[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 h?ia4
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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。 no/]Me!j=  
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模型 y\S7oD(OR  
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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。 H]!y |p  
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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. mhVoz0%1X  
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光源 ?X9 =4Z~w  
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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。 ?}]kIK}MC  
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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。 r2](~&i2  
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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。 L$Leo6<3a  
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视网膜的散射 rgYuF,BT.  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 p;7 4+q  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 rqFs[1wr>R  
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脚本 R_qo]WvR;  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： L@z !,r,  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 TN %"RL  
余下的脚本计算与屈光度有关的所有参数。 r$#G%FMv  
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分析 b66X])+4jE  
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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。 UC1!J =f  
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脚本代码 K7hf m%`N  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Y/S3)o  

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Dim entity As T_ENTITY p0rwiBC=q  
Dim op As T_OPERATION Ib2@Wi   
Dim mat As T_MODELMATERIAL tqQ0lv^J  
Dim A As Double GVEWd/:X(  
Dim pupilDiam As Double Idlu1g  
Dim eID As Long MA+-2pMc|7  
Dim parID As Long \ZFQ?e,d  
Dim count As Integer IMGqJc,7  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double R1.sq(z`  
Dim tlens As Double, nlens As Double Nr"N\yOA/  
Dim curv As Double, conic As Double ]|N4 #4  
Dim ok As Long X[Ek'=}  

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Sub Main BZ?W>'B%$  
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    '用户输入对话框 }Hz-h4Z  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 tHtV[We.:  
        TextBox 220,21,40,21,.TextBox1 'default: 0 #Q3PzDfj  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 #tZf>zrs  
        OKButton 40,91,90,21 e(#IewKp  
        CancelButton 190,91,90,21 qd+[ShrhqZ  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 _GO+fB/Q1  
        TextBox 220,49,40,21,.TextBox2 'default: 4 {1MGb%xW  
    End Dialog zw:C*sY  
    Dim dlg As UserDialog t;!]z-Y>  
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    ok = Dialog (dlg) }[z<iij4  
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    If ok=0 Then    'cancel button was pressed }6J7<g  
        Print "Execution cancelled." *e<Eu>fW#&  
        End
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    End If 9>Uq$B  
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    'Assign accommodation and pupil diameter & use defaults if field left empty lB!vF ~A&  
    If dlg.TextBox1 = "" Then ]1?=jlUl  
        A = 0           'Default accommodation Lq-33#n/  
    Else ^$IZLM?E~  
        A = CDbl(dlg.TextBox1) ahtYSz_FM  
    End If o}=.
  
