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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 AG><5 }  
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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。 3^5h:OaT  
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    模型 RAWzQE }  
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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。 Nxna H!wS  
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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. udmLHc  
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    光源 f3S 8~!  
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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。 sf/m@425  
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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。 Lp/'-Y_  
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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。 %J Jp/I  
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    图2. 字母F光源的设定方法光 X}Om)WCr  
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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 <@[;IX`YN  
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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。 \iaZV.#f  
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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。 /GX>L)  
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    图5. 视网膜重点采样规格设定
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    脚本 Nu3gkIz5z-  
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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: ![$`Ivro`  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 7r^Cs#b+I  
    余下的脚本计算与屈光度有关的所有参数。 )B+R|PZ,  
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    分析 5D2mZ/  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 &-{%G=5~e%  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 b8Z_o N5!  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. S=lCzL;j"  
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    Dim entity As T_ENTITY dNY'uv&Y  
    Dim op As T_OPERATION &@'%0s9g  
    Dim mat As T_MODELMATERIAL ij#v_~g3  
    Dim A As Double ,X1M!'  
    Dim pupilDiam As Double cMF)2^w}  
    Dim eID As Long Nsq=1) <  
    Dim parID As Long uF1 4;  
    Dim count As Integer Ly3!0P.<  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ^*4#ZvpG2  
    Dim tlens As Double, nlens As Double I\1"E y  
    Dim curv As Double, conic As Double )P?Fni}  
    Dim ok As Long YFPse.2$a  
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    Sub Main n#Dy YVb  
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        '用户输入对话框 &WLN   
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 xb%Q[V_m  
            TextBox 220,21,40,21,.TextBox1 'default: 0 >~Gy+-  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 H ?9Bo!  
            OKButton 40,91,90,21 _ Pzgn@D  
            CancelButton 190,91,90,21 g!' x5#]n  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ^|6#Vx  
            TextBox 220,49,40,21,.TextBox2 'default: 4 -^yc<%U  
        End Dialog lP)n$?u  
        Dim dlg As UserDialog 74:( -vS  
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        ok = Dialog (dlg) :RukW.MR  
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        If ok=0 Then    'cancel button was pressed re/u3\S  
            Print "Execution cancelled." F):kF_ho  
            End Gey-8  
        End If H.]V-|U  
    :h(3Ep  
        'Assign accommodation and pupil diameter & use defaults if field left empty ~Q Q1ZP3  
        If dlg.TextBox1 = "" Then ?lgE9I]  
            A = 0           'Default accommodation /DH`7E  
        Else ^H2TSaJ;  
            A = CDbl(dlg.TextBox1) Sin)]zG~0  
        End If 2]Cn<zJ  
    -6uLww=w4  
        If dlg.TextBox2 = "" Then y7CXE6Y  
            pupilDiam = 4   'Default pupil diameter l{.PyU5)  
        Else ~,};FI  
            pupilDiam = CDbl(dlg.TextBox2) 1|-C(UW>  
        End If frm[<-~w0  
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        Print " " lul  
        Print "Accommodation = " & A & " Diopters" Iurz?dt4w  
        Print "Pupil Diameter = " & pupilDiam & " mm" 4clCZ@\K^  
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        ' Calculate new parameters with accommodation 0vDvp`ie#4  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness "QS(4yw?jg  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens % q!i  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens )BI%cD  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens %La/E#  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens N4-Y0BO  
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        tlens = 3.767 + 0.04*A                  'Lens thickness >k@{NP2b  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction _X<V` , p  
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        'Adjust parameters to account for accommodation s nxwe  
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        '************************************************************************* rk&oKd_&i  
        'Aqueous thickness (Position of Lens) 2uY:p=DxG9  
        '************************************************************************* w^HI lA  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) o](ORS$~  
        GetCustomElement eID, entity :4X,5X7tW=  
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        parID = FindFullName( "Geometry.Arizona Eye" ) @q]!C5  
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        ' Delete any shift(s) in z #=Xa(<t  
        count = 0 :mCGY9d4L  
        While GetOperationCount(eID)>count wod{C!  
            GetOperation eID, count, op n]5Pfg|a  
            If op.Type="ShiftZ" Then I 6<LKI/  
                DeleteOperation eID,count #3?"#),q  
                count=count-1 >tL" 8@z9  
            End If s:,fXg25J  
            count=count+1 a04S&ezj  
        Wend ka R55  
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        'Set new shift in E6G;fPd= E  
        op.Type = "ShiftZ" j9RpYz  
        op.val1 = taq F3Vvqt*2  
        op.parent = parID 6~s{HI!  
