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    [分享]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: 2020-12-09
    简介 ^\PRz 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。 -;cF)C--12  
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    模型 4b<|jVl\  
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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。 Q0xGd(\  
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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. p&I>xu8fl  
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    光源 jm%P-C @  
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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。 w10~IP  
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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。 FWu:5fBZY  
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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。 y],op G6  
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    图2. 字母F光源的设定方法光 =mLp g4  
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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 ]#NfH-T  
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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。 IhzY7U)}T  
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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。 tD`^qMua  
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    图5. 视网膜重点采样规格设定
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    脚本 rOOo42Y W`  
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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: XOX$uLm  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 Q=! lbW  
    余下的脚本计算与屈光度有关的所有参数。 sDs.da#*2  
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    分析 a5Vlfx  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 G1it 3^*$  
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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 rXmrT%7k  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. mvH}G8  
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    Dim entity As T_ENTITY j&dCP@G  
    Dim op As T_OPERATION ,Gy,bcv{  
    Dim mat As T_MODELMATERIAL Fep@VkN  
    Dim A As Double K"[jrvZ=  
    Dim pupilDiam As Double _*=4xmB.=  
    Dim eID As Long *0oa2fz%  
    Dim parID As Long V|A.M-XLv4  
    Dim count As Integer 8Y%  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double >"UXY)  
    Dim tlens As Double, nlens As Double X*#\JF4$i  
    Dim curv As Double, conic As Double 5M>p%/  
    Dim ok As Long zEQQ4)mA  
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    Sub Main _"F=4`lJ  
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        '用户输入对话框 iLQO .'{U  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ZuWh gnp  
            TextBox 220,21,40,21,.TextBox1 'default: 0 mx1Bk9h%Xe  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 &OFVqm^  
            OKButton 40,91,90,21 iuqJPW^}  
            CancelButton 190,91,90,21 c='W{47  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 JoB-&r}\V*  
            TextBox 220,49,40,21,.TextBox2 'default: 4 B^M L}$  
        End Dialog tag)IWAiE  
        Dim dlg As UserDialog _`C|K>:  
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        ok = Dialog (dlg) -mO<(wfV>  
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        If ok=0 Then    'cancel button was pressed lp d~U2&  
            Print "Execution cancelled." ;[lLFI  
            End 8WLh7[  
        End If L4+R8ojG  
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        'Assign accommodation and pupil diameter & use defaults if field left empty `6Q+N=k~Z  
        If dlg.TextBox1 = "" Then ku57<kb  
            A = 0           'Default accommodation =|O]X|y-lZ  
        Else ~K)FuL[*  
            A = CDbl(dlg.TextBox1) 6_8yQ  
        End If L kafB2y  
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        If dlg.TextBox2 = "" Then p? +!*BZ  
            pupilDiam = 4   'Default pupil diameter ,: z]15fX  
        Else J#w=Z>oz<  
            pupilDiam = CDbl(dlg.TextBox2) u<n['Ur}|  
        End If / E!6]b/  
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        Print " " u ?F},VL;  
        Print "Accommodation = " & A & " Diopters" \2f?)id~  
        Print "Pupil Diameter = " & pupilDiam & " mm" oN83`Z  
    [N*S5^>1  
        ' Calculate new parameters with accommodation .1h\r, #  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 4ke.p<dG  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens b*Hk} !qH  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens j$u  
    &B+_#V=X@  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Z@JTZMN_  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 0jXDjk5'<  
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        tlens = 3.767 + 0.04*A                  'Lens thickness b V_<5PHP  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction _=[pW2p  
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        'Adjust parameters to account for accommodation 2nFr?Y3g,  
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        '************************************************************************* 8;UkZN"hy5  
        'Aqueous thickness (Position of Lens) RY,L'Gt O  
        '************************************************************************* ncsk(`lo  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) sBxCi~  
        GetCustomElement eID, entity ][\ uH|  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 8M['-  
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        ' Delete any shift(s) in z *MWI`=c  
        count = 0 >G0ihhVt  
        While GetOperationCount(eID)>count xnZ  
            GetOperation eID, count, op MA 6uJT  
            If op.Type="ShiftZ" Then cnDBT3$~Z  
                DeleteOperation eID,count ~a>3,v -  
                count=count-1 fhHTp_u)2  
            End If mL@7,GD  
            count=count+1 *:chN' <  
        Wend Kna@K$6{w=  
    &4p~i Z  
        'Set new shift in {X\FS   
        op.Type = "ShiftZ" :bP <H  
        op.val1 = taq ' b,zE[Q  
        op.parent = parID |L)qH"Eo  
        AddOperation eID, op !uKuO  
        Print "Set aqueous humor thickness = " & taq-0.55 HM\}C.u  
    5e'**tbKH  
        '************************************************************************* U<yKC8  
        'Radius and conic constant of anterior lens ${U H!n{  
        '************************************************************************* %)r1?H} #%  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) [!#;QQ&M  
        GetConic eID, entity, curv, conic ;4vx+>-  
    _ =(v? 2:?  