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    If dlg.TextBox2 = "" Then UQ3@@:L_  
        pupilDiam = 4   'Default pupil diameter `x} Dk<HF  
    Else N\q)LM !M  
        pupilDiam = CDbl(dlg.TextBox2) `4%;qLxngP  
    End If Px?Ao0)Z,  
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    Print " " :Sc8PLT  
    Print "Accommodation = " & A & " Diopters" fYhR#FVI  
    Print "Pupil Diameter = " & pupilDiam & " mm" \V^*44+ <!  
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    ' Calculate new parameters with accommodation Ud#X@xK<h  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness +~d1;0l|  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 85D^@{  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens L}W1*L$;<  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens B:-U`CHHQ  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens \2Og>{"U  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 1TNz&=e  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction .G}k/`a  
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    'Adjust parameters to account for accommodation 'Y!pY]Z  
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    '************************************************************************* 5Lsm_"0  
    'Aqueous thickness (Position of Lens) hCM8/Vvx6  
    '************************************************************************* dTN$y\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) PK6*}y  
    GetCustomElement eID, entity 0e+W/Tq  
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    parID = FindFullName( "Geometry.Arizona Eye" ) >z=Ou<,  
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    ' Delete any shift(s) in z +z-[s6q2m  
    count = 0 ~BZXt7DE  
    While GetOperationCount(eID)>count ;8P_av}C  
        GetOperation eID, count, op
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        If op.Type="ShiftZ" Then p jKt:R}  
            DeleteOperation eID,count $PSY:Zz  
            count=count-1 TDlZ!$g(  
        End If $!G`D=  
        count=count+1 V+lRi"m?|  
    Wend Q,.By&  
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    'Set new shift in _Vjpw,  
    op.Type = "ShiftZ" jfUJ37zNZr  
    op.val1 = taq ]9jZndgC  
    op.parent = parID &<au/^F  
    AddOperation eID, op DVI7]+=nV  
    Print "Set aqueous humor thickness = " & taq-0.55 ~TDzq -U)  
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    '************************************************************************* :peqr!I+K  
    'Radius and conic constant of anterior lens }YQ:6I  
    '************************************************************************* .APVjqG  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) S%kS#U${|  
    GetConic eID, entity, curv, conic D(Qa>B"1  
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    SetConic eID, entity, 1/Rant, CCant RqXi1<6j#  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !
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    '************************************************************************* M% @  
    'Radius and conic constant of posterior lens o{V#f_o  
    '************************************************************************* 14H'!$  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) R"*R99  
    GetConic eID, entity, curv, conic -vV'Lw(  
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    SetConic eID, entity, 1/Rpost, CCpost GR%{T'ZD`  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost dK.R[aQ  
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    '************************************************************************* !z MDP/V  
    'Lens thickness (Position of posterior lens surface) cC%j!8!  
    '************************************************************************* [Tb\woU  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) p1D()-  
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    ' Delete any z-shift(s) D`Gt  
    count = 0 SK+@HnKd  
    While GetOperationCount(eID)>count @`wn<%o$  
        GetOperation eID, count, op qD-fw-,:  
        If op.Type="ShiftZ" Then -es"0wS<u  
            DeleteOperation eID,count D`VFf\7  
            count=count-1 j0FW8!!-g  
        End If 'T7x@a`b)  
        count=count+1 >,"sHm}l%  
    Wend ;i\C]*  
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    'Set new z-shift  H4:ZTl_$  
    op.Type = "ShiftZ" B'}"AC"  
    op.val1 = tlens Nb;H`<JP  
    op.parent = parID b`CWp;6Y  
    AddOperation eID, op #~k[6YR 0  
    Print "Set lens thickness = " & tlens Uoji@  
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    '************************************************************************* x=]S.XI  
    'Lens index of refraction ;W{b $k@g  
    '************************************************************************* ewnfeg1  
    eID = FindMaterial( "Lens" ) d~@q%-`lA  
    GetModelMaterial eID, mat r`6:Q&&  
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    mat.Nd = nlens ,Ff n)+  
    SetModelMaterial eID, mat Au.:OeJm  
    Print "Set lens index of refraction = " & nlens *HE^1IEl  
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    '************************************************************************* _KN/@(+F  
    'Pupil diameter 3;_ n{&  
    '************************************************************************* LA4<#KP  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ~W03{9(Vp8  
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    'Adjust pupil diameter (trimming volume inner hole) NTmi 2c  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" T8XY fcc*h  
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    ' Adjust pupil location to just in front of the lens pSfYu=#f  
    parID = FindFullName( "Geometry.Arizona Eye" ) *(QH{!-$s  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) uzBz}<M=  
    count = 0 s0C:m  
    While GetOperationCount(eID)>count p[v#EyoC  
        GetOperation eID, count, op WeMAe w/d  
        If op.Type="ShiftZ" Then 3f
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            DeleteOperation eID,count >w|*ei:@S  
            count=count-1 M#,Q ^rH#  
        End If ".U^ifF  
        count=count+1 27D!'S  
    Wend OH6^GPF6  
    op.Type = "ShiftZ" ,gx)w^WTm  
    op.val1 = taq-0.01 PaO-J&<  
    op.parent = parID \we\0@v  
    AddOperation eID, op UBZ9A  
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    Print "Set pupil diameter = " & pupilDiam $t/rOo9cV  
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    'Update AZ Eye subassembly Description Ug%_@t/?  
    eID = FindFullName( "Geometry.Arizona Eye" ) PmX2[7  
    GetEntity eID, entity DN8}glVxV  
    entity.Description = "Accommodation = " & A & "D" z[nS$]u  
    SetEntity eID, entity h7yqk4'Lq  
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    Update :c.JhE3D  
    Print "DONE!" 06mlj6hV  
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End Sub y\c"b-lQX  
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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： .Y*f2A.v  
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Accommodation = 4 Diopters aM=D84@  
Pupil Diameter = 4 mm 9X}I>  
Set aqueous humor thickness = 2.81 jO~:<y3 =  
Set anterior lens radius = 10.4 and conic constant = -2.375869 1X1 NtS@  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 GK*v{`  
Set lens thickness = 3.927 , YW|n:X  
Set lens index of refraction = 1.42672 ,!#ccv+Vm%  
Set pupil diameter = 4 /JJw 6[N  
DONE! kv{}C)kt3  
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