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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 {srP3ll P  
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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。 ?9~^QRLT  
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    模型 HA,o2jZ?In  
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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。 G=:/v  
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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. +hN>Q $E  
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    光源  i;O_B5 d  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 :c/54Ss~  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 Bv<gVt  
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ,:t,$A  
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    图2. 字母F光源的设定方法光 4#IT" i  
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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  V9) /  
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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。 OijuOLt  
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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。 D;R~!3f./b  
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    图5. 视网膜重点采样规格设定
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    脚本 &>\;4E.O5  
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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: Q a (Sb  
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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。 +YvF+E  
    余下的脚本计算与屈光度有关的所有参数。 E;a,].  
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    分析 =o 9s?vOJ  
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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。 ;^ME  
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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 => (g_\  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used.  FSMM  
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    Dim entity As T_ENTITY <odi>!ViH  
    Dim op As T_OPERATION FOG{dio  
    Dim mat As T_MODELMATERIAL T1d@=&0"  
    Dim A As Double )V1xL_hx/  
    Dim pupilDiam As Double d'';0[W)  
    Dim eID As Long 9Vt ^q%DC  
    Dim parID As Long G=cRdiy`C  
    Dim count As Integer x {NBhq(4  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double PLz{EQ[cV  
    Dim tlens As Double, nlens As Double hQ|mow@Zmz  
    Dim curv As Double, conic As Double 1K9.3n   
    Dim ok As Long zQ=b|p]|W  
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    Sub Main <MS>7Fd2  
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        '用户输入对话框 !P{ /;Q  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 O<$w-(  
            TextBox 220,21,40,21,.TextBox1 'default: 0 .:?v;rYk{  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 -YQh F;/  
            OKButton 40,91,90,21 }eLApFHEDg  
            CancelButton 190,91,90,21 x:)H Ii q/  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1  qra XAQ  
            TextBox 220,49,40,21,.TextBox2 'default: 4 'UX^]  
        End Dialog No7-fX1B  
        Dim dlg As UserDialog  R[m-jUL  
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        ok = Dialog (dlg) 0cmd +`  
    -- %XkO  
        If ok=0 Then    'cancel button was pressed 5ngs1ZF@  
            Print "Execution cancelled." A-r;5?S  
            End =aVvv+T  
        End If 9?\cm}^?  
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        'Assign accommodation and pupil diameter & use defaults if field left empty k1z`92"  
        If dlg.TextBox1 = "" Then )x!q;^Js9A  
            A = 0           'Default accommodation `<tRfl}qs  
        Else h{)m}"n<R  
            A = CDbl(dlg.TextBox1) ->I.D?p  
        End If }[eUAGhDU  
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        If dlg.TextBox2 = "" Then ~3s ?.[}d  
            pupilDiam = 4   'Default pupil diameter sK%b16#  
        Else nq_$!aB_K  
            pupilDiam = CDbl(dlg.TextBox2) RJ?)O#}  
        End If .f$2-5q  
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        Print " " 7FH-l(W  
        Print "Accommodation = " & A & " Diopters" .gy:Pl]w  
        Print "Pupil Diameter = " & pupilDiam & " mm" m@ <,bZkl  
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        ' Calculate new parameters with accommodation HW[&q  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness j*QdD\)  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens  8~T}BC  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens |r+ x/,2-  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens wbWC &X.  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens J;>;K6pW  
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        tlens = 3.767 + 0.04*A                  'Lens thickness V~PGmn[V  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction {EZR}N  
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        'Adjust parameters to account for accommodation #eYYu2ND  
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        '************************************************************************* E0qJ.v  
        'Aqueous thickness (Position of Lens) Z+V%~C1  
        '************************************************************************* 3\Amj}RJ  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) FqJd  
        GetCustomElement eID, entity kVLZdXn,q2  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 6c+29@  
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        ' Delete any shift(s) in z d%}?%VH  
        count = 0 "L5w]6C4  
        While GetOperationCount(eID)>count Vw ;iE=L  
            GetOperation eID, count, op 1[OY- G  
            If op.Type="ShiftZ" Then C+\z$/q  
                DeleteOperation eID,count ^%*qe5J  
                count=count-1 _*}D@yy&  
            End If + _ehzo97  
            count=count+1 `/1rZ#  
        Wend YAR$6&  
    #_\**%,<  
        'Set new shift in ,w"cY?~<  
        op.Type = "ShiftZ" e3n^$'/\r  
        op.val1 = taq zecM|S_  
        op.parent = parID kPOk.F%)  
        AddOperation eID, op ZWGelZP~  
        Print "Set aqueous humor thickness = " & taq-0.55 XSx!11  
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        '************************************************************************* G l/3*J  
        'Radius and conic constant of anterior lens H5]q*D2  
        '************************************************************************* euY+jc%  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) w*'DlP<7  
        GetConic eID, entity, curv, conic v$`3}<3-  
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        SetConic eID, entity, 1/Rant, CCant @<P;F  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 8Ud.t =2  
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        '************************************************************************* f`vWCb  
        'Radius and conic constant of posterior lens 1grcCL q  
        '************************************************************************* Up-^km  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) D7R;IA-w  
        GetConic eID, entity, curv, conic 1$))@K-I  
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        SetConic eID, entity, 1/Rpost, CCpost s4 , `  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost =WF@S1  
    xz:  
        '************************************************************************* aIT0t0.  
