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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 aAbK{=/y_!  
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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。 ?lPn{oB9"  
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    模型 ,<CFjtelO  
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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。 G(3wI}  
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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. b)[2t^zG  
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    光源 gX%"Ki7.  
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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。 c%+_~iBUN  
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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。 sd5)We  
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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。 <-h[I&."  
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    图2. 字母F光源的设定方法光 rJM/.;Ag  
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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 W; zzc1v  
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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。 %HD0N&  
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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。 96d&vm~m1  
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    图5. 视网膜重点采样规格设定
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    脚本 VZ]}9k  
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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: 0JXXJ:dB  
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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。 %D49A-R  
    余下的脚本计算与屈光度有关的所有参数。 ~='}(Fg:  
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    分析 F|&%Z(@a  
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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。 (XNd]G  
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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 7P:/ (P  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. GQ0(lS  
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    Dim entity As T_ENTITY @;X#/dZe  
    Dim op As T_OPERATION 0C4Os p  
    Dim mat As T_MODELMATERIAL C'6c,  
    Dim A As Double RN2z/F Uf  
    Dim pupilDiam As Double "#8I &xZK  
    Dim eID As Long w$0*5n>)  
    Dim parID As Long (7C$'T-ZK  
    Dim count As Integer |)OC1=As  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double zgl$ n  
    Dim tlens As Double, nlens As Double f{-,"6Y1  
    Dim curv As Double, conic As Double )Vo%}g?6!  
    Dim ok As Long JYnyo$m/  
    (\%J0kR3[  
    Sub Main D^S"6v" z  
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        '用户输入对话框 eB9F35[  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 i(YR-vYK  
            TextBox 220,21,40,21,.TextBox1 'default: 0 \rY\wa  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 i(4.7{*  
            OKButton 40,91,90,21 bD=R/yA  
            CancelButton 190,91,90,21 ;;N#'.xD  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 I9h{fB  
            TextBox 220,49,40,21,.TextBox2 'default: 4 3uL$+F  
        End Dialog LX}|%- iv  
        Dim dlg As UserDialog %ed TW[C`  
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        ok = Dialog (dlg) em2Tet  
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        If ok=0 Then    'cancel button was pressed t$PJ*F67M  
            Print "Execution cancelled." ;?Q0mXr  
            End {<zE}7/2-  
        End If _6->D[dB  
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        'Assign accommodation and pupil diameter & use defaults if field left empty ]YY4{E(9d  
        If dlg.TextBox1 = "" Then ^97[(89G9  
            A = 0           'Default accommodation i "aQm  
        Else .*?)L3n+t  
            A = CDbl(dlg.TextBox1) Lr Kx  
        End If _8 l=65GW  
    7 6HB@'xY  
        If dlg.TextBox2 = "" Then 4M;S&LA  
            pupilDiam = 4   'Default pupil diameter 1pqYB]*u_  
        Else GuF-HP}xM  
            pupilDiam = CDbl(dlg.TextBox2) b/4gs62{k  
        End If bd3>IWihp  
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        Print " " z=4E#y `?U  
        Print "Accommodation = " & A & " Diopters" @h5Q?I  
        Print "Pupil Diameter = " & pupilDiam & " mm" z'zC  
    `F~Fb S  
        ' Calculate new parameters with accommodation kdMB.~(K=  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness xM>dv5<E  
    %5;kNeD\Fq  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens KF7d`bRe  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens )5TX3#=;(G  
    :~p_(rE  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens BbI),iP  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ?[ D6|gp  
    nZ`=Up p)  
        tlens = 3.767 + 0.04*A                  'Lens thickness 4VzSqb  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction &WdP=E"  
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        'Adjust parameters to account for accommodation FYK}AR<=  
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        '************************************************************************* :0Fwaw9PH"  
        'Aqueous thickness (Position of Lens) )EG-xo@X  
        '************************************************************************* i k0w\*  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5 d|+c<  
        GetCustomElement eID, entity )Y?E$=M +B  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 7RgnL<t~:8  
