[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 NouT~K`'  
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。 $Z$BF  
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模型 T&cf6soo  
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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。 _@SC R%  
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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. ZC@Pfba[`  
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光源 ~xkcQ{  
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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。 D8G5,s-.  
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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。 9x23## s  
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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。 ?7*.S Lt  
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视网膜的散射 \0). ODA(  
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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。 gwm!Pw j  
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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。 kc-=5l  
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脚本 l|9'M'a  
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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： qILb>#  
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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。 g[';1}/B4  
余下的脚本计算与屈光度有关的所有参数。 {bHUZen  
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分析 Swa0TiT(  
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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。 h!=h0  
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脚本代码 =g
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. /9ctmW1!<  
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Dim entity As T_ENTITY YLJ^R$pi  
Dim op As T_OPERATION 7zM9K+3L  
Dim mat As T_MODELMATERIAL ttOk6-  
Dim A As Double ]-8WM5\qJM  
Dim pupilDiam As Double e[ yN  
Dim eID As Long `6$|d,m5  
Dim parID As Long V56WgOBxz  
Dim count As Integer UodBK7y  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double p<1y
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Dim tlens As Double, nlens As Double i/j53towe  
Dim curv As Double, conic As Double wXjidOd$  
Dim ok As Long vAp<Muj(a  
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Sub Main WP2=1"X63  
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    '用户输入对话框 @}=(4%  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 o?Aj6fNY?  
        TextBox 220,21,40,21,.TextBox1 'default: 0 .G.WPVE  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 nr2 Q[9~  
        OKButton 40,91,90,21 CP~mKmMV  
        CancelButton 190,91,90,21 4-~Z{#-  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Kv<f<>|L  
        TextBox 220,49,40,21,.TextBox2 'default: 4 =Ox}WrU~  
    End Dialog WQ{[q" O  
    Dim dlg As UserDialog G4uG"  
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    ok = Dialog (dlg) W1 k]P.  
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    If ok=0 Then    'cancel button was pressed rtS' 90`  
        Print "Execution cancelled." nl qn:[BU  
        End 8[;vC$  
    End If _0(%^5
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    'Assign accommodation and pupil diameter & use defaults if field left empty k,[*h-{8  
    If dlg.TextBox1 = "" Then DY -5(6X  
        A = 0           'Default accommodation H
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    Else T]ls&cW5  
        A = CDbl(dlg.TextBox1) Dn6U8s&  
    End If d2V X\  
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    If dlg.TextBox2 = "" Then #~!"`B?#*  
        pupilDiam = 4   'Default pupil diameter =e4 r=I  
    Else 
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        pupilDiam = CDbl(dlg.TextBox2) ;h\T7pwwb  
    End If =hkYQq`Q  
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    Print " " _]-4d_&3(  
    Print "Accommodation = " & A & " Diopters" &W,jR|B  
    Print "Pupil Diameter = " & pupilDiam & " mm" g:>'+(H;  
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    ' Calculate new parameters with accommodation $P=C7;  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness U}LW8886  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens b~J)LXj]w  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens d=/0A\O  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens  .qgUD  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens G18w3BFx  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 8.i4QaU  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction m[^lu1\wn  
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    'Adjust parameters to account for accommodation Snx!^4+MF  
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    '************************************************************************* [ QiG0D_'=  
    'Aqueous thickness (Position of Lens) rZ~w_DK*  
    '************************************************************************* 2yZr!Rb~*  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) E5w;75,  
    GetCustomElement eID, entity !cwZ*eM  
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    parID = FindFullName( "Geometry.Arizona Eye" ) <h/%jM>9/  
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    ' Delete any shift(s) in z ?13qDD:  
    count = 0 V)j[`,M:  
    While GetOperationCount(eID)>count =V[uXm  
        GetOperation eID, count, op y0%1YY  
        If op.Type="ShiftZ" Then FTf#"'O  
            DeleteOperation eID,count pk :P;\  
            count=count-1 cCe~OlXQ  
        End If AcC &Q:g  
        count=count+1 CkT(\6B-  
    Wend 5E&#Kh(I  
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    'Set new shift in (N7uaZ?Z  
    op.Type = "ShiftZ" |eqBCZn  
    op.val1 = taq *m~-8_ >;  
    op.parent = parID X@rA2);6  
    AddOperation eID, op TSlB.pw%v  
    Print "Set aqueous humor thickness = " & taq-0.55 [9 W@<p  
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    '************************************************************************* fpD$%.y'J  
    'Radius and conic constant of anterior lens "& ,ov#  
    '************************************************************************* JvpGxj  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6l#
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    GetConic eID, entity, curv, conic (W ~K1]  
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    SetConic eID, entity, 1/Rant, CCant /wV|;D^ )  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Wg']a/m  
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    '************************************************************************* #BC"bY  
    'Radius and conic constant of posterior lens [#PE'i4  
    '************************************************************************* `o[l%I\Q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) W>
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    GetConic eID, entity, curv, conic (_T{Z>C/J  
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    SetConic eID, entity, 1/Rpost, CCpost jD: N)((  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost #b/qR^2qW  
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    '************************************************************************* {&  o^p!  
