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infotek 2021-10-22 09:55

Arizona眼睛模型

简介 z5sKV7&\[n  
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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。 =,08D^xY  
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模型 >R.!Qze\G  
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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。 3ZvQUH/{W  
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Table 1. AZ眼睛模型的定义
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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. -cUw}  
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光源 5 L-6@@/  
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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。 9A}y^=!`  
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图1. 光源和提示信息使用
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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。 I#W J";kqB  
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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。 '47E8PIJ|  
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图2. 字母F光源的设定方法光 /EL3Tt  
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图3. 字母F在视网膜上位置点列图
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视网膜的散射 &*~_ "WyU  
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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。 u#3Cst8Y  
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图4. 视网膜朗伯散射设定
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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。 `<% w4 E  
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图5. 视网膜重点采样规格设定
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脚本 ~sCdvBA  
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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: ;]2d%Qt  
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图6. 用户对话框的创建与编辑
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图7. 用户对话框编辑器
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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。 :/;;|lGw  
余下的脚本计算与屈光度有关的所有参数。 z~;@Mo"*f  
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分析 Ystd[  
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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。 B> zQ[e@t  
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图7. 字母F在视网膜上颜色分析
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脚本代码 @$?*UI6y  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 7#9fcfL  
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Dim entity As T_ENTITY *(nu0  
Dim op As T_OPERATION CbT ;#0  
Dim mat As T_MODELMATERIAL s18A  
Dim A As Double 1xsB@D  
Dim pupilDiam As Double |PLWF[+t8  
Dim eID As Long TZ PUVOtL_  
Dim parID As Long #LG<o3An  
Dim count As Integer A)nE+ec1  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ymA8`k5>@  
Dim tlens As Double, nlens As Double qkq^oHI  
Dim curv As Double, conic As Double /qXP\ a  
Dim ok As Long t},71Ry  
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Sub Main R78lV -};Q  
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    '用户输入对话框 jft@ 'W53  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 f7 zGz  
        TextBox 220,21,40,21,.TextBox1 'default: 0 :Y&h'FGZm  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 (vbI4&r  
        OKButton 40,91,90,21 kJ B u7  
        CancelButton 190,91,90,21 .vpx@_;]9  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 {uiL91j.  
        TextBox 220,49,40,21,.TextBox2 'default: 4 SCXtBZ`.G  
    End Dialog k i{8f  
    Dim dlg As UserDialog mB*;>   
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    ok = Dialog (dlg) \2)~dV:6+  
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    If ok=0 Then    'cancel button was pressed '6Yx03t  
        Print "Execution cancelled." g<MCvC@  
        End 4-q8:5  
    End If < #7j~<  
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    'Assign accommodation and pupil diameter & use defaults if field left empty N`5 mPE  
    If dlg.TextBox1 = "" Then h) W|~y@  
        A = 0           'Default accommodation 3F9AnS  
    Else 2r#W#z%vS  
        A = CDbl(dlg.TextBox1) 6 kAXE\T  
    End If ;d||u  
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    If dlg.TextBox2 = "" Then /@K1"/fqH  
        pupilDiam = 4   'Default pupil diameter A)u,Hvn  
    Else bH_zWk  
        pupilDiam = CDbl(dlg.TextBox2) Y/G~P,9  
    End If +L#Q3}=s  
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    Print " " GP=&S|hi  
    Print "Accommodation = " & A & " Diopters" (hIy31Pf  
    Print "Pupil Diameter = " & pupilDiam & " mm" KoTQc0b!  
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    ' Calculate new parameters with accommodation 0 I[3%Q{  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness R8fB 8 )  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens |j7{zsH  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens WB=|Ty ~l  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens nSh}1Arp/  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens B}Sl1)E  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ?-9It|R  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction C(5B/W6  
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    'Adjust parameters to account for accommodation 2<Q3-|/i  
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    '************************************************************************* ffS]%qa  
    'Aqueous thickness (Position of Lens) ^Euqy,8}  
    '************************************************************************* +`Ypc  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) MbjMO"}  
    GetCustomElement eID, entity 5<L+T  
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    parID = FindFullName( "Geometry.Arizona Eye" ) |fg{Fpc  
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    ' Delete any shift(s) in z =aE!y5  
    count = 0 hha^:,  
    While GetOperationCount(eID)>count 0|@* `-:VO  
        GetOperation eID, count, op YCEdt>5PA  
        If op.Type="ShiftZ" Then KcNh3CR  
            DeleteOperation eID,count UqaV9  
            count=count-1 @b"J FB|  
        End If q~*>  
        count=count+1 Dg2=;)"L  
    Wend #&ZwQw  
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    'Set new shift in O %?d0K  
    op.Type = "ShiftZ" <hSrx7o  
    op.val1 = taq DZ~qk+,I  
    op.parent = parID x6={)tj  
    AddOperation eID, op i$!-mYi+Q!  
