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infotek 2022-02-25 09:52

Arizona眼睛模型

简介 tKx~1-  
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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。 hwBfdZ  
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模型 Rmt~,cW!\  
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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。 <~'"<HwtK  
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. GmEJhr.3`=  
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光源 hl(hJfp  
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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。 |5~#&v_  
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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。 z] P SpUd  
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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。 `nv~NLkl  
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图2. 字母F光源的设定方法光 ,nLy4T&"  
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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 Tx=-Bb~;  
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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。 8\ +T8(m  
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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。 w QH<gJE/:  
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图5. 视网膜重点采样规格设定
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脚本 (Hz^)5(~  
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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: '4Ixqb+  
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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。 DV+xg3\(>1  
余下的脚本计算与屈光度有关的所有参数。 $@Rxrx_@M  
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分析 g\(G\ tnu>  
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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。 DiScFx |rE  
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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 /-ch`u md  
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  1. Option Explicit     'Remove this to enable non-dimensioned variables to be used. c74.< @w  
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    Dim entity As T_ENTITY z8~NZ;A  
    Dim op As T_OPERATION ./k/KSR  
    Dim mat As T_MODELMATERIAL k\YG^I  
    Dim A As Double yw[g!W  
    Dim pupilDiam As Double t#/YN.@r  
    Dim eID As Long |zNX=mAV  
    Dim parID As Long c9'vDTE%~  
    Dim count As Integer :P\7iW  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double %~JJ.&  
    Dim tlens As Double, nlens As Double +L| ?~p`V  
    Dim curv As Double, conic As Double WZejp}x  
    Dim ok As Long Gg3,:A_ w  
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    Sub Main dA`IEQJL  
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        '用户输入对话框 -M~:lK]n   
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 -.@r#d/  
            TextBox 220,21,40,21,.TextBox1 'default: 0 eRstD>r  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Uq,^Wy  
            OKButton 40,91,90,21 }wjw:M  
            CancelButton 190,91,90,21 N1S{suic  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 uR4z &y  
            TextBox 220,49,40,21,.TextBox2 'default: 4 qIE9$7*X  
        End Dialog +z\^t_"f  
        Dim dlg As UserDialog Nk 8B_{  
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        ok = Dialog (dlg) Mj?`j_X  
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        If ok=0 Then    'cancel button was pressed |`,2ri*5A  
            Print "Execution cancelled." :WS@=sZN  
            End m6K}|j  
        End If +wU@ynw  
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        'Assign accommodation and pupil diameter & use defaults if field left empty ,RI Gc US  
        If dlg.TextBox1 = "" Then UiP"Ixg6  
            A = 0           'Default accommodation Apag{Z]^B  
        Else LTCb@L{^i  
            A = CDbl(dlg.TextBox1) bMu+TgAT,  
        End If Y%aCMP9j~9  
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        If dlg.TextBox2 = "" Then  #ut  
            pupilDiam = 4   'Default pupil diameter 7~% ?#  
        Else 8oseYH  
            pupilDiam = CDbl(dlg.TextBox2) rjAn@!|:+  
        End If z}9(x.I  
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        Print " " z`}qkbvi  
        Print "Accommodation = " & A & " Diopters" o]_dJB  
        Print "Pupil Diameter = " & pupilDiam & " mm" t%FwXaO#  
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        ' Calculate new parameters with accommodation Xp% v.M  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness o#gWbAG;]b  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens hJ? O],4J  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens XS{Qnx_#  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 1Z2HUzqh.  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ({)+3]x  
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        tlens = 3.767 + 0.04*A                  'Lens thickness .},'~NM]  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \fd v]f  
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        'Adjust parameters to account for accommodation /NFj(+&g+  
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        '************************************************************************* LEf^cM=>  
        'Aqueous thickness (Position of Lens) u@M,qo`  
        '************************************************************************* 0<@KG8@hI;  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~<5!?6Yt  
        GetCustomElement eID, entity yYYSeH  
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        parID = FindFullName( "Geometry.Arizona Eye" ) E_wCN&`[  
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        ' Delete any shift(s) in z  . iI  
        count = 0 ]^7@}Ce_  
        While GetOperationCount(eID)>count s`8= 3]w  
            GetOperation eID, count, op UHkMn  
