[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 Gb+cT  
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。 Ai\"w0  
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模型 <e"O`*ZJ  
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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。 H6?ZE  
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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. <y5V],-U  
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光源 u%?u`n2'  
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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。 o~!4&  
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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。 pj>b6^TI6C  
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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。 r4caIV  

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视网膜的散射 AfW63;kH  
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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。 ~a m]G0  
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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。 J411bIxD+q  
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脚本 Qfo'w%px  
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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： XPXC7_fV  
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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。 T:x5 ,vpM  
余下的脚本计算与屈光度有关的所有参数。 J]ivIQ  
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分析 JbzYr]k  
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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。 8h9t8?  
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脚本代码 ||hy+f[A  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. hZI9*=`,"  
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Dim entity As T_ENTITY 
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Dim op As T_OPERATION 4
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Dim mat As T_MODELMATERIAL vrn IEur  
Dim A As Double
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Dim pupilDiam As Double
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Dim eID As Long &q1(v3cOO  
Dim parID As Long ',8]vWsl  
Dim count As Integer 1JgnuBX"  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double UV)[a%/SB&  
Dim tlens As Double, nlens As Double Q@%VJPLv.  
Dim curv As Double, conic As Double G,>tC`!  
Dim ok As Long l0Jpf9Aue  
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Sub Main _Pa(5-S'KR  
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    '用户输入对话框 +^<CJNDL9  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 MdU_zY(c  
        TextBox 220,21,40,21,.TextBox1 'default: 0 .{HU1/!  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ] =b?^'  
        OKButton 40,91,90,21 ~b5aT;ObR  
        CancelButton 190,91,90,21 wQb")3dw  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 nXK"BYe  
        TextBox 220,49,40,21,.TextBox2 'default: 4 eOy{]<l3  
    End Dialog 8gJ"7,}-'  
    Dim dlg As UserDialog ~FH''}3:3
 
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    ok = Dialog (dlg) 2|tZ xlt-  
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    If ok=0 Then    'cancel button was pressed ywmx6q4MFL  
        Print "Execution cancelled." !40{1U&@a`  
        End 8U\;N  
    End If {#uX   
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    'Assign accommodation and pupil diameter & use defaults if field left empty HoymGU`w  
    If dlg.TextBox1 = "" Then T_6,o[b8  
        A = 0           'Default accommodation :g'"*VXYB  
    Else ?)Z~H,Q(z  
        A = CDbl(dlg.TextBox1) "vH@b_>9|  
    End If _.J{U0N  
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    If dlg.TextBox2 = "" Then CY)Wuv ^  
        pupilDiam = 4   'Default pupil diameter @`k!7? Sq  
    Else f!P.=Qo[=  
        pupilDiam = CDbl(dlg.TextBox2) h(d<':|  
    End If #g4X`AHB  
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    Print " " LH]nJdq?)  
    Print "Accommodation = " & A & " Diopters" eN>=x40  
    Print "Pupil Diameter = " & pupilDiam & " mm" -{pcb7.xuv  
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    ' Calculate new parameters with accommodation + R])u5c'  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness o?$D09j;;  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ?.|qRzWL  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens p4<&NMG  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens r&0v,WSp&S  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens r4Pm i  
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    tlens = 3.767 + 0.04*A                  'Lens thickness -[`,MZf  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Rla1,{1  
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    'Adjust parameters to account for accommodation O]m,zk  
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    '************************************************************************* 76} N/C  
    'Aqueous thickness (Position of Lens)  s4;
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    '************************************************************************* z^{VqC*o+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) m$*dPje  
    GetCustomElement eID, entity vNd4Fn)H  
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    parID = FindFullName( "Geometry.Arizona Eye" ) :v Pzw!  
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    ' Delete any shift(s) in z GasIOPzK  
    count = 0 +aEE(u6%E@  
    While GetOperationCount(eID)>count 9w}A7('  
        GetOperation eID, count, op mxq
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        If op.Type="ShiftZ" Then &0K H00l  
            DeleteOperation eID,count ss236&  
            count=count-1 bf'@sh%W  
        End If >7@F4a  
        count=count+1 ]|Vm*zO  
    Wend Ca*^U-  
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    'Set new shift in C \H%4p1r  
    op.Type = "ShiftZ" E{_p&FF  
    op.val1 = taq (lwkg8WC  
    op.parent = parID 7zgU>$i  
    AddOperation eID, op '?v.O}  
    Print "Set aqueous humor thickness = " & taq-0.55 $wdIOfaH  
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    '************************************************************************* ]. IUQ*4t  
    'Radius and conic constant of anterior lens C*/d%eHD  
    '************************************************************************* [|<|a3']|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) xQm!  
