[技术]Arizona眼睛模型 [复制链接]

简介 3e47UquZ  
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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。 ,c$tKj5ulQ  
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模型 6-tIe_5  
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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。 7l/lY-zO  
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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. O(2c_!d  
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光源 W)J5
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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。 hmOGteAf-  
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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。 )8rF'pxI  
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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。 .5!`wwVi  
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视网膜的散射 ti6X=@ P:  
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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。 8!!h6dQgI  
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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。 fe`_0lxj  
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脚本 Qk>U=]U  
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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： [q3zs_nz  
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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。 4vN:Kj  
余下的脚本计算与屈光度有关的所有参数。 3RGmmX"?G  
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分析 lVq5>:'}^;  
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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。 ^,
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脚本代码 U*\K<fw   
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. X<Cfy  
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Dim entity As T_ENTITY N6u>V~i  
Dim op As T_OPERATION _6,\;"it?8  
Dim mat As T_MODELMATERIAL #
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Dim A As Double tA< UkP
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Dim pupilDiam As Double x*'H@!!G  
Dim eID As Long D84&=EpVZ  
Dim parID As Long F7*)u-4Yn  
Dim count As Integer X
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double MI(#~\Y~P  
Dim tlens As Double, nlens As Double cUG^^3!  
Dim curv As Double, conic As Double & C)
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Dim ok As Long G,$nq4  
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Sub Main T*0;3&sA  
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    '用户输入对话框 Nj2l>[L;  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Z:
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        TextBox 220,21,40,21,.TextBox1 'default: 0 'm6bfS^T  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 n~\; +U  
        OKButton 40,91,90,21 C"**>OGe  
        CancelButton 190,91,90,21 !DSm[Z1  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ] L#c <0  
        TextBox 220,49,40,21,.TextBox2 'default: 4 j[A(@w"  
    End Dialog 7rRI-wZ  
    Dim dlg As UserDialog B'(zhjV  
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    ok = Dialog (dlg) @M-w8!.~  
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    If ok=0 Then    'cancel button was pressed c;X,-Q9  
        Print "Execution cancelled." Lhux~,EH  
        End j|Vl\Z&o)  
    End If ,'`yh|}G\  
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    'Assign accommodation and pupil diameter & use defaults if field left empty m^qFaf
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    If dlg.TextBox1 = "" Then w*/@|r39  
        A = 0           'Default accommodation SDE+"MjBY  
    Else in
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        A = CDbl(dlg.TextBox1) -`\^_nVC  
    End If &Lt$~}*&6  
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    If dlg.TextBox2 = "" Then ?uL-qsU  
        pupilDiam = 4   'Default pupil diameter gM;m{gXYK  
    Else \ZV>5N3hS  
        pupilDiam = CDbl(dlg.TextBox2) 2[pOGc$  
    End If VPT?z  
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    Print " " v.C  
    Print "Accommodation = " & A & " Diopters" f9>pMfi:@  
    Print "Pupil Diameter = " & pupilDiam & " mm" %Y;^$%X%_  
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    ' Calculate new parameters with accommodation F5cNF5  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness !<~.>5UQ  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens XtZd% #2},  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens _p1!8*0]  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 3>L5TYa  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Yq|_6zbYf  
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    tlens = 3.767 + 0.04*A                  'Lens thickness "k@[7 7  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction T|BlFJ0"  
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    'Adjust parameters to account for accommodation LB]3-F
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    '************************************************************************* }ixCbuD  
    'Aqueous thickness (Position of Lens) }UGS
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    '************************************************************************* t~K[`=G\ex  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) OZf@cOTWK  
    GetCustomElement eID, entity T>(X`(  
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    parID = FindFullName( "Geometry.Arizona Eye" ) `G:1  
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    ' Delete any shift(s) in z VV$#<D<)  
    count = 0 ue7D' UZL>  
    While GetOperationCount(eID)>count hV,T889'  
        GetOperation eID, count, op x!s=Nola  
