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    [技术]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 2[;~@n1P  
    [9B1%W  
    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。 &YcOmI/MM  
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    模型 pp@B]We  
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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。 T--%UZD]W  
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    Table 1. AZ眼睛模型的定义
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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. I!Z"X&  
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    光源 3<xDxj 0<  
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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。 rlA/eQrS  
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    图1. 光源和提示信息使用
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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。 x$bUd 9  
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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。 x}nBU q:  
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    图2. 字母F光源的设定方法光 5&h">_j  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 M0~%[nX  
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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。 =<#G~8WYz  
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    图4. 视网膜朗伯散射设定
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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。 P tLWFO  
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    图5. 视网膜重点采样规格设定
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    脚本 1YJ?Y  
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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: Z/:F)c,x  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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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。 -4sKB>b  
    余下的脚本计算与屈光度有关的所有参数。 rhy-o?  
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    分析 _@!vF,Wcf  
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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。 JO0o@M5H  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 W dD889\  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. m7g*zu2#  
    Xd5s8C/}  
    Dim entity As T_ENTITY aEvbGo  
    Dim op As T_OPERATION yDKH;o  
    Dim mat As T_MODELMATERIAL r6'dEa  
    Dim A As Double 1=C12  
    Dim pupilDiam As Double NWvIwt{  
    Dim eID As Long !?0C(VL(:  
    Dim parID As Long n#b{  
    Dim count As Integer k]5tU\;Yw  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ~{tO8 ]  
    Dim tlens As Double, nlens As Double ){w{#  
    Dim curv As Double, conic As Double #jrlNg4(  
    Dim ok As Long _^#eO`4"  
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    Sub Main (0b\%;}  
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        '用户输入对话框 < $e#o H  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ]!"w?-h Si  
            TextBox 220,21,40,21,.TextBox1 'default: 0 ufIvvZ*  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 4n6AK`E  
            OKButton 40,91,90,21 ,++HiYOG}e  
            CancelButton 190,91,90,21 #f24a?n|  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 k}H7bZug  
            TextBox 220,49,40,21,.TextBox2 'default: 4 zpT^:Ag  
        End Dialog bUm%#a  
        Dim dlg As UserDialog  P>iZ gv  
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        ok = Dialog (dlg) ]zaTX?F:  
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        If ok=0 Then    'cancel button was pressed I V# 8W  
            Print "Execution cancelled." sV,Yz3E<u$  
            End $Y_S`#c@i  
        End If `x/i1^/_@  
    p03I&d@w>  
        'Assign accommodation and pupil diameter & use defaults if field left empty = NZgbl  
        If dlg.TextBox1 = "" Then V&:x+swt  
            A = 0           'Default accommodation qS @3:R  
        Else MWA,3I\.  
            A = CDbl(dlg.TextBox1) %K|f,w=m  
        End If k+-?b(z)$  
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        If dlg.TextBox2 = "" Then ajk}&`Wj"  
            pupilDiam = 4   'Default pupil diameter AZc= Bbh  
        Else *cXq=/s  
            pupilDiam = CDbl(dlg.TextBox2) XdCP!iq*8  
        End If X/2GTU7?  
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        Print " " 2A~o)7JaZ  
        Print "Accommodation = " & A & " Diopters" r/'!#7dLG-  
        Print "Pupil Diameter = " & pupilDiam & " mm" }i"[5:  
    gR# k'   
        ' Calculate new parameters with accommodation 4x[_lsj   
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness /7#e  
    z+Fu{<#(  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens R)JH D7 1  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Hq:: F?  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens GWuKDq  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens AJEbiP  
    O)vGIp?f't  
        tlens = 3.767 + 0.04*A                  'Lens thickness C}mhnU@  
    !;|#=A9  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction hxMRmH[f:  
    mN]WjfII  
        'Adjust parameters to account for accommodation #W)m({}  
    E7iAN\vo  
        '************************************************************************* C_Q3^mLx  
        'Aqueous thickness (Position of Lens) CdRJ@Lf  
        '************************************************************************* PY7H0\S)  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) __ 9FQ{Ra  
        GetCustomElement eID, entity x6R M)rr  
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        parID = FindFullName( "Geometry.Arizona Eye" ) ?j/FYi  
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        ' Delete any shift(s) in z W..*!UGl  
        count = 0 LEPLoF3,  
        While GetOperationCount(eID)>count @ !su7  
            GetOperation eID, count, op Wjl2S+Cc  
            If op.Type="ShiftZ" Then 9!X3Cv|+L  
                DeleteOperation eID,count H%Gz"  
                count=count-1 G$TO'Ciu:  
            End If Z[*unIk  
            count=count+1 o FP8s[B  
        Wend *:xOenI  
    Vu.=,G  
        'Set new shift in YT+b{   
        op.Type = "ShiftZ" */IiL%g4u  
        op.val1 = taq XjL3Ar*  
        op.parent = parID @!dIa1Q"  
        AddOperation eID, op S=) c7t?a  
        Print "Set aqueous humor thickness = " & taq-0.55 Up?RN%gq  
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        '************************************************************************* [G$#jUt/O  
        'Radius and conic constant of anterior lens G1jj:]1  
        '************************************************************************* Wx]Xa]-  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) f}2}Ta  
        GetConic eID, entity, curv, conic 2mzn{S)nV  
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        SetConic eID, entity, 1/Rant, CCant vc"!3x-G*  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant kqih`E9P7B  
    nQOdM#dP  
        '************************************************************************* $T3_~7N  
        'Radius and conic constant of posterior lens qA)YYg/G  
        '************************************************************************* -)(=~|,Pq/  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ,V!"4 T,Z  
        GetConic eID, entity, curv, conic !@Qk=Xkg  
    y*^UGJC:  
        SetConic eID, entity, 1/Rpost, CCpost q]OIP"yv  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost _x(hlHFk  
    b)'CP Cu*  
        '************************************************************************* .%n_{ab1  
        'Lens thickness (Position of posterior lens surface) [pTdeg;QE  
        '************************************************************************* Hj r'C?[  
    ^7+;XUyg  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,L-/7}"VHA  
    ?&wrz  
        ' Delete any z-shift(s) oH6zlmqG"  
        count = 0 7mYcO3{5{  
        While GetOperationCount(eID)>count KJQ8Yhq  
            GetOperation eID, count, op lFt!  
