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infotek 2022-02-25 09:52

Arizona眼睛模型

简介 t2)rUWg  
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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。 sIy^m}02  
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模型 ml+; Rmvb  
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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。 6ZP"p<xX  
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. P09;ng67  
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光源 va0{>Dc+  
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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。 | AozR ~  
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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。 }n>p4W"OM  
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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。 i uF*.hc,%  
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图2. 字母F光源的设定方法光 C@'h<[v`1v  
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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 G6$kv2(k`@  
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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。 24z< gO  
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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。 f,018]|  
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图5. 视网膜重点采样规格设定
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脚本 tp63@L|Q  
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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: @`q:IIgW  
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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。 Ab{ K<:l  
余下的脚本计算与屈光度有关的所有参数。 PoG-Rqe  
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分析 MkfBu 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。 1H6<[iHW  
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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 X-K=!pET  
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  1. Option Explicit     'Remove this to enable non-dimensioned variables to be used. ]>=}*=  
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    Dim entity As T_ENTITY (nf~x  
    Dim op As T_OPERATION }fb#G<3  
    Dim mat As T_MODELMATERIAL a7r%X -  
    Dim A As Double TO]@ Zu1  
    Dim pupilDiam As Double $u]jy0X<Y;  
    Dim eID As Long _Kl_61k  
    Dim parID As Long c;Pe/d  
    Dim count As Integer M2OIBH4!  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double mr*JJF0Z  
    Dim tlens As Double, nlens As Double hT`J1nNt  
    Dim curv As Double, conic As Double v+46 QK|I&  
    Dim ok As Long WrQDX3  
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    Sub Main [>8}J "  
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        '用户输入对话框 dCi?SIN  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 q&s3wDl/  
            TextBox 220,21,40,21,.TextBox1 'default: 0 $rv8K j+  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 G_bG  
            OKButton 40,91,90,21 r`W)0oxD  
            CancelButton 190,91,90,21 n.!#P|  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ORe(]I`Z  
            TextBox 220,49,40,21,.TextBox2 'default: 4 $PTP/^  
        End Dialog l{I6&^!KS  
        Dim dlg As UserDialog eKE#Yr d=x  
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        ok = Dialog (dlg) iU$] {c2;A  
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        If ok=0 Then    'cancel button was pressed } ()5"QB  
            Print "Execution cancelled." #lmB AL~3  
            End .7e2YI,S  
        End If KHe=O1 %QO  
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        'Assign accommodation and pupil diameter & use defaults if field left empty [I '0,y  
        If dlg.TextBox1 = "" Then *6sl   
            A = 0           'Default accommodation (G zb  
        Else g7}Gip}.>  
            A = CDbl(dlg.TextBox1) [ey:e6,T9  
        End If 1"zDin!A  
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        If dlg.TextBox2 = "" Then 8ja$g,  
            pupilDiam = 4   'Default pupil diameter Wk~W Ozr}^  
        Else |n+qMql'  
            pupilDiam = CDbl(dlg.TextBox2) UW N*j_9i  
        End If |^:cG4e  
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        Print " " QLXN*c  
        Print "Accommodation = " & A & " Diopters" 7C,&*Ax,9  
        Print "Pupil Diameter = " & pupilDiam & " mm" E27vR 7  
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        ' Calculate new parameters with accommodation t[ubn+  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness V=R 3)GC  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens R<\F:9  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens %eX{WgH  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens .>= (' -  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens H5DC[bZMb%  
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        tlens = 3.767 + 0.04*A                  'Lens thickness {@eJtF+2  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction .z]Wyx&/U  
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        'Adjust parameters to account for accommodation }SX,^|eN  
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        '************************************************************************* *@Lp`thq  
        'Aqueous thickness (Position of Lens) }+)fMZz  
        '************************************************************************* gp5_Z-me  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Sh/T,  
        GetCustomElement eID, entity <v)1<*I  
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        parID = FindFullName( "Geometry.Arizona Eye" ) #*QO3y~ZM  
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        ' Delete any shift(s) in z gRCdY8GH  
        count = 0 't1 ax^-g  
        While GetOperationCount(eID)>count )Ub_@)X3%l  
            GetOperation eID, count, op ;T"zV{;7BR  
            If op.Type="ShiftZ" Then Wr<j!>J6Ki  
                DeleteOperation eID,count iIMd!Q.)@  
                count=count-1 n,jKmA  
            End If "3Uv]F  
            count=count+1 K~AR*1??[  
        Wend 8B /\U'  
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        'Set new shift in d6'{rje(  
        op.Type = "ShiftZ" /M|2 62%  
        op.val1 = taq Jy)KqdkX+  
        op.parent = parID q;R],7Re  
        AddOperation eID, op + fC=UAZ  
        Print "Set aqueous humor thickness = " & taq-0.55 w1hPc!I  
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        '************************************************************************* Sm)Ha:[4  
        'Radius and conic constant of anterior lens M.x=<:upp  
        '************************************************************************* y`\@N"Cf  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ~k!j+>yT  
        GetConic eID, entity, curv, conic kqM045W7  
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        SetConic eID, entity, 1/Rant, CCant qlb- jL  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 9{(.Il J>  
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        '************************************************************************* =8t]\Y?  
