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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 u33zceE8  
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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。 WEVl9]b'e+  
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    模型 X>/K/M  
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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。 r{V.jZ%p'Z  
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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. %O/d4  
    AP ;*iyQ[  
    光源 S.]MOB dt  
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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。 :A*0]X;  
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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。 wWFW,3b  
    !VNbj\Bp  
    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。 =~$U^IsWA  
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    图2. 字母F光源的设定方法光 b_mWu@$  
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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 O,]_ tp  
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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。 )(.%QSA\C  
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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。 1)gv%_  
    :@WLGK*u.  
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    图5. 视网膜重点采样规格设定
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    脚本 `~|DoSi^d  
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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: {\luieG  
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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。 5{HtJ?sKc5  
    余下的脚本计算与屈光度有关的所有参数。 -P*xyI  
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    分析 !rz)bd3$  
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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。 5(KG=EHj_  
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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 tw]/,>\G  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. b%<164i  
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    Dim entity As T_ENTITY >]^>gUmq  
    Dim op As T_OPERATION yIlV[_  
    Dim mat As T_MODELMATERIAL F"Uh/EO<  
    Dim A As Double G~O" /WM  
    Dim pupilDiam As Double \!m!ibr  
    Dim eID As Long df!+T0  
    Dim parID As Long vB=;_=^i 1  
    Dim count As Integer {$3j/b  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double kRQ~hRT6  
    Dim tlens As Double, nlens As Double QZ?O;K1|y  
    Dim curv As Double, conic As Double Euqjxz  
    Dim ok As Long 2(hvv-  
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    Sub Main _jiQL66pY  
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        '用户输入对话框 Tln9q0"W  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 $R8>u#K!  
            TextBox 220,21,40,21,.TextBox1 'default: 0 9=H}yiJz  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 aX:#'eDB  
            OKButton 40,91,90,21 *O!T!J  
            CancelButton 190,91,90,21 bx;yHIRb  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1  dD:  
            TextBox 220,49,40,21,.TextBox2 'default: 4 r(pwOOx  
        End Dialog #aj|vox}  
        Dim dlg As UserDialog sbs[=LW4  
    ;5-R =e(KA  
        ok = Dialog (dlg) b{zAJ`|#[n  
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        If ok=0 Then    'cancel button was pressed h=!M6yap<  
            Print "Execution cancelled." !T)T_P[  
            End Zlr{L]c  
        End If z|Hy>|+  
    2O$95 M  
        'Assign accommodation and pupil diameter & use defaults if field left empty Cc@=?  
        If dlg.TextBox1 = "" Then qPL^zM+  
            A = 0           'Default accommodation &b 5T&-C<  
        Else Y]hV-_2+Do  
            A = CDbl(dlg.TextBox1) 2f`WDL  
        End If s*aH`M7^0  
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        If dlg.TextBox2 = "" Then e 4 p*51ra  
            pupilDiam = 4   'Default pupil diameter A Z]P+v  
        Else &G0l&8pa  
            pupilDiam = CDbl(dlg.TextBox2) 14mXx}O  
        End If }Q47_]5  
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        Print " " TP{>O%b  
        Print "Accommodation = " & A & " Diopters" R)sp  
        Print "Pupil Diameter = " & pupilDiam & " mm" MMd0O X)P  
    YtV |e|aD  
        ' Calculate new parameters with accommodation aQ32p4C  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness $,8CH)w  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens Pd)K^;em  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens D?iy.Dg  
    6U;Jg_zS  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens gJ<@;O8zu0  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 6T R8D\  
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        tlens = 3.767 + 0.04*A                  'Lens thickness 6V.awg,  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction +A]&AkTw  
    &>&dhdTQ  
        'Adjust parameters to account for accommodation [ c ~LY4:  
    } l:mN  
        '************************************************************************* kHt!S9r  
        'Aqueous thickness (Position of Lens) f?/|;Zo4  
        '************************************************************************* 2neF<H?^o  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) XR{5]lKt_  
        GetCustomElement eID, entity dNR7e   
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        parID = FindFullName( "Geometry.Arizona Eye" ) A6@+gP<  
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        ' Delete any shift(s) in z ;FV~q{  
        count = 0 :6 Hxxh  
        While GetOperationCount(eID)>count GVjv** U  
            GetOperation eID, count, op g28S3 '2  
            If op.Type="ShiftZ" Then .Ws iOJU  
                DeleteOperation eID,count I}*]m%'-Y  
                count=count-1 kGB#2J  
            End If ?)A]q' O  
            count=count+1 :J=+;I(UI  
        Wend &LCUoTzj  
    wc<2Uc  
        'Set new shift in DBj;P|L_  
        op.Type = "ShiftZ" (hhdbf  
        op.val1 = taq X";QA":  
        op.parent = parID qP7&LtU  
        AddOperation eID, op :0J-ek.;  
        Print "Set aqueous humor thickness = " & taq-0.55 9pVf2|5hj  
    ROJ'-Vde9  
        '************************************************************************* K B`1%=  
        'Radius and conic constant of anterior lens #U ",,*2  
        '************************************************************************* j6&zRFX  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) )z ?&" I  
        GetConic eID, entity, curv, conic *@-q@5r}!  
