[技术]Arizona眼睛模型 [复制链接]

简介 -Kg@Sj/U}R  
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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。 L:Wy- Z  
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模型 SJU93n"G/  
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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。 i`&yPw  
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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. 344,mnAd  
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光源 pE `Q4:<A  
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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*1M  
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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。 %J.Rm0F
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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。 @1n0<V/  
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视网膜的散射 "6Dz~5  
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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。 ] {NY;|&I'  
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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。 SF_kap%JM  
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脚本 -8 &f=J)  
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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： `dL9sfj>  
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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。 P\2QH@p@t  
余下的脚本计算与屈光度有关的所有参数。 g"T~)SQP  
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分析 8 6L&u:o:  
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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。 Q;5\(
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脚本代码 _&F6As !{  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. v0$6@K;M4G  
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Dim entity As T_ENTITY v11mu2  
Dim op As T_OPERATION PI{sO |  
Dim mat As T_MODELMATERIAL o.Cj+`0}5  
Dim A As Double sS-5W-&P{T  
Dim pupilDiam As Double <CA lJ  
Dim eID As Long u8?ceM^r  
Dim parID As Long %{HqF>=~  
Dim count As Integer 'kh%^_FH7  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double r`S]`&#}(  
Dim tlens As Double, nlens As Double hlUF9
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Dim curv As Double, conic As Double ,%KB\;1mn'  
Dim ok As Long '|]zBpz  
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Sub Main H<NYm#a"  
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    '用户输入对话框 _&dGo(B  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Zb9@U: \  
        TextBox 220,21,40,21,.TextBox1 'default: 0 5T  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 dUe"qH29s  
        OKButton 40,91,90,21 5mFi)0={y  
        CancelButton 190,91,90,21 ZnJnjW PQ  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 =r_ SMTu  
        TextBox 220,49,40,21,.TextBox2 'default: 4 l|&|+u#  
    End Dialog @8CD@SDv  
    Dim dlg As UserDialog Vm6^'1CY  
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    ok = Dialog (dlg) ho(Y?'^t3  
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    If ok=0 Then    'cancel button was pressed IsRsjhg8x  
        Print "Execution cancelled." KX9ZwsC0  
        End X`aED\#\h  
    End If w1KQ9H*  
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    'Assign accommodation and pupil diameter & use defaults if field left empty -_314j=`/  
    If dlg.TextBox1 = "" Then 8wy"m=>=b}  
        A = 0           'Default accommodation d

