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    [分享]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: 2020-12-09
    简介 fov=Yd!  
    zhX`~){N6  
    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。 _`X#c-J  
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    模型 ic0v*Y$  
    |h=+&*(:  
    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。 eFj6p<  
    01{r^ZT`RH  
    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. rv%ye H  
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    光源 A{8K#@!  
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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。 VM]GYz|#]  
    iy.%kHC  
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    图1. 光源和提示信息使用
    4/`h@]8P  
    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。 e:GgA  
    5e/qgI)M5  
    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。 |DFvZ6}  
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    图2. 字母F光源的设定方法光 kToVBU$  
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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 8G5) o`  
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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。 pe!dm}!h[  
    .?i-rTF:  
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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。 uFm+Y]h  
    &G pA1  
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    图5. 视网膜重点采样规格设定
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    脚本 hSkc9jBF  
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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: \=w'HZH#+  
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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。 62MRI    
    余下的脚本计算与屈光度有关的所有参数。 YH'$_,8peM  
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    分析 @3 -,=x  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 e'~-`Z9-)  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 "+n4c'  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. SLJ&{`"7  
    pwFU2}I  
    Dim entity As T_ENTITY X!7VyE+n  
    Dim op As T_OPERATION q:Y6fbt<7  
    Dim mat As T_MODELMATERIAL e~+(7_2  
    Dim A As Double " K 8&{=  
    Dim pupilDiam As Double *t#s$Ga  
    Dim eID As Long IU Y> ih  
    Dim parID As Long #cj\~T.,,  
    Dim count As Integer HDF!`  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double i\=z'  
    Dim tlens As Double, nlens As Double SUH mBo"}  
    Dim curv As Double, conic As Double OuOk=  
    Dim ok As Long *<*0".#  
    Dd!Sr8L[  
    Sub Main %6NO0 F^  
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        '用户输入对话框 0$eyT-:d  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 -ajM5S=d*  
            TextBox 220,21,40,21,.TextBox1 'default: 0 0PnD|]9:  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 QP6z?j.  
            OKButton 40,91,90,21 ]ZzoJ7lr  
            CancelButton 190,91,90,21 ^Yj"RM$;N  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 K-J|/eB  
            TextBox 220,49,40,21,.TextBox2 'default: 4 ="uKWt6n'  
        End Dialog {8^Gs^c c  
        Dim dlg As UserDialog V19e>  
    EKZ$Q4YE  
        ok = Dialog (dlg) xT9Yes&  
    8{R_6BS  
        If ok=0 Then    'cancel button was pressed *0%4l_i  
            Print "Execution cancelled." p+, 1Fi  
            End IK*oFo{C=K  
        End If :8p&#M  
    /635B*g  
        'Assign accommodation and pupil diameter & use defaults if field left empty (Ij0AeJ#  
        If dlg.TextBox1 = "" Then [096CK  
            A = 0           'Default accommodation IFiTTIlT0  
        Else #|qm!aGs  
            A = CDbl(dlg.TextBox1) `1nRcY  
        End If `S"W8_m  
    i]it5  
        If dlg.TextBox2 = "" Then G/v|!}?wG  
            pupilDiam = 4   'Default pupil diameter r%0pQEl  
        Else Y)$52m5rM  
            pupilDiam = CDbl(dlg.TextBox2) <"* "1(wN  
        End If 3c c1EQ9  
    mJ)tHv"7  
        Print " " o_iEkn  
        Print "Accommodation = " & A & " Diopters" 12idM*  
        Print "Pupil Diameter = " & pupilDiam & " mm" C&=x3Cz  
    ecn}iN  
        ' Calculate new parameters with accommodation O$a#2p&  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness RnHQq'J|\  
    )T>8XCL\}  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ./$ <J6-J  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens b.QpHrnhtK  
    x+4v s s  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens EPc!p>  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens CE)*qFs  
    HtxLMzgz<<  
        tlens = 3.767 + 0.04*A                  'Lens thickness lp(Nv(S  
    _-n Y2)  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^w>&?A'!  
    aiYo8+{!#  
        'Adjust parameters to account for accommodation P3G:th@j=  
    ] bIt@GB  
        '************************************************************************* }/20%fP  
        'Aqueous thickness (Position of Lens) : (cb2j(C  
        '************************************************************************* |V lMma z  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ASR-a't6  
        GetCustomElement eID, entity H ZPcd_(  
    h-7A9:  
        parID = FindFullName( "Geometry.Arizona Eye" ) ~L~]QN\3  
    29%=:*R$  
        ' Delete any shift(s) in z b7bSTFZxC  
        count = 0 >;,gGH  
        While GetOperationCount(eID)>count 7R: WX:  
            GetOperation eID, count, op B22b&0  
            If op.Type="ShiftZ" Then m$?.Yig?  
