[分享]Arizona眼睛模型 [复制链接]

简介 i8F^ N=  
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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。 f^P:eBgpx  
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模型 uSeRn@  
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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。 ?#OGH`ZvkI  
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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. zYCrfr  
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光源 Ck71N3~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。 Q&zEa0^rG6  
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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。 S7{L-"D=y  
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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。 C$9+p@G6  
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视网膜的散射 $$UMc-Pq  
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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。 z:RclDm  
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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。 :)!X%2_  
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脚本 aBo8?VV]8  
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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： $
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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。 d>ltL`xn  
余下的脚本计算与屈光度有关的所有参数。 [;bZQ6JR  
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分析 (C<~:Y?%  
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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。 PQla-  
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脚本代码 Gp=X1 F  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. h/h`?vWu  
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Dim entity As T_ENTITY 5O.dRp7dJ  
Dim op As T_OPERATION Ql1HaC/5)-  
Dim mat As T_MODELMATERIAL
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Dim A As Double {@T8i^EI  
Dim pupilDiam As Double RX-qL,dc  
Dim eID As Long SU0K#:  
Dim parID As Long W)3IS&;P  
Dim count As Integer ~vD7BO`  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 44H#8kV  
Dim tlens As Double, nlens As Double Qr`WPTQr"  
Dim curv As Double, conic As Double T6s~f$G  
Dim ok As Long [emUyF  
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Sub Main &^ECQ  
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    '用户输入对话框 GA19=gow  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 5):2;hk  
        TextBox 220,21,40,21,.TextBox1 'default: 0 % K$om|]p  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 wRgh`Hc\}  
        OKButton 40,91,90,21 sOc<'):TK  
        CancelButton 190,91,90,21 _pu G?p  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 y %dUry%>  
        TextBox 220,49,40,21,.TextBox2 'default: 4 OrXx0Hn  
    End Dialog "%O,*t  
    Dim dlg As UserDialog Lod$&k@@  
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    ok = Dialog (dlg) DKV^c'  
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    If ok=0 Then    'cancel button was pressed ,vB
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        Print "Execution cancelled." 9>qc1z  
        End M8Y\1
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    End If P0m;AqS#R  
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    'Assign accommodation and pupil diameter & use defaults if field left empty rbP" n)0=  
    If dlg.TextBox1 = "" Then qaBjV6loy  
        A = 0           'Default accommodation &1hJ?uM01  
    Else b .9]b  
        A = CDbl(dlg.TextBox1) c5_?jKpl  
    End If ;6N@raP7  
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    If dlg.TextBox2 = "" Then
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        pupilDiam = 4   'Default pupil diameter )A]
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    Else "hRw_<  
        pupilDiam = CDbl(dlg.TextBox2) zx7*Bnu0  
    End If {7^7)^@  
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    Print " " ?#@
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    Print "Accommodation = " & A & " Diopters" H-%)r&"vn  
    Print "Pupil Diameter = " & pupilDiam & " mm" *&X.  
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    ' Calculate new parameters with accommodation Y21,!$4gb  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness vt`hY4  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens fo])=KM  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 1gp3A
 
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens EK:!.Fl  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens wyO@oi Vn  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ]Xcqf9k  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \LB =_W$  
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    'Adjust parameters to account for accommodation ^6v ob  
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    '************************************************************************* ^n5[pF}Gw  
    'Aqueous thickness (Position of Lens) >'#G$f  
    '************************************************************************* {.9phW4Vr?  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) |xaJv:96%  
    GetCustomElement eID, entity 84[T!cDk  
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    parID = FindFullName( "Geometry.Arizona Eye" ) se](hu~w  
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    ' Delete any shift(s) in z E^S[8=  
    count = 0 }S6Sz&)  
    While GetOperationCount(eID)>count IC}?oXs5G  
        GetOperation eID, count, op P>%\pCJ])  
        If op.Type="ShiftZ" Then .?b2Bd!MC  
            DeleteOperation eID,count c@:L7#8  
            count=count-1 y|!%C-P  
