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infotek 2022-02-25 09:52

Arizona眼睛模型

简介 ^7KH _t8  
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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。 @qlK6tE`  
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模型 2eol gXp  
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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。 .oUTqki  
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. {_Rr 6  
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光源 o;R2p $  
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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。 Nyj( 0W  
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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。 #c?j\Y9nz  
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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。 pF Rg?-  
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图2. 字母F光源的设定方法光 Pjjewy1}^  
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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 TS9|a{j3!  
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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。 $$5aUI:$~$  
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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。 Y+*0~xm4  
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图5. 视网膜重点采样规格设定
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脚本 ~W+kiTsD?  
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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: &NoS=(s,  
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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。 ( _)jkI \  
余下的脚本计算与屈光度有关的所有参数。 $5< #n@  
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分析 R:k5QD9/&p  
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屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 Z}l3l`h!  
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图7. 字母F在视网膜上颜色分析
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脚本代码 qHrA%k^!2O  
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  1. Option Explicit     'Remove this to enable non-dimensioned variables to be used. r )~ T@'y  
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    Dim entity As T_ENTITY ;1.,Sn+zO  
    Dim op As T_OPERATION }O^zl#  
    Dim mat As T_MODELMATERIAL G) 7;;  
    Dim A As Double M#VE]J  
    Dim pupilDiam As Double vUU9$x  
    Dim eID As Long .my0|4CQ#@  
    Dim parID As Long EzV96+  
    Dim count As Integer db6b-Y{   
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ie\"$i.98H  
    Dim tlens As Double, nlens As Double V'T ,4  
    Dim curv As Double, conic As Double -Sx\Xi"<o=  
    Dim ok As Long 5Z\#0":e  
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    Sub Main ~ga`\% J  
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        '用户输入对话框  Q&g^c2  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 $lIz{ySJv  
            TextBox 220,21,40,21,.TextBox1 'default: 0 'BPp ]R#{  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 dhr3,&+T2  
            OKButton 40,91,90,21 @I/]D6 ~"  
            CancelButton 190,91,90,21 k_q0Q;6w!l  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 k |%B?\m  
            TextBox 220,49,40,21,.TextBox2 'default: 4 5nO% Ke=  
        End Dialog w1#gOwA,$  
        Dim dlg As UserDialog ?5 cI'  
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        ok = Dialog (dlg) "WK{ >T  
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        If ok=0 Then    'cancel button was pressed z3M6V}s4  
            Print "Execution cancelled." >W`4aA  
            End Z->p1xkX  
        End If "7V2lu  
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        'Assign accommodation and pupil diameter & use defaults if field left empty [YT>*BH?  
        If dlg.TextBox1 = "" Then 9Z'8!$LYg  
            A = 0           'Default accommodation ``e$AS  
        Else Pgus42f%  
            A = CDbl(dlg.TextBox1) EC8b=B<DE  
        End If [7S} g  
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        If dlg.TextBox2 = "" Then Ii_ojQP-z  
            pupilDiam = 4   'Default pupil diameter fasgmi}  
        Else 5<j%EQN|D  
            pupilDiam = CDbl(dlg.TextBox2) GF%314Xu  
        End If UHxE)]J  
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        Print " " HnCzbt@  
        Print "Accommodation = " & A & " Diopters" MFm"G  
        Print "Pupil Diameter = " & pupilDiam & " mm" )Ocl=H|=  
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        ' Calculate new parameters with accommodation mAW, ?h  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness H0SQ"?  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens % v7[[U{T  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens tl'9IGlc  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens e-*.Ca  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens | j a-  
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        tlens = 3.767 + 0.04*A                  'Lens thickness cEd+MCN  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction QZhj b  
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        'Adjust parameters to account for accommodation pBP.x#|  
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        '************************************************************************* A7`1-#  
        'Aqueous thickness (Position of Lens) ${nX:!)  
        '************************************************************************* <u:WlaS  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 'fNKlPMv4D  
        GetCustomElement eID, entity B8%{}[q  
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        parID = FindFullName( "Geometry.Arizona Eye" ) d)R352  
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        ' Delete any shift(s) in z `TPOCxM Mo  
        count = 0 fH ?ha  
        While GetOperationCount(eID)>count ee#): -p  
            GetOperation eID, count, op <K4 ,7J$}h  
            If op.Type="ShiftZ" Then lP!;3iJ B  
                DeleteOperation eID,count zf>5,k'x'A  
                count=count-1 m&iH2|  
            End If "y<?Q}1  
            count=count+1 FSb Hn{@  
        Wend t/PlcV_M"  
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        'Set new shift in gOK\%&S]  
        op.Type = "ShiftZ" ?cEskafb>  
        op.val1 = taq .*JA!B  
        op.parent = parID eBO@7F$  
        AddOperation eID, op D'hW|  
        Print "Set aqueous humor thickness = " & taq-0.55 >xn}N6Rj2~  
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        '************************************************************************* *8tI*Pus  
        'Radius and conic constant of anterior lens ([V V%ovZ  
        '************************************************************************* nbTVU+  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) [ dE.[  
        GetConic eID, entity, curv, conic VCcr3Dx()F  
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        SetConic eID, entity, 1/Rant, CCant 34R!x6W0  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant M}wXJ8aF?  
