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    [分享]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: 2020-12-09
    简介 >Z%qkU/  
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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。 v:.`~h/b  
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    模型 o& -c5X4  
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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。 8/4i7oOC  
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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. Vm6 0aXm_  
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    光源 2g'o5B\ *  
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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。 8<#S:O4kA  
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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.qu_,IZ  
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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。 tZ4Zj`x|^  
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    图2. 字母F光源的设定方法光 JY6&CL`C  
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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 #}y(D{zc  
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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。 <OR f{  
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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%%[_6<%M  
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    图5. 视网膜重点采样规格设定
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    脚本 m`3Mev  
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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: Zcq 4?-&  
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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。 3jaY\(`%h  
    余下的脚本计算与屈光度有关的所有参数。 S zqY@  
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    分析 k~P{Rm;F  
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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。 ? FlV<nE"J  
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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 fD>0  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. E\ 'X|/$a  
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    Dim entity As T_ENTITY IQ9jTkW l  
    Dim op As T_OPERATION [>pqf  
    Dim mat As T_MODELMATERIAL {1jywb }  
    Dim A As Double q^.\8zFf  
    Dim pupilDiam As Double ZJ|@^^GcL  
    Dim eID As Long  `LWZ!Q  
    Dim parID As Long %uVbI'n)  
    Dim count As Integer nV$ctdusQ  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ":o1g5?  
    Dim tlens As Double, nlens As Double -_>g=a@&  
    Dim curv As Double, conic As Double $1(FN+ M b  
    Dim ok As Long XIrNT:h4  
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    Sub Main *C0gpEf9S  
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        '用户输入对话框 GA8cA)]zOD  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 wn$:L9"YN  
            TextBox 220,21,40,21,.TextBox1 'default: 0 0lvX,78G;  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 zF F=v7[j  
            OKButton 40,91,90,21 wu2AhMGmw  
            CancelButton 190,91,90,21 ~6hG"t]:  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 H$ sNp\[{  
            TextBox 220,49,40,21,.TextBox2 'default: 4 )kE(%q:*P$  
        End Dialog bnWKfz5  
        Dim dlg As UserDialog T21SuM  
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        ok = Dialog (dlg) 8J- ;/  
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        If ok=0 Then    'cancel button was pressed P'nbyF  
            Print "Execution cancelled." :EUV#5V.  
            End I)-u)P?2x  
        End If >Kd(.r[Er  
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        'Assign accommodation and pupil diameter & use defaults if field left empty E"[^^<I  
        If dlg.TextBox1 = "" Then _n3Jf<Y  
            A = 0           'Default accommodation ~YuRi#CTD:  
        Else \E'Nk$V3  
            A = CDbl(dlg.TextBox1) J6!t"eB+  
        End If u%#s_R  
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        If dlg.TextBox2 = "" Then oadlyqlw#  
            pupilDiam = 4   'Default pupil diameter P80z@!  
        Else SZ9xj^"g  
            pupilDiam = CDbl(dlg.TextBox2) dwc$?Bg,5  
        End If by {G{M`X  
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        Print " " ==psPyLF@  
        Print "Accommodation = " & A & " Diopters" ZOFBT(oV  
        Print "Pupil Diameter = " & pupilDiam & " mm" o E&Zf/  
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        ' Calculate new parameters with accommodation _ +,2b:D:  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness NVnKgGlHgd  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens (u]ajT  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens k3m|I*_\L  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 6'Sc=;;:  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 's{-1aW  
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        tlens = 3.767 + 0.04*A                  'Lens thickness ;8~`fK  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction NgKbf vt  
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        'Adjust parameters to account for accommodation PL8{|Q  
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        '************************************************************************* S^ ?OKqS  
        'Aqueous thickness (Position of Lens) LnJ/t(KV  
        '************************************************************************* y+RT[*bX5o  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) y(:hN)  
        GetCustomElement eID, entity >GiM?*cC  
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        parID = FindFullName( "Geometry.Arizona Eye" ) `h M:U  
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        ' Delete any shift(s) in z SVp]}!jI  
        count = 0 US)wr  
        While GetOperationCount(eID)>count I~S`'()J  
            GetOperation eID, count, op yZ,k8TJ",  
            If op.Type="ShiftZ" Then i:WHql"Kw_  
                DeleteOperation eID,count @A6\v+ih  
                count=count-1 _Z6/r^c  
            End If qy@gW@IU  
            count=count+1 J`O4]XRY  
        Wend 8\8uXOS  
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        'Set new shift in GI$t8{M  
        op.Type = "ShiftZ" >b-rAO\{}  
        op.val1 = taq 0$,Ag;"^?  
