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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 h%uZYsK  
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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。 .?loO3 m  
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    模型 =Lf,?"S  
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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。 N 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. ]d! UJ&<?  
    UdpF@Q  
    光源 LhA/xf  
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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。 3`t%g[D1  
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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。 ;)D];u|_  
    -;^j:L{   
    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。 hpO`]  
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    图2. 字母F光源的设定方法光 tFp Ygff<  
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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 YS/Yd[ e  
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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。 &m-PC(W+  
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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。 A#EDk U,  
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    图5. 视网膜重点采样规格设定
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    脚本 ,-8"R`UI8  
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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: au: fw  
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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。 ywGd>@  
    余下的脚本计算与屈光度有关的所有参数。 }`% *W`9b  
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    分析 Oo5w?+t  
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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。 !dyXJ Q  
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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 (^T F%(H  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. tn(JC%?^  
    }wr{W:j  
    Dim entity As T_ENTITY 5m\<U`  
    Dim op As T_OPERATION {< )1q ;  
    Dim mat As T_MODELMATERIAL  HN=V"a  
    Dim A As Double ,(d) Qg  
    Dim pupilDiam As Double [uC ]*G]  
    Dim eID As Long &"f";  
    Dim parID As Long TC!Yb_H}gN  
    Dim count As Integer [^Os kJ4  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Dz>^IMsY  
    Dim tlens As Double, nlens As Double l?Udn0F  
    Dim curv As Double, conic As Double {o_X`rgrL  
    Dim ok As Long x$5) ^ud?  
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    Sub Main ~.{/0T  
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        '用户输入对话框 H?<N.Dq  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 dP# |$1  
            TextBox 220,21,40,21,.TextBox1 'default: 0 (eI5_`'VC  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 4|buk]9  
            OKButton 40,91,90,21 tItX y  
            CancelButton 190,91,90,21 -lbm* -(  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 zMbN;tu  
            TextBox 220,49,40,21,.TextBox2 'default: 4 dgR g>)V  
        End Dialog "-e \p lKj  
        Dim dlg As UserDialog ;X?}x%$  
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        ok = Dialog (dlg) s )noo  
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        If ok=0 Then    'cancel button was pressed Wk~W Ozr}^  
            Print "Execution cancelled." |n+qMql'  
            End (D#B_`;-  
        End If 6G1@smP  
    )j9SGLo  
        'Assign accommodation and pupil diameter & use defaults if field left empty Y2a5bc P  
        If dlg.TextBox1 = "" Then cii_U=   
            A = 0           'Default accommodation O@u?h9?cf>  
        Else |L%Z,:yO  
            A = CDbl(dlg.TextBox1) z.7cy@N6  
        End If QS%%^+E2  
    :[wsKFaV+  
        If dlg.TextBox2 = "" Then ?I6fye7  
            pupilDiam = 4   'Default pupil diameter  CJ1 7n  
        Else JlH&??  
            pupilDiam = CDbl(dlg.TextBox2) En~5"yW5>]  
        End If ;YA(|h<  
    o< |cA5f\  
        Print " " qaY1xPWz"  
        Print "Accommodation = " & A & " Diopters" oe%} ?u  
        Print "Pupil Diameter = " & pupilDiam & " mm" >p)MawT]  
    (!ZM{Js%  
        ' Calculate new parameters with accommodation ?oVx2LdD|  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness rf $QxJ  
    5:pM 4J  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens AJh w  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Rn}l6kbM  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens kE:nsXI )  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens DK$X2B"cV  
    (\\eo  
        tlens = 3.767 + 0.04*A                  'Lens thickness kDEPs$^  
    %SX|o-B~.o  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction CnpV:>V=  
    .X@FXx&  
        'Adjust parameters to account for accommodation I KqQ>Z-q~  
     O{QA  
        '************************************************************************* 7op`s5i  
        'Aqueous thickness (Position of Lens) 1,6}_MA  
        '************************************************************************* #yI mKEYX  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) k3u "A_"c  
        GetCustomElement eID, entity T ? $:'XJ  
    Gr7=:+0n|P  
        parID = FindFullName( "Geometry.Arizona Eye" ) tz5e"+Tz  
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        ' Delete any shift(s) in z q1z"-~i )E  
        count = 0 k jg~n9#T  
        While GetOperationCount(eID)>count OBMTgZHxv  
            GetOperation eID, count, op @JtM5qB  
            If op.Type="ShiftZ" Then @LS@cCC,a  
                DeleteOperation eID,count Z3#P,y9@  
                count=count-1 5>CEl2mSl  
            End If dYG,_ji  
            count=count+1 ?%O(mC]u&  
        Wend C9~52+S  
    :Pvzl1  
        'Set new shift in \?Z{hmN  
        op.Type = "ShiftZ" 6hlc1?  
