[技术]Arizona眼睛模型 [复制链接]

简介 &G-#*OG  
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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。 5)d,G9  
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模型 R`@8.]cpPy  
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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。 @<D'-mMt  
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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. QKp+;$SE'  

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光源 (dzH3_U  
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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。 I~\O  
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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。 {S5RK-ax  
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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。 A Gv!c($  
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视网膜的散射 Jj2g5={  
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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。 0JmFQ^g(  
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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。 9{_8cpm4  
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脚本 89hF)80  
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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： 4bP13f  
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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。 yC0C`oC  
余下的脚本计算与屈光度有关的所有参数。 <^d!Vzr]  
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分析 *6:v}#b[  
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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。 iJFr4o/R  
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脚本代码 j7K5SS_]  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. kW#S]fsfU  
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Dim entity As T_ENTITY \Ke8W,)ew  
Dim op As T_OPERATION ?N:B  
Dim mat As T_MODELMATERIAL FC6xFg^  
Dim A As Double +a|"{  
Dim pupilDiam As Double Rv98\VD"  
Dim eID As Long M|d={o9Hp  
Dim parID As Long t{!/#eQC  
Dim count As Integer fV 3r|Bp  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double =/[ltUKs:a  
Dim tlens As Double, nlens As Double WP}ixcq#  
Dim curv As Double, conic As Double LIF|bE9kd  
Dim ok As Long F9-[%l  
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Sub Main |pJC:woq  
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    '用户输入对话框 @
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ^oYPyk`9  
        TextBox 220,21,40,21,.TextBox1 'default: 0 FKC\VF  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 +=7:4LFOL  
        OKButton 40,91,90,21 o+NMA (  
        CancelButton 190,91,90,21 '_V #;DI  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ;J]25j]]  
        TextBox 220,49,40,21,.TextBox2 'default: 4 +]c/&Xo!  
    End Dialog ^5>s7SGB"  
    Dim dlg As UserDialog r4u z} jl{  

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    ok = Dialog (dlg) 3V?817&6z  
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    If ok=0 Then    'cancel button was pressed <?YA,"~  
        Print "Execution cancelled." %]!adro~  
        End Ql8bt77eI-  
    End If eJHp6)2  
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    'Assign accommodation and pupil diameter & use defaults if field left empty bHE7yv [  
    If dlg.TextBox1 = "" Then xST4}Mb^f  
        A = 0           'Default accommodation -p`L%xj\  
    Else NgVR,G|1  
        A = CDbl(dlg.TextBox1) ?DPHo)w  
    End If v`x|]-/M&  
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    If dlg.TextBox2 = "" Then _\\ -md:  
        pupilDiam = 4   'Default pupil diameter D<bI2  
    Else yzR=A%V8A  
        pupilDiam = CDbl(dlg.TextBox2) }^Gd4[(,g  
    End If Lg4YED9#  
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    Print " " jZd}OC<  
    Print "Accommodation = " & A & " Diopters" uFG<UF  
    Print "Pupil Diameter = " & pupilDiam & " mm" L&kr{7q  
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    ' Calculate new parameters with accommodation w_Uh  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness XN#&NT{t}  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens n-J2/j  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens x GH1epf  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens U%>'"  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 8AL\ST51x"  
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    tlens = 3.767 + 0.04*A                  'Lens thickness
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction fvqd'2 t  
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    'Adjust parameters to account for accommodation QA?oJ_}y  
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    '************************************************************************* 1/;o
 