        If op.Type="ShiftZ" Then u5rvrn ]  
            DeleteOperation eID,count %`5K8eB  
            count=count-1 af@a /  
        End If :qj^RcmVPL  
        count=count+1 &P}t<;  
    Wend <aaT,J8%[  
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    'Set new shift in _qf~ hhi  
    op.Type = "ShiftZ" U%@C<o "  
    op.val1 = taq q+8de_"]  
    op.parent = parID "pK<d~Wu  
    AddOperation eID, op n>eDN\5  
    Print "Set aqueous humor thickness = " & taq-0.55 b#6mUl2  
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    '************************************************************************* kGnT4R*E  
    'Radius and conic constant of anterior lens i;]0>g4  
    '************************************************************************* Z~94<*LEp  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) uc"%uc'  
    GetConic eID, entity, curv, conic |n;);T(  
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    SetConic eID, entity, 1/Rant, CCant > fV"bj.  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 4*f+np  
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    '************************************************************************* X)RgXl{  
    'Radius and conic constant of posterior lens Io
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    '************************************************************************* ZZHQ?p-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) kUGFg{"  
    GetConic eID, entity, curv, conic *rxYal4ad  
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    SetConic eID, entity, 1/Rpost, CCpost Z6Mjc/  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost E6xdPjoWy  
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    '************************************************************************* W58?t6! =  
    'Lens thickness (Position of posterior lens surface) Xe:^<$z  
    '************************************************************************* &D-z|ZjgHi  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5"b1: w@  
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    ' Delete any z-shift(s) +C7W2!I[G2  
    count = 0 lq3D!+m  
    While GetOperationCount(eID)>count
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        GetOperation eID, count, op CflyK@  
        If op.Type="ShiftZ" Then (4q/LuP^d  
            DeleteOperation eID,count `mD!z.`U  
            count=count-1 8"d??3ZXJ  
        End If se>\5k  
        count=count+1
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    Wend -Mrt%1g  
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    'Set new z-shift 6)i>qz).
 
    op.Type = "ShiftZ" 7J6Z?  
    op.val1 = tlens +CSv@ />3  
    op.parent = parID Oop6o$k  
    AddOperation eID, op .C+(E@eyA  
    Print "Set lens thickness = " & tlens
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    '************************************************************************* bxO/FrwTj{  
    'Lens index of refraction 1VG]|6f  
    '************************************************************************* d+]=l+&  
    eID = FindMaterial( "Lens" ) _~umE/tz  
    GetModelMaterial eID, mat `?l /HUw  
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    mat.Nd = nlens 2(\PsN w!  
    SetModelMaterial eID, mat >e-0A  
    Print "Set lens index of refraction = " & nlens 16@
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    '************************************************************************* OA}; pQ9QN  
    'Pupil diameter /7+b.h])^  
    '************************************************************************* ~W4SFp  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 6v%ePFul  
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    'Adjust pupil diameter (trimming volume inner hole) pNQ7uy  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" GCr]x '  
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    ' Adjust pupil location to just in front of the lens 74 )G.!  
    parID = FindFullName( "Geometry.Arizona Eye" ) Vep41\g^  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) a!u5}[{  
    count = 0 WLVkrTvX  
    While GetOperationCount(eID)>count  >PQ?|Uk  
        GetOperation eID, count, op V)5,E>;EN  
        If op.Type="ShiftZ" Then P&[&Dj  
            DeleteOperation eID,count o
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            count=count-1 km^ZF<.@  
        End If -U_,RMw~  
        count=count+1 b9T6JS j  
    Wend <|G!Qn?2-  
    op.Type = "ShiftZ" <:nyRy}  
    op.val1 = taq-0.01 Tw*p^rU  
    op.parent = parID G[_Z|Xi1  
    AddOperation eID, op 8 ?y|  
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    Print "Set pupil diameter = " & pupilDiam +`mI\+y,  
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    'Update AZ Eye subassembly Description !5[SNr3^  
    eID = FindFullName( "Geometry.Arizona Eye" ) Sj/v:  
    GetEntity eID, entity Z1$U[Tsd  
    entity.Description = "Accommodation = " & A & "D" o.zP1n|G~r  
    SetEntity eID, entity Bzt:9hr6BO  
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    Update EASmB  
    Print "DONE!" xA2I+r*o  
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End Sub 3q@JhB  
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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： %WmTG }L)  
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Accommodation = 4 Diopters H~Uy/22aQy  
Pupil Diameter = 4 mm i<tJG{A=  
Set aqueous humor thickness = 2.81 ^Ojg}'.Ygv  
Set anterior lens radius = 10.4 and conic constant = -2.375869 6<5:m:KE  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 4 540Lw'A  
Set lens thickness = 3.927 6 A#xFPYY{  
Set lens index of refraction = 1.42672 ,BGUIu6  
Set pupil diameter = 4 ;
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DONE! |:2B)X