            If op.Type="ShiftZ" Then =R|HV;9 h  
                DeleteOperation eID,count }C?'BRX  
                count=count-1 Tv=mgH=b  
            End If P>D)7 V9Hh  
            count=count+1 =BAr .m+"  
        Wend AKfDXy  
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        'Set new shift in HM1Fz\Sf  
        op.Type = "ShiftZ" ~jk|4`I?T  
        op.val1 = taq p)-^;=<B3  
        op.parent = parID o#Dk& cH  
        AddOperation eID, op rJ4S%6w  
        Print "Set aqueous humor thickness = " & taq-0.55 v{N`.~,^  
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        '************************************************************************* Y\P8 v  
        'Radius and conic constant of anterior lens AeM^73t  
        '************************************************************************* |aS.a&vwR  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) H$t_Xw==  
        GetConic eID, entity, curv, conic xm~`7~nFR  
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        SetConic eID, entity, 1/Rant, CCant k]|~>9eY]  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant T3<4B!UB&  
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        '************************************************************************* vn8aFA  
        'Radius and conic constant of posterior lens U< fGGCw  
        '************************************************************************* Pmx -8w  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) cqkV9f8Ro  
        GetConic eID, entity, curv, conic pah'>dAL  
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        SetConic eID, entity, 1/Rpost, CCpost 'JE`(xD  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost /36:ms A  
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        '************************************************************************* u&vf+6=9Dd  
        'Lens thickness (Position of posterior lens surface) =y*IfG9b  
        '************************************************************************* CK@@HSm}l  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) (5YM?QAd  
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        ' Delete any z-shift(s) h;"4+uw  
        count = 0 Sz`,X0a  
        While GetOperationCount(eID)>count 4p F*"B  
            GetOperation eID, count, op zC!t;*8a  
            If op.Type="ShiftZ" Then <'oQ \eB  
                DeleteOperation eID,count H*R"ntI?w  
                count=count-1  V}CG:9;  
            End If cV6D<,)  
            count=count+1 #trK^(  
        Wend !e<^? r4  
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        'Set new z-shift UI0VtR]   
        op.Type = "ShiftZ" (w3YvG.  
        op.val1 = tlens wwZ,;\  
        op.parent = parID Yj49t_$b  
        AddOperation eID, op M6j y\<a  
        Print "Set lens thickness = " & tlens C&%_a~  
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        '************************************************************************* tyFzSrfc  
        'Lens index of refraction XpHrt XD  
        '************************************************************************* #;yZ  
        eID = FindMaterial( "Lens" ) 1))8 A@,  
        GetModelMaterial eID, mat gwMNYMI  
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        mat.Nd = nlens 8nV+e~-w  
        SetModelMaterial eID, mat oMa6(3T?E  
        Print "Set lens index of refraction = " & nlens l ymCH  
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        '************************************************************************* Vc Z3 X4/  
        'Pupil diameter $U~]=.n  
        '************************************************************************* TvbE2Q;/UL  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) aW7^d'ZZ\  
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        'Adjust pupil diameter (trimming volume inner hole) 46h<,na?,  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" #_p\Ie*rd  
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        ' Adjust pupil location to just in front of the lens I efn$  
        parID = FindFullName( "Geometry.Arizona Eye" ) Wne@<+mX  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) kxv1Hn"`{E  
        count = 0 x%B/  
        While GetOperationCount(eID)>count b \2 ds,  
            GetOperation eID, count, op c^W)07-X5y  
            If op.Type="ShiftZ" Then j\M?~=*w  
                DeleteOperation eID,count z2GY:<s  
                count=count-1 G 3ptx! D  
            End If gcT%c|.  
            count=count+1 s$j,9uRr  
        Wend f@!.mDm]  
        op.Type = "ShiftZ" P&Vv/D  
        op.val1 = taq-0.01 (4nq>;$3  
        op.parent = parID Q$"D]!G  
        AddOperation eID, op |sE'XT4ag  
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        Print "Set pupil diameter = " & pupilDiam S f# R0SA  
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        'Update AZ Eye subassembly Description f/?P514h  
        eID = FindFullName( "Geometry.Arizona Eye" ) H Pz+Dm  
        GetEntity eID, entity w7L) '9  
        entity.Description = "Accommodation = " & A & "D" G3T]`Atf  
        SetEntity eID, entity 9\(| D#  
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        Update [$UI8tV  
        Print "DONE!" qHsA1<wg  
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    End Sub q) KKvO  
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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: mt.))#1  
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    Accommodation = 4 Diopters E]r?{t`]  
    Pupil Diameter = 4 mm 0"z9Q\{}  
    Set aqueous humor thickness = 2.81 F!K>Kz  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 |_U= z;Y  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 u*9V&>o  
    Set lens thickness = 3.927 'J|_2*  
    Set lens index of refraction = 1.42672 .=; ;  
    Set pupil diameter = 4 (/] J3  
    DONE!
silence唯爱 2022-02-25 13:53
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