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        SetConic eID, entity, 1/Rant, CCant EWu iaw.  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ,wry u|7"$  
    o*O "\/pmF  
        '************************************************************************* ?L<UOv7;t  
        'Radius and conic constant of posterior lens H3p4,Y}'#  
        '************************************************************************* N=O+X~  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) H#1*'e>  
        GetConic eID, entity, curv, conic ?1-n\ka  
    f{+LCMbC6  
        SetConic eID, entity, 1/Rpost, CCpost 3/A[LL|  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost g9FVb7In_  
    h-?q6O/|  
        '************************************************************************* >,] eL  
        'Lens thickness (Position of posterior lens surface) [B2>*UPl  
        '************************************************************************* 4y]:Gq z~  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) w]o:c(x@  
    H}jK3;8E  
        ' Delete any z-shift(s) ch)Ps2i  
        count = 0 M f%^\g.}  
        While GetOperationCount(eID)>count 5Gw!9{ke  
            GetOperation eID, count, op K=!ZI/+ju  
            If op.Type="ShiftZ" Then t[f9Z  
                DeleteOperation eID,count 1,%#O;ya  
                count=count-1 @MlU!oR&  
            End If (IoPU+1b  
            count=count+1 7tf81*e  
        Wend lt2Nwt0bv  
    .qb_/#Bas  
        'Set new z-shift |`)V^e_  
        op.Type = "ShiftZ" ard3yNQt  
        op.val1 = tlens Vtz yB  
        op.parent = parID s5zGg]0  
        AddOperation eID, op ,/w852|ub  
        Print "Set lens thickness = " & tlens f@F^W YQm  
    Il&"=LooZ  
        '************************************************************************* #g-*n@ 1  
        'Lens index of refraction o $HJg  
        '************************************************************************* z2s|.M]&-D  
        eID = FindMaterial( "Lens" ) r 0?hX  
        GetModelMaterial eID, mat  [A%e6  
    hD6ur=G8u  
        mat.Nd = nlens z!1/_]WJ,  
        SetModelMaterial eID, mat SqA+u/"j2  
        Print "Set lens index of refraction = " & nlens `!Ge"JB6   
    FkxhEat8  
        '************************************************************************* k`2B9,z  
        'Pupil diameter ;@7 #w  
        '************************************************************************* \MFWK#W  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 0oi5]f6g?8  
    %)6 :eIS  
        'Adjust pupil diameter (trimming volume inner hole) BJO~$/R?v  
    wzQdKlV  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" xV n]m9i  
    T`w};]z^d2  
        ' Adjust pupil location to just in front of the lens RESGI}u  
        parID = FindFullName( "Geometry.Arizona Eye" ) jB/q1vFO  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) '+q'H  
        count = 0 IYM@(c@ld0  
        While GetOperationCount(eID)>count |q!2i  
            GetOperation eID, count, op M#lVPXS  
            If op.Type="ShiftZ" Then *p#YK|  
                DeleteOperation eID,count a9@l8{)RX  
                count=count-1 K3r>nGLBo  
            End If wkZ2Y-#='  
            count=count+1 ZAo)_za&mH  
        Wend i:Z.;z$1  
        op.Type = "ShiftZ" t6L^ #\'  
        op.val1 = taq-0.01 xBI"{nGoN  
        op.parent = parID T`'3Cp$q  
        AddOperation eID, op c;|&>Fp  
    MlC-Aad(  
        Print "Set pupil diameter = " & pupilDiam I|3v&E 1  
     ]O9f"cj  
        'Update AZ Eye subassembly Description W}e[.iX;  
        eID = FindFullName( "Geometry.Arizona Eye" ) RJ@e5A6_  
        GetEntity eID, entity RY/ Z~]  
        entity.Description = "Accommodation = " & A & "D" &A5[C{x  
        SetEntity eID, entity h&)vdCCk  
    MTITIecw=  
        Update _OxnHf:|  
        Print "DONE!" fN*4(yw  
         |z7Crz  
    End Sub n%ArA])_&  
    yA>p[F  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: 1'U%7#;E  
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    Accommodation = 4 Diopters vVN[bD<  
    Pupil Diameter = 4 mm %"KWjwp  
    Set aqueous humor thickness = 2.81 (zLIv9$  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 n$![b_)*  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 E~g}DKs_5  
    Set lens thickness = 3.927 rgZ rE;*;  
    Set lens index of refraction = 1.42672 W lLZtgq  
    Set pupil diameter = 4 Zn 5m.=z  
    DONE! 9B;Sk]y  
     
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