[技术]Arizona眼睛模型 [复制链接]

简介 {K/xI  
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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。 a][Tb0Ox  
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模型 d,j)JnY3V  
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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。 {;JFoe+  
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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. akgvV~
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光源 "!Hm.^1  
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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。 o1&Oug  
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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。
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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。 `DP4u\6_  
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视网膜的散射 cT'<,#^/  
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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。 :&O6Y-/B  
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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。 m&6)Vt  
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脚本 jsw0"d(  
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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： W -5wjc  
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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。 "nn>I}jK  
余下的脚本计算与屈光度有关的所有参数。 7{u1ynt  
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分析 #)<WQZ)  
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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。 e5m-7{h@  
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脚本代码 ^36m$J$  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. OQby=}A  
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Dim entity As T_ENTITY rp,PhS  
Dim op As T_OPERATION UE%~SVi.#  
Dim mat As T_MODELMATERIAL <0^L L  
Dim A As Double /Os;,g  
Dim pupilDiam As Double *Zk$P.]  
Dim eID As Long $N17GqoC  
Dim parID As Long !" 7ip9a  
Dim count As Integer |),3`*N  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double J~1=?</  
Dim tlens As Double, nlens As Double 3Qoa?*  
Dim curv As Double, conic As Double Eza B}BLQ9  
Dim ok As Long vKcc|#  
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Sub Main uSn<]OrZo`  
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    '用户输入对话框 SXm Hn.?  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ; Uf]-uS  
        TextBox 220,21,40,21,.TextBox1 'default: 0 9A9yZlt  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 6 2#dSd}HG  
        OKButton 40,91,90,21 @m(ja@YC  
        CancelButton 190,91,90,21 |a[Id  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 uMM?s?q  
        TextBox 220,49,40,21,.TextBox2 'default: 4 !TdbD56  
    End Dialog xO` O$ie  
    Dim dlg As UserDialog {qjw  S1v  
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    ok = Dialog (dlg) *u`[2xmuYf  
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    If ok=0 Then    'cancel button was pressed ;bxL$1  
        Print "Execution cancelled." xr'gi(.o  
        End d(8X?k.S  
    End If $ -n?q w  
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    'Assign accommodation and pupil diameter & use defaults if field left empty I~P]_DmM  
    If dlg.TextBox1 = "" Then W_P&;)E  
        A = 0           'Default accommodation s.uV,E*wu  
    Else sT|FgB  
        A = CDbl(dlg.TextBox1) j_2yTz"G-  
    End If ~^pV>>LX|  
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    If dlg.TextBox2 = "" Then pSlosv(6  
        pupilDiam = 4   'Default pupil diameter a jyuk@  
    Else tHV81F1J  
        pupilDiam = CDbl(dlg.TextBox2) ('7qJkV  
    End If GH!Lu\y\  
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    Print " " [#Y7iN&  
    Print "Accommodation = " & A & " Diopters" XrD@q  
    Print "Pupil Diameter = " & pupilDiam & " mm" xsIuPL#_  
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    ' Calculate new parameters with accommodation BVk&TGa;[$  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness S>s{t=AY~  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens U4hFPK<  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens !E
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Xitsbf=Gg  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens G`1FD  
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    tlens = 3.767 + 0.04*A                  'Lens thickness +vh 4I  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction D[ -Gzqh  
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    'Adjust parameters to account for accommodation orcPKCz|"  
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    '************************************************************************* k&h3"  
    'Aqueous thickness (Position of Lens) {BA1C (  
    '************************************************************************* qz .{[l  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) )LP=IT  
    GetCustomElement eID, entity z|:3,$~sN  
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    parID = FindFullName( "Geometry.Arizona Eye" ) CtO`t5  
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    ' Delete any shift(s) in z LyB &u()  
    count = 0 1D/9lR,  
    While GetOperationCount(eID)>count r(#]Z  
        GetOperation eID, count, op d?uN6JH9  
        If op.Type="ShiftZ" Then sD[G?X  
            DeleteOperation eID,count YAvOV-L  
            count=count-1 E0Y>2HOuL  
        End If 0$~zeG"  
        count=count+1 XpLK0YI  
    Wend XpH]CF  
