[技术]Arizona眼睛模型 [复制链接]

简介 (0r3/t?DQ  
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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。 z+wA rPxc  
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模型 ]=I@1B;_m  
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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。 d#Y^>"|$.  
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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. O2E/jj  
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光源 |Nn)m  
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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。 t;Sb/3  
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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。 ~O0 $Suv  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。  2DtM20<>  
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视网膜的散射 =,=A,kI[;  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ,t?B+$E  
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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。 2B[X,rL.pX  
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脚本 p!7FpxZY  
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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： KNvZm;Q6  
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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。 /wEhVR`=  
余下的脚本计算与屈光度有关的所有参数。 v5#jZ$<F  
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分析 *20jz<  
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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。 x.!V^HQSN  
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脚本代码 4K#>f4(U`g  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. vjGo;+K  
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Dim entity As T_ENTITY kWMl  
Dim op As T_OPERATION |&
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Dim mat As T_MODELMATERIAL DrUO-  
Dim A As Double &tLgG4pd  
Dim pupilDiam As Double d9fC<Tp  
Dim eID As Long I(L,8n5  
Dim parID As Long {M4gF8(M  
Dim count As Integer mP~QWx![N  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double JxdDC^> 0  
Dim tlens As Double, nlens As Double D&&9^t9S  
Dim curv As Double, conic As Double #4Rx]zW^%  
Dim ok As Long kzQ+j8.,U  
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Sub Main y1eWpPJa  
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    '用户输入对话框 u^+7hkk  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 58tARLDr  
        TextBox 220,21,40,21,.TextBox1 'default: 0 EPI4!3]  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 9iIhte.  
        OKButton 40,91,90,21 h,u,^ r  
        CancelButton 190,91,90,21 i/;\7n  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Db}j?ik/  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Xv5wJlc!d  
    End Dialog mW(W\'~_~  
    Dim dlg As UserDialog |PCm01NU!  
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    ok = Dialog (dlg) Olt?~}  
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    If ok=0 Then    'cancel button was pressed ?
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        Print "Execution cancelled." B:yGS*.tu  
        End hB]Np1('  
    End If @su^0 9n  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ios&n)W&  
    If dlg.TextBox1 = "" Then $kdB |4C  
        A = 0           'Default accommodation a8e6H30Sm  
    Else ed{ -/l~j  
        A = CDbl(dlg.TextBox1) r,8 [O  
    End If T?CdZc.
 
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    If dlg.TextBox2 = "" Then +<Nn~1  
        pupilDiam = 4   'Default pupil diameter zOAd~E  
    Else ,hm\   
        pupilDiam = CDbl(dlg.TextBox2) ojm @t  
    End If Ytp(aE:  
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    Print " " HT
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    Print "Accommodation = " & A & " Diopters" })H wh).  
    Print "Pupil Diameter = " & pupilDiam & " mm" hohfE3rd  
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    ' Calculate new parameters with accommodation GE:vp>>}`  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness !3c\NbU  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens }1L4"}L.  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens cN-?l7  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens z3{G9Np  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens kr^P6}'  
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    tlens = 3.767 + 0.04*A                  'Lens thickness .O5Z8 p  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 7JD' )
 
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    'Adjust parameters to account for accommodation 8?B!2  
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    '************************************************************************* Hp|kQJ[LE  
    'Aqueous thickness (Position of Lens) g>E LGG|Q  
    '************************************************************************* ^ glri$m  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) IEL%!RFG  
    GetCustomElement eID, entity <6%?OJhp  
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    parID = FindFullName( "Geometry.Arizona Eye" ) :;%2BSgFU  
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    ' Delete any shift(s) in z yM6pd U]i  
    count = 0 UP$.+<vm  
    While GetOperationCount(eID)>count D=A&+6B@-  
        GetOperation eID, count, op h6L&\~pf  
        If op.Type="ShiftZ" Then ;Zcswt8]u  
            DeleteOperation eID,count 4@+`q *  
            count=count-1 VD;01"#'  
        End If kYE9M8s;  
        count=count+1 (U DnsF  
    Wend ;>%r9pz
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    'Set new shift in o"s)eh  
    op.Type = "ShiftZ" Y,qI@n<  
    op.val1 = taq j7Yu>cr  
    op.parent = parID ]? c B:}  
    AddOperation eID, op ;}I:\P  
    Print "Set aqueous humor thickness = " & taq-0.55 '&P%C" 5  
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    '************************************************************************* +)AG*  
    'Radius and conic constant of anterior lens d(ZO6Nr Q  
    '************************************************************************* 7(1|xYCx$  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) R+hU8 pu  
    GetConic eID, entity, curv, conic udK%>  
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    SetConic eID, entity, 1/Rant, CCant &C5_g$Ma.Z  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant pHGYQ;:L  
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    '************************************************************************* A;q9rD,_  
    'Radius and conic constant of posterior lens mX"oW_EK  
    '************************************************************************* +uF>2b6'  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) f#>,1,S  
    GetConic eID, entity, curv, conic /$Ir5=B  
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    SetConic eID, entity, 1/Rpost, CCpost ?6!JCQJ<  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost *g"Nq+i@  
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    '************************************************************************* (Bb5?fw  
    'Lens thickness (Position of posterior lens surface) ZoW?nxY  
    '************************************************************************* a@K%06A;'
 
