[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 +?zyFb]Km  
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。 oJVpNE[3]  
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模型 RX4O1Z0  
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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。 "tBdz V  
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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. G5egyP;  
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光源 us
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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。 3}= .7qm  
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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。 ]|<PV5SY3.  
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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。 1*S It5?4  
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视网膜的散射 p<?~~7V  
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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。 L7_(K
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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。 MB"uJUk  
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脚本 9"52b9U  
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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： NoO>CjeFb  
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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。 Y;6<AIx>  
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分析 jWLZ!a3+  
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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。 (9*s:)zD-  
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脚本代码 q~p,A>K  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. !H{)L@f  
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Dim entity As T_ENTITY >9a%"<(2#  
Dim op As T_OPERATION N#@xo)-H  
Dim mat As T_MODELMATERIAL MG>g?s
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Dim A As Double leiED'  
Dim pupilDiam As Double </t_<I0{  
Dim eID As Long E$.|h;i]Q  
Dim parID As Long FH)bE#4  
Dim count As Integer kuu9'Sqc'b  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 3:<+9X  
Dim tlens As Double, nlens As Double kMKI=>s+  
Dim curv As Double, conic As Double )wP0U{7?v  
Dim ok As Long Odxq]HlbO  
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Sub Main :{h,0w'd  
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    '用户输入对话框 9<kKno  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 k^Tu9}[W1  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ?)<zrE5p  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 5IW^^<kiu  
        OKButton 40,91,90,21 _t6siB_u  
        CancelButton 190,91,90,21 ,a?)#X  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 |.=Ee+HZ  
        TextBox 220,49,40,21,.TextBox2 'default: 4 -?e~dLu  
    End Dialog >4ebvM 0|  
    Dim dlg As UserDialog *0{MAm  
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    ok = Dialog (dlg) >ly= O  
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    If ok=0 Then    'cancel button was pressed Q}^ n  
        Print "Execution cancelled." [4 g5{eX  
        End aBr%"&Z.MG  
    End If JnhHV(H  
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    'Assign accommodation and pupil diameter & use defaults if field left empty {5.,gb@6  
    If dlg.TextBox1 = "" Then j_&/^-;e  
        A = 0           'Default accommodation cmt3ceCb  
    Else 9V?MJZ@aG  
        A = CDbl(dlg.TextBox1) c1wgb8  
    End If L}nj#z4g  
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    If dlg.TextBox2 = "" Then 4I"QT(;  
        pupilDiam = 4   'Default pupil diameter cy)L%`(7  
    Else & ?/h5<  
        pupilDiam = CDbl(dlg.TextBox2) gwThhwR  
    End If 6TfL|W<  
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    Print " " u~LisZ&tP  
    Print "Accommodation = " & A & " Diopters" EM vV  
    Print "Pupil Diameter = " & pupilDiam & " mm" A&$!s)8z  
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    ' Calculate new parameters with accommodation 8Qu7x[tK?  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness $7TY
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens _ H$Cm  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ~#I1!y~`  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens @WhcY*R2  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 7Yk6C5C  
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    tlens = 3.767 + 0.04*A                  'Lens thickness RK'3b/T  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction +/\.%S/  
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    'Adjust parameters to account for accommodation IZJV6c
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    '************************************************************************* kt[#@M!}  
    'Aqueous thickness (Position of Lens) F!pUfF,&  
    '************************************************************************* &^9f)xb  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) l3-KswU  
    GetCustomElement eID, entity 3WPMS/  
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    parID = FindFullName( "Geometry.Arizona Eye" ) X?>S24I"9  
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    ' Delete any shift(s) in z }y=7r!{@  
    count = 0 rRT9)wDa  
    While GetOperationCount(eID)>count S31:}   
        GetOperation eID, count, op bn<&Xe  
        If op.Type="ShiftZ" Then )KXLL;]  
            DeleteOperation eID,count k B2+Tr  
            count=count-1 B'
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        End If OMKEn!Wq  
        count=count+1 UY}lJHp0  
    Wend hJFQ/(  
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    'Set new shift in qf)
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    op.Type = "ShiftZ" g^B6NF  
    op.val1 = taq 71K6] ~<  
    op.parent = parID $|(roC(  
    AddOperation eID, op .]r[0U  
    Print "Set aqueous humor thickness = " & taq-0.55 aMv  
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    '************************************************************************* Yo7ctwzdH;  
    'Radius and conic constant of anterior lens f$2lq4P{  
    '************************************************************************* ),
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) zc/S  
    GetConic eID, entity, curv, conic ^4s#nf:}  
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    SetConic eID, entity, 1/Rant, CCant 50_%Tl[  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant q#OLb"bTr  
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    '************************************************************************* !o*oT}6n  
    'Radius and conic constant of posterior lens X+&@$v1  
    '************************************************************************* ld9zOq  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ShCAkaj_  
    GetConic eID, entity, curv, conic 5fVdtJk7  
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    SetConic eID, entity, 1/Rpost, CCpost r\Man'h$  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost m{b(^K9}  
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    '************************************************************************* z2"2Xqy<U  
    'Lens thickness (Position of posterior lens surface) @Ki`g(],P  
    '************************************************************************* u;=("S{"0  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) bE0S)b)  
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    ' Delete any z-shift(s) W9eR3q  
    count = 0 T( ;BEyc?  
