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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 E4r.ky`#~  
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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。 ]BfS270  
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    模型 r?pZ72 q  
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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。 X]!D;7^  
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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. C`NmZwL  
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    光源 )7dEi+v52  
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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。 +%XnMl  
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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。 .xl.P7@JJ  
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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。 )t%h[0{{  
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    图2. 字母F光源的设定方法光 F+uk AT  
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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 Efx=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。 t`YWwI.  
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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。 _R^y\1Qu  
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    图5. 视网膜重点采样规格设定
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    脚本 L^FcS\r;  
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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: 9i=B  
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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。 =K(JqSw+M  
    余下的脚本计算与屈光度有关的所有参数。 8sg|MWSU  
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    分析 '#D8*OP^  
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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。 0%<+J;'o  
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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 eT[&L @l]b  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. x[X`a  
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    Dim entity As T_ENTITY I[D8""U  
    Dim op As T_OPERATION ER^QV(IvP8  
    Dim mat As T_MODELMATERIAL #U ASH&  
    Dim A As Double E\M-k\cSj  
    Dim pupilDiam As Double $1Z6\G O  
    Dim eID As Long e2w&&B-  
    Dim parID As Long HB iBv-=,  
    Dim count As Integer mgQIhXH5L  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Ef@,hX  
    Dim tlens As Double, nlens As Double 5 1dSFr<#  
    Dim curv As Double, conic As Double Ri)uq\E/#  
    Dim ok As Long vt1lR5  
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    Sub Main x({C(Q'O  
    *Y6xvib9*  
        '用户输入对话框 L/Vx~r`P  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 2@khSWV  
            TextBox 220,21,40,21,.TextBox1 'default: 0 ke%pZ 7{u  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 F)Oe9x\/  
            OKButton 40,91,90,21 :O-1rD  
            CancelButton 190,91,90,21 F9flSeN  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 %J~WC$=Qv  
            TextBox 220,49,40,21,.TextBox2 'default: 4 pqR\>d 0  
        End Dialog m3.sVI0I  
        Dim dlg As UserDialog -VT+O+9_A  
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        ok = Dialog (dlg) 9 OT,TpA  
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        If ok=0 Then    'cancel button was pressed 9Q.#\  
            Print "Execution cancelled."  L,LNv  
            End 6b=q-0yj  
        End If Vba.uKNjk  
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        'Assign accommodation and pupil diameter & use defaults if field left empty ae+*=,  
        If dlg.TextBox1 = "" Then $}o b,i^W  
            A = 0           'Default accommodation -{jdn%Y7CK  
        Else F]+~x/!  
            A = CDbl(dlg.TextBox1) y2|R.EU\m<  
        End If R 9 4^4I  
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        If dlg.TextBox2 = "" Then `{Tk@A_yd  
            pupilDiam = 4   'Default pupil diameter K8I$]M   
        Else `[fx yg:u  
            pupilDiam = CDbl(dlg.TextBox2) fV\]L4%  
        End If rS8 w\`_  
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        Print " " :iF%cy.  
        Print "Accommodation = " & A & " Diopters" # Su~`]  
        Print "Pupil Diameter = " & pupilDiam & " mm" gVR@&bi7  
    +&=?BC}L9^  
        ' Calculate new parameters with accommodation WyhhCR=;  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness B&?sF" Y  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens $ &UZy|9  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens PkuTg";  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens } ^kL|qmjR  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Cb;WZ3HR  
    9pKGr@&   
        tlens = 3.767 + 0.04*A                  'Lens thickness #]Y>KX2HG  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction q(M:QWA q  
    jM)C4ii.-$  
        'Adjust parameters to account for accommodation cmwPuK$  
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        '************************************************************************* 9ooY?J  
        'Aqueous thickness (Position of Lens) dtt~ Bd  
        '************************************************************************* ?Bi*1V<R  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) muON> ^MbC  
        GetCustomElement eID, entity D<$XyP  
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        parID = FindFullName( "Geometry.Arizona Eye" ) V9NTs8LKc  
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        ' Delete any shift(s) in z *iA4:EIP  
        count = 0 \*t~==WB  
        While GetOperationCount(eID)>count $.%rAa_H  
            GetOperation eID, count, op !^c@shLN4  
            If op.Type="ShiftZ" Then  l! bv^  
                DeleteOperation eID,count ]b?9zeT*'l  
                count=count-1 k(VB+k"3  
            End If s@4nWe  
            count=count+1 e.d #wyeX  
        Wend Hh;:`;}  
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        'Set new shift in T#@lDpO  
        op.Type = "ShiftZ" WiL2  
        op.val1 = taq `_ %S  
        op.parent = parID cf_|nL#9  
        AddOperation eID, op U&Wwyu:4i  
        Print "Set aqueous humor thickness = " & taq-0.55 CT a#Q,  
    B5%n(,Lx  
        '************************************************************************* jhgX{xc  
        'Radius and conic constant of anterior lens T4/fdORS  
        '************************************************************************* T=f|,sK +7  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Ga>uFb}W~  
        GetConic eID, entity, curv, conic C BYX]  
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        SetConic eID, entity, 1/Rant, CCant ;h=*!7:  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant <yA}i"-1W  
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        '************************************************************************* zdl%iop3e  
        'Radius and conic constant of posterior lens 6Q&r0>^{  
        '************************************************************************* h Ov={:  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) qVqRf.-\  
        GetConic eID, entity, curv, conic xiF7}]d+  
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        SetConic eID, entity, 1/Rpost, CCpost /'2O.d0}.  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ^jB8Q  
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        '************************************************************************* DhLqhME53  
        'Lens thickness (Position of posterior lens surface) 6d[_G$'nk  
        '************************************************************************* ,fDEz9-,  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) _ZB\L^j)  
    \`V$ 'B{.  
