[技术]Arizona眼睛模型 [复制链接]

简介 0{-`Th+h  
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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。 .F4oo=
 
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模型 *e%Dg{_  
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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。 XpR.rq$]  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. zwMQXI'k83  
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光源 w
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 XI]OA7Zis  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 :-$cdZ3E  
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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。 A *a{  
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视网膜的散射 9@(O\xr  
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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。 Dm>T"4B`/  
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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。 ''$`;?t>  
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脚本 )W[KD,0+j  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： )o05Vda  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 [P.@1mV  
余下的脚本计算与屈光度有关的所有参数。 r$b:1C~  
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分析 ;6DR.2}?>  
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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。 tfi2y]{A  
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脚本代码 p+u{W"I`  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. VaD:  
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Dim entity As T_ENTITY vS~AxeW/7R  
Dim op As T_OPERATION ;yRwoTc)Y  
Dim mat As T_MODELMATERIAL $-C6pZN(X  
Dim A As Double k$9Gn9L%  
Dim pupilDiam As Double ;s}-X_O<  
Dim eID As Long d/0/$Bz}P  
Dim parID As Long &M!4]pow
 
Dim count As Integer yC9:sQ'k  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double X;K8,A7`  
Dim tlens As Double, nlens As Double *T.={>HE8  
Dim curv As Double, conic As Double uf{SxEa  
Dim ok As Long Ig40#pA  
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Sub Main Ktg&G<%J0  
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    '用户输入对话框 9Q SUCN_  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 }M"-5K}  
        TextBox 220,21,40,21,.TextBox1 'default: 0 iqU.a/~y  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1  y)N.LS  
        OKButton 40,91,90,21 b&hF')_UOz  
        CancelButton 190,91,90,21 Y-}hNZn"{  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 UDIac;vT  
        TextBox 220,49,40,21,.TextBox2 'default: 4 w]]x[D]L  
    End Dialog :ofE8]  
    Dim dlg As UserDialog ,g<>`={kK+  
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    ok = Dialog (dlg) ,iA2si  
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    If ok=0 Then    'cancel button was pressed F1Zk9%L%9$  
        Print "Execution cancelled." C%x(`S^/  
        End |Oj,S|Z:  
    End If _js2^<7v}  
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    'Assign accommodation and pupil diameter & use defaults if field left empty l(0&6ENyj  
    If dlg.TextBox1 = "" Then <.y^  
        A = 0           'Default accommodation I&Eg-96@  
    Else TkoCyD9  
        A = CDbl(dlg.TextBox1) hc@;}a\Y  
    End If 37ri b  
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    If dlg.TextBox2 = "" Then 0qaG#&!  
        pupilDiam = 4   'Default pupil diameter -\sKSY5{R  
    Else
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        pupilDiam = CDbl(dlg.TextBox2) &CPe$'FYI  
    End If ]R2Z
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    Print " " g-TX;(  
    Print "Accommodation = " & A & " Diopters" {~B4F}ES  
    Print "Pupil Diameter = " & pupilDiam & " mm" %n V@'3EI  
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    ' Calculate new parameters with accommodation BT*K,p  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness OFPd6,(E  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Eb{4.17b  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 6|(7G64{
 
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens se*pkgWbz  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens cbg3bi  
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    tlens = 3.767 + 0.04*A                  'Lens thickness `P)64So-1  

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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction D$
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    'Adjust parameters to account for accommodation H 29 _ /  
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    '************************************************************************* hTNYjXj  
    'Aqueous thickness (Position of Lens) 1<Ztk;$A
 
