[技术]Arizona眼睛模型 [复制链接]

简介 YV%y KD  
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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。 qwhDv+o  
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模型 HxUJ 0Q  
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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。 p :{,~ 1  
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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. uNKf!\Y  
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光源 t,NE`LC  
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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。 , wXixf2  
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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。 [n]C  
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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。 QLxe1[qI  
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视网膜的散射 :(Ak:  
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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。 }!uwWBw`  
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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。 {K N7Y"AI  
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脚本 dvE~EZcS  
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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： Aflf]G1  
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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。 B.A;1VE5  
余下的脚本计算与屈光度有关的所有参数。 x.9[c m-!  
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分析 FM=XoMP q  
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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。 |J"\~%8  
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脚本代码 _WGWU7h  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. c8N pk<  
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Dim entity As T_ENTITY ]n!oa  
Dim op As T_OPERATION \#v(f2jPF  
Dim mat As T_MODELMATERIAL +4n}H}9l  
Dim A As Double $0cE iq?Hf  
Dim pupilDiam As Double x*!*2{  
Dim eID As Long 8Ow#W5_3|  
Dim parID As Long \'r;1W  
Dim count As Integer 8%`h:f
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double SmS6B5j\R  
Dim tlens As Double, nlens As Double ?AVn
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Dim curv As Double, conic As Double "yK)9F[9Mo  
Dim ok As Long \qDY0hIv t  
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Sub Main th{ie2$  
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    '用户输入对话框 )8taMC:H^  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 9e7):ZupO  
        TextBox 220,21,40,21,.TextBox1 'default: 0 _&N:%;9uD  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 _}j6Pw'  
        OKButton 40,91,90,21 %EYh*g{G  
        CancelButton 190,91,90,21 sC ?e%B  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 k~2FlRoC^  
        TextBox 220,49,40,21,.TextBox2 'default: 4 xouBBb=  
    End Dialog /eBcPu"[Vb  
    Dim dlg As UserDialog 5Z(q|nn7P  
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    ok = Dialog (dlg) |RBL5,t^  
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    If ok=0 Then    'cancel button was pressed ]D^zTl3=q  
        Print "Execution cancelled." =I9hGj6  
        End a *bc#!e  
    End If /GO((v+J  
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    'Assign accommodation and pupil diameter & use defaults if field left empty +jN)$Y3Ya  
    If dlg.TextBox1 = "" Then +O1=Ao  
        A = 0           'Default accommodation J!"m{ 8-  
    Else x}f)P  
        A = CDbl(dlg.TextBox1) vos-[$  
    End If a~k*Gd(  
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    If dlg.TextBox2 = "" Then 3!Mb<W.3  
        pupilDiam = 4   'Default pupil diameter :4>LtfA  
    Else Pk8(2fAYk  
        pupilDiam = CDbl(dlg.TextBox2) 6|Crc$4l  
    End If rc}=`D`  
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    Print " " )LL.fPic  
    Print "Accommodation = " & A & " Diopters" :UfaMe5  
    Print "Pupil Diameter = " & pupilDiam & " mm" >p3S,2SM  
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    ' Calculate new parameters with accommodation :io~{a#.2\  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness j[=P3Z0q  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens '<wZe.Q!  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens s{fL~}Yz  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens rD>q/,X=\  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ` kZ"5}li  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ]2z Gb5s"  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Tt{ft?H71  
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    'Adjust parameters to account for accommodation ?o(Y\YJf  
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    '************************************************************************* 6w0r)  
    'Aqueous thickness (Position of Lens) "; ?^gA  
    '************************************************************************* Bn Nu/02.=  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) mTa
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    GetCustomElement eID, entity Csm23QLsg)  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ZQ~EaI9R  
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    ' Delete any shift(s) in z d`KW]HJw  
    count = 0 "oCXG`.k&  
    While GetOperationCount(eID)>count +B O
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        GetOperation eID, count, op {Y
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        If op.Type="ShiftZ" Then zh4m`}p  
            DeleteOperation eID,count M5B?`mTl  
            count=count-1 T)cbpkH4  
        End If 84-7!< 6i  
        count=count+1 YifTC-Q;  
    Wend m6 a@Y<  
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    'Set new shift in T(bFn?  
