[技术]Arizona眼睛模型 [复制链接]

简介 JXrMtSp\  
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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。 4?`7XJ0a  
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模型 K7|BXGL8r8  
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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。 ^+88z>  
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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. ;TY
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光源 k
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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。 C 7v 8  
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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。 uXXwMc<p  
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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。 Y`%:hvy~  
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视网膜的散射 )!'SSVaRs  
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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。 vtmvvv  
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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。 tT'+3  
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脚本 C,.$g>)MZK  
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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： dx?4)lb  
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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。 1 %K^(J;  
余下的脚本计算与屈光度有关的所有参数。 *s}dtJ  
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分析 6p])2]N>p  
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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。 ND77(I$3s  
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脚本代码 jNBvy1  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 0P_q
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Dim entity As T_ENTITY *DcJ).  
Dim op As T_OPERATION .-Yhpw>f  
Dim mat As T_MODELMATERIAL =J:6p-\*  
Dim A As Double p'tB4V qT  
Dim pupilDiam As Double Zl^#U c"  
Dim eID As Long +zn&DG0\X  
Dim parID As Long }}y~\TB~}  
Dim count As Integer KF(N=?KO  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double >VIb|YA  
Dim tlens As Double, nlens As Double kqdF)Wa am  
Dim curv As Double, conic As Double s~V%eq("}  
Dim ok As Long j+YA/54`  
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Sub Main V/"P};n  
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    '用户输入对话框 +X#JCLD  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 tj7{[3~-[  
        TextBox 220,21,40,21,.TextBox1 'default: 0 0Rgo#`7l  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 #[=%+*Q  
        OKButton 40,91,90,21 T$
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        CancelButton 190,91,90,21 tj<a , l  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 m$

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        TextBox 220,49,40,21,.TextBox2 'default: 4 zI1-l9 o  
    End Dialog !} ~K'1"  
    Dim dlg As UserDialog 2vbm=~)$F  
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    ok = Dialog (dlg) &b~if}vcb  
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    If ok=0 Then    'cancel button was pressed 6'E3Q=}d  
        Print "Execution cancelled." d'y\~M9(  
        End fdk]i/*)  
    End If 1VRexp  
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    'Assign accommodation and pupil diameter & use defaults if field left empty <B"M} Y>_P  
    If dlg.TextBox1 = "" Then TX/Ng+v S  
        A = 0           'Default accommodation gN./u   
    Else /8](M5X]f  
        A = CDbl(dlg.TextBox1) (x"TM),Q  
    End If WJD1U?`  
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    If dlg.TextBox2 = "" Then B}Lz#'5_  
        pupilDiam = 4   'Default pupil diameter ;G 27S<Q  
    Else >M1m(u84#  
        pupilDiam = CDbl(dlg.TextBox2) X"'c2gaa_  
    End If ;ndsq[k>  
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    Print " " pzL !42  
    Print "Accommodation = " & A & " Diopters" _DlkTi5(w  
    Print "Pupil Diameter = " & pupilDiam & " mm" KaRdO  
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    ' Calculate new parameters with accommodation 7*D*nY4+  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ]gxt+'iAFS  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens \Pv_5LAo  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Sw<V/t  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens P[|FK(l  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens i
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    tlens = 3.767 + 0.04*A                  'Lens thickness xUp[)B6?:  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction w>RBth^p  
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    'Adjust parameters to account for accommodation 3M/iuu  
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    '************************************************************************* ]{` 8C  
    'Aqueous thickness (Position of Lens) +Xa^3 =B  
    '************************************************************************* ?52{s"N0>  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) /hC[>t<  
    GetCustomElement eID, entity .iDxq8l  
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    parID = FindFullName( "Geometry.Arizona Eye" ) F4=+xd >0  
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    ' Delete any shift(s) in z &3jq'@6  
    count = 0 1-HL#y*7$  
    While GetOperationCount(eID)>count ;=&D_jGf]  
        GetOperation eID, count, op $6&P 69<  
        If op.Type="ShiftZ" Then 95`Q=I|i  
            DeleteOperation eID,count jGM+  
            count=count-1 bu;3Ib3\  
        End If Y}'8`.  
