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    [技术]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 ?$T^L"~  
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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。 "qd|!:bE  
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    模型 k!}(a0h  
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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。 Z)2d4:uv  
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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. ^L)TfI_n  
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    光源 `GdH ,:S>  
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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。 'Grii,  
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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。 T!ZjgCY}  
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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。 xPPA8~Dm*  
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    图2. 字母F光源的设定方法光 jC4>%!{m  
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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 ;?tH8jf>  
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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。 \Ta5c31S+  
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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。 BDvkY  
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    图5. 视网膜重点采样规格设定
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    脚本 GDSXBa*7  
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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&! &R#  
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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。 %UrNPk  
    余下的脚本计算与屈光度有关的所有参数。 yRyXlZC  
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    分析 +]A,fmI.  
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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。 o>C,Db~L/  
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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 ))f@9m  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. G=|?aK{p  
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    Dim entity As T_ENTITY Dg.~"h5mT  
    Dim op As T_OPERATION e'A_4;~@s  
    Dim mat As T_MODELMATERIAL K~,!IU_QG  
    Dim A As Double wGNE b  
    Dim pupilDiam As Double 1C{0 R.  
    Dim eID As Long <<u]WsW{C  
    Dim parID As Long *6` ^8Y\  
    Dim count As Integer %xCL&}bY  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double JCn HEH  
    Dim tlens As Double, nlens As Double <q!HY~"V  
    Dim curv As Double, conic As Double P|@[D=y  
    Dim ok As Long @i!+Z  
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    Sub Main -Yse^(^"s  
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        '用户输入对话框 ocWl]h].  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 e}yF2|0FD  
            TextBox 220,21,40,21,.TextBox1 'default: 0 ,$:u^;V(  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 eLPtdP5k  
            OKButton 40,91,90,21 ygnZ9ikh<-  
            CancelButton 190,91,90,21 ejZ-A?f-K  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9;v3 (U+:  
            TextBox 220,49,40,21,.TextBox2 'default: 4 #X'-/q`.  
        End Dialog pLCj"D).M  
        Dim dlg As UserDialog Y GOkqI  
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        ok = Dialog (dlg) STjb2t,a  
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        If ok=0 Then    'cancel button was pressed "zJxWXI  
            Print "Execution cancelled." 9 nc_$H{  
            End 8iaMr278W  
        End If lqOpADLS3  
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        'Assign accommodation and pupil diameter & use defaults if field left empty ai$l7]7  
        If dlg.TextBox1 = "" Then ?wG  
            A = 0           'Default accommodation /!5ohQlPJ  
        Else hbJy<e1W  
            A = CDbl(dlg.TextBox1) VVch%  
        End If #BP0MY&  
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        If dlg.TextBox2 = "" Then $7Hwu^c(  
            pupilDiam = 4   'Default pupil diameter wE.jf.q  
        Else a%m )8N;C  
            pupilDiam = CDbl(dlg.TextBox2) jy.L/s  
        End If '6qH@r4Z<  
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        Print " "  ,c`6-  
        Print "Accommodation = " & A & " Diopters" b}Gm{;s!  
        Print "Pupil Diameter = " & pupilDiam & " mm" h SS9mQ  
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        ' Calculate new parameters with accommodation Fz(;Eo3  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 6Zn[l,\  
    cI8\d 4/py  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 8Gy]nD  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens _@XueNU1hS  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens liPrxuP`  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens w,j!%N  
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        tlens = 3.767 + 0.04*A                  'Lens thickness 1YMi4.  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction JJ)  
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        'Adjust parameters to account for accommodation dLH@,EKl)  
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        '************************************************************************* n-M6~   
        'Aqueous thickness (Position of Lens) 9'H:pb2  
        '************************************************************************* B^TgEr  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) SHPDbBS  
        GetCustomElement eID, entity N~v<8vJq`  
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        parID = FindFullName( "Geometry.Arizona Eye" ) ?E!M%c@,  
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        ' Delete any shift(s) in z uaP5(hUI  
        count = 0 $bMmyDw  
        While GetOperationCount(eID)>count V_$<^z|  
            GetOperation eID, count, op j07A>G-=  
            If op.Type="ShiftZ" Then <Ffru?o4j  
                DeleteOperation eID,count >?JUGXAi'{  
                count=count-1 <bW~!lv  
            End If aj1g9 y  
            count=count+1 30I-E ._F  
        Wend ? }ff O  
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        'Set new shift in Xbx=h^S  
        op.Type = "ShiftZ" 1 Lg{l  
        op.val1 = taq #lMIs4i.  
        op.parent = parID \25EI]  
        AddOperation eID, op $HOe){G  
        Print "Set aqueous humor thickness = " & taq-0.55 A?n5;mvq#  
    7R5ebMW V  
        '************************************************************************* :_HdOm  
        'Radius and conic constant of anterior lens DQu)?Rsk  
        '************************************************************************* a6 :hH@,  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) #G(ivRo  
        GetConic eID, entity, curv, conic X^&--@l}T!  
