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    [分享]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: 2020-12-09
    简介 Kf=6l#J7  
    %DyukUJ  
    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。 ]M^ k~Xa  
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    模型 ^d6}rtG  
    ^eF%4DUC;  
    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。 {WokH;a/  
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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. etnq{tE5  
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    光源 {tS^Q*F  
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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。 qW~Z#Si  
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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。 5(9SIj^O  
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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。 kHWW\?O  
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    图2. 字母F光源的设定方法光 [p&n]T  
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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 :?uUh  
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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。 =1|^) 4M,x  
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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`=WgB  
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    图5. 视网膜重点采样规格设定
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    脚本 egXHp<bqw  
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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: kjj4%0"  
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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。 x]6-r`O7r  
    余下的脚本计算与屈光度有关的所有参数。 UO1WtQyu,H  
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    分析 `7D]J*?`  
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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。 @p$Nw.{'  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 h0cdRi  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. p&s~O,Bw$  
    =00c1v  
    Dim entity As T_ENTITY bHKTCPf  
    Dim op As T_OPERATION *dAQ{E(rO  
    Dim mat As T_MODELMATERIAL 2\4ammwT  
    Dim A As Double cD%_+@GaU  
    Dim pupilDiam As Double '!hA!eo>J  
    Dim eID As Long A,'F`au  
    Dim parID As Long .S_7R/2(?  
    Dim count As Integer +!~"o oQZh  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Tqf:G4!  
    Dim tlens As Double, nlens As Double O|} p=ny  
    Dim curv As Double, conic As Double mi';96  
    Dim ok As Long x]Pp|rHj  
    p{vGc-zP .  
    Sub Main *2T"lpl  
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        '用户输入对话框 Vr ^UEu.w?  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 /Kd9UQU  
            TextBox 220,21,40,21,.TextBox1 'default: 0 +QW| 8b  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 =#Z+WD-E  
            OKButton 40,91,90,21 3|0wD:Dy  
            CancelButton 190,91,90,21 {i^F4A@=Z  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 : MEB] }  
            TextBox 220,49,40,21,.TextBox2 'default: 4  5(\H:g\z  
        End Dialog {aVRvZH4  
        Dim dlg As UserDialog sU$<v( `"  
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        ok = Dialog (dlg) eY V Jk7  
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        If ok=0 Then    'cancel button was pressed '>^!a!<G  
            Print "Execution cancelled." =j"bLX6;  
            End FokSg[)5  
        End If hh[@q*C  
    Be~ '@  
        'Assign accommodation and pupil diameter & use defaults if field left empty 'lMDlTU O  
        If dlg.TextBox1 = "" Then Y6[ O s1  
            A = 0           'Default accommodation AX]cM)w  
        Else 2PC:F9dh\  
            A = CDbl(dlg.TextBox1) xE5VXYU  
        End If M{jJ>S{g  
    pSl4^$2XR  
        If dlg.TextBox2 = "" Then ;L@p|]fu  
            pupilDiam = 4   'Default pupil diameter v&)G~cz  
        Else JKF/z@Vbe\  
            pupilDiam = CDbl(dlg.TextBox2) j0~ dJ#  
        End If 0JXXJ:dB  
    7$JOIsM  
        Print " " .O&[9`"'  
        Print "Accommodation = " & A & " Diopters" 3(,c^F  
        Print "Pupil Diameter = " & pupilDiam & " mm" 5 D <  
    H oO1_{q"  
        ' Calculate new parameters with accommodation 4g)$(5jI}  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Y M,UM>  
    m2\[L/W]  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens :I2spBx  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens j%)@f0Ng  
    m^o?{ (K  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens fP/;t61Z  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens jpkKdQX)  
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        tlens = 3.767 + 0.04*A                  'Lens thickness "#.L\p{Zy  
    A\})H  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 2t;3_C  
    #('GGzL6c  
        'Adjust parameters to account for accommodation J6mUU3F9f  
    s[;1?+EI  
        '************************************************************************* p:ubj'(U05  
        'Aqueous thickness (Position of Lens) %x8vvcO^t  
        '************************************************************************* q\/xx`L  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ]$!7;P  
        GetCustomElement eID, entity [M2xF<r6t  
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        parID = FindFullName( "Geometry.Arizona Eye" ) KP_7h/e  
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        ' Delete any shift(s) in z Jow{7@FG  
        count = 0 F8xu&Vk0:  
        While GetOperationCount(eID)>count MM*9Q`cB  
            GetOperation eID, count, op kvN<o-B  
            If op.Type="ShiftZ" Then Z~K} @  
                DeleteOperation eID,count g: YUuZ  
                count=count-1 3$3%W<&^  
            End If Xdh@ ^`  
            count=count+1 mGo NT  
        Wend blUS6"kV}  
    F$S/zh$)0  
        'Set new shift in nK`H;k  
        op.Type = "ShiftZ" t!59upbN}3  
        op.val1 = taq d*$x|B|V  
        op.parent = parID `_x#`%!#2  
        AddOperation eID, op b_)SMAsO7  
        Print "Set aqueous humor thickness = " & taq-0.55 I:WPP'L4o  
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        '************************************************************************* 0x # V   
        'Radius and conic constant of anterior lens %reW/;)l{  
        '************************************************************************* AMN`bgxW  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 3}B-n!|*  
        GetConic eID, entity, curv, conic p2gu@!   