                DeleteOperation eID,count H"_v+N5=  
                count=count-1 L_^`k4ct  
            End If `mrCu>7  
            count=count+1 D3y>iQd   
        Wend z=qWJQ  
    %VWp&a8  
        'Set new shift in x@Y|v@}BE  
        op.Type = "ShiftZ" /u=aX  
        op.val1 = taq mH)OB?+lq  
        op.parent = parID B%fU'  
        AddOperation eID, op L?HF'5o  
        Print "Set aqueous humor thickness = " & taq-0.55 `NQ{)N0!  
    fWj@e"G  
        '************************************************************************* zrrz<dW  
        'Radius and conic constant of anterior lens -,^WaB7u\  
        '************************************************************************* 45) D+  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) -bA!PeI  
        GetConic eID, entity, curv, conic as(*B-_n~  
    7H%_sw5S.  
        SetConic eID, entity, 1/Rant, CCant zka?cOmYF[  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant bE d?^h  
    8b7;\C~$p  
        '************************************************************************* 8"i/wMP]  
        'Radius and conic constant of posterior lens F$h'p4$T  
        '************************************************************************* G?<pBMy  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) )pS8{c)E  
        GetConic eID, entity, curv, conic ")ED)&e  
    uf]Y^,2  
        SetConic eID, entity, 1/Rpost, CCpost Rboof`pVt  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost &:No}6  
    9 ZGV%Tw  
        '************************************************************************* 1i3V!!r  
        'Lens thickness (Position of posterior lens surface) \45(#H<$  
        '************************************************************************* Ff<)4`J  
    4{Udz!  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) )Oievu_"|  
    < eQ[kM  
        ' Delete any z-shift(s) J)*8|E9P  
        count = 0 nW GR5*e:  
        While GetOperationCount(eID)>count @Dj:4  
            GetOperation eID, count, op ufP Cx|x~  
            If op.Type="ShiftZ" Then >jMH#TZaX  
                DeleteOperation eID,count ]RD5Ex!K?  
                count=count-1 (@q3^)I4  
            End If C_G1P)k  
            count=count+1 4.Z(:g  
        Wend ~KRnr0  
    K2HvI7$-  
        'Set new z-shift 3]^'  
        op.Type = "ShiftZ" X`1p'JD  
        op.val1 = tlens o,FUfO}F  
        op.parent = parID gI{ =0  
        AddOperation eID, op ;Iq5|rzDn  
        Print "Set lens thickness = " & tlens lsY `c"NW>  
    B\[-fq  
        '************************************************************************* -!TcQzHUs  
        'Lens index of refraction JYV\oV{  
        '************************************************************************* v9rVpYc"  
        eID = FindMaterial( "Lens" ) 3ji:O T  
        GetModelMaterial eID, mat x: ~d@  
    Gw{+xz KJ  
        mat.Nd = nlens ao$):,2*  
        SetModelMaterial eID, mat 7|Dn+ =  
        Print "Set lens index of refraction = " & nlens tS<h8g_  
    j"hASBTgp  
        '************************************************************************* TwFb%YM  
        'Pupil diameter azX`oU,l  
        '************************************************************************* 9p`r7:  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) O]{*(J/t  
    {|6z+vR  
        'Adjust pupil diameter (trimming volume inner hole) ]"sRS`0+  
    m}5q]N";x  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" fHfY}BQS  
    ?3jdg]&  
        ' Adjust pupil location to just in front of the lens s$GF 95^  
        parID = FindFullName( "Geometry.Arizona Eye" ) {mSJUK?TKl  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) dy:d=Z  
        count = 0 Y<Q\d[3^F  
        While GetOperationCount(eID)>count Ae49n4J  
            GetOperation eID, count, op {/ &B!zvl  
            If op.Type="ShiftZ" Then :Jl Di>B  
                DeleteOperation eID,count 0S.?E.-&0  
                count=count-1 4seciz0?  
            End If GN%(9N'W  
            count=count+1 >^3zU   
        Wend FH*RU1Z  
        op.Type = "ShiftZ" J]fS({(\I  
        op.val1 = taq-0.01 Mr* |9h  
        op.parent = parID .pvxh|V  
        AddOperation eID, op uV~e|X "9s  
    uTGcQs}  
        Print "Set pupil diameter = " & pupilDiam H/J<Pd$p  
    K@r*;T  
        'Update AZ Eye subassembly Description Y6ben7j%-  
        eID = FindFullName( "Geometry.Arizona Eye" ) *#2Rvt*Ox  
        GetEntity eID, entity @^? XaU  
        entity.Description = "Accommodation = " & A & "D" T"!EK&  
        SetEntity eID, entity C3S`}o.  
    'qy#)F  
        Update l~1AT%  
        Print "DONE!" lLCdmxbT  
         ` X}85  
    End Sub HmV /> 9  
    o:UXPAj  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: &p"(-  
    G9RP^  
    Accommodation = 4 Diopters s'L?;:)dyB  
    Pupil Diameter = 4 mm irMd jG  
    Set aqueous humor thickness = 2.81 *IZf^-=Q  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 (X}@^]lpa  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 Y {c5  
    Set lens thickness = 3.927 ut5yf$%  
    Set lens index of refraction = 1.42672 HC7JMj  
    Set pupil diameter = 4 Z;b+>2oL  
    DONE! <LA^%2jT  
    \+Y!ILOI  
    ow.6!tl0=h  
    QQ:2987619807 \!H{Ks{#R.  
     
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