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    Else t 1&p> v  
        A = CDbl(dlg.TextBox1) PkVXn  
    End If BFEo:!'F  
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    If dlg.TextBox2 = "" Then d@w I: 7  
        pupilDiam = 4   'Default pupil diameter D^TKv;%d  
    Else &1?Q]ZRp  
        pupilDiam = CDbl(dlg.TextBox2) v$mA7|(t!  
    End If pD>3c9J'^F  
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    Print " " lO) B/N&  
    Print "Accommodation = " & A & " Diopters" K^>qn,]H'  
    Print "Pupil Diameter = " & pupilDiam & " mm" 'rF TtT  
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    ' Calculate new parameters with accommodation -~-2 g  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ,2cw9?<  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens @+2Zt%  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens z[k2&=
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens $`5DGy?RU  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens *1%g
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    tlens = 3.767 + 0.04*A                  'Lens thickness |/(5GX,X  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction <B fwR$  
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    'Adjust parameters to account for accommodation `C()H@;  
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    '************************************************************************* }.hBmhnZmI  
    'Aqueous thickness (Position of Lens) O:U@m@7  
    '************************************************************************* 3gM{lS}h#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) E?zp?t:a  
    GetCustomElement eID, entity H}$#aXEAn  
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    parID = FindFullName( "Geometry.Arizona Eye" ) AH} nTm  
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    ' Delete any shift(s) in z >2|#b  
    count = 0 ]6aM %r=c  
    While GetOperationCount(eID)>count 980+Y  
        GetOperation eID, count, op QxkfP%_g  
        If op.Type="ShiftZ" Then %z.G3\s0  
            DeleteOperation eID,count dqe_&C@*O  
            count=count-1 ,S8Vfb &  
        End If c]LH.  
        count=count+1 ZHBwoC#5}  
    Wend f*I5m=  
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    'Set new shift in z6!
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    op.Type = "ShiftZ" OYzJE@r^  
    op.val1 = taq A1@-;/H3  
    op.parent = parID z=xHk|+'  
    AddOperation eID, op @Yg7F>s  
    Print "Set aqueous humor thickness = " & taq-0.55 \x+DEy'4;5  
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    '************************************************************************* 5FzRusNiA  
    'Radius and conic constant of anterior lens Uy
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    '************************************************************************* r" D|1  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) lz*PNT{E  
    GetConic eID, entity, curv, conic Cjh&$aq  
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    SetConic eID, entity, 1/Rant, CCant s%:fB(  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant i~,k2*o  
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    '************************************************************************* T'V(%\w  
    'Radius and conic constant of posterior lens m^=, RfUUd  
    '************************************************************************* X1-s,[j'  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) oY]VP+b!  
    GetConic eID, entity, curv, conic k`t'P6 bU  
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    SetConic eID, entity, 1/Rpost, CCpost . 9 NS  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 9,Mp/.T"\  
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    '************************************************************************* {7wvC)WW  
    'Lens thickness (Position of posterior lens surface) V;6M[ic}  
    '************************************************************************* bDkE*4SRX  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) `8-aHPF-  
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    ' Delete any z-shift(s) (HF,p,h_  
    count = 0 4"2/"D0  
    While GetOperationCount(eID)>count 4Rm3'Ch  
        GetOperation eID, count, op C0W~Tk\C2  
        If op.Type="ShiftZ" Then SQ!lgm1bA  
            DeleteOperation eID,count `SW " RLS3  
            count=count-1 GKSy|z  
        End If RmQt%a7\{  
        count=count+1 JA}'d7yEa  
    Wend =4D_-Q  
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    'Set new z-shift HLk"a-+'  
    op.Type = "ShiftZ" </Id';|v  
    op.val1 = tlens 8.^U6xA  
    op.parent = parID z]YhQIU4n8  
    AddOperation eID, op \,EPsQV0?  
    Print "Set lens thickness = " & tlens >(rB[ZJ  
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    '************************************************************************* 5
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    'Lens index of refraction l!y _P  
    '************************************************************************* ;40m goN  
    eID = FindMaterial( "Lens" ) i6CY
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    GetModelMaterial eID, mat Ib\G{$r  
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    mat.Nd = nlens O}-7 V5  
    SetModelMaterial eID, mat I3Lsj}69  
    Print "Set lens index of refraction = " & nlens h%s  
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    '************************************************************************* \.a .'l  
    'Pupil diameter nc~d*K\!  
    '************************************************************************* )R@gnTe  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) E?mp6R]}%  
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    'Adjust pupil diameter (trimming volume inner hole) WS/+Yl  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 55LF  
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    ' Adjust pupil location to just in front of the lens D:E_h  
    parID = FindFullName( "Geometry.Arizona Eye" ) Q$0%~`t
 
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]M(f^  
    count = 0 sri#L+I  
    While GetOperationCount(eID)>count -C}59G8  
        GetOperation eID, count, op }hitU(5t0  
        If op.Type="ShiftZ" Then :"^< aLj  
            DeleteOperation eID,count `_A?a_[*  
            count=count-1 mtQ{6u  
        End If P i!r}m  
        count=count+1 xg^^@o  
    Wend .b`P!  
    op.Type = "ShiftZ" U_;J.{n  
    op.val1 = taq-0.01 ]~Vu-@ /}  
    op.parent = parID 'F?Znd2L  
    AddOperation eID, op Qf>Pb$c$U  
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    Print "Set pupil diameter = " & pupilDiam &jZ|@K?  
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    'Update AZ Eye subassembly Description U<Y'.!  
    eID = FindFullName( "Geometry.Arizona Eye" ) F` 5/9?;|  
    GetEntity eID, entity
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    entity.Description = "Accommodation = " & A & "D" .0E4c8R\X  
    SetEntity eID, entity 0,$-)Sk
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    Update ZV]e-  
    Print "DONE!" fKz"z{\,0  
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End Sub s]vJUC,s  
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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： yXV|
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Accommodation = 4 Diopters 62l0 Z-  
Pupil Diameter = 4 mm '#i]SU&*  
Set aqueous humor thickness = 2.81 I/V)z9  
Set anterior lens radius = 10.4 and conic constant = -2.375869 XH:gQ9FD  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 _#D\*0J  
Set lens thickness = 3.927 >_aio4j}r  
Set lens index of refraction = 1.42672 ,V]A63J  
Set pupil diameter = 4 7;}3{z  
DONE! nuO3UD3