[技术]Arizona眼睛模型 [复制链接]

简介 3JO:n6  
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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。 A)0m~+?{J  
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模型 ( I~XwP&  
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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。 fA,!d J  
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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. C /VXyl@o  
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光源 blS4AQ?
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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。 G!Q)?N   
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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。 N1t:i? q&  
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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。 Q 7?4GxMj  
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视网膜的散射 ozr+6z  
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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。 cE#Y,-f  
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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。 %iML??S  
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脚本 YRXe 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： J)+eEmrU  
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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。 [!$>:_Vq/  
余下的脚本计算与屈光度有关的所有参数。 :@L5=2Z+  
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分析 w, wt<@}  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Ve
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脚本代码 x]M1UBnMN  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used.  O@$i
 
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Dim entity As T_ENTITY Q^OzFfR6  
Dim op As T_OPERATION
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Dim mat As T_MODELMATERIAL }Z=Qy;zk  
Dim A As Double `w}"
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Dim pupilDiam As Double z@j&vW  
Dim eID As Long lX7^LB  
Dim parID As Long V-|}.kOH2  
Dim count As Integer AJ}Q,E  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double )}v2Z3:  
Dim tlens As Double, nlens As Double ZG|T-r;~  
Dim curv As Double, conic As Double VP&lWPA}\$  
Dim ok As Long [8n4lE[)"  
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Sub Main IU}`5+:m  
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    '用户输入对话框 w4mL/j  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 MJoC*8QxM  
        TextBox 220,21,40,21,.TextBox1 'default: 0
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 `x3c},'@k  
        OKButton 40,91,90,21 U# gmk0>t{  
        CancelButton 190,91,90,21 ;'ur
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 O!jCQ{ T  
        TextBox 220,49,40,21,.TextBox2 'default: 4 :gn!3P}p?  
    End Dialog r+2dBp3  
    Dim dlg As UserDialog jLg4_N1SD  
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    ok = Dialog (dlg) N 2\,6<  
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    If ok=0 Then    'cancel button was pressed v>6r|{  
        Print "Execution cancelled." I nk76-  
        End C;|Ru*  
    End If 3yDvr*8-@  
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    'Assign accommodation and pupil diameter & use defaults if field left empty &H6Fkza;4  
    If dlg.TextBox1 = "" Then O #"O.GX<  
        A = 0           'Default accommodation T^
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    Else b~-9u5.L1  
        A = CDbl(dlg.TextBox1) Wk?XlCj  
    End If ~rD* Y&#.  
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    If dlg.TextBox2 = "" Then *
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        pupilDiam = 4   'Default pupil diameter xfilxd  
    Else B(hNBq7  
        pupilDiam = CDbl(dlg.TextBox2)  *hba>LZ  
    End If 6aL
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    Print " " a"EXR-+8  
    Print "Accommodation = " & A & " Diopters" }
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    Print "Pupil Diameter = " & pupilDiam & " mm" n:{yri+  
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    ' Calculate new parameters with accommodation IlY,V  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness U}NNbGQj  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens v?}/WKe+0  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens TAP/gN'  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens SRMy#j-  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens / wEr>[8S  
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    tlens = 3.767 + 0.04*A                  'Lens thickness &A>J>b  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 4&tY5m>  
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    'Adjust parameters to account for accommodation [e(-  
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    '************************************************************************* 9,4a?.*4~  
    'Aqueous thickness (Position of Lens) x\lua  
    '************************************************************************* >%{h_5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) % nR:Rc!  
    GetCustomElement eID, entity f?)qZ
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    parID = FindFullName( "Geometry.Arizona Eye" ) 6_XTeu  
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    ' Delete any shift(s) in z e_Y>
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    count = 0 ,^/;!ErR$  
    While GetOperationCount(eID)>count MYu-[Hg  
        GetOperation eID, count, op ]:F]VRPT  
        If op.Type="ShiftZ" Then  7p{lDQ  
