[技术]Arizona眼睛模型 [复制链接]

简介 3p'(E\V
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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。 V<d`.9*}  
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模型 '9AYE"7Ydk  
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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。 |Lc.XxBkc  
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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. [Fr <tKtB  
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光源 GEki34 n0  
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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。 Nh6!h%  
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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。 T lB+ tV>  
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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。 ~VPE9D@  
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视网膜的散射 DWU(ld:_  
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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。 ~JOC8dO  
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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。 gq+#=!(2  
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脚本 ^i17MvT'  
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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： 8b+%:eJ  
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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。 E_K32)J-  
余下的脚本计算与屈光度有关的所有参数。 8|rlP  
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分析 ,f[Oy:fr  
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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。 iM{cr&0  
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脚本代码 BU%gXr4Ra  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 7T=:dv  
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Dim entity As T_ENTITY  C0j`H(  
Dim op As T_OPERATION wUmcA~3D  
Dim mat As T_MODELMATERIAL nsi&r  
Dim A As Double rF . Oo0  
Dim pupilDiam As Double ^+9i~PjL  
Dim eID As Long ]U5/!e  
Dim parID As Long '6Yx03t  
Dim count As Integer g<MCvC@  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 4-q8:5  
Dim tlens As Double, nlens As Double o>\epQt~/p  
Dim curv As Double, conic As Double ] U[4r9V  
Dim ok As Long Iyt.`z  
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Sub Main Ba;tEF{X  
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    '用户输入对话框 w'P!<JaZ  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ?) VBkA5j  
        TextBox 220,21,40,21,.TextBox1 'default: 0 W/<C$T4  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 i8`0-  
        OKButton 40,91,90,21 :Pi="  
        CancelButton 190,91,90,21 e>$E67h<~  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Y/G~P,9  
        TextBox 220,49,40,21,.TextBox2 'default: 4 +L#Q3}=s  
    End Dialog 7By&cdl  
    Dim dlg As UserDialog !a9/8U_>XF  
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    ok = Dialog (dlg) =7<g;u  
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    If ok=0 Then    'cancel button was pressed wRj&k(?*  
        Print "Execution cancelled." lNqF@eCT9  
        End LT)G"U~  
    End If  8=j_~&*  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ~Z x_"  
    If dlg.TextBox1 = "" Then el^WBC3  
        A = 0           'Default accommodation 5U%a$.yr  
    Else ?h'd\.j{  
        A = CDbl(dlg.TextBox1) *W=R:Bl!  
    End If T&kr IZw  
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    If dlg.TextBox2 = "" Then UU]a).rz  
        pupilDiam = 4   'Default pupil diameter r WPoR/M  
    Else hIMD2  
        pupilDiam = CDbl(dlg.TextBox2) DsF<P@O6  
    End If x8E!Ko](  
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    Print " "  .'^Pg  
    Print "Accommodation = " & A & " Diopters" OG}m+K&<  
    Print "Pupil Diameter = " & pupilDiam & " mm" ~>|o3&G{  
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    ' Calculate new parameters with accommodation Cw&U*H  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ma(E}s  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens {/SLDy
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens w&^_2<a2  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens cAc>p-y
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens G,JNUok  
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    tlens = 3.767 + 0.04*A                  'Lens thickness @b"J FB|  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Q{+N{/tF  
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    'Adjust parameters to account for accommodation 8.4+4Vxh   
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    '************************************************************************* W4o$J4IX{  
    'Aqueous thickness (Position of Lens) 8\@&~&(y:
 
    '************************************************************************* D "9Hv3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) l|p \8=  
    GetCustomElement eID, entity _qQB.Dzo:  
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    parID = FindFullName( "Geometry.Arizona Eye" ) o&b1-=MC2  
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    ' Delete any shift(s) in z 1Ydym2  
    count = 0 Y1Qg|U o  
    While GetOperationCount(eID)>count h#!u"'JW  
        GetOperation eID, count, op O+Qt8,  
        If op.Type="ShiftZ" Then LU4k/  
            DeleteOperation eID,count Auz.wes  
            count=count-1 NRgNW1#  
        End If dwAFJhgh  
        count=count+1 O4i5fVy{  
    Wend WGeTL`}dh  
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    'Set new shift in L#^'9v}Hb  
    op.Type = "ShiftZ" !R.*Vn[  
    op.val1 = taq k9pOY]_Y  
    op.parent = parID 46cd5SLK  
    AddOperation eID, op wa*/Am9;~  
    Print "Set aqueous humor thickness = " & taq-0.55 HKZD*E((  
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    '************************************************************************* Mk~]0d  
    'Radius and conic constant of anterior lens r|>a;nY  
    '************************************************************************* :L!O/Bd8V  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) B5Y 3GWhrx  
    GetConic eID, entity, curv, conic Dtw1q-  
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    SetConic eID, entity, 1/Rant, CCant &hb:~>
 