        op.parent = parID $B4}('&4FQ  
        AddOperation eID, op `sN3iD!@R  
        Print "Set aqueous humor thickness = " & taq-0.55 9B'l+nP  
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        '************************************************************************* F|V_i C+  
        'Radius and conic constant of anterior lens %_1~z[Dv  
        '************************************************************************* Wuosr3P  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6mEW*qp2F  
        GetConic eID, entity, curv, conic UL[4sv6\9  
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        SetConic eID, entity, 1/Rant, CCant z$-/yT"M  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 7& k lX  
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        '************************************************************************* xn@?CP`-y  
        'Radius and conic constant of posterior lens CBSJY&:K  
        '************************************************************************* % @Ks<"9  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) .,,?[TI  
        GetConic eID, entity, curv, conic +M@G 8l  
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        SetConic eID, entity, 1/Rpost, CCpost N>Y`>5  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost F4 Ft~:a  
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        '************************************************************************* @D"#B@j  
        'Lens thickness (Position of posterior lens surface) 1elcP`N1  
        '************************************************************************* 6FSw_[)  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) M)EKS  
    :M|c,SQK  
        ' Delete any z-shift(s) gKb4n Nt  
        count = 0 (L|SE4  
        While GetOperationCount(eID)>count 2I?HBz1v  
            GetOperation eID, count, op 4,s: G.g  
            If op.Type="ShiftZ" Then <$Uj ~jN  
                DeleteOperation eID,count ]vQo^nOo  
                count=count-1 UXQ{J5Ox+  
            End If V.Xz n  
            count=count+1 wc bs-arH  
        Wend #A]7cMZ'W  
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        'Set new z-shift |,dMF2ADc  
        op.Type = "ShiftZ" QJdSNkc6  
        op.val1 = tlens }~QB2&3  
        op.parent = parID `y YgL@Zt  
        AddOperation eID, op gyCb\y+\a  
        Print "Set lens thickness = " & tlens .[2MPjg  
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        '************************************************************************* XN=<s;U  
        'Lens index of refraction ;%dkwKO  
        '************************************************************************* 7U.g4x|<  
        eID = FindMaterial( "Lens" ) 6^{ hY^Z  
        GetModelMaterial eID, mat c_ygwO3.Q  
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        mat.Nd = nlens ]; ^OY\,  
        SetModelMaterial eID, mat =53LapTPJ  
        Print "Set lens index of refraction = " & nlens i+&= "Z@  
    'R]Z9h  
        '************************************************************************* RX2= iO"  
        'Pupil diameter 'hya#rC&(  
        '************************************************************************* {f^30Fw  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) R@VO3zsW  
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        'Adjust pupil diameter (trimming volume inner hole) XIjSwR kYJ  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" uhc0,V;S  
    r]HLO'<]  
        ' Adjust pupil location to just in front of the lens ]LSa(7>EU  
        parID = FindFullName( "Geometry.Arizona Eye" ) E0O{5YF^T  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) TJ; v}HSo  
        count = 0 5\4>H6  
        While GetOperationCount(eID)>count 2OT6*+D  
            GetOperation eID, count, op e#nTp b  
            If op.Type="ShiftZ" Then +:'Po.{"  
                DeleteOperation eID,count oC7#6W:@w  
                count=count-1 rXm!3E6JL  
            End If wd#AA#J;*  
            count=count+1 E?9_i :IX  
        Wend wj'iU&aca  
        op.Type = "ShiftZ" e0$mu?wd-  
        op.val1 = taq-0.01 xrX("ili  
        op.parent = parID so8-e  
        AddOperation eID, op .<NXk"\!y  
    "V^jAPDXb  
        Print "Set pupil diameter = " & pupilDiam RDqC$Gu  
    YKx0Zs  
        'Update AZ Eye subassembly Description H~G=0_S  
        eID = FindFullName( "Geometry.Arizona Eye" ) F_r eBPx  
        GetEntity eID, entity kcOpO<oE  
        entity.Description = "Accommodation = " & A & "D" ^|K*lI/  
        SetEntity eID, entity ffB]4  
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        Update &&y@/<t  
        Print "DONE!" {(q U n  
         V3+%KkN  
    End Sub Q-au)R,  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: ttKfZ0  
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    Accommodation = 4 Diopters (qG$u&  
    Pupil Diameter = 4 mm U)PumU+z$u  
    Set aqueous humor thickness = 2.81 @'rO=(-b  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 [ho'Pc3A<  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 y(S0 2v>l  
    Set lens thickness = 3.927  y]+A7|  
    Set lens index of refraction = 1.42672 }I10hy~W  
    Set pupil diameter = 4 LPNv4lT[u  
    DONE! .cabw+& 7  
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