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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 1(@$bsgu2  
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    人眼光学模型可用来设计眼科用设备,光学系统注定了要与人眼一起使用。本文演示了这样一个模型:Arizona眼睛模型,在Jim Schwiegerling教授的书中有详细描述:《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源,并包括一个基于想要的屈光度来调整模型的内嵌脚本。 &%rM|  
    # ][i!9$  
    模型 fJlNxdVr  
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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。 di/Q Jrw  
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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. Tc(=J7*r&  
    F ,472H  
    光源 OK]QDb  
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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。 }@q/.Ct! x  
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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。 |OJWQU![by  
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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。 +vy fhw4  
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    图2. 字母F光源的设定方法光 V<UChD)N`  
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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 o#p%IGG`  
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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。 bVzi^R"  
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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。 bVUIeX'  
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    图5. 视网膜重点采样规格设定
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    脚本 !Q[v"6?  
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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: XY| y1L 3[  
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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。 jn5xYKv  
    余下的脚本计算与屈光度有关的所有参数。 yIL=jzm`7  
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    分析 dLp1l2h!0  
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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。 bq E'9GI  
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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 6|NH*#s  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. rk8pL[|  
    ZwDL  
    Dim entity As T_ENTITY #`u}#(  
    Dim op As T_OPERATION ,Iyc0  
    Dim mat As T_MODELMATERIAL 8vVE  
    Dim A As Double &q>8D'  
    Dim pupilDiam As Double ]B3](TH"  
    Dim eID As Long  ?CAU+/  
    Dim parID As Long hty'L61\z  
    Dim count As Integer w!"L\QT  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double `0NU c)`  
    Dim tlens As Double, nlens As Double (S!UnBb&  
    Dim curv As Double, conic As Double Q~]oN  
    Dim ok As Long -LiGO#U  
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    Sub Main Hi09?AX  
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        '用户输入对话框 Q|)>9m!tt  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 !}!KT(% %  
            TextBox 220,21,40,21,.TextBox1 'default: 0 ceG\Q2  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 `a& L  
            OKButton 40,91,90,21 m~&  
            CancelButton 190,91,90,21 {c*$i^T  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 2V@5:tf  
            TextBox 220,49,40,21,.TextBox2 'default: 4 \< .BN;t{  
        End Dialog .hW>#  
        Dim dlg As UserDialog %k#+nad  
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        ok = Dialog (dlg) P7-k!p"  
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        If ok=0 Then    'cancel button was pressed i W6O9 ~  
            Print "Execution cancelled." \na$Sb+  
            End ;$iT]S  
        End If CC=I|/mBM  
    "zcAYg^U  
        'Assign accommodation and pupil diameter & use defaults if field left empty 7 {92_xRL  
        If dlg.TextBox1 = "" Then Tm`@5  
            A = 0           'Default accommodation TAUl{??,  
        Else +DRt2a #  
            A = CDbl(dlg.TextBox1) fJ/INL   
        End If t5E$u(&+'B  
    &^$@LH3  
        If dlg.TextBox2 = "" Then 6vK`J"d{~D  
            pupilDiam = 4   'Default pupil diameter %d+Fq=<  
        Else DoczQc-U+  
            pupilDiam = CDbl(dlg.TextBox2) 'b.jKkW7  
        End If Xgx/ubca0  
    XdJD"|,h  
        Print " " C?|sQcCE  
        Print "Accommodation = " & A & " Diopters" C)U4Fr ?E:  
        Print "Pupil Diameter = " & pupilDiam & " mm" @S3L%lOH  
    "9xJ},:-  
        ' Calculate new parameters with accommodation 2-'_Nwkl*  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ~a_hOKU5  
    m^oG9&";  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 'yCVB&`b  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens .h <=C&Yg  
    vT#R>0@mi  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens d9JAt-6z2  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens |y7TYjg6  
    dlo`](5m  
        tlens = 3.767 + 0.04*A                  'Lens thickness _t-6m2A  
    <9&GOaJ  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 6H0kY/quL|  
    F2zo !a8  
        'Adjust parameters to account for accommodation oL~1M=r  
    }$<v  
        '************************************************************************* M;XU"8  
        'Aqueous thickness (Position of Lens) N_ ODr]L  
        '************************************************************************* Vl$RMW@Ds  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) |\Gkhi>;  
        GetCustomElement eID, entity B4un6-<i  
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        parID = FindFullName( "Geometry.Arizona Eye" ) J <z ^C  