        count=count+1 994  
    Wend Mn<G9KR  
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    'Set new shift in A7{l60(5  
    op.Type = "ShiftZ" -uho;  
    op.val1 = taq !11x&Db  
    op.parent = parID FQV]/  
    AddOperation eID, op 6usy0g D  
    Print "Set aqueous humor thickness = " & taq-0.55 ^uU'Qc4S=  
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    '************************************************************************* ?dWfupO{  
    'Radius and conic constant of anterior lens 3YtFO;-  
    '************************************************************************* I'23$IzPA  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) fS( )F*J  
    GetConic eID, entity, curv, conic $!+t2P@d.5  
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    SetConic eID, entity, 1/Rant, CCant c"vF i~Db  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant >a5M:s)  
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    '************************************************************************* EYe)d+E*  
    'Radius and conic constant of posterior lens a@1r3az  
    '************************************************************************* Ch`nDIne  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) b!>w4MPe  
    GetConic eID, entity, curv, conic z8#c!h<@;  
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    SetConic eID, entity, 1/Rpost, CCpost R]oi&"H@r)  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 9.bMA<X  
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    '************************************************************************* ya+eGD@N':  
    'Lens thickness (Position of posterior lens surface) %h"+J  
    '************************************************************************* IIN"'7Z^R  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) _g%Wx?K9  
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    ' Delete any z-shift(s) 5W0'r'{  
    count = 0 ?V6+o`bm  
    While GetOperationCount(eID)>count myp}DI(  
        GetOperation eID, count, op PI"&-lXI-m  
        If op.Type="ShiftZ" Then Z19d Ted33  
            DeleteOperation eID,count 8&AHu  
            count=count-1 .3(=UQ  
        End If $(2c0S{1  
        count=count+1 #8N9@  
    Wend C*e)UPK`  
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    'Set new z-shift R~-r8dWcw  
    op.Type = "ShiftZ" 7\'ow|)}v  
    op.val1 = tlens 6B
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    op.parent = parID !ul)e;a  
    AddOperation eID, op X#s:C=q1  
    Print "Set lens thickness = " & tlens 'E/vE0nN?  
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    '************************************************************************* |?c v5l7E  
    'Lens index of refraction Dh*>361y-  
    '************************************************************************* H}}]Gh.T  
    eID = FindMaterial( "Lens" ) AJRfl%3  
    GetModelMaterial eID, mat J~Gq#C^e  
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    mat.Nd = nlens O,Xf.O1c  
    SetModelMaterial eID, mat M5C}*c9  
    Print "Set lens index of refraction = " & nlens 05".;(  
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    '************************************************************************* s'LY)_n  
    'Pupil diameter MSPzOJQPy  
    '************************************************************************* )t G`a ;  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 6gS<h\h0  
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    'Adjust pupil diameter (trimming volume inner hole) u7!X#<  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" oB27Y&nO  
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    ' Adjust pupil location to just in front of the lens a;p3M
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    parID = FindFullName( "Geometry.Arizona Eye" ) ?YY'-\h?  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) w'q}aQS  
    count = 0 %YhZ#>WT  
    While GetOperationCount(eID)>count  A_: Bz:  
        GetOperation eID, count, op ?i*kwEj=  
        If op.Type="ShiftZ" Then *Yk3y-   
            DeleteOperation eID,count #UH|,>W6  
            count=count-1 WU-.lg'c'  
        End If /}?"O~5M"  
        count=count+1 [((P,v*  
    Wend /H+j6*}r  
    op.Type = "ShiftZ" zBWn*A[4  
    op.val1 = taq-0.01 D_,}lsrb  
    op.parent = parID gIS<"smOo  
    AddOperation eID, op ukV1_QeN[  
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    Print "Set pupil diameter = " & pupilDiam d$<HMs:o@  
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    'Update AZ Eye subassembly Description ^{8r(1,  
    eID = FindFullName( "Geometry.Arizona Eye" ) Oy$*ZG)  
    GetEntity eID, entity z65|NO6JW.  
    entity.Description = "Accommodation = " & A & "D" x$9UHEb kM  
    SetEntity eID, entity )*N]Q  
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    Update #SQao;>  
    Print "DONE!" n~\"W  
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End Sub E1:{5F5/  
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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： ;5 cg<~t  
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Accommodation = 4 Diopters D0,U2d  
Pupil Diameter = 4 mm IbQ3*  
Set aqueous humor thickness = 2.81 %-?HC
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Set anterior lens radius = 10.4 and conic constant = -2.375869 gW'aK>*c  
Set posterior lens radius = -4.424557 and conic constant = -3.081019
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Set lens thickness = 3.927 c[@-&o`  
Set lens index of refraction = 1.42672 -~eNC^t;W  
Set pupil diameter = 4 fB[I1Z  
DONE! XoM+"R"