    op.Type = "ShiftZ" 7/Mhz{o;W  
    op.val1 = taq E
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    op.parent = parID [M:BJ%*  
    AddOperation eID, op OSCeTkR  
    Print "Set aqueous humor thickness = " & taq-0.55 :sekMNM  
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    '************************************************************************* YRP$tz+ _  
    'Radius and conic constant of anterior lens @33-UP9o  
    '************************************************************************* PciiDh~/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) +tFl  
    GetConic eID, entity, curv, conic qgsKbsl  

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    SetConic eID, entity, 1/Rant, CCant 2d-C}&}L\  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant T8J[B( )L  
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    '************************************************************************* GwZ(3  
    'Radius and conic constant of posterior lens mdIa`OZr  
    '************************************************************************* 6Vc&g  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) jiAN8t*P  
    GetConic eID, entity, curv, conic <7sGA{  
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    SetConic eID, entity, 1/Rpost, CCpost v"smmQZik  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost =ZN~*HLl}  
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    '*************************************************************************
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    'Lens thickness (Position of posterior lens surface) S%m$LM]NCg  
    '************************************************************************* a(`@u&]WZ  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) s:#\U!>0`  
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    ' Delete any z-shift(s) ].<B:]:,  
    count = 0 G2}e@L0  
    While GetOperationCount(eID)>count AIFI@#3  
        GetOperation eID, count, op KZSvT{  
        If op.Type="ShiftZ" Then sYb(g'W*'  
            DeleteOperation eID,count YV>]c9!q  
            count=count-1 B>M@'  
        End If -V)DKf"f  
        count=count+1 Q'S"$^~{  
    Wend {z/Y~rf  
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    'Set new z-shift K0O&-v0"1  
    op.Type = "ShiftZ" Ljjuf=]  
    op.val1 = tlens !z]2+  
    op.parent = parID d%:   
    AddOperation eID, op * "Z5bKL  
    Print "Set lens thickness = " & tlens <)\  
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    '************************************************************************* B#K{Y$!v  
    'Lens index of refraction WD7IF+v  
    '************************************************************************* td#B$$[  
    eID = FindMaterial( "Lens" ) &z(E-w/S  
    GetModelMaterial eID, mat /&#Gh?
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    mat.Nd = nlens :v!e8kM\x  
    SetModelMaterial eID, mat GF-\WD  
    Print "Set lens index of refraction = " & nlens d}t7bgk'j  
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    '************************************************************************* 3,<$z1Jm  
    'Pupil diameter sox0:9Oqnf  
    '************************************************************************* 54%@q[-  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ;NHZ
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    'Adjust pupil diameter (trimming volume inner hole) E9IU,P6a  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" %cl=n!T  
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    ' Adjust pupil location to just in front of the lens jr<`@  
    parID = FindFullName( "Geometry.Arizona Eye" ) 1]i{b/ 4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) As;@T$G  
    count = 0 *|T]('xwC  
    While GetOperationCount(eID)>count Pu=,L#+FN  
        GetOperation eID, count, op L:ox$RU  
        If op.Type="ShiftZ" Then $-}a<UFE;  
            DeleteOperation eID,count <n)J~B^  
            count=count-1 [%a
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        End If ,X05&'@Z  
        count=count+1 U$fh ~w<[  
    Wend
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    op.Type = "ShiftZ" ]c.1&OB7o  
    op.val1 = taq-0.01 1'[RrJ$Q  
    op.parent = parID ke sg]K  
    AddOperation eID, op -r6cK,WVU  
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    Print "Set pupil diameter = " & pupilDiam GEdWpYKS-`  
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    'Update AZ Eye subassembly Description H<|ilL'fX  
    eID = FindFullName( "Geometry.Arizona Eye" ) 3$u3ssOL  
    GetEntity eID, entity 
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    entity.Description = "Accommodation = " & A & "D" qW1d;pt  
    SetEntity eID, entity wE.CZ%f  
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    Update ' DZYN {}  
    Print "DONE!" \{HbL,s  
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End Sub sw={bUr6G`  
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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： o"te7nBI  
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Accommodation = 4 Diopters ADTx _tE  
Pupil Diameter = 4 mm Nq`@ >Ml  
Set aqueous humor thickness = 2.81 PgeC\#;9  
Set anterior lens radius = 10.4 and conic constant = -2.375869 "0Wi-52=V  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 M7O5uW`  
Set lens thickness = 3.927 CWP),]#n  
Set lens index of refraction = 1.42672 EqN<""2  
Set pupil diameter = 4 JumZ>\'p(  
DONE! Z`UwXp_s