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        '************************************************************************* OLj\-w^  
        'Radius and conic constant of posterior lens <x),,a=X  
        '************************************************************************* NCf"tK'5n  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) <(e8sNe  
        GetConic eID, entity, curv, conic lw(e3j  
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        SetConic eID, entity, 1/Rpost, CCpost ow'lRHZ  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 92'wkS  
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        '************************************************************************* ^:jN3@ Q%  
        'Lens thickness (Position of posterior lens surface) i o3yLIy,  
        '************************************************************************* j9/-"dTL  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 8g >b  
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        ' Delete any z-shift(s) nB ".'=  
        count = 0 *AIEl"29  
        While GetOperationCount(eID)>count X{-9FDW  
            GetOperation eID, count, op T^}  
            If op.Type="ShiftZ" Then D8# on!  
                DeleteOperation eID,count 1SV^){5I  
                count=count-1 <[/%{sUNC  
            End If ? QDWuPhN  
            count=count+1 ]fI/(e_U  
        Wend #DkD!dW(l  
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        'Set new z-shift BD#.-xWV  
        op.Type = "ShiftZ" te4= S  
        op.val1 = tlens D["MUB4l  
        op.parent = parID -NBiW6b~  
        AddOperation eID, op Us~ X9n_F  
        Print "Set lens thickness = " & tlens )Os Lrq/  
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        '************************************************************************* 8)\M:s~7&  
        'Lens index of refraction `4CWE_k  
        '************************************************************************* Kt.~aaG_  
        eID = FindMaterial( "Lens" ) r++i=SQax  
        GetModelMaterial eID, mat h.whjiCFa  
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        mat.Nd = nlens ]PNow S\  
        SetModelMaterial eID, mat 7nHTlI1 b  
        Print "Set lens index of refraction = " & nlens e^$j5jV  
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        '************************************************************************* I 2HT2c$  
        'Pupil diameter nD,{3B#  
        '************************************************************************* !|m9|  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 5GAy "Xd  
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        'Adjust pupil diameter (trimming volume inner hole) 3An(jt$%Q  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ? 4)v`*  
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        ' Adjust pupil location to just in front of the lens {sC=J hs-  
        parID = FindFullName( "Geometry.Arizona Eye" ) $~'Tf>e  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) i!MwBYk  
        count = 0 hWcTI{v  
        While GetOperationCount(eID)>count /b.oEGqZX  
            GetOperation eID, count, op nb@"?<L!  
            If op.Type="ShiftZ" Then G"S5ki`o  
                DeleteOperation eID,count &(&  
                count=count-1 ;>2#@QP  
            End If En9R>A;`  
            count=count+1 -rDz~M+  
        Wend $ehg@WK}.  
        op.Type = "ShiftZ" ->yeJTsE9  
        op.val1 = taq-0.01 (buw^ ,NwZ  
        op.parent = parID ;WI]vn  
        AddOperation eID, op 3DoRE2}  
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        Print "Set pupil diameter = " & pupilDiam &P n]  
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        'Update AZ Eye subassembly Description ~|) 9RUXr>  
        eID = FindFullName( "Geometry.Arizona Eye" ) [a8+(  
        GetEntity eID, entity H(\V+@~>AD  
        entity.Description = "Accommodation = " & A & "D"  ]R Mb,hJ  
        SetEntity eID, entity wR7aQg  
    'H=weH  
        Update ~5t?C<wo  
        Print "DONE!" $ly0h W  
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    End Sub gEKO128  
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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: v>WB FvyD  
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    Accommodation = 4 Diopters YhgUCF#  
    Pupil Diameter = 4 mm v"k 4ATWP  
    Set aqueous humor thickness = 2.81 9oq)X[  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 s-Y+x  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 *:QXz<_x+  
    Set lens thickness = 3.927 2xmT#m  
    Set lens index of refraction = 1.42672 UpeQOC  
    Set pupil diameter = 4 b|E/LKa  
    DONE!
silence唯爱 2022-02-25 13:53
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