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        SetConic eID, entity, 1/Rant, CCant Jw^h<z/Ux  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 6n/KL  
    nv3TxG  
        '************************************************************************* E O"  
        'Radius and conic constant of posterior lens X{iidTW`xv  
        '************************************************************************* F.D6O[pZ  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) q)PSHr=Z  
        GetConic eID, entity, curv, conic iZ0.rcQj'o  
    OqX+ R4S  
        SetConic eID, entity, 1/Rpost, CCpost &zPM# Q  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Q'[~$~&`  
    9y*(SDF  
        '************************************************************************* +!t *LSF  
        'Lens thickness (Position of posterior lens surface) ltHuN;C\  
        '************************************************************************* 7'5/T]Z  
    f5R%F ~  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 2|`~3B)#  
    sA }X)aP  
        ' Delete any z-shift(s) qJ$S3B  
        count = 0 y*8;T v|  
        While GetOperationCount(eID)>count 6wb M$|yFj  
            GetOperation eID, count, op }dSFv   
            If op.Type="ShiftZ" Then R=W$3Ue~,  
                DeleteOperation eID,count z.W1Za  
                count=count-1 tfv@ )9  
            End If (JiEV3GH  
            count=count+1 II.Wa&w}  
        Wend k,y#|bf,Y  
    .>'J ^^  
        'Set new z-shift hG3RZN#ejq  
        op.Type = "ShiftZ" +PO& z!F  
        op.val1 = tlens G+iJS!=  
        op.parent = parID %Jn5M(myC  
        AddOperation eID, op 'IER9%V$  
        Print "Set lens thickness = " & tlens `~@}f"c`u  
    b{ W ,wn  
        '************************************************************************* $'lJ_ jL  
        'Lens index of refraction UL" <V  
        '************************************************************************* V{0V/Nv  
        eID = FindMaterial( "Lens" ) [ HjGdC  
        GetModelMaterial eID, mat +7K]5p;!~  
    E} ]SGU"  
        mat.Nd = nlens + >v{#A_u  
        SetModelMaterial eID, mat 87nsWBe  
        Print "Set lens index of refraction = " & nlens dRTpGz  
    U9AtC.IG!  
        '************************************************************************* cH7D@p}  
        'Pupil diameter s_,&"->  
        '************************************************************************* vaZ?>94  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) GF Rd:e  
    9a.[>4}  
        'Adjust pupil diameter (trimming volume inner hole) wD[qE  
    EtB56FU\  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" <JJi  
    8\Eq(o}7  
        ' Adjust pupil location to just in front of the lens L^nS%lm  
        parID = FindFullName( "Geometry.Arizona Eye" ) m$$98N  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) CY9`HQ1  
        count = 0 J~G"D-l<9/  
        While GetOperationCount(eID)>count 1x|/z,   
            GetOperation eID, count, op i)e)FhEY6  
            If op.Type="ShiftZ" Then fGLOXbsA  
                DeleteOperation eID,count ;Y16I#?;Kh  
                count=count-1 nzu 3BVv  
            End If lc0ZfC  
            count=count+1 GG_A'eX:I  
        Wend n1c Q#u  
        op.Type = "ShiftZ" fKT(.VN q5  
        op.val1 = taq-0.01 fI0L\^b%  
        op.parent = parID #kGxX@0  
        AddOperation eID, op on1mu't_;  
    RrqZ5Gonj  
        Print "Set pupil diameter = " & pupilDiam 5(OF~mX#  
    ~LzTqMHM  
        'Update AZ Eye subassembly Description ';7|H|,F  
        eID = FindFullName( "Geometry.Arizona Eye" ) ({x<!5XL  
        GetEntity eID, entity BF6H_g  
        entity.Description = "Accommodation = " & A & "D" Web8"8eD  
        SetEntity eID, entity /7zy5  
      s/'gl  
        Update }c,}+{q  
        Print "DONE!" cjO,#W0&f  
         `+/[0B=.  
    End Sub VbX$i!>8  
    f:g<Bz=u)*  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: -nT+!3A8  
    ?0Ca-T Rz  
    Accommodation = 4 Diopters Jq`fD~(7  
    Pupil Diameter = 4 mm am05>c9  
    Set aqueous humor thickness = 2.81 (;h]'I@  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 j|(bDa4\  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 _>:g&pS/  
    Set lens thickness = 3.927 Vt4}!b(O  
    Set lens index of refraction = 1.42672 ig/716r|  
    Set pupil diameter = 4 $Y0bjS2J  
    DONE! A1f]HT  
    0+:.9*g=k  
    FZmYv%J  
    QQ:2987619807 uf)W? `e~  
     
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