8Z;wF  
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    'Update AZ Eye subassembly Description %G9:M;|'  
    eID = FindFullName( "Geometry.Arizona Eye" ) q2VQS1R`8  
    GetEntity eID, entity ien >Ou  
    entity.Description = "Accommodation = " & A & "D" n7~!klF-  
    SetEntity eID, entity <UJgl{-  
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    Update
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    Print "DONE!" sY?pp '}a  
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End Sub WeG
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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： C3fSSa%b  
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Accommodation = 4 Diopters 9wLV\>i  
Pupil Diameter = 4 mm bK `'zi  
Set aqueous humor thickness = 2.81 HjTK/x'_'L  
Set anterior lens radius = 10.4 and conic constant = -2.375869 9F~U% >GX  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ~ei\~;n\@  
Set lens thickness = 3.927 t?^C9(;6  
Set lens index of refraction = 1.42672 >j1\]uo  
Set pupil diameter = 4 }?B=R#5  
DONE! kzCD>m  
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