[技术]Arizona眼睛模型 [复制链接]

简介 6Yodx$  
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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。 Q~Mkf&s  
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模型 .Vnb+o  
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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。 \|QB;7u  
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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. tB~#;:g  
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光源 Y`]P&y  
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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。 dV :}  
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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。 jGz~}&B  
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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。 N6-7RoA+  
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视网膜的散射 6}I X{nQI  
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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。 |"9&F  
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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。 $%DoLpE>  
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脚本 `9[n5-t  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： K<5yjG8&  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 U&])ow):  
余下的脚本计算与屈光度有关的所有参数。 (c)/&~aE  
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分析 : pUu_  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 WM|G/'q  
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脚本代码 &t8,326;  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. +u$JMp  
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Dim entity As T_ENTITY v.8kGF  
Dim op As T_OPERATION Wfd`v  
Dim mat As T_MODELMATERIAL S`5bcxI_  
Dim A As Double 0;><
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Dim pupilDiam As Double ?sdSi--  
Dim eID As Long lq_UCCnv5  
Dim parID As Long Mo N/?VA  
Dim count As Integer *s 4Ym
  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double hR|xU
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Dim tlens As Double, nlens As Double 5[
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Dim curv As Double, conic As Double yW'{Z]09  
Dim ok As Long vv,<#4d
 
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Sub Main dpq(=s`s  
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    '用户输入对话框 "$(D7yFO  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 6T4DuF  
        TextBox 220,21,40,21,.TextBox1 'default: 0 S>T ;`,  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1
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        OKButton 40,91,90,21 <B|b'XVH2  
        CancelButton 190,91,90,21 Ln&~t(7  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 =dNE1rdzNa  
        TextBox 220,49,40,21,.TextBox2 'default: 4 vd#)+  
    End Dialog Rq+7&%dy  
    Dim dlg As UserDialog DjK7_'7(L  
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    ok = Dialog (dlg) b(|&e  
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    If ok=0 Then    'cancel button was pressed o?/H<k\5
  
        Print "Execution cancelled." ^wZx=kas  
        End M.dX;iM<  
    End If Cx~;oWZ  
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    'Assign accommodation and pupil diameter & use defaults if field left empty [7PC\  
    If dlg.TextBox1 = "" Then ;\A_-a_(#  
        A = 0           'Default accommodation pJe!~eyHm  
    Else d:>^]5cE&  
        A = CDbl(dlg.TextBox1) 0/]h"5H3  
    End If EMe1!)  
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    If dlg.TextBox2 = "" Then mYo~RXKGF  
        pupilDiam = 4   'Default pupil diameter 4"eFR'g  
    Else |$IL:W6  
        pupilDiam = CDbl(dlg.TextBox2) ^#e|^]] L  
    End If 6B@e[VtG$  
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    Print " " Xa>'DO2  
    Print "Accommodation = " & A & " Diopters" HFjSM~  
    Print "Pupil Diameter = " & pupilDiam & " mm" \(Nx)F  
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    ' Calculate new parameters with accommodation Q{S
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness *^; MWI  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 4=^Ha%l  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens k*2khh-  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens xC9?rLUZ  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens `"ks0@^U  
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    tlens = 3.767 + 0.04*A                  'Lens thickness y,rdyt  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction <f:(nGj  
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    'Adjust parameters to account for accommodation {7oPDP  
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    '************************************************************************* ))dqC l  
    'Aqueous thickness (Position of Lens) l v:GiA"X  
    '************************************************************************* ddl]! ^IK  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) m#[c]v{  
    GetCustomElement eID, entity R*
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    parID = FindFullName( "Geometry.Arizona Eye" ) ]vR Ol.  
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    ' Delete any shift(s) in z hFycSu  
    count = 0 ;s$4/b/~  
    While GetOperationCount(eID)>count I_Lm[  
        GetOperation eID, count, op X)j%v\#`U  
        If op.Type="ShiftZ" Then
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            DeleteOperation eID,count 1jKj'7/K  
            count=count-1 OB=bRLd.IR  
        End If &x*l{s[  
        count=count+1 1+3-Z>^e  
    Wend tkptm%I_  
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    'Set new shift in \>"Zn7  
    op.Type = "ShiftZ" lz>.mXdx  
    op.val1 = taq DsxNg  
    op.parent = parID 4@F8-V3q4  
    AddOperation eID, op $Sy}im
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    Print "Set aqueous humor thickness = " & taq-0.55 dj] O  
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    '************************************************************************* :rufnmsP<U  
    'Radius and conic constant of anterior lens !W&|kvT^  
    '************************************************************************* daA&!vnbH*  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) v#g:]T  
    GetConic eID, entity, curv, conic P^Og(F8;  
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    SetConic eID, entity, 1/Rant, CCant Zd-QZ<c";t  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant .&bc3cW  
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    '************************************************************************* *h?}~!AjY  
    'Radius and conic constant of posterior lens )Mflt0fp  
    '************************************************************************* &q-P O  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) D=D.s)ns*  
    GetConic eID, entity, curv, conic N1y,~Z  
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    SetConic eID, entity, 1/Rpost, CCpost ey<z#Q5+  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost _E0yzkS  
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    '************************************************************************* ~k@{b&  
    'Lens thickness (Position of posterior lens surface) Pu!C,7vUQ  
    '************************************************************************* K",Xe>  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) pXQ$n:e  
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    ' Delete any z-shift(s) Y nTx)uW  
    count = 0 ?a,`{1m0\  
    While GetOperationCount(eID)>count %qrUP\rn  
        GetOperation eID, count, op P?8$VAkj  
        If op.Type="ShiftZ" Then 06pY10<>X  
            DeleteOperation eID,count f@Ve,i  
            count=count-1 y{P~!Y
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        End If }HbUB$5  
        count=count+1 z+0#H39&  
    Wend &R<K>i  
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    'Set new z-shift HmsXV_B8[Y  
    op.Type = "ShiftZ" O#8lJ%?  
    op.val1 = tlens \\oa[nvL~  
    op.parent = parID RWDPsZC  
    AddOperation eID, op :< ]sJfN  
    Print "Set lens thickness = " & tlens 4w 7vgB  
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    '************************************************************************* \`/ P*  
    'Lens index of refraction ^h`rA"F\  
    '************************************************************************* &=Y%4vq  
    eID = FindMaterial( "Lens" ) CX{M@x3m  
    GetModelMaterial eID, mat m60hTJ?N)  
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    mat.Nd = nlens {pRa%DF  
    SetModelMaterial eID, mat I[06R
 
