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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 P;V$%r`yD  
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    人眼光学模型可用来设计眼科用设备,光学系统注定了要与人眼一起使用。本文演示了这样一个模型:Arizona眼睛模型,在Jim Schwiegerling教授的书中有详细描述:《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源,并包括一个基于想要的屈光度来调整模型的内嵌脚本。 (9#$za>  
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    模型 JH4hy9i  
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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。 K/Q%tr1W0  
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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. ^/0c`JG!x  
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    光源 w)# Lu/  
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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。 Z%Kkh2-uh  
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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。 g[D(]t\#x  
    Ix-bJE6+I,  
    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。 ?5N7,|K)  
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    图2. 字母F光源的设定方法光 0tL#-47  
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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 Jv,*rQH  
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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。 _~l*p"PL<  
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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。 6njwrqo  
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    图5. 视网膜重点采样规格设定
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    脚本 $QNII+o  
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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`:K'  
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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。 q':P9 o*N?  
    余下的脚本计算与屈光度有关的所有参数。 8wi2&j_  
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    分析 P^)J^{r  
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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。 LX!MDZz  
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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 .|VWYN  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. Vx~N`|yY  
    R7 WGc[  
    Dim entity As T_ENTITY ![ce=9@t<  
    Dim op As T_OPERATION apkmb<  
    Dim mat As T_MODELMATERIAL oEuV&m|yX  
    Dim A As Double \FL`b{!+ N  
    Dim pupilDiam As Double ,. K}uW  
    Dim eID As Long Rxf.@E  
    Dim parID As Long k"L?("~   
    Dim count As Integer &gr)U3w  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double a(s% 3"*Q  
    Dim tlens As Double, nlens As Double Ec/-f `8  
    Dim curv As Double, conic As Double aANzL  
    Dim ok As Long <5xlP:Cx  
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    Sub Main 7`G FtX}  
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        '用户输入对话框 a3Fe42G2c|  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 \Wn0,%x2  
            TextBox 220,21,40,21,.TextBox1 'default: 0 TwT@_~ IM  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ar%!h~  
            OKButton 40,91,90,21 :&'[#%h8  
            CancelButton 190,91,90,21 y.6Yl**l  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 n a3st*3V_  
            TextBox 220,49,40,21,.TextBox2 'default: 4 a9sbB0q-K@  
        End Dialog ?j:g.a+U  
        Dim dlg As UserDialog q=J8SvSRl  
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        ok = Dialog (dlg) |/M^q{h&7s  
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        If ok=0 Then    'cancel button was pressed ,QZNH?Cp/  
            Print "Execution cancelled." AB0>|.  
            End \Q~HL_fy|Y  
        End If 1oSU>I_i  
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        'Assign accommodation and pupil diameter & use defaults if field left empty DQ{"6-  
        If dlg.TextBox1 = "" Then i\yp(tE%^  
            A = 0           'Default accommodation Q\qI+F2?  
        Else tDQo1,(oY  
            A = CDbl(dlg.TextBox1) zir?13N7  
        End If dSkx*#FEE  
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        If dlg.TextBox2 = "" Then S4!}7NOh  
            pupilDiam = 4   'Default pupil diameter vk K8D#K  
        Else -SeHz.` N  
            pupilDiam = CDbl(dlg.TextBox2) Mf_urbp]  
        End If 1<n'F H3  
    8_h:_7e  
        Print " " 0V!@*Z  
        Print "Accommodation = " & A & " Diopters" 3$#=* Zp  
        Print "Pupil Diameter = " & pupilDiam & " mm" &f_ua)cyY  
    J*zm*~8\  
        ' Calculate new parameters with accommodation e'MLLC [  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 4Mr)~f rc  
    YX,xC-37y  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 8v12<ktR`  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens in>.Tax*  
    U+7!Vpq  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens FrL ;1zt  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens tFrNnbmlQ  
    AY)R2> fW%  
        tlens = 3.767 + 0.04*A                  'Lens thickness N&YQZ^o  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction i^_?C5  
    f)9{D[InM^  
        'Adjust parameters to account for accommodation kgGMA 7Jy  
    f`Wces=5  
        '************************************************************************* U!D\Vd  
        'Aqueous thickness (Position of Lens) _2p D  
        '************************************************************************* #Ab,h#f*7  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) =+>^:3cCQ  
        GetCustomElement eID, entity 1_RN*M +#  
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        parID = FindFullName( "Geometry.Arizona Eye" ) k.K;7GZC  
    5 cz6\A&  
        ' Delete any shift(s) in z s{@3G8  
        count = 0 bG&vCH;}%  
        While GetOperationCount(eID)>count T.B} k`$  
            GetOperation eID, count, op n\'@]qG)Z4  
            If op.Type="ShiftZ" Then ,Jqk0cW2  
                DeleteOperation eID,count EhK~S(r^  
                count=count-1 p5?8E$VHV  
            End If Hr/3nq}.  
            count=count+1 snti*e4"V  
        Wend :j[a X7Sq2  
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        'Set new shift in O od?ifA  
        op.Type = "ShiftZ" h$#zuqm  
        op.val1 = taq qytH<UB  
        op.parent = parID S/H!a:_5r  
        AddOperation eID, op ?CHFy2%Y  
        Print "Set aqueous humor thickness = " & taq-0.55 w W1>#F  
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        '************************************************************************* $]I" ,ef  
        'Radius and conic constant of anterior lens 5l,Q=V^@l  
        '************************************************************************* fNNik7  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) q+)csgN  
        GetConic eID, entity, curv, conic u8sK~1CPf  
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        SetConic eID, entity, 1/Rant, CCant e,rCutA)  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant [ (eO_I5ep  
    ]YqeI*BX  
        '************************************************************************* A_xUP9g@?  