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) P-_6wfg,;>  
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    ' Delete any z-shift(s) *uRBzO}  
    count = 0 ]"As1"  
    While GetOperationCount(eID)>count [-1^-bb  
        GetOperation eID, count, op 4&lv6`G `  
        If op.Type="ShiftZ" Then q4h]o^+  
            DeleteOperation eID,count x M/+L:_<  
            count=count-1 /|m2WxK)  
        End If {_
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        count=count+1 .^33MWu6  
    Wend v|,1[i{  
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    'Set new z-shift .&iawz  
    op.Type = "ShiftZ" \##zR_%  
    op.val1 = tlens IZ-1c1   
    op.parent = parID |)DGkOtd  
    AddOperation eID, op Mmj;-u  
    Print "Set lens thickness = " & tlens \[i1JG  
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    '************************************************************************* se2!N:|R!G  
    'Lens index of refraction tmYz R%i  
    '************************************************************************* ;W )Y OT  
    eID = FindMaterial( "Lens" ) np^N8$i:n  
    GetModelMaterial eID, mat QD&`^(X1p  
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    mat.Nd = nlens qbN =
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    SetModelMaterial eID, mat j?\Qh  
    Print "Set lens index of refraction = " & nlens ./Zk`-OBT  
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    '************************************************************************* Y=?3 js?O  
    'Pupil diameter Xf]d. :  
    '************************************************************************* 9MJG;+B~  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) zV37$Hb  
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    'Adjust pupil diameter (trimming volume inner hole) 9wUkh}s  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ?pmHFlx  
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    ' Adjust pupil location to just in front of the lens R$<&ie6UQ  
    parID = FindFullName( "Geometry.Arizona Eye" ) OU_g
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) !sP{gi#=  
    count = 0 &-6Gc;f8  
    While GetOperationCount(eID)>count 7M~K,E(7~  
        GetOperation eID, count, op 20h, ^  
        If op.Type="ShiftZ" Then WIxy}3_to  
            DeleteOperation eID,count %JBz5G  
            count=count-1 ;7V%#-  
        End If `5.'_3  
        count=count+1 _4So{~Gf1  
    Wend I-*S&SiXjI  
    op.Type = "ShiftZ" %
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    op.val1 = taq-0.01 pofie$  
    op.parent = parID n5NsmVW\x  
    AddOperation eID, op xGg )Y#  
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    Print "Set pupil diameter = " & pupilDiam j{A y\n(  
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    'Update AZ Eye subassembly Description 'G4ICtHQ  
    eID = FindFullName( "Geometry.Arizona Eye" ) X`>i&I]  
    GetEntity eID, entity @o _}g !9=  
    entity.Description = "Accommodation = " & A & "D" Lck
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    SetEntity eID, entity }2.`N%[  
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    Update G4X|Bka  
    Print "DONE!" nRS}}6Q  
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End Sub 3yF,ak{Sl  
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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： <0&*9ZeD  
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Accommodation = 4 Diopters $ @`V  
Pupil Diameter = 4 mm IueFx u  
Set aqueous humor thickness = 2.81 *zvx$
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Set anterior lens radius = 10.4 and conic constant = -2.375869 .}TZxla0Zr  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 <uw9DU7G  
Set lens thickness = 3.927 m8hk:4Ae  
Set lens index of refraction = 1.42672 ?mxMk6w  
Set pupil diameter = 4 K`zdc`/  
DONE! 9IfmW^0