    Print "Set lens index of refraction = " & nlens 4q@[k:'  
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    '************************************************************************* +).=}.k  
    'Pupil diameter -s91/|n  
    '************************************************************************* O15~\8#'  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) b!EqYT  
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    'Adjust pupil diameter (trimming volume inner hole) %3K'[2F  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Y\(?&7Aax  
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    ' Adjust pupil location to just in front of the lens et
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    parID = FindFullName( "Geometry.Arizona Eye" ) Sn;q:e3i{A  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 2:[G4  
    count = 0 p5nrPL  
    While GetOperationCount(eID)>count ZGd7e.u=  
        GetOperation eID, count, op 7Z81+I|&8  
        If op.Type="ShiftZ" Then |;C;d"JC2  
            DeleteOperation eID,count *unJd"<*&@  
            count=count-1 _UF'Cf+Y  
        End If bh5C  
        count=count+1 DxP65wU  
    Wend 7:C2xC  
    op.Type = "ShiftZ" iA"H*0  
    op.val1 = taq-0.01 H Mfhe[A?  
    op.parent = parID |'L$ogt6  
    AddOperation eID, op /cD]m  
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    Print "Set pupil diameter = " & pupilDiam DCCijN  
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    'Update AZ Eye subassembly Description d\ Xijy  
    eID = FindFullName( "Geometry.Arizona Eye" ) (rf8"T!"  
    GetEntity eID, entity ,z$U=uo  
    entity.Description = "Accommodation = " & A & "D" p1\EC#Q  
    SetEntity eID, entity Q>/[*(.Wd  
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    Update ?d)eri8,  
    Print "DONE!" ).r04)/  
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End Sub .YIb ny1  
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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： m8v=pab e  
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Accommodation = 4 Diopters  Y}Nd2  
Pupil Diameter = 4 mm kQtnT7  
Set aqueous humor thickness = 2.81 `lE8dwL  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Rd+`b  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 !ma'*X  
Set lens thickness = 3.927 &PEw8: TX  
Set lens index of refraction = 1.42672 onUF@3V  
Set pupil diameter = 4 mk?F+gh  
DONE! ::k/hP9.^