[技术]Arizona眼睛模型 [复制链接]

简介 ]\5@N7h  
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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。 =2uE\6Fl,  
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模型 ?xh_qy;  
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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。 -B:Z(]3#\  
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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. 2uFaAAT  
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光源 H
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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。 X<@ytHBv  
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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。 3S1V^C-eBx  
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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。 0h!2--Aur  
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视网膜的散射 ^(m`5]qr7J  
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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。 #b\&Md|;  
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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。 Ht? u{\p@  
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脚本 :Q2\3  
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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： _Ptf^+  
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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。 q_>DX,A  
余下的脚本计算与屈光度有关的所有参数。 \<|a>{`7]i  
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分析 }D dg  
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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。  s=#IoNh  
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脚本代码 a8M.EFa:  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. S$W *i@x?  
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Dim entity As T_ENTITY LW_Y  
Dim op As T_OPERATION ( f8g}2  
Dim mat As T_MODELMATERIAL .Y'kDuUu  
Dim A As Double ;nLQ?eS\  
Dim pupilDiam As Double o;FjpZ  
Dim eID As Long #[sC H  
Dim parID As Long V'c9DoSRI\  
Dim count As Integer ;1S{xd*^N  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double <9-tA\`8N  
Dim tlens As Double, nlens As Double iJ42` 51  
Dim curv As Double, conic As Double N\H{p%8  
Dim ok As Long U"-mLv"|  
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Sub Main meR%);\  
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    '用户输入对话框 }llzO  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 l*_b)&CH  
        TextBox 220,21,40,21,.TextBox1 'default: 0 )ty *_@N0  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ;Iw'TF   
        OKButton 40,91,90,21 *[ Wh9 ,H  
        CancelButton 190,91,90,21 ~J)4(411  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 )_+"  
        TextBox 220,49,40,21,.TextBox2 'default: 4 v7O{8K+  
    End Dialog [KWF7GQi  
    Dim dlg As UserDialog fouy??  
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    ok = Dialog (dlg) wX#\\Jgi  
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    If ok=0 Then    'cancel button was pressed WSDNTfpI  
        Print "Execution cancelled." f:7Y  
        End F xFK  
    End If ~
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    'Assign accommodation and pupil diameter & use defaults if field left empty a9QaFs"  
    If dlg.TextBox1 = "" Then PG<N\  
        A = 0           'Default accommodation :KX/`   
    Else 1Od:I}@  
        A = CDbl(dlg.TextBox1) _?kf9.  
    End If q,u>`]}
 
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    If dlg.TextBox2 = "" Then fhH* R*4  
        pupilDiam = 4   'Default pupil diameter 2:p2u1Q O  
    Else b${Kj3(  
        pupilDiam = CDbl(dlg.TextBox2) pe,c  
    End If DX$`\PA  
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    Print " " 42z9N\ f  
    Print "Accommodation = " & A & " Diopters" k%In   
    Print "Pupil Diameter = " & pupilDiam & " mm" M*c\=(  
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    ' Calculate new parameters with accommodation 7Fy^K;V"  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Tj:+:B(HB  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens v{% /aw  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens "a,Tc2xk  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens uT-WQ/id  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens MIR17%G  
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    tlens = 3.767 + 0.04*A                  'Lens thickness E\V>3rse  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction @~63%6r#4M  
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    'Adjust parameters to account for accommodation Ccc6 ko_  
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    '************************************************************************* ~MhPzu&B  
    'Aqueous thickness (Position of Lens) m};
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    '************************************************************************* 3\(s=-vh  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) [MiD%FfcNH  
    GetCustomElement eID, entity TfZO0GL$  
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    parID = FindFullName( "Geometry.Arizona Eye" ) !)\`U/.W  
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    ' Delete any shift(s) in z |23 }~c,  
    count = 0 (nE$};c<b2  
    While GetOperationCount(eID)>count ZVGw
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        GetOperation eID, count, op H/, tE0ZV  
        If op.Type="ShiftZ" Then fmSw%r|pT  
            DeleteOperation eID,count /(}V!0\?  