        'Radius and conic constant of posterior lens j"}*T  
        '************************************************************************* ,VCyG:dw  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) tasIDoo+!J  
        GetConic eID, entity, curv, conic }j^i}^Du,  
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        SetConic eID, entity, 1/Rpost, CCpost ! ='rc-E  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }RzWJ@QD<  
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        '************************************************************************* +@94;me  
        'Lens thickness (Position of posterior lens surface) E8pB;\Z(  
        '************************************************************************* 6A>dhU  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) S#MZV@nGF  
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        ' Delete any z-shift(s) M@`;JjtSA  
        count = 0 $* AYcy7  
        While GetOperationCount(eID)>count H7d/X  
            GetOperation eID, count, op 8dO!  
            If op.Type="ShiftZ" Then gLE:g5v6  
                DeleteOperation eID,count Jll-`b 1  
                count=count-1 uW30ep'  
            End If 7[> 6i  
            count=count+1 t/cY=Wp  
        Wend U&Wt%U{  
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        'Set new z-shift =<{np  
        op.Type = "ShiftZ" <J`0mVOX  
        op.val1 = tlens {zn!vJX  
        op.parent = parID [3(7  4  
        AddOperation eID, op d Vj_8>  
        Print "Set lens thickness = " & tlens %/|9@er  
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        '************************************************************************* Ove<mFI\  
        'Lens index of refraction h-G)o[MA  
        '************************************************************************* (Dw,DY9  
        eID = FindMaterial( "Lens" ) q=%RDG+  
        GetModelMaterial eID, mat 4x  
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        mat.Nd = nlens KVT-P};jy*  
        SetModelMaterial eID, mat *:Vq:IU[D  
        Print "Set lens index of refraction = " & nlens w2 a1mU/  
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        '************************************************************************* vRs,zL$W  
        'Pupil diameter Y~L2  
        '************************************************************************* :c8&N-`  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) |y0(Q V  
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        'Adjust pupil diameter (trimming volume inner hole) )L#i%)+  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ` :o4'CG  
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        ' Adjust pupil location to just in front of the lens -(  
        parID = FindFullName( "Geometry.Arizona Eye" ) 9aze>nxh.  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Nv(9N-9r  
        count = 0 ldiD2 Q  
        While GetOperationCount(eID)>count )iYxt:(,  
            GetOperation eID, count, op {u#;?u=|  
            If op.Type="ShiftZ" Then t m7^yn:  
                DeleteOperation eID,count {]:7bV#JP  
                count=count-1 Dp)=0<$y  
            End If KwPOO{4]g  
            count=count+1 /atW8 `&  
        Wend VU&7P/\f%  
        op.Type = "ShiftZ" @\f^0^G  
        op.val1 = taq-0.01 ] lrWgm  
        op.parent = parID H@%GSE  
        AddOperation eID, op 0:9.;x9_  
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        Print "Set pupil diameter = " & pupilDiam K i'Fn"  
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        'Update AZ Eye subassembly Description w8U&ls1b  
        eID = FindFullName( "Geometry.Arizona Eye" ) P_*" dza  
        GetEntity eID, entity j2QmxTa!  
        entity.Description = "Accommodation = " & A & "D" ]sE?ezu  
        SetEntity eID, entity FB{KH .  
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        Update &6ZD136  
        Print "DONE!" 23Nw!6S  
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    End Sub nV-mPyfL8  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: X voo=  
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    Accommodation = 4 Diopters Exc9` 7%.  
    Pupil Diameter = 4 mm v(ZYS']d2  
    Set aqueous humor thickness = 2.81 'VzP};  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ??M"6k  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 ZWc]$H?  
    Set lens thickness = 3.927 Z0Vl+  
    Set lens index of refraction = 1.42672 <vONmE a  
    Set pupil diameter = 4 - jb0o/:  
    DONE!
silence唯爱 2022-02-25 13:53
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