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    [技术]Arizona眼睛模型 [复制链接]

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    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 TZ?Os4+  
    A <4_DVd@@  
    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。 wYZT D*A2h  
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    模型 3/X-Cr+d  
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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。 B\Xh 3l]+j  
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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. :w@F?:C  
    (+|X<Bl:`  
    光源 nD7|8,'  
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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。 ]JOephX2R  
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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^Hi=aV  
    ,eR8 ~(`=  
    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。 b9!.-^<8y  
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    图2. 字母F光源的设定方法光 &~RR&MdZ2  
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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 wZ#Rlv,3Wa  
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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。 Ab/j(xr=  
    1%%'6cWWu  
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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。 F8H'^3`b`U  
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    图5. 视网膜重点采样规格设定
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    脚本 0o;O`/x  
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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: "< v\M85&  
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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。 \i!Son.<  
    余下的脚本计算与屈光度有关的所有参数。 |g%mP1O  
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    分析 Ur^j$B}  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 LOr|k8tL%  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 IS BV%^la|  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. m 41t(i  
    V >Hf9sZ  
    Dim entity As T_ENTITY NBjeH tT  
    Dim op As T_OPERATION AVG>_$<  
    Dim mat As T_MODELMATERIAL t|V0x3X  
    Dim A As Double C9qJP^F  
    Dim pupilDiam As Double MxOD8TDF4  
    Dim eID As Long + E/y ~s  
    Dim parID As Long 'xnnLCm.  
    Dim count As Integer S_v(S^x6  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double /- 4$7qd  
    Dim tlens As Double, nlens As Double *f5l=lDOB  
    Dim curv As Double, conic As Double &.Q8Mi aT  
    Dim ok As Long [3N[i(Wlk  
    w5KPB5/zu  
    Sub Main u=r`t(Z1H  
    #`;/KNp 9  
        '用户输入对话框 2 -Xdoxw  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1  )zq.4  
            TextBox 220,21,40,21,.TextBox1 'default: 0 K=?VDN  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ar.AL'  
            OKButton 40,91,90,21 W2Luz;(U  
            CancelButton 190,91,90,21 ?m0IehI  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 5\Fz!  
            TextBox 220,49,40,21,.TextBox2 'default: 4 cCY/gEv  
        End Dialog 4f^C\i+q  
        Dim dlg As UserDialog K-eY|n  
    eKN$jlg  
        ok = Dialog (dlg) >u0w.3r#  
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        If ok=0 Then    'cancel button was pressed M2@b1;  
            Print "Execution cancelled." C+{l7QT$t  
            End 93O;+Z5J  
        End If !}KqB8;  
    % ."@Q$lA  
        'Assign accommodation and pupil diameter & use defaults if field left empty in-C/m#  
        If dlg.TextBox1 = "" Then }-@4vl x$  
            A = 0           'Default accommodation DJ@|QQ  
        Else ;heHefbvvd  
            A = CDbl(dlg.TextBox1) =Z G:x<Hg  
        End If p?X02 >yA  
    fNu'((J-  
        If dlg.TextBox2 = "" Then 9\;|x  
            pupilDiam = 4   'Default pupil diameter ILwn&[A0  
        Else v$wBxCY  
            pupilDiam = CDbl(dlg.TextBox2) ?=;qK{)37  
        End If ^pnG0(9  
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        Print " " 27F~(!n  
        Print "Accommodation = " & A & " Diopters" :-`7Q\c}  
        Print "Pupil Diameter = " & pupilDiam & " mm" *e#<n_%R  
    QK`i%TXJ  
        ' Calculate new parameters with accommodation o*g|m.SjL  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness h*B|fy4K9U  
    s;flzp8  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ~z5R{;Nbz|  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ]rN5Ao}2  
    v%{.A)  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens X+k}2HvNG  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens qmy%J  
    _c$9eAe  
        tlens = 3.767 + 0.04*A                  'Lens thickness ]iNEw9  
    #-% A[7Cdp  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction sOCs13A"  
    l`-bFmpA  
        'Adjust parameters to account for accommodation t*<#<a  
    <#GB[kQa  
        '************************************************************************* COzyG.R.  
        'Aqueous thickness (Position of Lens) jjM\.KL]  
        '************************************************************************* 8vSse  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) >>i@r@  
        GetCustomElement eID, entity bI)u/  
    8X|r4otn4  
        parID = FindFullName( "Geometry.Arizona Eye" ) ^u}L;`L  
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        ' Delete any shift(s) in z 5}$b0<em~  
        count = 0 E37<"(;  
        While GetOperationCount(eID)>count K_?W\Yg   
            GetOperation eID, count, op |t iUej  
            If op.Type="ShiftZ" Then ~9)"!   