            count=count-1 TTOd0a  
        End If U| N`X54  
        count=count+1 6=')*_~/  
    Wend (g4g-"rc  
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    'Set new shift in ;3?M?E/$s  
    op.Type = "ShiftZ" d>AVUf<o~  
    op.val1 = taq vuAAaKz  
    op.parent = parID 17 j7j@s)  
    AddOperation eID, op F~DG:x~  
    Print "Set aqueous humor thickness = " & taq-0.55 JI*ikco-  
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    '************************************************************************* "
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    'Radius and conic constant of anterior lens /kJ*WA?J  
    '************************************************************************* \`XJz{Lm]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) /60[T@Mz  
    GetConic eID, entity, curv, conic =x^I 5Pn  
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    SetConic eID, entity, 1/Rant, CCant O]PfQ  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant n!N;WL3k  
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    '************************************************************************* 9m'[52{o  
    'Radius and conic constant of posterior lens ivagS\Q  
    '************************************************************************* @O3
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) pDKJLa  
    GetConic eID, entity, curv, conic E""/dC:B  
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    SetConic eID, entity, 1/Rpost, CCpost _*;cwMne-  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost We4 FR4`  
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    '************************************************************************* Ke/P[fo  
    'Lens thickness (Position of posterior lens surface) rxz3Mqg  
    '************************************************************************* +<q^[<pS  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) C )I"yeS.  
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    ' Delete any z-shift(s) ^Qr P.l#pZ  
    count = 0 c]"B)I1L  
    While GetOperationCount(eID)>count lLJb3[ e.  
        GetOperation eID, count, op ,Utw!]  
        If op.Type="ShiftZ" Then G|MDo|q]  
            DeleteOperation eID,count 54;iLL  
            count=count-1 bFVdv&  
        End If Mb9q<4  
        count=count+1 Z8#I  
    Wend $x)'_o}e  
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    'Set new z-shift )N6R#  
    op.Type = "ShiftZ" mvL'l)  
    op.val1 = tlens g SwG=e\  
    op.parent = parID w|Mj8Lc+  
    AddOperation eID, op (o:CxhV  
    Print "Set lens thickness = " & tlens ?I0 i%nH  
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    '************************************************************************* Nb8<8O ^  
    'Lens index of refraction (gf\VYM-7  
    '************************************************************************* sogbD9Jc  
    eID = FindMaterial( "Lens" ) #wd \&  
    GetModelMaterial eID, mat B~aOs>1 S]  
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    mat.Nd = nlens ]q3Kd{B  
    SetModelMaterial eID, mat ?rOb?cu-  
    Print "Set lens index of refraction = " & nlens 6P~"7k  
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    '************************************************************************* qB39\j  
    'Pupil diameter b mm@oi  
    '************************************************************************* $`Xx5Ts7  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) VoyH:  
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    'Adjust pupil diameter (trimming volume inner hole) StDmJ]  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 'f}S,i +q  
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    ' Adjust pupil location to just in front of the lens )f!dG(\&#  
    parID = FindFullName( "Geometry.Arizona Eye" ) _%2Umy|  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) pjCWg4ya  
    count = 0 )eFFtnu5  
    While GetOperationCount(eID)>count )[)]@e  
        GetOperation eID, count, op G}-.
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        If op.Type="ShiftZ" Then #rpqt{ml  
            DeleteOperation eID,count 9v F2aLPk  
            count=count-1 Ntnmd  
        End If u/[]g+  
        count=count+1 GA_`C"mx  
    Wend N.G*ii\  
    op.Type = "ShiftZ" SN{*:\>,  
    op.val1 = taq-0.01 7 h1"8#X  
    op.parent = parID s4gNS eA  
    AddOperation eID, op xs I/DW  
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    Print "Set pupil diameter = " & pupilDiam /8MQqZ C  
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    'Update AZ Eye subassembly Description _o?(t\B9{  
    eID = FindFullName( "Geometry.Arizona Eye" ) ]Z-oUO Z<k  
    GetEntity eID, entity G; [AQ:Iy  
    entity.Description = "Accommodation = " & A & "D" .lBY"W&{  
    SetEntity eID, entity M',D  
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    Update J=X% xb  
    Print "DONE!" =[K)<5,@  
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End Sub ]X~g@O{>_  
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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： ow_y  
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Accommodation = 4 Diopters M91lV(Z   
Pupil Diameter = 4 mm unnx#e]  
Set aqueous humor thickness = 2.81 !NYM(6!(  
Set anterior lens radius = 10.4 and conic constant = -2.375869 iL_F*iK5  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 2]3HX3  
Set lens thickness = 3.927
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Set lens index of refraction = 1.42672 E)O|16f|>  
Set pupil diameter = 4 9I\3T6&tr  
DONE! ZGpTw[5ql