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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 A3q#,%  
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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。 u,=?|M\  
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    模型 AEFd,;GF  
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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。 LZ(K{+U/  
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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. @L607[!?  
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    光源 / U~yYh  
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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。 r4?|sAK  
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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。 /;y`6WG%2  
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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。 Oq}7q!H  
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    图2. 字母F光源的设定方法光 AOqL&z  
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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 0uGTc[^^M  
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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。 uE%2kB*]  
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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。 T$DFTr\\  
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    图5. 视网膜重点采样规格设定
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    脚本 ^%U`|GBZp  
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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: :hf%6N='kI  
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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。 gEgd/Le  
    余下的脚本计算与屈光度有关的所有参数。 eQfXUpk3@I  
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    分析 je%y9*V  
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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。 $P #KL//  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 I;{Ua *  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. |b!Bb<5  
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    Dim entity As T_ENTITY ?'tFTh  
    Dim op As T_OPERATION g/i.b&  
    Dim mat As T_MODELMATERIAL Yqt~h  
    Dim A As Double ki ?V eFp  
    Dim pupilDiam As Double A#F6~QX(.9  
    Dim eID As Long =6qSo @  
    Dim parID As Long 0OtUb:8LX  
    Dim count As Integer Izfq`zS+\s  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double #zb67mg~  
    Dim tlens As Double, nlens As Double 1 a%1C`d  
    Dim curv As Double, conic As Double |uJjO>8]|  
    Dim ok As Long (|tR>R.Wxg  
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    Sub Main h;OHpvk  
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        '用户输入对话框 ciCQe]fS  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 vU#>3[aC  
            TextBox 220,21,40,21,.TextBox1 'default: 0 }fhGofN$e  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 4Ub7T=LG  
            OKButton 40,91,90,21 0/~{,  
            CancelButton 190,91,90,21 L*{E-m/  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ;;432^jD  
            TextBox 220,49,40,21,.TextBox2 'default: 4 r;"Qu  
        End Dialog Rf{YASPIw&  
        Dim dlg As UserDialog iW[%|ddk  
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        ok = Dialog (dlg) ?:7$c  
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        If ok=0 Then    'cancel button was pressed ?]_A~_J!  
            Print "Execution cancelled." y@ c[S;  
            End @Fb 2c0?Y  
        End If K[q-[q#yc  
    * YLp C^&  
        'Assign accommodation and pupil diameter & use defaults if field left empty fDChq[LAn  
        If dlg.TextBox1 = "" Then 8`|Z9umW*  
            A = 0           'Default accommodation Rvj[Csgi  
        Else LiEDTXRz  
            A = CDbl(dlg.TextBox1) A%EGu4  
        End If =o[H2o y  
    XU`vs`/   
        If dlg.TextBox2 = "" Then >PUT(yNL  
            pupilDiam = 4   'Default pupil diameter 'lgS;ItpKu  
        Else 'pT8S  
            pupilDiam = CDbl(dlg.TextBox2) k !g%vx  
        End If 2:1 kSR^Ky  
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        Print " " yk2XfY  
        Print "Accommodation = " & A & " Diopters" 75c\.=G9q<  
        Print "Pupil Diameter = " & pupilDiam & " mm" }x"8v&3CM_  
    ii ^Nxnc=  
        ' Calculate new parameters with accommodation y# IUDnRJ  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness *nHkK!d<N  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens xv_Z$&9e>l  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens rxeOT# N}  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens YcM 0A~<  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens |_16IEJ  
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        tlens = 3.767 + 0.04*A                  'Lens thickness #ahe@|E'Y  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction )24 1-b V  
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        'Adjust parameters to account for accommodation Shu=oweJ  
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        '************************************************************************* wkD"EuW(  
        'Aqueous thickness (Position of Lens) YS>VQl  
        '************************************************************************* 9i!|wkx  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) @KU^B_{i  
        GetCustomElement eID, entity fczH^+mI  
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        parID = FindFullName( "Geometry.Arizona Eye" ) ['aiNhlbt  
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        ' Delete any shift(s) in z \WM"VT  
        count = 0 D|/ 4),v  
        While GetOperationCount(eID)>count q]gF[&QZ  
            GetOperation eID, count, op 7"Q;Yi2(  
            If op.Type="ShiftZ" Then ,veI'WHMB  
                DeleteOperation eID,count eMUt%zvb  
                count=count-1 E<tJ8&IGk  
            End If R7Z!  
            count=count+1 Ym9~/'%]  
        Wend hJ~=eYK?J  
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        'Set new shift in ;2547b[ ]  
        op.Type = "ShiftZ" A7aW]  
        op.val1 = taq B?;P:!/1  
        op.parent = parID +<sv/gEt  
        AddOperation eID, op %"AB\lL.  
