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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 7vO3+lT/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。 50h?#u6?  
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    模型 3H"bivK  
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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。 0} v_usP  
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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. Q #!|h:K  
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    光源 <g9@iUOI  
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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。 t$+[(}@ +  
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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。 BO]}E:C9  
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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。 <;)qyP  
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    图2. 字母F光源的设定方法光 ~d5f]6#`  
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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 HYqDaRn  
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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。 {jVEstP  
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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。 D X|yL!4[  
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    图5. 视网膜重点采样规格设定
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    脚本 [&_c.ti  
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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: t^ax:6;"|  
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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。 pXL@&]U+  
    余下的脚本计算与屈光度有关的所有参数。 DMeP9D  
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    分析 svT1b'=\$I  
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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。 83~9Xb=!\  
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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 @)hrj2Jw  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. >n!,KUu]  
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    Dim entity As T_ENTITY WJXQM[  
    Dim op As T_OPERATION I[td:9+hK@  
    Dim mat As T_MODELMATERIAL (=de#wh2]  
    Dim A As Double )'pc1I  
    Dim pupilDiam As Double +xGz~~iNh  
    Dim eID As Long 97XGJ1HI  
    Dim parID As Long zLeId83>  
    Dim count As Integer vbn'CY]QU  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double qYi<GI*|@  
    Dim tlens As Double, nlens As Double Q|3SYJf  
    Dim curv As Double, conic As Double ~C;1}P%9x  
    Dim ok As Long F~qiNV  
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    Sub Main O7KR~d  
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        '用户输入对话框 JE[+  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 $hCPmiI  
            TextBox 220,21,40,21,.TextBox1 'default: 0 71$MhPvd<  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 pN]$|#%q(  
            OKButton 40,91,90,21 slV7,4S&!  
            CancelButton 190,91,90,21 MZ/PXY  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 x?|C-v  
            TextBox 220,49,40,21,.TextBox2 'default: 4 +ISXyGu  
        End Dialog -4}I02  
        Dim dlg As UserDialog Z T5p  
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        ok = Dialog (dlg) ":o1g5?  
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        If ok=0 Then    'cancel button was pressed $1(FN+ M b  
            Print "Execution cancelled." ;4g_~fB  
            End x: Nd>Fb  
        End If IdvBQ [Gj  
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        'Assign accommodation and pupil diameter & use defaults if field left empty SdI/  
        If dlg.TextBox1 = "" Then E\%'/3o  
            A = 0           'Default accommodation k*;2QED  
        Else N%2UL&w#B  
            A = CDbl(dlg.TextBox1) +]!`>  
        End If jE&Onzc  
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        If dlg.TextBox2 = "" Then .QhH!#Y2D  
            pupilDiam = 4   'Default pupil diameter gw1| ?C  
        Else R+s_uwS  
            pupilDiam = CDbl(dlg.TextBox2) X> *o\   
        End If &M,"%w!  
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        Print " " >VAZ^kgi  
        Print "Accommodation = " & A & " Diopters" MKuy?mri~  
        Print "Pupil Diameter = " & pupilDiam & " mm" 7 -(LWH  
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        ' Calculate new parameters with accommodation (5"BKu1t  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness <N{pMz  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens Oc]&1>M  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens |sw&sfH[FD  
    D4"](RXH  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens biFN]D  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens F7(~v2|  
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        tlens = 3.767 + 0.04*A                  'Lens thickness ]Mh7;&<6[  
    ]c8$%  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction jH*+\:UP-  
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        'Adjust parameters to account for accommodation 6]|NB&  
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        '************************************************************************* !d1}IU-h  
        'Aqueous thickness (Position of Lens) r: _- Cj  
        '************************************************************************* %qzpt{'?<  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) _ +,2b:D:  
        GetCustomElement eID, entity ifu "e_^  
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        parID = FindFullName( "Geometry.Arizona Eye" ) cLQvzd:h=  
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        ' Delete any shift(s) in z ;+-$=l3[a  
        count = 0 ; y#6Nx,:  
        While GetOperationCount(eID)>count Po[u6K2&  
            GetOperation eID, count, op h(;qnV'c  
            If op.Type="ShiftZ" Then b'$j* N  
                DeleteOperation eID,count XR^VRn6O  
                count=count-1 /$hfd?L  
            End If &)vX7*j  
            count=count+1 (n-8p6x(  
        Wend dXh@E 7  
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        'Set new shift in {rWu`QT  
        op.Type = "ShiftZ" _%s_w)  
        op.val1 = taq *@Z/L26s;=  
        op.parent = parID D PnKr/  
        AddOperation eID, op s,^?|Eo;0  
        Print "Set aqueous humor thickness = " & taq-0.55 `h M:U  
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        '************************************************************************* SVp]}!jI  
        'Radius and conic constant of anterior lens US)wr  
        '************************************************************************* KQ/v](7 7  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) E{r_CR+8  
        GetConic eID, entity, curv, conic VEd#LSh  
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        SetConic eID, entity, 1/Rant, CCant &Ko}Pv  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant { e2 (  
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        '************************************************************************* =&,zWNz)  
        'Radius and conic constant of posterior lens @2 dp5  
        '************************************************************************* pFSVSSQRV|  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @+}Q<  
        GetConic eID, entity, curv, conic ?ZSG4La\  
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        SetConic eID, entity, 1/Rpost, CCpost `QR2!W70o3  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost +[r%y,k  
    b]s=Uv#)  
        '************************************************************************* ja~b5Tf9  
        'Lens thickness (Position of posterior lens surface) +D4Nu+~BSN  
        '************************************************************************* /-$`GT?l  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) N|Ua|^  
     | qHWM  
        ' Delete any z-shift(s) V#!ypX]AB[  
        count = 0 rK~362|mo  
        While GetOperationCount(eID)>count AnPm5i.  
