[技术]Arizona眼睛模型 [复制链接]

简介 `dDa}b  
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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。 ejVdxVr\7  
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模型 4otl_l(`yv  
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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。 e^QVn\<c  
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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. 9`B0fv Q&  
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光源 AYcgi  
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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。 F?z
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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。 -0$:|p?@^  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 -/>9c-F  
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视网膜的散射
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 o@9+mM"B)  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 "(,2L,Zh  
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脚本 1a$IrQE  
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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： 56DoO'  
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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。 +~Tu0?{Z 0  
余下的脚本计算与屈光度有关的所有参数。 nIn2 *r  
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分析 nA_%2F'W}  
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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。 pY
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脚本代码 7+nm31,<O  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. |0sPka/u16  
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Dim entity As T_ENTITY +ZA)/  
Dim op As T_OPERATION %2"J:0j  
Dim mat As T_MODELMATERIAL I[0!SIqY  
Dim A As Double $DebXxJw0l  
Dim pupilDiam As Double rp's
 
Dim eID As Long pu9^e4B9  
Dim parID As Long 19c@`?  
Dim count As Integer A]o4Mf0>I  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 3[d>&xk@$  
Dim tlens As Double, nlens As Double E.`6oX\L|  
Dim curv As Double, conic As Double s5D:  
Dim ok As Long z.oU4c
 
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Sub Main yNCEz/4  
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    '用户输入对话框 eC! #CK  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ]$A(9Pn"  
        TextBox 220,21,40,21,.TextBox1 'default: 0 SZhOm  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 mwC=o5O  
        OKButton 40,91,90,21 GZ3 ]N  
        CancelButton 190,91,90,21 J !HjeZ  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 %m&@o~
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        TextBox 220,49,40,21,.TextBox2 'default: 4 5~H#(d<oZ  
    End Dialog V'
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    Dim dlg As UserDialog t"vRc4mf  
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    ok = Dialog (dlg) a.2L*>p  
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    If ok=0 Then    'cancel button was pressed H8{ol6wc)6  
        Print "Execution cancelled." {X~gwoz  
        End V}WB*bE  
    End If 4J0Rvod_  
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    'Assign accommodation and pupil diameter & use defaults if field left empty N&,]^>^u  
    If dlg.TextBox1 = "" Then [?k8}B)mHB  
        A = 0           'Default accommodation k@dN$O%p  
    Else ][&9]omB  
        A = CDbl(dlg.TextBox1) (R!hjw~  
    End If IkPN?N  
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    If dlg.TextBox2 = "" Then rl08R  
        pupilDiam = 4   'Default pupil diameter 2]cRXJ7h  
    Else _S}A=hK'  
        pupilDiam = CDbl(dlg.TextBox2) 4_/?:$KO  
    End If /Ncm^b4  
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    Print " " Wb}c=hZv  
    Print "Accommodation = " & A & " Diopters" zfA GtT<  
    Print "Pupil Diameter = " & pupilDiam & " mm" z4X}O {  
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    ' Calculate new parameters with accommodation Az;t"  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness r!PpUwod  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens g%[c<l9  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens `Ag{)  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens s$D ^>0  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens "VG+1r+]4  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ;!!n{l$r'  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction $5
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    'Adjust parameters to account for accommodation aFz5leD  
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    '************************************************************************* ?W^c4NtP  
    'Aqueous thickness (Position of Lens) L|P5=/d  
    '************************************************************************* #|&Sc_#4)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) :L44]K5FL  
    GetCustomElement eID, entity fk1ASV<rN  
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    parID = FindFullName( "Geometry.Arizona Eye" ) eIRLNxt+v  
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    ' Delete any shift(s) in z z|EEVNFd&  
    count = 0 ,(8;y=wux  
    While GetOperationCount(eID)>count tg]x0#@s  
        GetOperation eID, count, op Bp8'pj;~  
        If op.Type="ShiftZ" Then (q+)'H%iK  
            DeleteOperation eID,count n8*;lK8  
            count=count-1 u/cg|]x&T  
        End If =  C4  
        count=count+1 <:SZAAoIV  
    Wend vVE2m=!v  
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    'Set new shift in 91=OF*w  
    op.Type = "ShiftZ" N(I&  
    op.val1 = taq ^6_e=jIN  
    op.parent = parID 3;S,3  
    AddOperation eID, op uwz)($~bp  
    Print "Set aqueous humor thickness = " & taq-0.55 .pvi!NnL-  