    'Aqueous thickness (Position of Lens) y9L14  
    '************************************************************************* IRW^ok.'b!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) n?xTkkr0  
    GetCustomElement eID, entity [syj#  
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    parID = FindFullName( "Geometry.Arizona Eye" ) RLVATM5  
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    ' Delete any shift(s) in z Da.G4,vLh  
    count = 0 8e&p\%1  
    While GetOperationCount(eID)>count )nfEQ)L;h}  
        GetOperation eID, count, op mJ5H=&Z  
        If op.Type="ShiftZ" Then skg|>R,kE  
            DeleteOperation eID,count nP3 E  
            count=count-1 pQa:pX  
        End If w7TJv4_  
        count=count+1 q7\Ovjs0  
    Wend d`y!cu2}  
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    'Set new shift in ZDt?j   
    op.Type = "ShiftZ" `]i []|  
    op.val1 = taq zjl!9M!  
    op.parent = parID p3(2?UO!  
    AddOperation eID, op kmPYx)o  
    Print "Set aqueous humor thickness = " & taq-0.55 pUYM}&dX  
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    '************************************************************************* pG3k   
    'Radius and conic constant of anterior lens ?C-Towo=i  
    '************************************************************************* vB\]u.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ]?+{aS-]?k  
    GetConic eID, entity, curv, conic 3gEMRy*+  
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    SetConic eID, entity, 1/Rant, CCant M@et6aud;K  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant #5} wuj%5  
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    '************************************************************************* sD;M!K_  
    'Radius and conic constant of posterior lens (Z]HX@"{J  
    '************************************************************************* 8' DW#%  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Mkxi~p%<r  
    GetConic eID, entity, curv, conic p'_%aVm7  
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    SetConic eID, entity, 1/Rpost, CCpost o5U(
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost zP\7S}p7%  
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    '************************************************************************* \3f&7wU  
    'Lens thickness (Position of posterior lens surface) "R>FqX6FB  
    '************************************************************************* RE2&mYt  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 2_^aw[-  
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    ' Delete any z-shift(s) %EbPI)yY3  
    count = 0 ED>prE0  
    While GetOperationCount(eID)>count Pz*_)N}j >  
        GetOperation eID, count, op XRx+Dddt;  
        If op.Type="ShiftZ" Then fxaJZz$o  
            DeleteOperation eID,count "TyJP[/  
            count=count-1 +ZMls [  
        End If G2bDf-1ew  
        count=count+1 *iBTI+"]  
    Wend Hmt^h(*/2  
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    'Set new z-shift .IBp\7W!?E  
    op.Type = "ShiftZ" Ysq'2  
    op.val1 = tlens `]Fx.)C#  
    op.parent = parID EP'h@zdz  
    AddOperation eID, op S{pXs&4O  
    Print "Set lens thickness = " & tlens fWfk[(M'9  
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    '************************************************************************* klg2
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    'Lens index of refraction 6tHO!`}1  
    '************************************************************************* fZ04!R  
    eID = FindMaterial( "Lens" ) v\16RD  
    GetModelMaterial eID, mat 7w,FX.=;cv  
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    mat.Nd = nlens 9{k97D/  
    SetModelMaterial eID, mat f`9 b*w
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    Print "Set lens index of refraction = " & nlens dI&!e#Y  
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    '************************************************************************* 5pr"d@.  
    'Pupil diameter J;_}lF9d@  
    '************************************************************************* kpL@P oQ/r  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) :I -V_4b  
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    'Adjust pupil diameter (trimming volume inner hole) fkf1m:Ckh  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" *.L81er5~  
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    ' Adjust pupil location to just in front of the lens ]f+ csB  
    parID = FindFullName( "Geometry.Arizona Eye" ) G'3qzBJ#  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) J)P$2#  
    count = 0 t`*!w|}(1  
    While GetOperationCount(eID)>count * #jsgj[  
        GetOperation eID, count, op m_?d=o  
        If op.Type="ShiftZ" Then _ZY)M  
            DeleteOperation eID,count 3"o"fl  
            count=count-1 }cT_qqw(f%  
        End If %K(<$!  
        count=count+1 nKW*Y}VO  
    Wend >:D j\"o  
    op.Type = "ShiftZ" !x!07`+^u  
    op.val1 = taq-0.01 [2"<W!p  
    op.parent = parID Q+g!V5'  
    AddOperation eID, op 6-?66gmT  
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    Print "Set pupil diameter = " & pupilDiam :Ad&$eg+  
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    'Update AZ Eye subassembly Description T&Lb<'f  
    eID = FindFullName( "Geometry.Arizona Eye" ) A.hd Kl  
    GetEntity eID, entity Cvn#=6V3  
    entity.Description = "Accommodation = " & A & "D" z9aY]lHY  
    SetEntity eID, entity N[kwO1  
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    Update m0v:\?S:  
    Print "DONE!" PRz/inru-  
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End Sub u_ABt?'  
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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： =Zi2jL?On  
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Accommodation = 4 Diopters fk_o@ G!0  
Pupil Diameter = 4 mm {&"N%;`Q  
Set aqueous humor thickness = 2.81 eImn+_ N3  
Set anterior lens radius = 10.4 and conic constant = -2.375869 [B+W%g(c-  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 `Od5Gh  
Set lens thickness = 3.927 -jMJAYjV  
Set lens index of refraction = 1.42672 c%=IL M4  
Set pupil diameter = 4 aH^RoG}  
DONE! 6`f2-f9%iq