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    [转载]FRED运用:Arizona眼睛模型 [复制链接]

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    离线xunjigd
     
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    只看楼主 倒序阅读 楼主  发表于: 2016-02-24
    简介 I:iMRvp  
    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。 W6i{ yne W  
    uStAZ ~b\  
    模型 =oSd M2  
    /m"/#; ^l  
    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。 N$]er'`  
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    Table 1. AZ眼睛模型的定义
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    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. kJ FWk  
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    光源  SW#/;|m  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 {m>ylE  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 e9KD mX_  
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 K'r;#I|"J  
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    图2. 字母F光源的设定方法光   < v]  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 k(dakFaC^  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ~/`/r%1/J  
    WZNq!K H  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 yKV{V?h?  
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    图5. 视网膜重点采样规格设定
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    脚本 (CxA5u1|l  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: T(7`$<TQ  
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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。 !lgL=Ys(  
    余下的脚本计算与屈光度有关的所有参数。 JkAM:,^(  
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    分析 ! dzgi:  
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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。 .r<a Py$  
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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 2H|:/y  
    :G1ddb&0+  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. (G"'Fb6d  
    9b+jT{Tg  
    Dim entity As T_ENTITY =#G 2}8mQD  
    Dim op As T_OPERATION r.H`3m.0q  
    Dim mat As T_MODELMATERIAL yV{B,T`W  
    Dim A As Double c1'@_Is  
    Dim pupilDiam As Double l'+3 6  
    Dim eID As Long [MTd<@  
    Dim parID As Long %F>~2g?$  
    Dim count As Integer ;?2)[a  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 6ZQ |L=Ytp  
    Dim tlens As Double, nlens As Double fc9;ZX7  
    Dim curv As Double, conic As Double O^@8Drgc  
    Dim ok As Long p'/\eBhG]=  
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    Sub Main C Bkoky 9&  
    Zo3!Hs ZA  
        '用户输入对话框 5CkG^9  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 .{1$;K @  
            TextBox 220,21,40,21,.TextBox1 'default: 0 @YI{E*?S  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 b{A[\ "  
            OKButton 40,91,90,21 ZLkl:'E_  
            CancelButton 190,91,90,21 *r`=hNr  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 QHk\Z  
            TextBox 220,49,40,21,.TextBox2 'default: 4 *'/,  
        End Dialog Bs~~C8+  
        Dim dlg As UserDialog OsgPNy0  
    ?*fa5=ql  
        ok = Dialog (dlg) <&5z0rDKWw  
    }T?X6LA$I8  
        If ok=0 Then    'cancel button was pressed G$<(>"Yr~$  
            Print "Execution cancelled." >f]/VaMH{  
            End AjVC{\Ik  
        End If CY1WT  
    E=sh^Q(A  
        'Assign accommodation and pupil diameter & use defaults if field left empty %6m/ve  
        If dlg.TextBox1 = "" Then Mg2+H+C~:  
            A = 0           'Default accommodation |p|Zv H  
        Else boo361L  
            A = CDbl(dlg.TextBox1) e HphM;C  
        End If D#g -mqar:  
    6>vR5pn  
        If dlg.TextBox2 = "" Then U%q)T61  
            pupilDiam = 4   'Default pupil diameter #dauXUKH  
        Else wNf:_^|}  
            pupilDiam = CDbl(dlg.TextBox2) \]ib%,:YU  
        End If 4>gfLK\R:  
    I5Vn#_q+b  
        Print " " ^)AECn  
        Print "Accommodation = " & A & " Diopters" [?]N GTr#  
        Print "Pupil Diameter = " & pupilDiam & " mm" ;wv[';J  
    ? x%s j  
        ' Calculate new parameters with accommodation |9E:S  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 'oa.-g5  
    }LUvh  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens PUdv1__C  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ng1E'c]0@  
    ?WI v4  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens q*hn5K*  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens H,7='n7"  
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        tlens = 3.767 + 0.04*A                  'Lens thickness Vk6c^/v  
    >q}3#TvP@  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction i).%GMv*r  
    y,D9O/VP  
        'Adjust parameters to account for accommodation X`8<;l  
    '}OdF*L  
        '************************************************************************* XcJ5KTn  
        'Aqueous thickness (Position of Lens) N63?4'_W  
        '************************************************************************* #VQZ"7nI@  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) A4j ,]hOD  
        GetCustomElement eID, entity SoIK<*J  
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        parID = FindFullName( "Geometry.Arizona Eye" ) Jf^3nBZ  
    @2Z|\ojJ  
        ' Delete any shift(s) in z wT@Z|.)  
        count = 0 x;mw?B[  
        While GetOperationCount(eID)>count yFE0a"0y  