    While GetOperationCount(eID)>count 4{fi=BA   
        GetOperation eID, count, op &=02.E@  
        If op.Type="ShiftZ" Then H2k>E}`  
            DeleteOperation eID,count Bb-x1{t  
            count=count-1 P6IhpB59  
        End If v[Ar{t&  
        count=count+1 N4HnW0  
    Wend {{2ZWK 6|  
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    'Set new z-shift V]vk9M2q[l  
    op.Type = "ShiftZ" 3!Bekn]  
    op.val1 = tlens hKX-]+6"  
    op.parent = parID /jS  
    AddOperation eID, op c&'T By  
    Print "Set lens thickness = " & tlens .5ingB3%  
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    '************************************************************************* 9KAXc(-  
    'Lens index of refraction bZtjg  
    '************************************************************************* 0Q>Yoa 11  
    eID = FindMaterial( "Lens" ) 0|4XV{\qT$  
    GetModelMaterial eID, mat I}?fy\1A&  
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    mat.Nd = nlens cT.1oaAM0  
    SetModelMaterial eID, mat -.z~u/uL  
    Print "Set lens index of refraction = " & nlens nnr(\r~  
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    '************************************************************************* 1lMU('r%  
    'Pupil diameter IClnh1=  
    '************************************************************************* D$ `yxc  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) a&y%|Gs^f  
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    'Adjust pupil diameter (trimming volume inner hole) hg\$>W~2  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" N %0F[sY6  
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    ' Adjust pupil location to just in front of the lens x:?1fvVR  
    parID = FindFullName( "Geometry.Arizona Eye" ) ,T1t`  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) O<o_MZN  
    count = 0 wcV~z:&^5  
    While GetOperationCount(eID)>count 1[B?nk  
        GetOperation eID, count, op *K0CUir|  
        If op.Type="ShiftZ" Then WH'[~O  
            DeleteOperation eID,count fv`%w  
            count=count-1 v}[7)oj|  
        End If \mv7"TM  
        count=count+1 >B~p[wh0  
    Wend U24?+/5D]  
    op.Type = "ShiftZ" PW.W.<CL  
    op.val1 = taq-0.01 Zx`h
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    op.parent = parID ZM4q@O)/  
    AddOperation eID, op vw+ @'+  
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    Print "Set pupil diameter = " & pupilDiam )7J@A%u  
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    'Update AZ Eye subassembly Description 4Jo:^JV  
    eID = FindFullName( "Geometry.Arizona Eye" ) qFvtqv2  
    GetEntity eID, entity "4L' 2w+  
    entity.Description = "Accommodation = " & A & "D" 4$vya+mAk5  
    SetEntity eID, entity #PtV=Ee1  
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    Update >F@7}Y(  
    Print "DONE!" -*tP_=-Dg  
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End Sub <PJwBA%{  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： V&NOp  
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Accommodation = 4 Diopters ##yi^;3Y  
Pupil Diameter = 4 mm |4wVWJ7   
Set aqueous humor thickness = 2.81 v>0xHQD*<M  
Set anterior lens radius = 10.4 and conic constant = -2.375869 JNk ]$ xz  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 TQbhK^]  
Set lens thickness = 3.927 >dZ x+7  
Set lens index of refraction = 1.42672 hv7!x=?8  
Set pupil diameter = 4 3LX<&."z  
DONE! SOeL@!_  
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