[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 Z<Ke/Xi  
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。 "0A !fRI~  
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模型 ;Quk
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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。 #Q_ d  
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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. w 7 j hS  
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光源 J |TA12s  
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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。 d<^o@  
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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。 lCMU{)  
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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。 By-A1|4Cp`  
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视网膜的散射 5PU$D`7it  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ,k5b,}tN  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 !F&Ss|(}  
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脚本 N [iv.B  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： m;"i4!  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 oAgO3x   
余下的脚本计算与屈光度有关的所有参数。 M4:}`p=  
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分析 |P"p/iY  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Jj$N3UCg7  
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脚本代码 pk
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. YQI&8~z  
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Dim entity As T_ENTITY k*8 ld-O  
Dim op As T_OPERATION pU|SUM  
Dim mat As T_MODELMATERIAL 62X;gb  
Dim A As Double FM3DJ?\L-  
Dim pupilDiam As Double `E),G;I  
Dim eID As Long }I\hOL
 
Dim parID As Long
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Dim count As Integer C?3?<FDL  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double T*%Q s&x;  
Dim tlens As Double, nlens As Double k2xOu9ncEj  
Dim curv As Double, conic As Double /k(KA [bS  
Dim ok As Long t(|\3$z  
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Sub Main ]~SOGAFW  
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    '用户输入对话框 ]oN:MS4r  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 tp,e:4\8Q  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Er6'Ig|U  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 oD]riA>jC  
        OKButton 40,91,90,21 7
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        CancelButton 190,91,90,21 u*ZRU 4U  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ,h
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        TextBox 220,49,40,21,.TextBox2 'default: 4 etEm#3  
    End Dialog ~ l'dpg  
    Dim dlg As UserDialog sz'IGy%  
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    ok = Dialog (dlg) Sn\S`D  
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    If ok=0 Then    'cancel button was pressed ]8|cVGMa  
        Print "Execution cancelled." H h4G3h0  
        End |(E.Sb  
    End If 6O^'J~wiI  
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    'Assign accommodation and pupil diameter & use defaults if field left empty *;~*S4/P   
    If dlg.TextBox1 = "" Then H*DWDJxmV  
        A = 0           'Default accommodation s^X(G!V{c  
    Else ic}M)S FD;  
        A = CDbl(dlg.TextBox1) |=7ouFl  
    End If @iZ"I i&+  
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    If dlg.TextBox2 = "" Then ^<8 c`k )e  
        pupilDiam = 4   'Default pupil diameter qYHAXc}$  
    Else %E95R8SL  
        pupilDiam = CDbl(dlg.TextBox2) . mDh9
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    End If :&#HrD[KT  
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    Print " " &R54?u^A  
    Print "Accommodation = " & A & " Diopters" vV.TK_y  
    Print "Pupil Diameter = " & pupilDiam & " mm" %z6.}4h  
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    ' Calculate new parameters with accommodation &j\<UPn  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness G:f\wK[  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens A4,tv#z  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens !%' 1x2?  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ESk<*-  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens yv:8=.r}M  
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    tlens = 3.767 + 0.04*A                  'Lens thickness LFsrqdzJ  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ceakTAB[  
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    'Adjust parameters to account for accommodation Lw 7,[?,Z  
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    '************************************************************************* `mro2A  
    'Aqueous thickness (Position of Lens) m>
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    '************************************************************************* 93="sS  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) V6.xp{[  
    GetCustomElement eID, entity PiD%PBmUl  
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    parID = FindFullName( "Geometry.Arizona Eye" )  D(}w$hi8  
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    ' Delete any shift(s) in z O2|[g8(_F  
    count = 0 z~TG~_s  
    While GetOperationCount(eID)>count {*VCR  
        GetOperation eID, count, op :`
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        If op.Type="ShiftZ" Then sd;J(<Ofh  
            DeleteOperation eID,count {shf\pm!o  
            count=count-1 >uS?Nz5/  
        End If L&wJ-}'l  
        count=count+1 S^,1N4  
    Wend R;9
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    'Set new shift in yoKl.U"&  
    op.Type = "ShiftZ" Byf5~OC  
    op.val1 = taq u<x2"0f  
    op.parent = parID oVPtA
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    AddOperation eID, op S/}6AX#F4  
    Print "Set aqueous humor thickness = " & taq-0.55 wYtL1D(  
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    '************************************************************************* Nf0'>`/  
    'Radius and conic constant of anterior lens _qg)^M6  
    '************************************************************************* 0MK|spc  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) `8Y& KVhu  
    GetConic eID, entity, curv, conic AtRu)v6r  
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    SetConic eID, entity, 1/Rant, CCant -!uut7Z|  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant T+z]ztO  
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    '************************************************************************* ueO&%  
    'Radius and conic constant of posterior lens 7Y$#* 7  
    '************************************************************************* ,3_;JT"5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) x{Y}1+Y4  
    GetConic eID, entity, curv, conic F|K=].  
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    SetConic eID, entity, 1/Rpost, CCpost nQuiRTU<  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost a []Iz8*6e  
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    '************************************************************************* =M"H~;f]  
    'Lens thickness (Position of posterior lens surface) p[BF4h{E  
    '************************************************************************* +Hz});ix<  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZV}"k_+-  
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    ' Delete any z-shift(s) BZy&;P  
    count = 0 [%(}e1T(  
    While GetOperationCount(eID)>count p<1z!`!P  
        GetOperation eID, count, op )X{x\ /N  
        If op.Type="ShiftZ" Then Qmxe*@{`  
            DeleteOperation eID,count Jy)E!{#x  
            count=count-1 6e,|HV  
        End If :34#z.O  
        count=count+1 rQ|^H
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    Wend L/1zG/@  