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    '************************************************************************* N"nd*?  
    'Radius and conic constant of anterior lens ,AxdCT  
    '************************************************************************* ZI
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 4"gM<z  
    GetConic eID, entity, curv, conic &
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    SetConic eID, entity, 1/Rant, CCant Z?wU  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant H&:jcgV*P  
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    '************************************************************************* >}+/{(K"E|  
    'Radius and conic constant of posterior lens I'V4D[H5  
    '************************************************************************* N5a*7EJv+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) :2 *g~6  
    GetConic eID, entity, curv, conic $GlWf  
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    SetConic eID, entity, 1/Rpost, CCpost u(fm@+$^  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost W[Ls|<Q  
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    '*************************************************************************  -i0~]*  
    'Lens thickness (Position of posterior lens surface) q@[QjGj@  
    '************************************************************************* z^'gx@YD*v  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) :]\([Q+a  
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    ' Delete any z-shift(s) d3D] k,  
    count = 0 9I}-[|`u  
    While GetOperationCount(eID)>count M7pOLP_1jB  
        GetOperation eID, count, op ;lHr =e7  
        If op.Type="ShiftZ" Then #"@|f  
            DeleteOperation eID,count x[a<mk  
            count=count-1 P-?0zF/T$  
        End If o,_?^'@  
        count=count+1  C uB`CI  
    Wend "N`[r iq{  
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    'Set new z-shift kM,C3x{A  
    op.Type = "ShiftZ" f&Gt|  
    op.val1 = tlens be.*#[  
    op.parent = parID A
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    AddOperation eID, op bbE!qk;hEP  
    Print "Set lens thickness = " & tlens !2ZF(@C/  
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    '************************************************************************* g:hjy@ w  
    'Lens index of refraction |?,A]|j  
    '************************************************************************* sB7# ~pA  
    eID = FindMaterial( "Lens" ) .+$Q<L  
    GetModelMaterial eID, mat 8WXQOo8  
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    mat.Nd = nlens .(K)?r-g5  
    SetModelMaterial eID, mat OCe!.`  
    Print "Set lens index of refraction = " & nlens pH9VTM.*  
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    '*************************************************************************  y3@H/U{  
    'Pupil diameter ;ub;lh3  
    '************************************************************************* HiZ*+T.B  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) h`^jyoF"(  
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    'Adjust pupil diameter (trimming volume inner hole) b3=rG(0f  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" l9{hq/V  
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    ' Adjust pupil location to just in front of the lens "~sW"n(F_  
    parID = FindFullName( "Geometry.Arizona Eye" ) 
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) wW>A_{Y  
    count = 0 J')o|5S1N  
    While GetOperationCount(eID)>count @>,^":`#  
        GetOperation eID, count, op akp-zn&je  
        If op.Type="ShiftZ" Then ?9 <:QE;I>  
            DeleteOperation eID,count >mwlsL~X  
            count=count-1 0"<H;7K#W  
        End If E(>=rD/+  
        count=count+1 cr7 }^s  
    Wend wr$("A(  
    op.Type = "ShiftZ" M\uiq38  
    op.val1 = taq-0.01 6]K_m(F  
    op.parent = parID 'j#*6x
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    AddOperation eID, op dqU~`b
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    Print "Set pupil diameter = " & pupilDiam 9+Np4i@  
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    'Update AZ Eye subassembly Description -_=nDH  
    eID = FindFullName( "Geometry.Arizona Eye" ) f,U.7E  
    GetEntity eID, entity !|S(Ms  
    entity.Description = "Accommodation = " & A & "D" }bb;~  
    SetEntity eID, entity L+b6!2O,  
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    Update G/)O@Ugp  
    Print "DONE!" WlOmJtt4)  
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End Sub R`NYEptJ  
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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： YL!P0o13r  
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Accommodation = 4 Diopters xG~P+n7t5$  
Pupil Diameter = 4 mm l!D}3jD  
Set aqueous humor thickness = 2.81 5'OrHk;u  
Set anterior lens radius = 10.4 and conic constant = -2.375869 c[0}AGJ  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 qU \w=  
Set lens thickness = 3.927 q}3`|'3  
Set lens index of refraction = 1.42672 p*XANGA  
Set pupil diameter = 4 (p"%O  
DONE! ROH|PKb7