        AddOperation eID, op B@\0b|  
        Print "Set aqueous humor thickness = " & taq-0.55 [vY)y\W{  
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        '************************************************************************* B1i'Mzm-4  
        'Radius and conic constant of anterior lens GLV`IkU %  
        '************************************************************************* CSm(yB{|pC  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) R5uz<  
        GetConic eID, entity, curv, conic 5/m*Lc+r  
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        SetConic eID, entity, 1/Rant, CCant Pff-eT+~m  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant N;m62N  
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        '************************************************************************* u |$GOSD  
        'Radius and conic constant of posterior lens l`JKQk   
        '************************************************************************* hE2{m{^A  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) K~5(j{Kb8  
        GetConic eID, entity, curv, conic MI8c>5?  
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        SetConic eID, entity, 1/Rpost, CCpost \jkDRR[  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost c1f`?i}.  
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        '************************************************************************* &j{I G`Trl  
        'Lens thickness (Position of posterior lens surface) )@.ODW;`  
        '************************************************************************* ,Qe`(vU*s  
    )=,;-&AR  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) yaX%<KBa\  
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        ' Delete any z-shift(s) ?* dfIc  
        count = 0 *qIns/@  
        While GetOperationCount(eID)>count 9 &Od7Cn  
            GetOperation eID, count, op ,(#n8|q4  
            If op.Type="ShiftZ" Then 0R,Y[).U  
                DeleteOperation eID,count [vCZD8"Y8  
                count=count-1 zjx'nK{eI  
            End If xoE,3Sn  
            count=count+1 +n8,=}  
        Wend 0j 'k%R[l  
    1 7hXg"B  
        'Set new z-shift `jDmbD +=  
        op.Type = "ShiftZ" -32.g \]  
        op.val1 = tlens =1F F2#zS  
        op.parent = parID q]*:RI?wGT  
        AddOperation eID, op ><;.vP  
        Print "Set lens thickness = " & tlens N%?8Bm~dP  
    j%*<W> O  
        '************************************************************************* UDa\*  
        'Lens index of refraction 04z2gAo  
        '************************************************************************* qjvIp-  
        eID = FindMaterial( "Lens" ) oX1{~lDJl  
        GetModelMaterial eID, mat W}oAgUd  
    rMUQh~a/  
        mat.Nd = nlens Wuji'sxTs  
        SetModelMaterial eID, mat ?DJ,YY9P  
        Print "Set lens index of refraction = " & nlens :cTwp K  
    1FC 1*7A[  
        '************************************************************************* ((_v>{  
        'Pupil diameter TqMy">>  
        '************************************************************************* #1f8A5<  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) B3Esfk  
    u:4?$%rB  
        'Adjust pupil diameter (trimming volume inner hole) D'Sdz\:4  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" <0)@Ikhx  
    1hgmlY`  
        ' Adjust pupil location to just in front of the lens K<tkNWasQ  
        parID = FindFullName( "Geometry.Arizona Eye" ) T k>N4yq  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) #bLeK$  
        count = 0 I#hzU8Cc  
        While GetOperationCount(eID)>count l. i&.;f  
            GetOperation eID, count, op rB%acTCz=[  
            If op.Type="ShiftZ" Then lV!@h}mG  
                DeleteOperation eID,count 0IjQqI  
                count=count-1 =u`^QE  
            End If +EgQj*F*  
            count=count+1 .W%{j()op  
        Wend ;zvg]  %  
        op.Type = "ShiftZ" =2[cpF]  
        op.val1 = taq-0.01  kQm\;[R  
        op.parent = parID pfvNVu  
        AddOperation eID, op "%Eyb\V!  
    #r)c@?T@j  
        Print "Set pupil diameter = " & pupilDiam X\1'd,V  
    Y 1vSwS%{T  
        'Update AZ Eye subassembly Description $ p{Q]|ww  
        eID = FindFullName( "Geometry.Arizona Eye" ) j^~WAWbFh  
        GetEntity eID, entity N5[fw z w  
        entity.Description = "Accommodation = " & A & "D" nPUq+cXy]C  
        SetEntity eID, entity Lw.N3!e[  
    fXYg %  
        Update vrIM!~*W  
        Print "DONE!" eESJk 14  
         P A9 ]L  
    End Sub `+QrgtcEy4  
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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: BY$%gIB6>  
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    Accommodation = 4 Diopters Jj'~\j  
    Pupil Diameter = 4 mm vf(\?Js ,  
    Set aqueous humor thickness = 2.81 L +s,,k  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 X Jy]d/  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 . \fzK  
    Set lens thickness = 3.927 DY{JA *N  
    Set lens index of refraction = 1.42672 G?d28p',.  
    Set pupil diameter = 4 :U<`iJwY  
    DONE! }45&s9m=  
     
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