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    'Set new shift in p*_^JU(<p  
    op.Type = "ShiftZ" ~rWys=  
    op.val1 = taq Vk>m/"  
    op.parent = parID 9Rg|oCP_  
    AddOperation eID, op 4._U  
    Print "Set aqueous humor thickness = " & taq-0.55 [Pnk@jIk4  
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    '************************************************************************* GV1SKa  
    'Radius and conic constant of anterior lens B?cn5  
    '************************************************************************* <^APq8>  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Ob"48{w$  
    GetConic eID, entity, curv, conic X
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    SetConic eID, entity, 1/Rant, CCant Sl?@c/Ng  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ?=22@Q}g  
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    '************************************************************************* $Z!$E,@c  
    'Radius and conic constant of posterior lens 1+f>t
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    '************************************************************************* F"k.1.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) #@*;Y(9Ol  
    GetConic eID, entity, curv, conic Ch~2w)HAA  
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    SetConic eID, entity, 1/Rpost, CCpost P}AfXgr  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost z)Is:LhS  
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    '************************************************************************* Y2
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    'Lens thickness (Position of posterior lens surface) {Gd<+tQg  
    '************************************************************************* _.ny<r:g  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) COF_a%  
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    ' Delete any z-shift(s) PW[NW-S`c  
    count = 0 U',9t  
    While GetOperationCount(eID)>count J(%Jg  
        GetOperation eID, count, op LZ97nvK  
        If op.Type="ShiftZ" Then Y_H|Fl^  
            DeleteOperation eID,count k|Hxd^^I  
            count=count-1 HR/"Nwr  
        End If :2qUel\PEC  
        count=count+1 $!(J4v=X  
    Wend b?p_mQKtZ  
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    'Set new z-shift *5\k1-$  
    op.Type = "ShiftZ" V8aLPJ0_  
    op.val1 = tlens L7_qs+  
    op.parent = parID eX;Tufe*(Q  
    AddOperation eID, op 3M;[.b  
    Print "Set lens thickness = " & tlens ~F</s.  
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    '************************************************************************* 4z_>Ci
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    'Lens index of refraction X"S-f;b#  
    '************************************************************************* N^G:m~>  
    eID = FindMaterial( "Lens" ) 8f^QO:  
    GetModelMaterial eID, mat PWwz<AI+  
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    mat.Nd = nlens ;Y&<psQeb  
    SetModelMaterial eID, mat !L+4YA  
    Print "Set lens index of refraction = " & nlens d:U2b"k=/u  
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    '************************************************************************* wTpjM@F?J|  
    'Pupil diameter 9^;)~ G  
    '************************************************************************* HG1)q\Xd  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) DE{tpN  
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    'Adjust pupil diameter (trimming volume inner hole) 36NENzK  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" rRTAWAs%T  
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    ' Adjust pupil location to just in front of the lens FmRCTH  
    parID = FindFullName( "Geometry.Arizona Eye" ) WBo|0(#  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) `
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    count = 0 W[5a'}OV  
    While GetOperationCount(eID)>count ;1S~'B&1Q  
        GetOperation eID, count, op i2a""zac  
        If op.Type="ShiftZ" Then uxGY/Zf  
            DeleteOperation eID,count 5 A/[x$q  
            count=count-1 &\3k(j  
        End If =@98Gl9!  
        count=count+1 /rKdxsI*  
    Wend c.-/e u^|  
    op.Type = "ShiftZ" 20 j9~+  
    op.val1 = taq-0.01 Q7 dXTS4H  
    op.parent = parID bNUb  
    AddOperation eID, op 7^{M:kYC!  
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    Print "Set pupil diameter = " & pupilDiam aoLYw 9  
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    'Update AZ Eye subassembly Description Y9b|lP7!  
    eID = FindFullName( "Geometry.Arizona Eye" ) ]Iku(<*Ya  
    GetEntity eID, entity
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    entity.Description = "Accommodation = " & A & "D" th@a./h"  
    SetEntity eID, entity "bO\Wt#Mf  
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    Update @yBg)1AL  
    Print "DONE!" %J*z!Fe8s  
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End Sub *O>O
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如果屈光度是4，光瞳直径是4，则会输出如下数据： `$IuN*  
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Accommodation = 4 Diopters &WSxg&YG)\  
Pupil Diameter = 4 mm zJp}
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Set aqueous humor thickness = 2.81 CNC3">Dk~9  
Set anterior lens radius = 10.4 and conic constant = -2.375869 hXsd12  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 #Y*?
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Set lens thickness = 3.927 7j9:s>D  
Set lens index of refraction = 1.42672 >900I4]I  
Set pupil diameter = 4 kB|jN~  
DONE! E7A psi4]