            If op.Type="ShiftZ" Then 9#U]?^DJ@  
                DeleteOperation eID,count nu+K N,3R"  
                count=count-1 `.pEI q^  
            End If aXj UDu7  
            count=count+1 wJ2cAX;"  
        Wend &v .S_Ym  
    Z(|$[GZP[  
        'Set new z-shift bdstxjJ`  
        op.Type = "ShiftZ" jw{N#QDh  
        op.val1 = tlens QD!NV*  
        op.parent = parID M}[Q2v\  
        AddOperation eID, op }nPt[77U_7  
        Print "Set lens thickness = " & tlens \u`P(fI!K%  
    k@lJ8(i^qU  
        '************************************************************************* D%o(HS\E  
        'Lens index of refraction -&7? !<f  
        '************************************************************************* VI4mEq,V  
        eID = FindMaterial( "Lens" ) UZs '[pm)  
        GetModelMaterial eID, mat ho{%7\  
    'e]>lRZ  
        mat.Nd = nlens y%%VJ}'X!  
        SetModelMaterial eID, mat H(.9tuA  
        Print "Set lens index of refraction = " & nlens #3 E"Ame  
    K!CVS7  
        '************************************************************************* 7I w^  
        'Pupil diameter TfZM0Wz  
        '************************************************************************* eG(YORkR  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Sc{&h8KMTb  
    Hb*Z_s  
        'Adjust pupil diameter (trimming volume inner hole) X8Z) W?vu  
    D+uo gRS61  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" H.l0kBeG  
    5fk A?Ecqq  
        ' Adjust pupil location to just in front of the lens ! N2uJ?t  
        parID = FindFullName( "Geometry.Arizona Eye" ) aB~k8]q.  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) s3A(`heoq  
        count = 0 f91]0B `C  
        While GetOperationCount(eID)>count Td|,3 n  
            GetOperation eID, count, op V z  
            If op.Type="ShiftZ" Then }bw^p.ci  
                DeleteOperation eID,count =Ks&m4  
                count=count-1 Ux',ma1JK  
            End If $rj:K)P  
            count=count+1 WDxcV%  
        Wend `m(ZX\W]  
        op.Type = "ShiftZ"  )XonFI  
        op.val1 = taq-0.01 'Y2$9qy-L  
        op.parent = parID c$[2tZ  
        AddOperation eID, op ASi2;Q_{_  
    E7h@Y~bNhW  
        Print "Set pupil diameter = " & pupilDiam c}OveR$'&  
    ,?m@Ko7Y  
        'Update AZ Eye subassembly Description \,NT5>  
        eID = FindFullName( "Geometry.Arizona Eye" ) BKTTta1mY  
        GetEntity eID, entity Cw:|(`9  
        entity.Description = "Accommodation = " & A & "D" yx?oxDJg  
        SetEntity eID, entity e^q^ AP+*  
    _hV34:1F  
        Update L>/$l(  
        Print "DONE!" &#C&0f8PnD  
         ^3sv2wh^|8  
    End Sub y'>9' /&  
    }!fIY7gv  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: HHw&BNQG  
    j^#\km B  
    Accommodation = 4 Diopters X n0HJ^"_  
    Pupil Diameter = 4 mm oNXYBeu+  
    Set aqueous humor thickness = 2.81 C\"C12n{  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 Oq<3&*  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 lv] U)p  
    Set lens thickness = 3.927 v,Kum<oi?  
    Set lens index of refraction = 1.42672 !2AD/dtt   
    Set pupil diameter = 4 A iR#:r  
    DONE! 6%t6u3  
     
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