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        ' Delete any shift(s) in z l`];CALA4  
        count = 0 3iiOxg?j  
        While GetOperationCount(eID)>count ezd@>(hJ  
            GetOperation eID, count, op lqKwjJ tX  
            If op.Type="ShiftZ" Then ]o_E]5"jO  
                DeleteOperation eID,count B^hK  
                count=count-1 *1}vn%wvn  
            End If Vb2")+*:  
            count=count+1 j MA%`*r  
        Wend w2tkJcQ3  
    J1Y3>40  
        'Set new shift in qj?I*peK)  
        op.Type = "ShiftZ" U3w*z6OG  
        op.val1 = taq OL[_2m*;9p  
        op.parent = parID 1z[blNs&  
        AddOperation eID, op >2)!w  
        Print "Set aqueous humor thickness = " & taq-0.55 I3?:KVa  
    sQT,@'"  
        '************************************************************************* 3*b!]^d:D  
        'Radius and conic constant of anterior lens < YuI}d~'  
        '************************************************************************* K9Pw10g'  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) g/,O51f'  
        GetConic eID, entity, curv, conic .]Z,O>N  
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        SetConic eID, entity, 1/Rant, CCant q}5&B =2pM  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant #60<$HO:Z  
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        '************************************************************************* 4U:+iumy2  
        'Radius and conic constant of posterior lens !!t@ H\  
        '************************************************************************* n1c Q#u  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) fKT(.VN q5  
        GetConic eID, entity, curv, conic fI0L\^b%  
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        SetConic eID, entity, 1/Rpost, CCpost on1mu't_;  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost e3>k"  
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        '************************************************************************* k4 %> F  
        'Lens thickness (Position of posterior lens surface) G,i%:my7  
        '************************************************************************* ,K[B/tD{j  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) z'X_ s.9F  
    ? 5 V-D8k  
        ' Delete any z-shift(s) l@YpgyqaL  
        count = 0 ]t3 NA*mM  
        While GetOperationCount(eID)>count Sq==)$G  
            GetOperation eID, count, op JXnPKAN  
            If op.Type="ShiftZ" Then gf2w@CVF>=  
                DeleteOperation eID,count *)d|:q3  
                count=count-1 z*>CP  
            End If ^q$vyY   
            count=count+1 ss 3fq}  
        Wend J0|}u1? l  
    ^ihXM]1{G  
        'Set new z-shift i]LK,'  
        op.Type = "ShiftZ" "$8<\k$LGT  
        op.val1 = tlens osX23T~-  
        op.parent = parID LGCL*Qbsg  
        AddOperation eID, op .< vg[  
        Print "Set lens thickness = " & tlens T}]Ao  
    ^NLKX5Q  
        '************************************************************************* (^Do#3  
        'Lens index of refraction Lou4M  
        '************************************************************************* qkUr5^1  
        eID = FindMaterial( "Lens" ) NI s4v(!  
        GetModelMaterial eID, mat cCV"(Oo[H|  
    )3B5"b,  
        mat.Nd = nlens y!!+IeReS  
        SetModelMaterial eID, mat Q84KU8?d  
        Print "Set lens index of refraction = " & nlens A1ebXXD )  
    $'FPst8Q<  
        '************************************************************************* ,n!xzoX_  
        'Pupil diameter 0XYO2 k  
        '************************************************************************* r rwsj`  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 3Ob"r`  
    \ bT]?.si  
        'Adjust pupil diameter (trimming volume inner hole) JcVq%~ {M  
    $=m17GD  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" JN KZ'9  
    kyo ,yD  
        ' Adjust pupil location to just in front of the lens Z%OSW  
        parID = FindFullName( "Geometry.Arizona Eye" ) NxX1_d  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) /l$noaskX  
        count = 0 xf]4!zE  
        While GetOperationCount(eID)>count -X}R(.}x  
            GetOperation eID, count, op ]VYl Eqe  
            If op.Type="ShiftZ" Then a@jP^VVk  
                DeleteOperation eID,count !Z'm@,+  
                count=count-1 M7> \Qk  
            End If Csc2yI%3  
            count=count+1 ,6buo~?W:  
        Wend GKd>AP_  
        op.Type = "ShiftZ" 3CHte*NL=  
        op.val1 = taq-0.01 F_Pd\Aq8  
        op.parent = parID #129 i2  
        AddOperation eID, op 86I*  
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        Print "Set pupil diameter = " & pupilDiam Go67VqJr  
    O46/[{p+8  
        'Update AZ Eye subassembly Description P%lLKSA  
        eID = FindFullName( "Geometry.Arizona Eye" ) B&$89]gs|  
        GetEntity eID, entity 8Z!ea3kAT  
        entity.Description = "Accommodation = " & A & "D" _/=ZkI5  
        SetEntity eID, entity 0Yjy  
    ,RHHNTB("  
        Update sq^"bLw  
        Print "DONE!" QE}@|H9xs  
         O9yQ9sl  
    End Sub o<'gM]$  
    X>6a@$MxP  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: Vi|jkyC8  
    #"M Pe4  
    Accommodation = 4 Diopters *3K"Kc2  
    Pupil Diameter = 4 mm Mww]l[1'EL  
    Set aqueous humor thickness = 2.81 D/Wuan?yPN  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 +J4t0x  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 u~kwNN9t3  
    Set lens thickness = 3.927 mN*P 2 *  
    Set lens index of refraction = 1.42672 w8i!Qi#y5D  
    Set pupil diameter = 4 @6!JW(,]\  
    DONE! I{PN6bn{>  
     
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