    Print "Set aqueous humor thickness = " & taq-0.55 ZF6?N?t}h8  
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    '************************************************************************* WaYT7 :  
    'Radius and conic constant of anterior lens Erd)P  
    '************************************************************************* 1lLL9l{UVw  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) j^'op|l  
    GetConic eID, entity, curv, conic }qOj^pkJ  
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    SetConic eID, entity, 1/Rant, CCant 9>na3ISh  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant p?,:  
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    '************************************************************************* ]K(>r#'nH  
    'Radius and conic constant of posterior lens (:2,Rr1"  
    '************************************************************************* ^%pM$3ov  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 1rmK#ld"=Z  
    GetConic eID, entity, curv, conic ,/>hWAx  
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    SetConic eID, entity, 1/Rpost, CCpost t^zmv PDK  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost DYKJVn7w  
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    '************************************************************************* 7$&3(#!N  
    'Lens thickness (Position of posterior lens surface) O>j_xW]V  
    '************************************************************************* =Vm"2g,aA  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) %t:pG}A>:C  
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    ' Delete any z-shift(s) UfUboxT  
    count = 0 &hb:~>  
    While GetOperationCount(eID)>count mgxoM|n6  
        GetOperation eID, count, op {q-<1|xj/J  
        If op.Type="ShiftZ" Then *6trK`tx^  
            DeleteOperation eID,count xF4>G0  
            count=count-1 vS{zLXg  
        End If 8I`t`C/4  
        count=count+1 b=Y:`&o=[  
    Wend r- ];@  
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    'Set new z-shift W%xg;uzp  
    op.Type = "ShiftZ" wtY*{m2  
    op.val1 = tlens 8- U1Y  
    op.parent = parID }bxW@(bs  
    AddOperation eID, op ]'2;6%. 4  
    Print "Set lens thickness = " & tlens <[e E5X(  
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    '************************************************************************* !F_BLHig  
    'Lens index of refraction 9$u'2TV  
    '************************************************************************* Gx]J6Z8  
    eID = FindMaterial( "Lens" ) _*SA_.0  
    GetModelMaterial eID, mat y.l`NTT] <  
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    mat.Nd = nlens lo%:$2*'p  
    SetModelMaterial eID, mat Gs% cod  
    Print "Set lens index of refraction = " & nlens EN =oA P  
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    '************************************************************************* _'yN4>=6u  
    'Pupil diameter .9<  i  
    '************************************************************************* $~[k?D  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) oP$l(k  
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    'Adjust pupil diameter (trimming volume inner hole) 4nfpPN t  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" py9HUyr5eZ  
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    ' Adjust pupil location to just in front of the lens `Eijy3>h  
    parID = FindFullName( "Geometry.Arizona Eye" ) e*7nq ~ B5  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) &3SQVOW ~T  
    count = 0 u7oHqo`  
    While GetOperationCount(eID)>count b0A*zQA_)  
        GetOperation eID, count, op ]5+db0  
        If op.Type="ShiftZ" Then Jv|uI1V  
            DeleteOperation eID,count Iq@:n_~  
            count=count-1 "t-u=aDl-.  
        End If B}%B4&Ij  
        count=count+1 nty^De%  
    Wend H WOl79-  
    op.Type = "ShiftZ" &: i|;^^2  
    op.val1 = taq-0.01 '8Q:}{  
    op.parent = parID f xWW "B*A  
    AddOperation eID, op _k0 X)N+li  
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    Print "Set pupil diameter = " & pupilDiam iBq|]  
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    'Update AZ Eye subassembly Description ^r u1QDT  
    eID = FindFullName( "Geometry.Arizona Eye" ) u*I=.  
    GetEntity eID, entity : "|M  
    entity.Description = "Accommodation = " & A & "D" rNgFsFQ>.  
    SetEntity eID, entity D5wy7`c  
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    Update VOkEDH  
    Print "DONE!" |a(%a43fC  
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End Sub s&<6{AU(id  
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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: ^^u{W|'CaH  
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Accommodation = 4 Diopters :N \j@yJK  
Pupil Diameter = 4 mm ewNzRH,b  
Set aqueous humor thickness = 2.81 l (EDe  
Set anterior lens radius = 10.4 and conic constant = -2.375869 "k)}qI{  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 @WV}VKm  
Set lens thickness = 3.927 mVg$z  
Set lens index of refraction = 1.42672 N3D{t\hg  
Set pupil diameter = 4 Sn I-dXNF  
DONE! MeXzWLH  
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