        ' Delete any z-shift(s) Di_2Plo)4  
        count = 0 -ezY= 0Q&  
        While GetOperationCount(eID)>count F7L&=K$2y  
            GetOperation eID, count, op -{XRA6  
            If op.Type="ShiftZ" Then thi1kJ`L  
                DeleteOperation eID,count |'ln?D:&  
                count=count-1 5<pftTcZ  
            End If 5vAf7\*  
            count=count+1 u=F+(NE"  
        Wend hf/2vt m  
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        'Set new z-shift /M~!sPW&?  
        op.Type = "ShiftZ" Z v_.na/^K  
        op.val1 = tlens , ^F)L|  
        op.parent = parID |s#'dS;  
        AddOperation eID, op UUKP"  
        Print "Set lens thickness = " & tlens #PDf,^  
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        '************************************************************************* Yb i%od&  
        'Lens index of refraction W!blAkM%i  
        '************************************************************************* uJHu>M}~  
        eID = FindMaterial( "Lens" ) X:a`B(@S  
        GetModelMaterial eID, mat YIt& >  
    (6CN/A{qe  
        mat.Nd = nlens RgorkZlVM  
        SetModelMaterial eID, mat ,mS/h~-5n  
        Print "Set lens index of refraction = " & nlens <e]Oa$  
    P7ph}mB  
        '************************************************************************* P&d"V<  
        'Pupil diameter Q-Ux<#  
        '************************************************************************* %<?0apO  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) FlfI9mm  
    I$NhXZ)KT  
        'Adjust pupil diameter (trimming volume inner hole) k%wn0Erd  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" .@-9'<K?~  
    6iEhsL&K  
        ' Adjust pupil location to just in front of the lens `nKH"TaX  
        parID = FindFullName( "Geometry.Arizona Eye" ) KfBTL!0#  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) YSJy`  
        count = 0 IKMeJ(:S  
        While GetOperationCount(eID)>count id<:p*  
            GetOperation eID, count, op +X`V|E,no  
            If op.Type="ShiftZ" Then ANIz, LS  
                DeleteOperation eID,count ^_5L"F]sP  
                count=count-1 IM$2VlC  
            End If #po5_dE\*  
            count=count+1 zWpqJK   
        Wend FJ*i\Q/D  
        op.Type = "ShiftZ" 1Gt/Tq$_b  
        op.val1 = taq-0.01 {7cX#1  
        op.parent = parID )&era ` e[  
        AddOperation eID, op P o jmC  
    n .!Ym X4  
        Print "Set pupil diameter = " & pupilDiam |9"p|6G?B  
    Eh-n  
        'Update AZ Eye subassembly Description `c/*H29  
        eID = FindFullName( "Geometry.Arizona Eye" ) 6.5T/D*TT  
        GetEntity eID, entity dC=)^(  
        entity.Description = "Accommodation = " & A & "D" *5zrZ]^  
        SetEntity eID, entity !zPG? q]3  
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        Update 2j(h+?N7k  
        Print "DONE!" nd;fy$<J\  
         ,f}UGd[a  
    End Sub -",=G\XZ  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: K =.%$A  
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    Accommodation = 4 Diopters S$f6a'  
    Pupil Diameter = 4 mm J--m[X  
    Set aqueous humor thickness = 2.81 h8\  T  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 [Q\GxX.  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 r]W  
    Set lens thickness = 3.927 ?[*0+h`en  
    Set lens index of refraction = 1.42672 `cx]e  
    Set pupil diameter = 4 U yw-2]!n  
    DONE! '(f/~"9B  
     
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