    '************************************************************************* -7Y'6''~W.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) y&O_Jyg<  
    GetCustomElement eID, entity `A}{ I}xq  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ph$&f0A6Xc  
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    ' Delete any shift(s) in z Q:xI} ]FM  
    count = 0 >5z`SZf  
    While GetOperationCount(eID)>count n6-!@RYr  
        GetOperation eID, count, op |H|eH~.yg&  
        If op.Type="ShiftZ" Then TJGKQyG$L  
            DeleteOperation eID,count {<V|Gr  
            count=count-1 ,:Y=,[n  
        End If 8aM% 9OU  
        count=count+1 mrBhvp""  
    Wend EXM/>PG  
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    'Set new shift in w]}cB+C+l#  
    op.Type = "ShiftZ" OG<]`!"  
    op.val1 = taq 6`PGV+3j  
    op.parent = parID MrygEC 5  
    AddOperation eID, op y`P7LC  
    Print "Set aqueous humor thickness = " & taq-0.55 fqp7a1qQl  
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    '************************************************************************* K|' ]Hje\  
    'Radius and conic constant of anterior lens (Gb{ckzs  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) l9Cy30O6  
    GetConic eID, entity, curv, conic 0i1?S6]d-  
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    SetConic eID, entity, 1/Rant, CCant ?9.?w-Q'  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant s_e#y{{C2  
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    '************************************************************************* Y(;[
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    'Radius and conic constant of posterior lens TbUkqABm  
    '************************************************************************* 
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Ra,on&OP`*  
    GetConic eID, entity, curv, conic ^ZZ@!Udy  
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    SetConic eID, entity, 1/Rpost, CCpost #T#FUI1p  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost '{_t
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    '************************************************************************* vf'jz
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    'Lens thickness (Position of posterior lens surface) \V7x3*nA  
    '************************************************************************* p<.!::*%(  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZkG##Jp\>  
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    ' Delete any z-shift(s) ^{,}, i  
    count = 0 Y-9j2.{  
    While GetOperationCount(eID)>count I,q~*d  
        GetOperation eID, count, op e}@J?tJK.L  
        If op.Type="ShiftZ" Then @!tmUme1c  
            DeleteOperation eID,count ,wy:RVv@e  
            count=count-1 w@D@,q'x  
        End If :=KGQ3V~eK  
        count=count+1 t5[JN:an  
    Wend `>HthK  
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    'Set new z-shift ku8Z;ONeH  
    op.Type = "ShiftZ"  6}ewBAq%  
    op.val1 = tlens 60gn`s,,  
    op.parent = parID R}YryzV5  
    AddOperation eID, op zL=I-fVq  
    Print "Set lens thickness = " & tlens Jrrk$0H^~  
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    '************************************************************************* -CNv=vj 3  
    'Lens index of refraction Hq
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    '************************************************************************* &~6O;}\  
    eID = FindMaterial( "Lens" ) l`G:@}P>G  
    GetModelMaterial eID, mat Y2~{qY  
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    mat.Nd = nlens tg4&j$  
    SetModelMaterial eID, mat E<_6OCz  
    Print "Set lens index of refraction = " & nlens O[J+dWyp  
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    '************************************************************************* !,WRXE&j  
    'Pupil diameter X=}0+W  
    '************************************************************************* 2{q
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ]nGA1S{  
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    'Adjust pupil diameter (trimming volume inner hole) f\_Q+!^  

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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" "K=)J'/n  
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    ' Adjust pupil location to just in front of the lens %&S]cEw  
    parID = FindFullName( "Geometry.Arizona Eye" ) l"g%vS,;`  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" )
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    count = 0 9%veU
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    While GetOperationCount(eID)>count alD|-{Bf  
        GetOperation eID, count, op =?x=CEW  
        If op.Type="ShiftZ" Then PhdL@Mr  
            DeleteOperation eID,count @Kb~!y@G  
            count=count-1 En%o7^W++  
        End If k18V4ATE]  
        count=count+1 qWK7K%-$E  
    Wend vCr$miZ  
    op.Type = "ShiftZ" )^xmy6k  
    op.val1 = taq-0.01 5Wjp_^!e  
    op.parent = parID &~i &~AJ  
    AddOperation eID, op <\ c8q3N  
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    Print "Set pupil diameter = " & pupilDiam p =O1aM  
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    'Update AZ Eye subassembly Description !7|9r$  
    eID = FindFullName( "Geometry.Arizona Eye" ) b8Sl3F?
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    GetEntity eID, entity Sv",E@!f  
    entity.Description = "Accommodation = " & A & "D" uQ)]g  
    SetEntity eID, entity LZ$!=vg4  
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    Update =,9'O/br  
    Print "DONE!" 3mpjSL  
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End Sub 2sq<"TlQXI  
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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： 6f1Y:qK'@  
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Accommodation = 4 Diopters WVFy ZpB  
Pupil Diameter = 4 mm ax}Xsk_  
Set aqueous humor thickness = 2.81 g_=ZcGC  
Set anterior lens radius = 10.4 and conic constant = -2.375869 6FAP *V;  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 1EB`6_>y  
Set lens thickness = 3.927 [Y+
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Set lens index of refraction = 1.42672 `UPmr50Wq  
Set pupil diameter = 4 HX^ P9jXT  
DONE! YzVLa,[