    'Lens thickness (Position of posterior lens surface) =[6^NR(  
    '************************************************************************* {]0e=#hw  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) J:xGEa t  
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    ' Delete any z-shift(s) Nwvlv{k'  
    count = 0 kv+%  
    While GetOperationCount(eID)>count ]Bhy=1  
        GetOperation eID, count, op IG781:,/  
        If op.Type="ShiftZ" Then 2jsbg{QS#_  
            DeleteOperation eID,count <W4F`6`x  
            count=count-1 :|S zD4Ag  
        End If N[%u>!  
        count=count+1 w5@5"M  
    Wend >4:d
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    'Set new z-shift Z_d"<k}I  
    op.Type = "ShiftZ" h9vcN#2
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    op.val1 = tlens i5,iJe0cA  
    op.parent = parID NGx3f3 9  
    AddOperation eID, op J2UQq7-y  
    Print "Set lens thickness = " & tlens }3pM,.  
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    '************************************************************************* ZN[<=w&(cB  
    'Lens index of refraction I \:WD"  
    '************************************************************************* }F`|_8L*v)  
    eID = FindMaterial( "Lens" ) O9=/\Kc  
    GetModelMaterial eID, mat h^M_yz-f  
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    mat.Nd = nlens x#rgFY,TY  
    SetModelMaterial eID, mat O%bbyR2  
    Print "Set lens index of refraction = " & nlens %uW=kr  
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    '************************************************************************* e8m,q~%#/  
    'Pupil diameter Ndmt$(b  
    '************************************************************************* |)-kUu  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) nm'l}/Ug  
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    'Adjust pupil diameter (trimming volume inner hole) ;b~ S/  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" >ohH4:  
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    ' Adjust pupil location to just in front of the lens jHLs 5%  
    parID = FindFullName( "Geometry.Arizona Eye" ) %@$UIO,(  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) S-Uod y  
    count = 0 sZ;|NAx)  
    While GetOperationCount(eID)>count ^t>mdxuq  
        GetOperation eID, count, op gI+8J.AG=  
        If op.Type="ShiftZ" Then D3pz69W  
            DeleteOperation eID,count G\.~/<Mg+  
            count=count-1 SZykG
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        End If H4/wO  
        count=count+1 c9(3z0!F?  
    Wend }^"6:;,  
    op.Type = "ShiftZ" YQVo7"`%  
    op.val1 = taq-0.01 .`or^`X3  
    op.parent = parID d2\!tJm  
    AddOperation eID, op *~rj!N?;  
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    Print "Set pupil diameter = " & pupilDiam K$E3RB_F  
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    'Update AZ Eye subassembly Description rhv~H"qzW  
    eID = FindFullName( "Geometry.Arizona Eye" ) Di9RRHn&q  
    GetEntity eID, entity }gp@0ri%5  
    entity.Description = "Accommodation = " & A & "D" c`6c)11K  
    SetEntity eID, entity [Nyt0l "z  
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    Update exRw, Nk4  
    Print "DONE!" % rBzA<  
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End Sub [KDxB>R<{  
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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： 6FS%9.Ws  
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Accommodation = 4 Diopters qxL\G &~  
Pupil Diameter = 4 mm sdp&D@  
Set aqueous humor thickness = 2.81 ?R`S-  
Set anterior lens radius = 10.4 and conic constant = -2.375869 2TK \pfD  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ts]e M1;  
Set lens thickness = 3.927 lExQp2E  
Set lens index of refraction = 1.42672 t)SZ2G1r  
Set pupil diameter = 4 i~B?p[  
DONE! GgO5
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