    GetConic eID, entity, curv, conic 6S2D\Bt,_  
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    SetConic eID, entity, 1/Rant, CCant PE]jYyyHtU  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Jf|J":S  
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    '************************************************************************* S)n~^q  
    'Radius and conic constant of posterior lens elJLT
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    '************************************************************************* &f|LjpMCf  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Xi6XV3G  
    GetConic eID, entity, curv, conic ,-vbR&  
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    SetConic eID, entity, 1/Rpost, CCpost b9%hzD,MR  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 4@4$kro  
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    '************************************************************************* bEMD2ABm  
    'Lens thickness (Position of posterior lens surface) Ih{(d O;  
    '************************************************************************* ^^{K[sLB  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) &+xNR2";  
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    ' Delete any z-shift(s) {qp XzxV  
    count = 0 *A@~!@XE4  
    While GetOperationCount(eID)>count Eii)zo8Xd  
        GetOperation eID, count, op dK#:io[Nz  
        If op.Type="ShiftZ" Then bfVKf}  
            DeleteOperation eID,count \{\*h/m  
            count=count-1 0%<Fc9#  
        End If 2h@/Q)z  
        count=count+1 >j4;{r+eQw  
    Wend P@`@?kMU  
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    'Set new z-shift G yvEc3|@  
    op.Type = "ShiftZ" }Cvf[
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    op.val1 = tlens mcP]k8?C  
    op.parent = parID f0~<qT?:n  
    AddOperation eID, op q3z<v:=1y  
    Print "Set lens thickness = " & tlens
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    '************************************************************************* @dvlSqm)  
    'Lens index of refraction rUc2'Ct  
    '************************************************************************* k-Hy>5;  
    eID = FindMaterial( "Lens" ) C?fd.2#U  
    GetModelMaterial eID, mat ?xWO>#/  
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    mat.Nd = nlens hbl:~O&a/  
    SetModelMaterial eID, mat g=0`^APq
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    Print "Set lens index of refraction = " & nlens 5V':3o;D__  
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    '************************************************************************* H9?(5  
    'Pupil diameter 9. 6"C<eYt  
    '************************************************************************* -y|>#`T/  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &G\Vn,1v  
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    'Adjust pupil diameter (trimming volume inner hole) U>H"N1  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" (u-K^xC  
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    ' Adjust pupil location to just in front of the lens 4W5[1GE.  
    parID = FindFullName( "Geometry.Arizona Eye" ) Ngi]I#Vz  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) vMu6u .e  
    count = 0 HL]8E}e\"  
    While GetOperationCount(eID)>count Lp.dF)C\  
        GetOperation eID, count, op %CV@FdB  
        If op.Type="ShiftZ" Then RL4J{4
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            DeleteOperation eID,count #Z#rOh  
            count=count-1 }$iKz*nx|  
        End If Y)H~*-vGu  
        count=count+1 NOM6},rp  
    Wend He vZ}.  
    op.Type = "ShiftZ" w%~UuJ#i  
    op.val1 = taq-0.01 T&+*dyNxMK  
    op.parent = parID o9\J vJk  
    AddOperation eID, op f@yInIzRJ  
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    Print "Set pupil diameter = " & pupilDiam h*d1G9%Q1  
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    'Update AZ Eye subassembly Description 6i'GM`>w  
    eID = FindFullName( "Geometry.Arizona Eye" ) 2>TOCBB"  
    GetEntity eID, entity H c,e&R  
    entity.Description = "Accommodation = " & A & "D" Jx@_OE_vp  
    SetEntity eID, entity ^x2zMB\t  
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    Update e_=TkG1E6  
    Print "DONE!" 0OCmyy  
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End Sub 4
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如果屈光度是4，光瞳直径是4，则会输出如下数据： {$qE>ic  
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Accommodation = 4 Diopters
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Pupil Diameter = 4 mm O]_a$U*6  
Set aqueous humor thickness = 2.81 ~'1gX`o:  
Set anterior lens radius = 10.4 and conic constant = -2.375869 {,aX|*1Ku~  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 
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Set lens thickness = 3.927 rj}O2~W~
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Set lens index of refraction = 1.42672 g'cLc5\  
Set pupil diameter = 4 J4?i\wD:  
DONE!  )OHGg  
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