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        SetConic eID, entity, 1/Rant, CCant ,\+N}F^  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant t; #@t/`  
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        '************************************************************************* {l/`m.Z  
        'Radius and conic constant of posterior lens D5Rp<PBq,  
        '************************************************************************* Dby|l#X  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) M).CyY;bm  
        GetConic eID, entity, curv, conic Zonn  
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        SetConic eID, entity, 1/Rpost, CCpost >@G"*le*)  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost MR4k#{:w  
    ^pY8'LF6  
        '************************************************************************* 73u97oe>1  
        'Lens thickness (Position of posterior lens surface) w?*79 u  
        '************************************************************************* ep5`&g]3  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4,YL15.  
    *e:I*L  
        ' Delete any z-shift(s) 'bH~KK5  
        count = 0 Y0Tw:1a  
        While GetOperationCount(eID)>count _ A{F2M  
            GetOperation eID, count, op z&#^9rM"  
            If op.Type="ShiftZ" Then )iC@n8f7o  
                DeleteOperation eID,count k=p[Mlic/  
                count=count-1 b ~]v'|5[  
            End If D\J.6W  
            count=count+1 gE*7[*2?t  
        Wend u^'X>n)oL#  
    h{\S'8  
        'Set new z-shift yZoJD{'?Sw  
        op.Type = "ShiftZ" 9zx9t  
        op.val1 = tlens ;2 ?fz@KZ  
        op.parent = parID GKUjtPu  
        AddOperation eID, op 4kV$JV.l  
        Print "Set lens thickness = " & tlens [\fwnS_1  
    BVus3Y5IJQ  
        '*************************************************************************  ]sP  
        'Lens index of refraction %ib7)8Ki0  
        '************************************************************************* XN\rq=  
        eID = FindMaterial( "Lens" ) rkdA4'66w  
        GetModelMaterial eID, mat ]TtID4qL  
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        mat.Nd = nlens  )L":I  
        SetModelMaterial eID, mat I 5ZDP|  
        Print "Set lens index of refraction = " & nlens nsq7dhq  
    V+U89j1g  
        '************************************************************************* z.h;}QRJ,@  
        'Pupil diameter +4qR5(W  
        '************************************************************************* ,j(E>g3  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Ck m:;q  
    9R-2\D]  
        'Adjust pupil diameter (trimming volume inner hole) tK#/S+l  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" %SCt_9u  
    &b%2Jx[+  
        ' Adjust pupil location to just in front of the lens M U '-  
        parID = FindFullName( "Geometry.Arizona Eye" ) k1P'Q&Na  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) p*1 B *R  
        count = 0 d}|z+D  
        While GetOperationCount(eID)>count MlS5/9m@^  
            GetOperation eID, count, op 3-Xd9ou  
            If op.Type="ShiftZ" Then "So "oT1  
                DeleteOperation eID,count xj AU Csq  
                count=count-1 /Q89y[  
            End If 7dE.\#6r  
            count=count+1 ?h| DeD!s  
        Wend m9D Tz$S.  
        op.Type = "ShiftZ" f+)LVT8p  
        op.val1 = taq-0.01 $n47DW &  
        op.parent = parID #2Vq"Zn  
        AddOperation eID, op w7q6v>  
    xDS]k]/(T  
        Print "Set pupil diameter = " & pupilDiam ,S`F xJcE  
    ~oK0k_{~  
        'Update AZ Eye subassembly Description +nB0O/m'U  
        eID = FindFullName( "Geometry.Arizona Eye" ) Ty7 `&  
        GetEntity eID, entity $Tt.r  
        entity.Description = "Accommodation = " & A & "D" {(t R<z)  
        SetEntity eID, entity sint":1FC  
    MpJ\4D5G  
        Update \;Q!}_ K  
        Print "DONE!" 5'`DrTOA  
         2\#$::B9  
    End Sub -Oz! GX  
    !\Cu J5U  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: ,R7j9#D  
    '*@=SM  
    Accommodation = 4 Diopters VP~%,=  
    Pupil Diameter = 4 mm z_A\\  
    Set aqueous humor thickness = 2.81 4+p1`  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 nKEw$~F  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 OJM2t`}_t  
    Set lens thickness = 3.927 _)YB*z5  
    Set lens index of refraction = 1.42672 VpY,@qh  
    Set pupil diameter = 4 j+gh*\:q  
    DONE! l0ZK)  
     
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