        SetConic eID, entity, 1/Rant, CCant 6A} 45  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant zL+M-2hV  
    _lOyT$DN  
        '************************************************************************* !`dn# j  
        'Radius and conic constant of posterior lens Eo{js?1G_  
        '************************************************************************* WZ@$bf}f0  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) )5U7w  
        GetConic eID, entity, curv, conic {'zs4)vw  
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        SetConic eID, entity, 1/Rpost, CCpost #fF';Y7  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost V#-8[G6Ra  
    }4*~*NoQ  
        '************************************************************************* ^+dL7g?+  
        'Lens thickness (Position of posterior lens surface) )}\J    
        '*************************************************************************  9\R+g5  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) sCAWrbOe>  
    ?CuwA-j  
        ' Delete any z-shift(s) z`y^o*qc]  
        count = 0 R?kyJ4S  
        While GetOperationCount(eID)>count ]*AQT7PH  
            GetOperation eID, count, op L q;=UE  
            If op.Type="ShiftZ" Then iC<qWq|S_m  
                DeleteOperation eID,count ~w$ ^`e!]  
                count=count-1 gs=(h*  
            End If 2o`L^^  
            count=count+1 AhSN'gWpbF  
        Wend 4"%LgV`  
    $C&E3 'O  
        'Set new z-shift hQbz}x  
        op.Type = "ShiftZ" ?xCWg.#l4V  
        op.val1 = tlens <a%RKjQvT  
        op.parent = parID NB)22 %  
        AddOperation eID, op ]AB4w+6!  
        Print "Set lens thickness = " & tlens P?YcZAJT*  
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        '************************************************************************* V0F&a~Q  
        'Lens index of refraction USyOHHPW@  
        '************************************************************************* YZ^;xV  
        eID = FindMaterial( "Lens" ) e:RgCDWL  
        GetModelMaterial eID, mat q{+Pf/M5  
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        mat.Nd = nlens S8)6@ECC  
        SetModelMaterial eID, mat zM|Y X<  
        Print "Set lens index of refraction = " & nlens ,9~2#[|lq  
    +T]D\];D  
        '************************************************************************* Vqxxm&^P  
        'Pupil diameter ~myY-nEY  
        '************************************************************************* 5g;i{T/6~x  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" )  F]KAnEf  
    nHF%PH#|o  
        'Adjust pupil diameter (trimming volume inner hole) &X OFc.u  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 59M\uVWR  
    !"QvV6Lq\  
        ' Adjust pupil location to just in front of the lens tx||<8  
        parID = FindFullName( "Geometry.Arizona Eye" ) mvt%3zCB!  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Ex}hk!  
        count = 0 # Q61c  
        While GetOperationCount(eID)>count F>[T)t{m=  
            GetOperation eID, count, op AqucP@  
            If op.Type="ShiftZ" Then phqmr5s^H  
                DeleteOperation eID,count ^;a~_9 m-  
                count=count-1 @j=Q$k.GF  
            End If FkY <I]F  
            count=count+1 S;I}:F#5  
        Wend 58o'Q  
        op.Type = "ShiftZ"  MON]rj7  
        op.val1 = taq-0.01 0hM!#BU5K  
        op.parent = parID C0%yGLh&  
        AddOperation eID, op w j<fi  
    m>ApN@n  
        Print "Set pupil diameter = " & pupilDiam Iju9#b6  
    swLrp 74  
        'Update AZ Eye subassembly Description yw+LT,AQ.  
        eID = FindFullName( "Geometry.Arizona Eye" ) q=`i  
        GetEntity eID, entity 8t >nL  
        entity.Description = "Accommodation = " & A & "D" k?;B1D8-n  
        SetEntity eID, entity B 42t  
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        Update ;30SnR/  
        Print "DONE!" aV`_@F-8  
         bn6WvC 3?  
    End Sub EN;s 8sC!  
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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: Dg o -Os@  
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    Accommodation = 4 Diopters yU'<b.]  
    Pupil Diameter = 4 mm _|I`A6`=  
    Set aqueous humor thickness = 2.81 q1?}G5a ?  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 &ws^Dm]R  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 ="J *v>  
    Set lens thickness = 3.927 D,P{ ,/  
    Set lens index of refraction = 1.42672 rc`}QoB)R  
    Set pupil diameter = 4 uJ T^=Y  
    DONE! X)b@ia'"Wp  
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    QQ:2987619807 lgQ"K(zY  
     
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