        Print "Set aqueous humor thickness = " & taq-0.55 N?c!uO|h|  
    }i9VV+L#1  
        '************************************************************************* G g{M  
        'Radius and conic constant of anterior lens \C"hL(4-  
        '************************************************************************* p u[S  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) nZ# 0L`@"Y  
        GetConic eID, entity, curv, conic US] I[Y6V  
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        SetConic eID, entity, 1/Rant, CCant +?GsIp@>jh  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Jmun^Q/h  
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        '************************************************************************* _kUtj(re  
        'Radius and conic constant of posterior lens (A~w IKY,  
        '************************************************************************* 1oL3y;>iL  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) fD2 )/5j1  
        GetConic eID, entity, curv, conic q4Y7 HE|ym  
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        SetConic eID, entity, 1/Rpost, CCpost ^8 cq qu  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost t+A9nvj)  
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        '************************************************************************* SF[}s uL  
        'Lens thickness (Position of posterior lens surface) H ~lvUHN  
        '************************************************************************* M[7$F&&n  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) (vwKC D&  
    ,y[8Vz?:  
        ' Delete any z-shift(s) 4ms"mIt  
        count = 0 e}TDo`q  
        While GetOperationCount(eID)>count T< o8lL  
            GetOperation eID, count, op .hK:-q,  
            If op.Type="ShiftZ" Then WO[O0!X  
                DeleteOperation eID,count X> U _v  
                count=count-1 9rgvwko  
            End If 1i;#cIG  
            count=count+1 `':G92}#  
        Wend E[c6*I  
    C{]1+eL  
        'Set new z-shift @J<RFgw#  
        op.Type = "ShiftZ" ~SYW@o  
        op.val1 = tlens yMJ(Sf  
        op.parent = parID F?b"Rv  
        AddOperation eID, op "$A5:1;  
        Print "Set lens thickness = " & tlens O-qpB;|  
    !>)o&sM  
        '************************************************************************* )8_MkFQe  
        'Lens index of refraction +w8$-eFY  
        '************************************************************************* rYrvd[/*&(  
        eID = FindMaterial( "Lens" ) R^@   
        GetModelMaterial eID, mat ?{wD%58^oG  
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        mat.Nd = nlens T (? CDc+  
        SetModelMaterial eID, mat deCi\n  
        Print "Set lens index of refraction = " & nlens T%SK";PAU$  
    ^n*:zmD  
        '************************************************************************* >YR2h/S  
        'Pupil diameter *Nur>11D  
        '************************************************************************* <yw56{w,  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) m[s$)-T  
    DY1"t7 9E  
        'Adjust pupil diameter (trimming volume inner hole) @]dv   
    ZNJ<@K-  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Z=(Tq1t  
    X u2+TK  
        ' Adjust pupil location to just in front of the lens gpogv -  
        parID = FindFullName( "Geometry.Arizona Eye" ) =4gPoS  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) )&qr2Cm*  
        count = 0 Ht|"91ZC5  
        While GetOperationCount(eID)>count $ J!PSF8PL  
            GetOperation eID, count, op >LJ<6s[=  
            If op.Type="ShiftZ" Then ; KT/;I  
                DeleteOperation eID,count I/go$@E"  
                count=count-1 Bv#?.0Ez;  
            End If +NVXFjPC  
            count=count+1 H{1'- wB  
        Wend P<=1O WC  
        op.Type = "ShiftZ" /ACau<U]t  
        op.val1 = taq-0.01 ] U,m 1  
        op.parent = parID @Y!B~  
        AddOperation eID, op YmLpGqNv  
    &FWz7O>1  
        Print "Set pupil diameter = " & pupilDiam Ey{p;;H  
    NKl`IiGv  
        'Update AZ Eye subassembly Description u@t~*E5BpM  
        eID = FindFullName( "Geometry.Arizona Eye" ) 2x~Pq_?y  
        GetEntity eID, entity "iUh.c=0F,  
        entity.Description = "Accommodation = " & A & "D" hp@F\9j  
        SetEntity eID, entity ZtY?X- 4_  
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        Update ~U5Tn3'~  
        Print "DONE!" ^0?ww&X  
         m;!X{CV  
    End Sub ha7mXGN%  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: BDLJDyf B  
    _}.WRFIJ@L  
    Accommodation = 4 Diopters C9*[/|T  
    Pupil Diameter = 4 mm LuVL <W  
    Set aqueous humor thickness = 2.81 j{6O:d6([$  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ll*Ez"  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 cUn>gT  
    Set lens thickness = 3.927 HhwAzk/G~  
    Set lens index of refraction = 1.42672 1'|gxYT  
    Set pupil diameter = 4 B qLL]%F  
    DONE! *:ErZ UyQM  
     
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