[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 oBqWIXM  
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。 N-cLp}D}WB  
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模型 64jFbbd-/  
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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。 PW)Gd +y  
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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. :,]*~
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光源 u:[vqlU  
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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。 6^vseVx  

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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。 =k+nC)e  
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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。 F\lnG  
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视网膜的散射 FWu[{X;  
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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。 E
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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。 rr;p;  
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脚本 njoU0f1`  
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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： HC[)):S*  
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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。 uOU?-WtPz  
余下的脚本计算与屈光度有关的所有参数。 <.6bni )  
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分析 V <;vy&&  
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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。 sb^%eUU])  
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脚本代码 N=hhuKt]  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. I<v:xTor  
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Dim entity As T_ENTITY SA1|7  
Dim op As T_OPERATION Q \E[py  
Dim mat As T_MODELMATERIAL Fy!-1N9|l  
Dim A As Double =%UX"K`  
Dim pupilDiam As Double #4Z]/D2G  
Dim eID As Long N9s ,..  
Dim parID As Long (sHvoE^q-  
Dim count As Integer UCv9G/$  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double M1sR+e$"  
Dim tlens As Double, nlens As Double LBs:O*;  
Dim curv As Double, conic As Double &-s/F`  
Dim ok As Long nWd]P\a'V  
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Sub Main [p7cgHSMt  
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    '用户输入对话框 K.{:H4_  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 eC71;"
 
        TextBox 220,21,40,21,.TextBox1 'default: 0 _r6aLm2n  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 |i-d#x8  
        OKButton 40,91,90,21 pjI< cQ&  
        CancelButton 190,91,90,21 l_`DQ
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 5m e|dvk  
        TextBox 220,49,40,21,.TextBox2 'default: 4 v o9Fj  
    End Dialog .S{Q }S  
    Dim dlg As UserDialog @aX$}  
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    ok = Dialog (dlg) 8D[,z 7n  
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    If ok=0 Then    'cancel button was pressed HRPNZ!B  
        Print "Execution cancelled." fT&>L  
        End ELlTR/NW  
    End If :W++`f&  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Gxj3/&]^Y  
    If dlg.TextBox1 = "" Then ?[|T"bE5[  
        A = 0           'Default accommodation iHp@R-g  
    Else ~qk5Mk4$  
        A = CDbl(dlg.TextBox1) ^JKV~+ Q  
    End If tk"+PTGJT  
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    If dlg.TextBox2 = "" Then J#pl7q)^w  
        pupilDiam = 4   'Default pupil diameter ~PoBvH
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    Else vXio /m  
        pupilDiam = CDbl(dlg.TextBox2) )kq3q5*_  
    End If %S2^i3  
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    Print " " *t,J4c  
    Print "Accommodation = " & A & " Diopters" ?4]#gCks  
    Print "Pupil Diameter = " & pupilDiam & " mm" oZY2K3J)  
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    ' Calculate new parameters with accommodation 
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness j\ dY  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens h7EKb-@  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens c]y"5;V8  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 7d7"^M  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens GCf3'u  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 7,\Uk|  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction :OF:(,J  
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    'Adjust parameters to account for accommodation 3Mnm2*\  
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    '************************************************************************* 3E!#?N|v  
    'Aqueous thickness (Position of Lens) .Q,IOCHk  
    '************************************************************************* HlkG^:)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) rt7Ma2tK  
    GetCustomElement eID, entity NW.<v /?=,  
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    parID = FindFullName( "Geometry.Arizona Eye" ) jf&LSK
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    ' Delete any shift(s) in z G%a8'3d,  
    count = 0 :y?xS  
    While GetOperationCount(eID)>count v}=3  
        GetOperation eID, count, op }HM8VAH  
        If op.Type="ShiftZ" Then GP%8
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            DeleteOperation eID,count e$k]z HlQ  
            count=count-1 _.xT :b36  
        End If I[~EQ{Iz  
        count=count+1 hSgfp  
    Wend o@?3i+%}8  
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    'Set new shift in G;n'c7BV  
    op.Type = "ShiftZ" VQm)32'  
    op.val1 = taq 1_Um6vS#  
    op.parent = parID
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    AddOperation eID, op KfU4#2}
 
