[技术]Arizona眼睛模型 [复制链接]

简介 <tTNtBb  
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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。 `GqF/?i  
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模型 iJ58RY  
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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。 '*Y mYU  
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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. >;G_o="X  
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光源 1Mq"f7X8  
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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。 u^C\aujg  
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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。 2pHR$GZ2  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 :Dr4?6hdr  
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视网膜的散射 aU +uPP  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 e+Mm!\;`  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 OvdBUcp[  
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脚本 ;,/G*`81B  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： jz'%(6#'gW  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 HU +271A8  
余下的脚本计算与屈光度有关的所有参数。 brE%/%!e  
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分析 T?n[1%K  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 bMqS:+  
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脚本代码 M+=q"#&  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ^s8JW"H  
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Dim entity As T_ENTITY tr 8Q{  
Dim op As T_OPERATION >Y3zO2Cr  
Dim mat As T_MODELMATERIAL 1{xkAy0  
Dim A As Double &@&^k$du8q  
Dim pupilDiam As Double GO#eI]>/r  
Dim eID As Long 8r.MODZG/  
Dim parID As Long jN+2+P%OL  
Dim count As Integer p{V(! v|  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double '~6l 6wi  
Dim tlens As Double, nlens As Double fK4O N'[R:  
Dim curv As Double, conic As Double Zg])uM]\2i  
Dim ok As Long '#r^W2  
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Sub Main Fw#wVs)@:  
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    '用户输入对话框 j~ qm5}  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ciPaCrV  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Im`R2_(]  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 \y/0)NL\  
        OKButton 40,91,90,21 6`'KM/  
        CancelButton 190,91,90,21 /P{'nI  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 i;+<5
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        TextBox 220,49,40,21,.TextBox2 'default: 4 4,6?sTuX  
    End Dialog oW/H8q<wY  
    Dim dlg As UserDialog 1UH_"Q03  
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    ok = Dialog (dlg) ,Hc,]TPC4  
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    If ok=0 Then    'cancel button was pressed SQ`ec95',  
        Print "Execution cancelled." CYk"  
        End }Tk*?tYt  
    End If YP}r15P  
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    'Assign accommodation and pupil diameter & use defaults if field left empty "CT`]:GGK  
    If dlg.TextBox1 = "" Then Z5

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        A = 0           'Default accommodation 3DrW[\  
    Else y{qKb:~wv  
        A = CDbl(dlg.TextBox1) Z@>WUw@F  
    End If FiNB$A  
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    If dlg.TextBox2 = "" Then EG!):P  
        pupilDiam = 4   'Default pupil diameter cNuBWLG  
    Else ^d/,9L\U  
        pupilDiam = CDbl(dlg.TextBox2) }D#[yE,=\  
    End If K}Pi"Le@W  
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    Print " " *&yt;|y  
    Print "Accommodation = " & A & " Diopters" /\uW[
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    Print "Pupil Diameter = " & pupilDiam & " mm" {&Sr<d
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    ' Calculate new parameters with accommodation ^cYt4NHXn  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness )pt#Pu  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens h|&qWv  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens bMF`KRP2  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens [kg*BaG:  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens p[gq^5WuC  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ig,v6lqhM  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 'x\{sv  
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    'Adjust parameters to account for accommodation <q#/z&F!  
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    '************************************************************************* l7=WO#Pb  
    'Aqueous thickness (Position of Lens) FiJU *  
    '************************************************************************* f0lK,U@P  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5l(Q#pSX  
    GetCustomElement eID, entity L%O( I  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ZYX(C
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    ' Delete any shift(s) in z v/lQ5R1  
    count = 0 -J=N  
    While GetOperationCount(eID)>count $
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        GetOperation eID, count, op u9%)_Q!14  
        If op.Type="ShiftZ" Then VjVL/SO/  
            DeleteOperation eID,count |F#L{=B  
            count=count-1 q+-Bl  
        End If x?B8b-*  
        count=count+1 (t)a u  
    Wend DR6 OR B7  
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    'Set new shift in #/Qe7:l  
    op.Type = "ShiftZ" Mw+8p}E  
    op.val1 = taq ?]L:j  
    op.parent = parID Xz, sL  
    AddOperation eID, op T&`H )o  
    Print "Set aqueous humor thickness = " & taq-0.55 0Bpix|mq  
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    '************************************************************************* $w$
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    'Radius and conic constant of anterior lens ~?)ST?&  
    '************************************************************************* 5#U*vGVT
 