            GetOperation eID, count, op xn@?CP`-y  
            If op.Type="ShiftZ" Then CBSJY&:K  
                DeleteOperation eID,count % @Ks<"9  
                count=count-1 .,,?[TI  
            End If +M@G 8l  
            count=count+1 5]; 8  
        Wend * @G4i  
    `+B+RQl}[  
        'Set new z-shift g$dL5N7  
        op.Type = "ShiftZ" /^uvY  
        op.val1 = tlens |gxU;"2`5~  
        op.parent = parID ~<v.WP<:  
        AddOperation eID, op \\hZlCV,  
        Print "Set lens thickness = " & tlens p>K'6lCa  
    [p!C+ |rro  
        '************************************************************************* 35RH|ci&  
        'Lens index of refraction P xpz7He  
        '************************************************************************* 2t[c^J  
        eID = FindMaterial( "Lens" ) =]xNpX)  
        GetModelMaterial eID, mat l(=#c/f  
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        mat.Nd = nlens ADv a@P  
        SetModelMaterial eID, mat NFLmM  
        Print "Set lens index of refraction = " & nlens < q; ]  
    6{lWUr  
        '************************************************************************* c#"\&~. P  
        'Pupil diameter r-N2*uYtu  
        '************************************************************************* -ZQ3^'f:0J  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ZFW}Vnl  
    jI;bVG  
        'Adjust pupil diameter (trimming volume inner hole) YXI DqTA+  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ?]9uHrdsN}  
    2z0HB+Y}x  
        ' Adjust pupil location to just in front of the lens ;S?1E:\av  
        parID = FindFullName( "Geometry.Arizona Eye" ) kP;:s  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) :jp?FF^j;  
        count = 0 K:y q^T7  
        While GetOperationCount(eID)>count ]; ^OY\,  
            GetOperation eID, count, op =53LapTPJ  
            If op.Type="ShiftZ" Then i+&= "Z@  
                DeleteOperation eID,count /=e[(5X|O  
                count=count-1 F|P2\SPL  
            End If oSa FmP  
            count=count+1 bq(*r:`"  
        Wend lmmyDg1R  
        op.Type = "ShiftZ" ljt1:@SN(  
        op.val1 = taq-0.01 p Hg8(ru|  
        op.parent = parID sM5 w~R>Y  
        AddOperation eID, op ?sS'T7r v  
    M\v4{\2l0  
        Print "Set pupil diameter = " & pupilDiam "apv)xdW  
    [tD*\\IA  
        'Update AZ Eye subassembly Description .k*2T<p$rC  
        eID = FindFullName( "Geometry.Arizona Eye" ) (ZEVbAY?i  
        GetEntity eID, entity !zJ.rYZ=g`  
        entity.Description = "Accommodation = " & A & "D" M;iaNL(  
        SetEntity eID, entity iT5H<uS  
    #[KwR\b{:+  
        Update X!2|_  
        Print "DONE!" <BU|?T6~  
         $s]@%6 f  
    End Sub +] 5a(/m.~  
    \ 3LD^[qi  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: >8 JvnBFx=  
    rk. UW  
    Accommodation = 4 Diopters !k s<VJh  
    Pupil Diameter = 4 mm %[Ds-my2  
    Set aqueous humor thickness = 2.81 $1dI  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 [ThzLk#m  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 CqX%V":2  
    Set lens thickness = 3.927 /uyQ>Y*-\Y  
    Set lens index of refraction = 1.42672 @B^'W'&C  
    Set pupil diameter = 4 F Q k;  
    DONE! @2$8o]et  
     
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