    Print "Set aqueous humor thickness = " & taq-0.55 FtUOgL)|  
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    '************************************************************************* "t<${  
    'Radius and conic constant of anterior lens U/ncD F%C  
    '************************************************************************* 6]i"lq
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) _}X_^taTZS  
    GetConic eID, entity, curv, conic 't$(Ruw  
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    SetConic eID, entity, 1/Rant, CCant Wgl7)Xk.)  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant `U4R% qhWA  
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    '************************************************************************* G>?hojvi  
    'Radius and conic constant of posterior lens f-9&n4=H  
    '************************************************************************* Y[A
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) :X>%6Xj?RV  
    GetConic eID, entity, curv, conic v535LwFW  
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    SetConic eID, entity, 1/Rpost, CCpost <RmI)g>'_^  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost |x|#n  
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    '************************************************************************* 3~"G(UP  
    'Lens thickness (Position of posterior lens surface) DLYk#d: q?  
    '************************************************************************* ~X^L3=!vf  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) esH>NH_  
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    ' Delete any z-shift(s) }/ 6
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    count = 0 5Sd+Cc  
    While GetOperationCount(eID)>count Egv (n@1  
        GetOperation eID, count, op 7Op6>i  
        If op.Type="ShiftZ" Then /I{<]m$  
            DeleteOperation eID,count ylF%6!V}4V  
            count=count-1 G#ov2  
        End If VnUWUIVJ  
        count=count+1 =6b^j]1  
    Wend ^[}^+  
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    'Set new z-shift o5gt`H"  
    op.Type = "ShiftZ" Z 6^AO=3  
    op.val1 = tlens *<n]"-  
    op.parent = parID "nXL7N0  
    AddOperation eID, op @Otom'O  
    Print "Set lens thickness = " & tlens T:aYv;#0  
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    '************************************************************************* w66iLQ\@  
    'Lens index of refraction {D1"bDZ  
    '************************************************************************* (tV/.x*G  
    eID = FindMaterial( "Lens" ) ~:r:?PwWG  
    GetModelMaterial eID, mat 42aYM!  
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    mat.Nd = nlens {-IH?!&v  
    SetModelMaterial eID, mat Xc;W9e(U  
    Print "Set lens index of refraction = " & nlens x@3Ix,b'  
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    '************************************************************************* <zE,T@c  
    'Pupil diameter smQ<lwA  
    '************************************************************************* "ewSh<t
 
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) s/+@o:  
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    'Adjust pupil diameter (trimming volume inner hole) _,:gSDW|  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" W'x/Kg,w-  
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    ' Adjust pupil location to just in front of the lens iE$qq~%  
    parID = FindFullName( "Geometry.Arizona Eye" ) n>
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) %EA|2O.D  
    count = 0 :,03)[u{8  
    While GetOperationCount(eID)>count @l:\0cO  
        GetOperation eID, count, op Jylav:  
        If op.Type="ShiftZ" Then Vo^ i7  
            DeleteOperation eID,count [+EmV>Y
 
            count=count-1 '{+5+ J  
        End If .$5QM&  
        count=count+1 4{JoeIRyz  
    Wend 7 sv 3=/`  
    op.Type = "ShiftZ" $_NYu  
    op.val1 = taq-0.01 R7u&`  
    op.parent = parID v< qN-zG  
    AddOperation eID, op a"gZw9m@  
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    Print "Set pupil diameter = " & pupilDiam v7x%V%K  
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    'Update AZ Eye subassembly Description T$[50~  
    eID = FindFullName( "Geometry.Arizona Eye" ) t]LOBy-Kv  
    GetEntity eID, entity P%MYr"<$E  
    entity.Description = "Accommodation = " & A & "D" T.\=R  
    SetEntity eID, entity c:(Xkzj  
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    Update 'jAX&7G`  
    Print "DONE!" ]t$wK  
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End Sub .YYfba#{  
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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： qzD<_ynA  
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Accommodation = 4 Diopters }pqnF53  
Pupil Diameter = 4 mm ?:DeOBAb  
Set aqueous humor thickness = 2.81 E Dh$UB
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Set anterior lens radius = 10.4 and conic constant = -2.375869 aQzDOeTi  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 4#?Sxs  
Set lens thickness = 3.927 @@->A9'L  
Set lens index of refraction = 1.42672 [XK^3pT_  
Set pupil diameter = 4 MvV\?Lzj   
DONE! 8NCu;s  
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