        'Lens thickness (Position of posterior lens surface) s'/_0  
        '************************************************************************* -= c&K&  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) uj}%S_9  
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        ' Delete any z-shift(s) %N\45nYU:  
        count = 0 K\}qY dPF  
        While GetOperationCount(eID)>count 0I)eYksh  
            GetOperation eID, count, op =s AOWI,8!  
            If op.Type="ShiftZ" Then 1Xcj=I- 4  
                DeleteOperation eID,count c~M'O26bW  
                count=count-1 P2>_qyX  
            End If 1.2qh"#  
            count=count+1 s Wj:m)  
        Wend 1h]nE/T.O  
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        'Set new z-shift O~Jf"Ht  
        op.Type = "ShiftZ" fuf' r>1n  
        op.val1 = tlens uf )!SxT  
        op.parent = parID  ^~B#r#  
        AddOperation eID, op A;xH{vo{  
        Print "Set lens thickness = " & tlens c8l\1ce?7  
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        '************************************************************************* 9nd,8Nji  
        'Lens index of refraction 7Or?$  
        '************************************************************************* 'uqY%&U  
        eID = FindMaterial( "Lens" ) ckdCd J  
        GetModelMaterial eID, mat RXO}mu]Iu  
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        mat.Nd = nlens tTq2 AR|  
        SetModelMaterial eID, mat 9$sx+=(  
        Print "Set lens index of refraction = " & nlens &)Vuh=  
    ,=u!hg  
        '************************************************************************* F{&0(6^p!  
        'Pupil diameter ~!fOl)F  
        '************************************************************************* c~Y  g(  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) _P_R`A)"  
    Urm(A9|N  
        'Adjust pupil diameter (trimming volume inner hole) /u'V>=D;f  
    utdus:B#0  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" :Mu]* N  
    !&G& ~*.x  
        ' Adjust pupil location to just in front of the lens #9(iu S+BU  
        parID = FindFullName( "Geometry.Arizona Eye" ) jjoyMg95  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) *]S&V'Di  
        count = 0 2G/CN"  
        While GetOperationCount(eID)>count xCU pMB7  
            GetOperation eID, count, op s9b+uUt%  
            If op.Type="ShiftZ" Then `g'9)Xf4KT  
                DeleteOperation eID,count 2reQd47  
                count=count-1 p ^I#9(PT  
            End If R5cpmCs@R  
            count=count+1 Vg`32nRN  
        Wend I!p[:.t7  
        op.Type = "ShiftZ" I(Q3YDdb  
        op.val1 = taq-0.01 }(UU~V  
        op.parent = parID CVgVyy^  
        AddOperation eID, op |HTTTz9R.  
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        Print "Set pupil diameter = " & pupilDiam Kb#Z(C9  
    {@67'jL  
        'Update AZ Eye subassembly Description DUs0L\  
        eID = FindFullName( "Geometry.Arizona Eye" ) Tml>>O  
        GetEntity eID, entity JW=P} h  
        entity.Description = "Accommodation = " & A & "D" tb'O:/  
        SetEntity eID, entity &(X-b"2  
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        Update lDtl6r/  
        Print "DONE!" &Ht5!zuW,  
         ET=-r  
    End Sub ^s3SzB@  
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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: }FAO.  
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    Accommodation = 4 Diopters .5YW >PV  
    Pupil Diameter = 4 mm 8CGjI?j  
    Set aqueous humor thickness = 2.81 ~&8bVA= .  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 a.G;s2>  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 5tu 4uYp;  
    Set lens thickness = 3.927 /U,;]^  
    Set lens index of refraction = 1.42672 4wx _@8  
    Set pupil diameter = 4 %1PNP<3r0  
    DONE! `BKV/Xl  
     
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