[技术]Arizona眼睛模型 [复制链接]

简介 (
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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。 N@Xg5huO  
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模型 8To7c  
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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。 >vlQ|/C  
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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. }FPM-M3y  
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光源 2BHKS-J*  
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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。 \s=QiPK  
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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。 KHvIN}V5?3  
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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。 xN6?yr  
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视网膜的散射 aSRjFL^  
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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。 GGCqtA^@7d  
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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。 {3_Gjb5\\4  
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脚本 'r~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： d>UnJ)V}  
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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。 W/sY
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余下的脚本计算与屈光度有关的所有参数。 ^[#=L4  
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分析 /w0
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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。 [~COYjp  

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脚本代码  m;c3Z-  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. "rsSW3_  
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Dim entity As T_ENTITY 0 <
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Dim op As T_OPERATION gSb,s [p&+  
Dim mat As T_MODELMATERIAL .@@an;C  
Dim A As Double sdrWOq  
Dim pupilDiam As Double sZKEUSFD #  
Dim eID As Long JRXRi*@  
Dim parID As Long u\f3qc,]F  
Dim count As Integer %y
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double J smB^  
Dim tlens As Double, nlens As Double T<P0T<  
Dim curv As Double, conic As Double k=`$6(>Fz  
Dim ok As Long q(gjT^aN  
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Sub Main 33 :@*  
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    '用户输入对话框 W2hA-1  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 w//omF'`  
        TextBox 220,21,40,21,.TextBox1 'default: 0 t{zBC?cR  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 h/HHKn  
        OKButton 40,91,90,21 Kk=L
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        CancelButton 190,91,90,21 QXs8:;T  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 KzNm^^#/$A  
        TextBox 220,49,40,21,.TextBox2 'default: 4 _lX8K:C(  
    End Dialog l[oe*aYN7  
    Dim dlg As UserDialog ^^U%cuKg  
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    ok = Dialog (dlg) >g]ON9CGH  
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    If ok=0 Then    'cancel button was pressed &<Zdyf?[Ou  
        Print "Execution cancelled." aBxiK[[`  
        End %m`zWg-  
    End If $Asr`Q1i   
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    'Assign accommodation and pupil diameter & use defaults if field left empty rEM#D]k  
    If dlg.TextBox1 = "" Then '#q4Bc1  
        A = 0           'Default accommodation 1'Rmg\(  
    Else 2)9r'ai?a  
        A = CDbl(dlg.TextBox1) FshC )[w,  
    End If <( EyXV  
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    If dlg.TextBox2 = "" Then lL0M^Nv  
        pupilDiam = 4   'Default pupil diameter U*\17YU6h  
    Else ~x#vZ=]8  
        pupilDiam = CDbl(dlg.TextBox2) OhFW*v  
    End If y3JMbl[S0  
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    Print " " A[)C:q,  
    Print "Accommodation = " & A & " Diopters" 4x=(Zw_X  
    Print "Pupil Diameter = " & pupilDiam & " mm" X{\jK]O  
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    ' Calculate new parameters with accommodation G\kpUdj}  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness `*_CElpP"  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 2w?hgNz  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ?aWx(dVQ  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens '3Q3lM'lh  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 8:dQ._#v  
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    tlens = 3.767 + 0.04*A                  'Lens thickness e.8$ga{  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction UQPU"F7.  