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    'Set new z-shift qd*3| O^  
    op.Type = "ShiftZ" )3<|<jwcx  
    op.val1 = tlens h8;B+#f`  
    op.parent = parID _j
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    AddOperation eID, op 8<(qN>R  
    Print "Set lens thickness = " & tlens "dfq
  
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    '************************************************************************* OE87&Cl"{t  
    'Lens index of refraction CW*Kd
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    '************************************************************************* [:gPp)f,  
    eID = FindMaterial( "Lens" ) 2XhtK  
    GetModelMaterial eID, mat yidUtSv=,  
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    mat.Nd = nlens J2cqnwUV  
    SetModelMaterial eID, mat K*;e>{p  
    Print "Set lens index of refraction = " & nlens VXt8y)?a  
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    '************************************************************************* T^LpoN/T  
    'Pupil diameter X|+o4R?  
    '************************************************************************* :uhU<H<,f  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Wbo{v r[2+  
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    'Adjust pupil diameter (trimming volume inner hole) <p"[jC2zF;  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" PI{;3X}9$,  
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    ' Adjust pupil location to just in front of the lens VW^6qf/,  
    parID = FindFullName( "Geometry.Arizona Eye" ) Cz=HxU80J  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) zfvMH"1  
    count = 0 X._skq  
    While GetOperationCount(eID)>count 4;anoqiG\  
        GetOperation eID, count, op gL%%2 }$  
        If op.Type="ShiftZ" Then 06@^knm  
            DeleteOperation eID,count _`yd"0Ux  
            count=count-1 }{>)2S  
        End If \7W>3  
        count=count+1 z3!j>X_w  
    Wend )eFXjnHN  
    op.Type = "ShiftZ" x] [/9e  
    op.val1 = taq-0.01 K)z{R n  
    op.parent = parID C[f'1O7  
    AddOperation eID, op JCoDe.  
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    Print "Set pupil diameter = " & pupilDiam ]IbX<  
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    'Update AZ Eye subassembly Description nulCk33x'=  
    eID = FindFullName( "Geometry.Arizona Eye" ) @c&}\#;  
    GetEntity eID, entity f,QoA  
    entity.Description = "Accommodation = " & A & "D" !u@XEN>/  
    SetEntity eID, entity ]dzBm!u  
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    Update AF ,*bb  
    Print "DONE!" u{#}Lo>B #  
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End Sub 3m RP.<=  
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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： +ZH-'l  
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Accommodation = 4 Diopters V<X[>C'  
Pupil Diameter = 4 mm oNW.-gNT  
Set aqueous humor thickness = 2.81 Y,1ZvUOB  
Set anterior lens radius = 10.4 and conic constant = -2.375869 uw'>tb@  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 
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Set lens thickness = 3.927 )8`7i{F  
Set lens index of refraction = 1.42672 HgH\2QL3&  
Set pupil diameter = 4 Yj%hgb:)  
DONE! wOW#A}m'vj  
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