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) n7S~nk  
    GetConic eID, entity, curv, conic "Q~-C|x  
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    SetConic eID, entity, 1/Rant, CCant *Q8d&$ ^  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ?0
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    '************************************************************************* }Myi0I<  
    'Radius and conic constant of posterior lens <2a7>\74E0  
    '************************************************************************* jreY'y:  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 'j+J?Y^  
    GetConic eID, entity, curv, conic tCdgtZm  
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    SetConic eID, entity, 1/Rpost, CCpost =K)au$BE|  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost E}$K&<J'-  
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    '************************************************************************* `_;VD?")*l  
    'Lens thickness (Position of posterior lens surface) @:s|X  
    '************************************************************************* _YH)E^If  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) |h,aV(Q  
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    ' Delete any z-shift(s) {]}}rx'|P  
    count = 0 !.'@3-w]  
    While GetOperationCount(eID)>count r$*p  
        GetOperation eID, count, op .hCOi<wB  
        If op.Type="ShiftZ" Then b:S#Sz$  
            DeleteOperation eID,count K6.
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            count=count-1 l}?'U  
        End If 4V7{
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        count=count+1 '~E&^K5hr  
    Wend @,-xaZ[  
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    'Set new z-shift (,E.1j]ji  
    op.Type = "ShiftZ" QMzBx*g(  
    op.val1 = tlens ^zv28Wq>  
    op.parent = parID r)dT,X[}F  
    AddOperation eID, op PF1m :Iz`d  
    Print "Set lens thickness = " & tlens EV@xUq!x.  
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    '************************************************************************* nJYcC"f  
    'Lens index of refraction 1_7}B4  
    '************************************************************************* @Zs}8YhC  
    eID = FindMaterial( "Lens" ) 0j1I  
    GetModelMaterial eID, mat DiAPs_@  
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    mat.Nd = nlens @>J4K#"  
    SetModelMaterial eID, mat :Q\b$=,:  
    Print "Set lens index of refraction = " & nlens w$7*za2  
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    '************************************************************************* n2R{$^JxO  
    'Pupil diameter Frt_X%  
    '************************************************************************* GCx]VN3&  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) <BQ4x.[  
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    'Adjust pupil diameter (trimming volume inner hole) O1@xF9<  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" (i7]N[  
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    ' Adjust pupil location to just in front of the lens MOyQ4<_  
    parID = FindFullName( "Geometry.Arizona Eye" ) Jjz:-Uqq2  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) K ^1bR(a  
    count = 0 <!&&Qd-d6H  
    While GetOperationCount(eID)>count z@cL<.0CE  
        GetOperation eID, count, op vcAs!ls+  
        If op.Type="ShiftZ" Then S@zsPzw  
            DeleteOperation eID,count fw_V'l#\  
            count=count-1 8@!/%"Kt2  
        End If r9G<HKl  
        count=count+1 R{3f5**0  
    Wend |-I[{"6q$@  
    op.Type = "ShiftZ" l?B\TA^  
    op.val1 = taq-0.01 '1=t{Rw
 
    op.parent = parID bzmT.!  
    AddOperation eID, op AFl]w'=  
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    Print "Set pupil diameter = " & pupilDiam K!k,]90Ko  
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    'Update AZ Eye subassembly Description }7vX4{Yn  
    eID = FindFullName( "Geometry.Arizona Eye" ) G;FY2;adK  
    GetEntity eID, entity #P-S.b  
    entity.Description = "Accommodation = " & A & "D" &&|*GAjJ  
    SetEntity eID, entity 0,nDyTS^  
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    Update xF5q=%n  
    Print "DONE!" c0u!V+V%  
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End Sub \A _g  
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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： T?)?"b\qz  
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Accommodation = 4 Diopters .wx;
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Pupil Diameter = 4 mm JMw1qPJQ  
Set aqueous humor thickness = 2.81 6Ez}A|i  
Set anterior lens radius = 10.4 and conic constant = -2.375869 N9Yc\?_NU_  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 y_38;8ex  
Set lens thickness = 3.927 h{yqNl  
Set lens index of refraction = 1.42672 8\`]T%h  
Set pupil diameter = 4 $TL~SVHj;{  
DONE! Nj qUUkc