        End If 0;'kv|  
        count=count+1 v%3mhk#  
    Wend po_||NIY  
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    'Set new shift in c_xtwdkL9  
    op.Type = "ShiftZ" &)L2a)  
    op.val1 = taq }
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    op.parent = parID IWN:GFH(  
    AddOperation eID, op HBYqqEO  
    Print "Set aqueous humor thickness = " & taq-0.55 10dVV[=  
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    '************************************************************************* !]Z> T5$  
    'Radius and conic constant of anterior lens a#W:SgE?Y  
    '************************************************************************* '2=u<
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 06 gE;iT  
    GetConic eID, entity, curv, conic ,YFuMek  
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    SetConic eID, entity, 1/Rant, CCant QLo^6S5!  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ?iG}Qj@5  
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    '************************************************************************* b3e:F{n ^  
    'Radius and conic constant of posterior lens Ltpd:c  
    '************************************************************************* ~,yHE3B\G  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) UwY<3ul  
    GetConic eID, entity, curv, conic BM{GSX  
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    SetConic eID, entity, 1/Rpost, CCpost qWe1`.o  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost J) v~  
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    '************************************************************************* VP=(",`  
    'Lens thickness (Position of posterior lens surface) KC o<%  
    '************************************************************************* BR\%
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) i](,
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    ' Delete any z-shift(s) u814ZN}  
    count = 0 R3F>"(P@tS  
    While GetOperationCount(eID)>count a_I!2w<I  
        GetOperation eID, count, op Q^/5hA  
        If op.Type="ShiftZ" Then hu\HK81m  
            DeleteOperation eID,count S{j|("W"[  
            count=count-1 *Id$%O  
        End If 2}]6~i  
        count=count+1 WZ5[tZf  
    Wend ~\/>b}^uf'  
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    'Set new z-shift Z$0r+phQk=  
    op.Type = "ShiftZ" (6z^m?t?  
    op.val1 = tlens hNc;,13  
    op.parent = parID 1N
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    AddOperation eID, op FCQoz"M  
    Print "Set lens thickness = " & tlens ,5'LbO-  
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    '************************************************************************* l?(nkg["nY  
    'Lens index of refraction dv-yZRU:  
    '************************************************************************* B{a:cz>0<  
    eID = FindMaterial( "Lens" ) G;V@oT  
    GetModelMaterial eID, mat @B ~![l  
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    mat.Nd = nlens ;_K+b,  
    SetModelMaterial eID, mat #})Oz| c  
    Print "Set lens index of refraction = " & nlens \v]}  
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    '*************************************************************************
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    'Pupil diameter !
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    '************************************************************************* QL}5vSl  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &d`Umm]  
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    'Adjust pupil diameter (trimming volume inner hole) O;f^'N  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ;|w &n  
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    ' Adjust pupil location to just in front of the lens !$AVlMnJ  
    parID = FindFullName( "Geometry.Arizona Eye" ) x+|Fw d  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) t*<vc]D  
    count = 0 jd l1Q<Z  
    While GetOperationCount(eID)>count /V~L:0%  
        GetOperation eID, count, op (U2G"  
        If op.Type="ShiftZ" Then n0U^gsD4J  
            DeleteOperation eID,count f1=BBQY >  
            count=count-1 8_>\A= E  
        End If =b32E^z,  
        count=count+1 CB_(9T72H  
    Wend lZ0+:DaP2  
    op.Type = "ShiftZ" BQSA;;n]  
    op.val1 = taq-0.01 J=*y>Zt-b  
    op.parent = parID T =3te|fv  
    AddOperation eID, op )&+_T+\  
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    Print "Set pupil diameter = " & pupilDiam 9Q]v#&1  
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    'Update AZ Eye subassembly Description zA&0H  
    eID = FindFullName( "Geometry.Arizona Eye" ) <Xp F  
    GetEntity eID, entity I.R3?+tZ  
    entity.Description = "Accommodation = " & A & "D" 5|m|R"I*Y  
    SetEntity eID, entity qS&PMQ"$  
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    Update >1pD'UZIy7  
    Print "DONE!" 90sMS]a  
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End Sub Qu!\Cx@  
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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： z(.$>O&6H  
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Accommodation = 4 Diopters
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Pupil Diameter = 4 mm ||`w MWq  
Set aqueous humor thickness = 2.81 dwrc"GK!o  
Set anterior lens radius = 10.4 and conic constant = -2.375869 FPaj p  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 1GOa'bxm  
Set lens thickness = 3.927 qqw6p j  
Set lens index of refraction = 1.42672 Hxb{bF  
Set pupil diameter = 4 l]WV?^*  
DONE! 6$ IXER  
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