                DeleteOperation eID,count ps .]N   
                count=count-1 #rO8Kf  
            End If &!aAO(g  
            count=count+1 [[d(jV=*  
        Wend l!}:|N Yh!  
    p Dx-2:}  
        'Set new shift in Ch$*Gm19Z  
        op.Type = "ShiftZ" 4'4\ ,o  
        op.val1 = taq 3kcTE&1^  
        op.parent = parID CC\*?BKj"  
        AddOperation eID, op n+lOb  
        Print "Set aqueous humor thickness = " & taq-0.55 :l7U>~ o  
    =[\s8XH,  
        '************************************************************************* ;,i]w"*  
        'Radius and conic constant of anterior lens 'TH15r@  
        '************************************************************************* a22Mufl  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) r<F hY  
        GetConic eID, entity, curv, conic -/{ 4Jf Wf  
    f7h*Vu`>  
        SetConic eID, entity, 1/Rant, CCant mWR4|1(  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 9% l%  
    kn)t'_jC  
        '************************************************************************* :1t~[-h^  
        'Radius and conic constant of posterior lens Q#h 9n]5  
        '************************************************************************* '>$]{vQ3  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Y]]}*8  
        GetConic eID, entity, curv, conic ]EwVpvTw  
    b=~i)`  
        SetConic eID, entity, 1/Rpost, CCpost >5s6u`\  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost `wF8k{Pb  
    n,$IfC"  
        '************************************************************************* A)%A!  
        'Lens thickness (Position of posterior lens surface) ?4H i-  
        '************************************************************************* 2I*;A5$N1  
    Bs?7:kN(  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /Q~gU<  
    &Tl 0Pf  
        ' Delete any z-shift(s) zIP6\u  
        count = 0 pv^O"Bs  
        While GetOperationCount(eID)>count '* \|; l#1  
            GetOperation eID, count, op "#(T  
            If op.Type="ShiftZ" Then ;<G=M2  
                DeleteOperation eID,count *tm0R>?!  
                count=count-1 Y0 D}g3`  
            End If PJcwH6m  
            count=count+1 r$]HIvJD  
        Wend 22f`LoM  
    U|g:`v7  
        'Set new z-shift )(y) A[  
        op.Type = "ShiftZ" uV 7BK+[O  
        op.val1 = tlens /-bO!RTwf  
        op.parent = parID <dW]\h?)  
        AddOperation eID, op rvr-XGK36\  
        Print "Set lens thickness = " & tlens (@iMLuewK  
    Oft4- 4$E  
        '************************************************************************* n_3O-X(  
        'Lens index of refraction 1"pw  
        '************************************************************************* o] mD"3_  
        eID = FindMaterial( "Lens" ) :n /@z4#  
        GetModelMaterial eID, mat ChCrL [2  
    P-ri=E}>  
        mat.Nd = nlens B<C*  
        SetModelMaterial eID, mat Duc#$YfGm  
        Print "Set lens index of refraction = " & nlens * S=\l@EW  
    D@!=d@V.  
        '************************************************************************* i;!H!-sM  
        'Pupil diameter IpP~Uz  
        '************************************************************************* ^h{)Gf,+\  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 'Ysx=  
    rk)##)  
        'Adjust pupil diameter (trimming volume inner hole) sg+uBCGB  
    I4&::y^ C  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" >Wz;ySEz  
    @:KJYm[  
        ' Adjust pupil location to just in front of the lens B/` !K  
        parID = FindFullName( "Geometry.Arizona Eye" ) It{;SKeo  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ^5=B`aich  
        count = 0 5 Kkdo!z  
        While GetOperationCount(eID)>count 7EXI6jGJ|  
            GetOperation eID, count, op b$Vz2Fzx  
            If op.Type="ShiftZ" Then o1<_fI  
                DeleteOperation eID,count }g4 M2|  
                count=count-1 %'[&U#-  
            End If f%V4pzOc"  
            count=count+1 A'2w>8  
        Wend .nyfYa+  
        op.Type = "ShiftZ" Nj?/J47?,  
        op.val1 = taq-0.01 WD1G&5XP  
        op.parent = parID +zy=50,   
        AddOperation eID, op S{Er?0wm.R  
    (&!NC[n,  
        Print "Set pupil diameter = " & pupilDiam rD*sl}  
    qbv#I;  
        'Update AZ Eye subassembly Description [ :zO}r:  
        eID = FindFullName( "Geometry.Arizona Eye" ) j\m_o% 4  
        GetEntity eID, entity P{u0ftyX}  
        entity.Description = "Accommodation = " & A & "D" d 9q(xZ5  
        SetEntity eID, entity v'e[GB 0  
    EOm:!D\  
        Update hcyM6:}  
        Print "DONE!" 7e<c$t#H  
         mW:!M!kk  
    End Sub z`\F@pX%wC  
    x:QgjK  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: zD<or&6  
    f4BnX(1u  
    Accommodation = 4 Diopters VqS#waNrx  
    Pupil Diameter = 4 mm AZmb!}m+d  
    Set aqueous humor thickness = 2.81 9D4NX<_  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 HQB(*  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 &\Amn?Iq  
    Set lens thickness = 3.927 ;s52{>&F]  
    Set lens index of refraction = 1.42672 ~ {Mn{  
    Set pupil diameter = 4 I}t#%/'YA  
    DONE! !tp1:'KG  
     
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