        'Radius and conic constant of posterior lens VSQxlAGk@  
        '************************************************************************* ~vv\A5O[|  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) HS[N]'dc  
        GetConic eID, entity, curv, conic xGVL|/?8  
    dd|/I1  
        SetConic eID, entity, 1/Rpost, CCpost ZW>?y$C+  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost &bw ``e&c  
    `|d&ta[{  
        '************************************************************************* xK;WJm"  
        'Lens thickness (Position of posterior lens surface) L7 f'  
        '************************************************************************* mIUpAOC`"Z  
    dX>l"))yR  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) XF=GmkO  
    ?Rg8u  
        ' Delete any z-shift(s) 3t^r;b  
        count = 0 a eo/4  
        While GetOperationCount(eID)>count ;zZGV4Qc~  
            GetOperation eID, count, op p@x1B &Z  
            If op.Type="ShiftZ" Then A"` (^#a  
                DeleteOperation eID,count kTe0"  
                count=count-1 ecl$z6'c  
            End If M+q|z0U  
            count=count+1 jhmWwT/O8^  
        Wend w+Cs=!  
    jf'#2-   
        'Set new z-shift q,H 0=\  
        op.Type = "ShiftZ" glvt umv  
        op.val1 = tlens `fUem,$)1F  
        op.parent = parID tzFgPeo$;  
        AddOperation eID, op ?]bZ6|;2  
        Print "Set lens thickness = " & tlens wtL_c  
    %`Q<_LTU  
        '************************************************************************* k2S6 SB  
        'Lens index of refraction =W Q_5}  
        '************************************************************************* 4lqowg0  
        eID = FindMaterial( "Lens" ) V$7SVq  
        GetModelMaterial eID, mat Z*Qra4GBl]  
    wt@q+9:  
        mat.Nd = nlens wZV/]jmlEt  
        SetModelMaterial eID, mat ixFuqPij  
        Print "Set lens index of refraction = " & nlens RO1xcCp  
    (!^(74  
        '************************************************************************* Im\{b=vT  
        'Pupil diameter !SFF 79$c  
        '************************************************************************* i C nWb  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 4LBMhLy  
    BEv>?T 0  
        'Adjust pupil diameter (trimming volume inner hole) l'2a?1/q  
    f/:XIG  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 2nFSu9}+r  
    6k=ink-/  
        ' Adjust pupil location to just in front of the lens v!pT!(h4  
        parID = FindFullName( "Geometry.Arizona Eye" ) ~Z'3(n*9  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) PB :Lj  
        count = 0 ~X/1%  
        While GetOperationCount(eID)>count . d;XLS~  
            GetOperation eID, count, op u!X$M?D4  
            If op.Type="ShiftZ" Then mt+IB4`  
                DeleteOperation eID,count N:y3tpG  
                count=count-1 4D`T_l  
            End If xM/B"SG2  
            count=count+1 YAIDSZ&l[  
        Wend s C9j73 vf  
        op.Type = "ShiftZ" (Hcd{]M~  
        op.val1 = taq-0.01 H?P:;1A]c  
        op.parent = parID 8W]6/st?]  
        AddOperation eID, op >g]kbes-\  
    kphv)a4z=  
        Print "Set pupil diameter = " & pupilDiam XZv(B^  
    A&2)iQ  
        'Update AZ Eye subassembly Description z~/z>_y$nv  
        eID = FindFullName( "Geometry.Arizona Eye" ) \V|\u=@H  
        GetEntity eID, entity %s;#epP$  
        entity.Description = "Accommodation = " & A & "D" "b!EtlT9  
        SetEntity eID, entity ['MG/FKuv  
    _M/ckv1q@  
        Update `o 6Hm  
        Print "DONE!" ;J~NfL  
         zUM;Qwl  
    End Sub @LS*WJ< w-  
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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: wjF/c  
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    Accommodation = 4 Diopters <|NP!eMsw8  
    Pupil Diameter = 4 mm ?*~W  
    Set aqueous humor thickness = 2.81 -,Q !:  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 t%e}'?#^  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 /HsJyp+t  
    Set lens thickness = 3.927 ISI\< qx  
    Set lens index of refraction = 1.42672 8I)66  
    Set pupil diameter = 4 a W`q  
    DONE! uoYG@L2  
    yVvO!  
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    QQ:2987619807 :A\8#]3  
     
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