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        ' Delete any shift(s) in z 1CJ1-]S(3  
        count = 0 O_ r-(wE4  
        While GetOperationCount(eID)>count dUB;ZB7  
            GetOperation eID, count, op YN)qMI_ `A  
            If op.Type="ShiftZ" Then oTvg%bX  
                DeleteOperation eID,count /mJb$5=1  
                count=count-1 Gu{1%bb#kL  
            End If lFuW8G,-f@  
            count=count+1 yE N3/-S+  
        Wend Pjq9BK9p  
    @B0fRG y  
        'Set new shift in <,O| fY%  
        op.Type = "ShiftZ" gGNo!'o  
        op.val1 = taq 0>m$e(Z  
        op.parent = parID BT(eU*m-  
        AddOperation eID, op 0<uL0FOT  
        Print "Set aqueous humor thickness = " & taq-0.55 lre(]oBXA  
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        '************************************************************************* 0Bgj.?l  
        'Radius and conic constant of anterior lens 6 [bQ'Ir^8  
        '************************************************************************* |9i[*]  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) !gyW15z'  
        GetConic eID, entity, curv, conic -^_^ByJe  
    R{H8@JLD  
        SetConic eID, entity, 1/Rant, CCant Y, Lpv|  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant >G1]#'6;  
    r+Sv(KS4i^  
        '************************************************************************* Foj|1zJS_  
        'Radius and conic constant of posterior lens ymrnu-p o  
        '************************************************************************* }x6)}sz7  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) xGOmvn^lQ  
        GetConic eID, entity, curv, conic DQ$m@_/4w  
    ~2[kCuu  
        SetConic eID, entity, 1/Rpost, CCpost ??Urm[Y.Z  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost \Dr( /n  
    v\(6uej^  
        '************************************************************************* Q-iBK*-w  
        'Lens thickness (Position of posterior lens surface) c;KMox/  
        '************************************************************************* Wt5pK[JV  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9h+T O_T@F  
    ?W dY{;&  
        ' Delete any z-shift(s) Y x66Xy  
        count = 0 kg(}%Ih  
        While GetOperationCount(eID)>count ;fQIaE&H  
            GetOperation eID, count, op + i /4G.=*  
            If op.Type="ShiftZ" Then ,ZYPffu<*  
                DeleteOperation eID,count Lf.Ia *R:  
                count=count-1 1 "t9x.  
            End If F1}d@^K 7d  
            count=count+1 .LM|@OeaD!  
        Wend ijcF[bm E  
    a$iDn_{  
        'Set new z-shift Qo]qs+  
        op.Type = "ShiftZ" TrgKl2xfx  
        op.val1 = tlens b5~p:f-&4B  
        op.parent = parID 2.{zf r  
        AddOperation eID, op DgRn^gL{Q  
        Print "Set lens thickness = " & tlens u!HbS*jqq  
    [@pumH>  
        '************************************************************************* p")"t`k7  
        'Lens index of refraction FBrh!vQ<  
        '************************************************************************* =(R3-['QIb  
        eID = FindMaterial( "Lens" ) U0W2  
        GetModelMaterial eID, mat hZ|0<u  
    jMX+uYx M  
        mat.Nd = nlens @d8Nr:  
        SetModelMaterial eID, mat zDm3 $P=  
        Print "Set lens index of refraction = " & nlens @I&k|\  
    >`yRL[c;  
        '************************************************************************* '19?  
        'Pupil diameter 8B "^}y\0  
        '************************************************************************* +~==qLsU  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" )  '"hSX=  
    Y~r)WV!G  
        'Adjust pupil diameter (trimming volume inner hole) rNm_w>bq  
    jW^]N$>  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ww+,GnV  
    M`9|8f,!a  
        ' Adjust pupil location to just in front of the lens oBnes*  
        parID = FindFullName( "Geometry.Arizona Eye" ) =|fB":vk  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 5+b73R3r  
        count = 0 0a!|*Z  
        While GetOperationCount(eID)>count FLG{1dS  
            GetOperation eID, count, op Vvv;m5.  
            If op.Type="ShiftZ" Then X_3hh}=  
                DeleteOperation eID,count |~v2~   
                count=count-1 WFmW[< g  
            End If 6@:<62!;  
            count=count+1 !F Zg' 9  
        Wend ^%\MOjSN  
        op.Type = "ShiftZ" J{5p4bkb  
        op.val1 = taq-0.01 p9MJa[}V  
        op.parent = parID 4,=;:#n,J  
        AddOperation eID, op +sq_fd ;'D  
    qjg Z  
        Print "Set pupil diameter = " & pupilDiam #op0|:/N  
    J9J/3O Q=  
        'Update AZ Eye subassembly Description ssH[\i  
        eID = FindFullName( "Geometry.Arizona Eye" ) v4X ` Ul*  
        GetEntity eID, entity T;,,!  
        entity.Description = "Accommodation = " & A & "D" m*lcIa  
        SetEntity eID, entity )g^O'e=m  
    On[yL$?  
        Update V1Gnr~GM  
        Print "DONE!" va"bw!zXo*  
         SUvrOl   
    End Sub D mky!Cp  
    g^jTdrW/s  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: CFoR!r:X  
    G2sj<F=AV  
    Accommodation = 4 Diopters \0e`sOS`L  
    Pupil Diameter = 4 mm %z~kHL  
    Set aqueous humor thickness = 2.81 :N_DJ51  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ^q|W@uG-(  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 \W\*'C8q\  
    Set lens thickness = 3.927 3m&  
    Set lens index of refraction = 1.42672 #\K"FE0PGz  
    Set pupil diameter = 4 N&$ ,uhmO  
    DONE! nuA 0%K  
     
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