            DeleteOperation eID,count O\xUv  
            count=count-1 u4%-e)$X  
        End If /#blXI  
        count=count+1 s:M:Ff  
    Wend k(et b#  
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    'Set new shift in ?(F~9V  
    op.Type = "ShiftZ" KY@k4S+  
    op.val1 = taq dP )YPy_`  
    op.parent = parID WKP=[o^  
    AddOperation eID, op <[(xGrEZV  
    Print "Set aqueous humor thickness = " & taq-0.55 ]ko>vQ4]3  
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    '************************************************************************* LqW~QEU(  
    'Radius and conic constant of anterior lens _bW#* Y5  
    '************************************************************************* @A g=2\9  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) oA`Ncu5  
    GetConic eID, entity, curv, conic (g5T2(_6L  
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    SetConic eID, entity, 1/Rant, CCant ~Xa >;  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 233jT@Z  
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    '************************************************************************* fy7]
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    'Radius and conic constant of posterior lens /1Ndir^c  
    '************************************************************************* l{6fR(d
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ZjbMk3Y  
    GetConic eID, entity, curv, conic TEv3;Z*N  
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    SetConic eID, entity, 1/Rpost, CCpost p9fx~[_5/  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost kz]qk15w  
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    '************************************************************************* !Vy/-N  
    'Lens thickness (Position of posterior lens surface) H&l/o  
    '************************************************************************* uPt({H  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Ea 0 j}  
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    ' Delete any z-shift(s) <\Lii0hi!  
    count = 0  9/`T]s"  
    While GetOperationCount(eID)>count p v%`aQ]o{  
        GetOperation eID, count, op qo/`9%^E?  
        If op.Type="ShiftZ" Then l.El3+  
            DeleteOperation eID,count 5V8WSnO  
            count=count-1 Nn>Oq+:  
        End If p{NVJ^!+  
        count=count+1 _I+QInD;)  
    Wend V& _  
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    'Set new z-shift qJj"WU5  
    op.Type = "ShiftZ" ?31#:Mg6g+  
    op.val1 = tlens ch!/k  
    op.parent = parID PF~w$ eeQ  
    AddOperation eID, op ^,*!Qk<c  
    Print "Set lens thickness = " & tlens c7Jfo x V  
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    '************************************************************************* /'O? 8X<  
    'Lens index of refraction A63=$  
    '************************************************************************* 2Jm#3zFYz3  
    eID = FindMaterial( "Lens" ) \AQ*T`Dq  
    GetModelMaterial eID, mat RR
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    mat.Nd = nlens N"L@  
    SetModelMaterial eID, mat =*>ri  
    Print "Set lens index of refraction = " & nlens B OKY X  
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    '************************************************************************* {el,CT#  
    'Pupil diameter n.F^9j+V  
    '************************************************************************* =^3 Z L  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) .Yg7V'R1  
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    'Adjust pupil diameter (trimming volume inner hole) \I"n~h^_  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" -Ph"#R&  
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    ' Adjust pupil location to just in front of the lens 1)Z4 (_  
    parID = FindFullName( "Geometry.Arizona Eye" ) *QH~z2:[  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) r^zra|]  
    count = 0 C)hS^D:  
    While GetOperationCount(eID)>count 1K\zamBg  
        GetOperation eID, count, op a!guZUg6  
        If op.Type="ShiftZ" Then 1#}}:  
            DeleteOperation eID,count DsX+/)d  
            count=count-1 s`#g<_{X  
        End If "d"6.ND  
        count=count+1 8GlRO4yd  
    Wend oDW)2*8yF  
    op.Type = "ShiftZ" q!f'?yFYK  
    op.val1 = taq-0.01 uSQRI9/ir2  
    op.parent = parID B5v5D[ o5  
    AddOperation eID, op tw k  
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    Print "Set pupil diameter = " & pupilDiam ^J~5k,7jX  
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    'Update AZ Eye subassembly Description wNvq['P  
    eID = FindFullName( "Geometry.Arizona Eye" ) *{x8@|K8  
    GetEntity eID, entity e5 N$+P"
 
    entity.Description = "Accommodation = " & A & "D" sU7fVke1   
    SetEntity eID, entity q8S
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    Update BK]5g[   
    Print "DONE!" #n_t5 O[  
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End Sub >lkjoEVQ  
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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： {iXQUj  
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Accommodation = 4 Diopters 5Sz&j  
Pupil Diameter = 4 mm GahIR9_2  
Set aqueous humor thickness = 2.81 N1fPutl$a
 
Set anterior lens radius = 10.4 and conic constant = -2.375869 >c)-o}bd^  
Set posterior lens radius = -4.424557 and conic constant = -3.081019  |\FJ  
Set lens thickness = 3.927 .k
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Set lens index of refraction = 1.42672 v`&>m'  
Set pupil diameter = 4 ;q?WU>c{?  
DONE! zX8'OoEH*9