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    'Adjust parameters to account for accommodation x-;`-Uo%  
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    '************************************************************************* Fe!9y2Mg  
    'Aqueous thickness (Position of Lens) qINTCm j  
    '************************************************************************* NBOCt)C;H  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 8@eOTzm  
    GetCustomElement eID, entity L;/n!k.A  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ,H[SI0];  
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    ' Delete any shift(s) in z Z a(|(M
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    count = 0 ahGT4d`)9  
    While GetOperationCount(eID)>count ,;jGJr  
        GetOperation eID, count, op {/ 2E*|W~I  
        If op.Type="ShiftZ" Then /X#z*GX  
            DeleteOperation eID,count N$#\Xdo  
            count=count-1 Dl,`\b@Fw3  
        End If N+g@8Q2s;5  
        count=count+1 [po "To  
    Wend fY W|p<Q0  
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    'Set new shift in 5o0Ch  
    op.Type = "ShiftZ" ]?K. S6  
    op.val1 = taq ar^i|`D  
    op.parent = parID ,={t8lN  
    AddOperation eID, op X.V[0$.;  
    Print "Set aqueous humor thickness = " & taq-0.55 cUk*C  
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    '************************************************************************* .F2:!h$  
    'Radius and conic constant of anterior lens caq} &A]C  
    '************************************************************************* `JURQ:l)3^  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 46No%cSiG  
    GetConic eID, entity, curv, conic 5?u}#zO  
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    SetConic eID, entity, 1/Rant, CCant bF-"tm  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant jndGiMA  
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    '************************************************************************* +%0z`E\?M#  
    'Radius and conic constant of posterior lens ]?L
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    '************************************************************************* r'4:)~]s  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) K$[$4 dX]  
    GetConic eID, entity, curv, conic WAPhv-6  
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    SetConic eID, entity, 1/Rpost, CCpost F- rQ3  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost {/8
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    '************************************************************************* 9A$m$  
    'Lens thickness (Position of posterior lens surface) k%81f'H  
    '************************************************************************* QlZ@ To  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /X*oS&-M  
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    ' Delete any z-shift(s) k$i'v:c|:i  
    count = 0 l=m(mf?QBg  
    While GetOperationCount(eID)>count MuI2?:~:*4  
        GetOperation eID, count, op RHY4P4B<v>  
        If op.Type="ShiftZ" Then xge7r3i  
            DeleteOperation eID,count SNpi=K!yn  
            count=count-1 8Ogv9  
        End If sRhKlUJG  
        count=count+1 H=^K@Ti:  
    Wend qUJ aeQ  
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    'Set new z-shift +[-i%b3q  
    op.Type = "ShiftZ" XNH4vG |  
    op.val1 = tlens obH;g*  
    op.parent = parID Yl^mAS[w&  
    AddOperation eID, op Xrqx\X  
    Print "Set lens thickness = " & tlens =H`Q~Xx  
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    '************************************************************************* $lwz-^1t.  
    'Lens index of refraction ~Ci{3j :]  
    '************************************************************************* g=8un`]7  
    eID = FindMaterial( "Lens" ) DBH#)4do@  
    GetModelMaterial eID, mat n6Z|Q@F  
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    mat.Nd = nlens R^&q-M=O[  
    SetModelMaterial eID, mat e@<?zS6  
    Print "Set lens index of refraction = " & nlens 7(a2L&k^  
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    '************************************************************************* ;{Ux_JEg  
    'Pupil diameter t*S." q  
    '************************************************************************* M[]A2'fS  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) chI.{R
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    'Adjust pupil diameter (trimming volume inner hole) \,G#<>S  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" @mQ:7-,~  
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    ' Adjust pupil location to just in front of the lens sy5 Fn~\R  
    parID = FindFullName( "Geometry.Arizona Eye" ) 2\<.0  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) :D:DnVZ-[@  
    count = 0 -0uV z)  
    While GetOperationCount(eID)>count y'C-[nk  
        GetOperation eID, count, op |UUdz_i!:  
        If op.Type="ShiftZ" Then oYM3Rgxf9Q  
            DeleteOperation eID,count 4"?^UBr  
            count=count-1 W7No
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        End If LV{Q,DrP  
        count=count+1 vIGw6BJI  
    Wend 'fd1Pj9~$  
    op.Type = "ShiftZ" ts~{w;c  
    op.val1 = taq-0.01 F\JUx L@8  
    op.parent = parID oMH.u^b]fT  
    AddOperation eID, op 7A$B{  
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    Print "Set pupil diameter = " & pupilDiam 5z$,6T  
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    'Update AZ Eye subassembly Description n$L51#'  
    eID = FindFullName( "Geometry.Arizona Eye" ) E+95WF|4k"  
    GetEntity eID, entity uzr\
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    entity.Description = "Accommodation = " & A & "D" ?9+@+q  
    SetEntity eID, entity I27,mS+]  
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    Update ]3{0J  
    Print "DONE!" <cN~jv-w$  
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End Sub A#wEuX=[  
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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： 7E$&2U^Js  
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Accommodation = 4 Diopters wucV_p.E  
Pupil Diameter = 4 mm <=K qcHb  
Set aqueous humor thickness = 2.81 Y$>-%KcKeI  
Set anterior lens radius = 10.4 and conic constant = -2.375869 BHDML.r }M  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 nSx8E7 |V  
Set lens thickness = 3.927 dtStTT  
Set lens index of refraction = 1.42672 Ut@RGg+f8  
Set pupil diameter = 4 (?)7)5H  
DONE! |s+0~$O;