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant %8a88
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    '************************************************************************* ]c'12 g]h  
    'Radius and conic constant of posterior lens SuU_psF  
    '************************************************************************* lSzLR~=Au  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) [j]3='2}G  
    GetConic eID, entity, curv, conic |3A/Og  
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    SetConic eID, entity, 1/Rpost, CCpost Pgg\(D#X`  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Rr|&~%#z  
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    '************************************************************************* Mr3;B+S  
    'Lens thickness (Position of posterior lens surface) =E?!!EIq.  
    '************************************************************************* ;/Z9M"!u[  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) (79y!&9p  
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    ' Delete any z-shift(s) 1dy>a=W  
    count = 0 ?Q]{P]  
    While GetOperationCount(eID)>count 6:v$g  
        GetOperation eID, count, op ymxYE#q  
        If op.Type="ShiftZ" Then "#a_--"k9  
            DeleteOperation eID,count 5D32d1A  
            count=count-1 Rt[zZv  
        End If lStYfO:<'v  
        count=count+1 "XEKoeG{  
    Wend `T gwa  
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    'Set new z-shift
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    op.Type = "ShiftZ" 0=2D90  
    op.val1 = tlens MifPZQ  
    op.parent = parID dvAvG.;U  
    AddOperation eID, op ;;9W/m~]  
    Print "Set lens thickness = " & tlens %6v
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    '************************************************************************* &{Zt(%\ '  
    'Lens index of refraction YB^[HE\#y  
    '************************************************************************* f
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    eID = FindMaterial( "Lens" ) Z*}5M4  
    GetModelMaterial eID, mat }T}9AQ}|  
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    mat.Nd = nlens me+F0:L  
    SetModelMaterial eID, mat !8Rsz:7^-  
    Print "Set lens index of refraction = " & nlens nnV(MB4z1  
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    '************************************************************************* *<PQp  
    'Pupil diameter Jv|uI1V  
    '************************************************************************* i,{'}B  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) "t-u=aDl-.  
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    'Adjust pupil diameter (trimming volume inner hole) fI5]ed eS  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" oQ!56\R  
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    ' Adjust pupil location to just in front of the lens [/s^(2%  
    parID = FindFullName( "Geometry.Arizona Eye" ) E,F'k2yU  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) \B0,?_i  
    count = 0 iBq|]  
    While GetOperationCount(eID)>count RJo"yB$1e6  
        GetOperation eID, count, op r+}5;fQJ  
        If op.Type="ShiftZ" Then x*G-?Xza)  
            DeleteOperation eID,count eVobs2s  
            count=count-1 /.'tfy$  
        End If jIq@@8@o  
        count=count+1 H8V${&!ho  
    Wend *?zyF@K{%  
    op.Type = "ShiftZ" u}eqU%  
    op.val1 = taq-0.01 wF +9Iu
 
    op.parent = parID FCC9Ht8U?  
    AddOperation eID, op Mpf
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    Print "Set pupil diameter = " & pupilDiam 5AvbKT  
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    'Update AZ Eye subassembly Description 7IrbwAGZ3  
    eID = FindFullName( "Geometry.Arizona Eye" ) /B$9B  
    GetEntity eID, entity -R^OYgF  
    entity.Description = "Accommodation = " & A & "D" #}/YnVk  
    SetEntity eID, entity Xndgs}zz  
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    Update r[ UZHX5+S  
    Print "DONE!" (vq0Gl  
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End Sub +1Qa7\  
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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： OJ (ho&((  
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Accommodation = 4 Diopters u!=9.3
 
Pupil Diameter = 4 mm 7oj ^(R,  
Set aqueous humor thickness = 2.81 sD|P*ir  
Set anterior lens radius = 10.4 and conic constant = -2.375869 #J1vN]g  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 LciSQ R!  
Set lens thickness = 3.927 uSeRn@  
Set lens index of refraction = 1.42672 SLzxFuV  
Set pupil diameter = 4 j.? '*?P  
DONE! 6qW/Td|g