            GetOperation eID, count, op $(1t~u<17  
            If op.Type="ShiftZ" Then $Itmm/M  
                DeleteOperation eID,count Tu vs}  
                count=count-1 7K"3[.  
            End If }e7Rpgu  
            count=count+1 (Jq m9  
        Wend L$ T2 bul  
    c&c  
        'Set new shift in RXXHg  
        op.Type = "ShiftZ" 4 ]oe`yx  
        op.val1 = taq X@~/.H5  
        op.parent = parID Y.m1d?H 1  
        AddOperation eID, op frcAXh9  
        Print "Set aqueous humor thickness = " & taq-0.55 |~9jO/&r  
    2CC"Z  
        '************************************************************************* M+t)#O4  
        'Radius and conic constant of anterior lens ?q!4REM  
        '************************************************************************* `I7s|9-=  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Au2^ T1F  
        GetConic eID, entity, curv, conic dsIbr"m  
    MTYV~S4/  
        SetConic eID, entity, 1/Rant, CCant ` nX, x-UM  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant iwnGWGcuS  
    XfcYcN  
        '************************************************************************* ~}OaX+!  
        'Radius and conic constant of posterior lens w1< pQ[A  
        '************************************************************************* ! fk W;|  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) zC*FeqFL<  
        GetConic eID, entity, curv, conic 8GkWo8rPk  
    /K H85/s  
        SetConic eID, entity, 1/Rpost, CCpost lBP?7`U  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost v&:[?<6-  
    t[|rp&xG  
        '************************************************************************* or-k~1D  
        'Lens thickness (Position of posterior lens surface) zlLZ8b+  
        '************************************************************************* 0+mR y57  
    5Sl"1HL  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;(K/O?nrJ  
    uGAQt9$>_  
        ' Delete any z-shift(s) TTG=7x:3  
        count = 0 F- kjv\  
        While GetOperationCount(eID)>count - ~z@W3\  
            GetOperation eID, count, op 7sVM[lr<  
            If op.Type="ShiftZ" Then 1F.._5_"]  
                DeleteOperation eID,count kR+}7G+  
                count=count-1 z ,;XWv?  
            End If 'e:4  
            count=count+1 }w)}=WmD  
        Wend KXMf2)pa  
    **P P  
        'Set new z-shift L#`X ]E  
        op.Type = "ShiftZ" @<DRFP  
        op.val1 = tlens +.djC3^:  
        op.parent = parID Bc!<!  
        AddOperation eID, op H[w';u[%  
        Print "Set lens thickness = " & tlens D <~UaHfk  
    =U84*HAv  
        '************************************************************************* :X":>M;;+  
        'Lens index of refraction a@g <cl7a,  
        '*************************************************************************  XY)X-K$  
        eID = FindMaterial( "Lens" ) xkf2;  
        GetModelMaterial eID, mat HnPy";{  
    [fCnq  
        mat.Nd = nlens XK~HfA?  
        SetModelMaterial eID, mat rFcz 0  
        Print "Set lens index of refraction = " & nlens t tr`  
    6[t(FcS  
        '************************************************************************* 3]S_w[Q4  
        'Pupil diameter [Zdrm:=]L  
        '************************************************************************* @oY+b!L  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 86LE )z  
    ="G2I\  
        'Adjust pupil diameter (trimming volume inner hole) -[!t=qi  
    "wH(t k4  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ]U@~vA#''  
    a2?@OJ  
        ' Adjust pupil location to just in front of the lens YuuTLX%3  
        parID = FindFullName( "Geometry.Arizona Eye" ) #^9bBF/  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) iB99.,o-&  
        count = 0 g mWwlkf9  
        While GetOperationCount(eID)>count 3'p 1m`8  
            GetOperation eID, count, op C}9GrIi  
            If op.Type="ShiftZ" Then !Th5x2  
                DeleteOperation eID,count zWPX  
                count=count-1 ,g'>Ib%  
            End If ,J2qLH1  
            count=count+1 [PXq<ST  
        Wend xA^E+f:W_  
        op.Type = "ShiftZ" 8@ f!,!Wn  
        op.val1 = taq-0.01 7"Nda3  
        op.parent = parID C-ORI}o  
        AddOperation eID, op d@^%fVhG  
    O\uIIuy  
        Print "Set pupil diameter = " & pupilDiam l4mRNYv)z  
    E el*P M  
        'Update AZ Eye subassembly Description +*W lj8  
        eID = FindFullName( "Geometry.Arizona Eye" ) ;4dFL\KU  
        GetEntity eID, entity kE6/d,  
        entity.Description = "Accommodation = " & A & "D" ;d>n2  
        SetEntity eID, entity ,^n&Q'p3  
    @gqZiFM)  
        Update >aVtYp B  
        Print "DONE!" " ;Cf@}i>  
         {tOf0W|  
    End Sub a/s5Oit2'X  
    ,_$J-F?  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: D HQxu4  
    LV1drc  
    Accommodation = 4 Diopters ?zP 2   
    Pupil Diameter = 4 mm s[eSPSFZ  
    Set aqueous humor thickness = 2.81 vC1fKo\p  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 QSzht$ 8  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 h$sOJs~6h  
    Set lens thickness = 3.927 mc`Z;D/mt  
    Set lens index of refraction = 1.42672 ;`xCfOY(  
    Set pupil diameter = 4 =!DX,S7  
    DONE!  mVS^HQ:  
    I%:?f{\  
    (文章来源:讯技光电)
     
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