        op.val1 = taq ey2S#%DF]  
        op.parent = parID 0O9Ni='Tn  
        AddOperation eID, op 9f2UgNqe9  
        Print "Set aqueous humor thickness = " & taq-0.55 4[.oPK=i  
    <D:.(AUeO  
        '************************************************************************* fI{ESXU  
        'Radius and conic constant of anterior lens V,mw[Hw  
        '************************************************************************* ZX>AE3wk  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) }@;ep&b*  
        GetConic eID, entity, curv, conic 6eT5ktf  
    u -;_y='m  
        SetConic eID, entity, 1/Rant, CCant Q~OxH'>>(  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Jbjmv: db  
    tZ'|DCT  
        '************************************************************************* 6A>dhU  
        'Radius and conic constant of posterior lens !D@ZYK;  
        '************************************************************************* S#MZV@nGF  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) xCg52zkH#  
        GetConic eID, entity, curv, conic qT%FmX  
    { vKLAxc  
        SetConic eID, entity, 1/Rpost, CCpost 4(|cG7>9-  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost &X|#R1\  
    M[mF8Zf  
        '************************************************************************* z`!XhU  
        'Lens thickness (Position of posterior lens surface) nSW=LjrO~<  
        '************************************************************************* .$qnZWcgG  
    b\3Oyp>  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) $"FQj4%d  
    F @mQQ  
        ' Delete any z-shift(s) ,u+PyG7 cb  
        count = 0 {)BTR%t  
        While GetOperationCount(eID)>count _JHd9)[  
            GetOperation eID, count, op UJM1VAJ0  
            If op.Type="ShiftZ" Then [Jogt#Fj ]  
                DeleteOperation eID,count [U5\bX@$  
                count=count-1 `-(|>5wWS  
            End If HkO7R `  
            count=count+1 "t (p&;d  
        Wend 7s/u(~d)  
    cd(GvX'  
        'Set new z-shift G&i!Hs  
        op.Type = "ShiftZ" 8zRP (+&W  
        op.val1 = tlens qAn!RkA  
        op.parent = parID #~7ip\Uf[  
        AddOperation eID, op np8gKV D  
        Print "Set lens thickness = " & tlens \HKxh:F'  
    )TVFtI=,NN  
        '************************************************************************* Nd$W0YN:  
        'Lens index of refraction TygW0b 1  
        '************************************************************************* K POa|$  
        eID = FindMaterial( "Lens" ) yzerOL  
        GetModelMaterial eID, mat wN;^[F  
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        mat.Nd = nlens \P.I)n`8 y  
        SetModelMaterial eID, mat sE:M@`2L  
        Print "Set lens index of refraction = " & nlens 77\] B  
    BI3@|,._N  
        '************************************************************************* ;_rF;9z9  
        'Pupil diameter 0`X]o'RxS  
        '************************************************************************* [H6hyG~  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) v6>_ j L  
    syaPpM Q-  
        'Adjust pupil diameter (trimming volume inner hole) H."EUcE{  
    -Z 4e.ay5  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" +y&Tf#.V/A  
    n 2)@S0{  
        ' Adjust pupil location to just in front of the lens WU71/PYm`  
        parID = FindFullName( "Geometry.Arizona Eye" ) A-ZN F4  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ^pQCNKLBY  
        count = 0 m9.{[K"  
        While GetOperationCount(eID)>count :_g$.h%%  
            GetOperation eID, count, op \l9qt5rS  
            If op.Type="ShiftZ" Then >'&p>Ad)  
                DeleteOperation eID,count ]Q>.HH  
                count=count-1 uTKD 4yig  
            End If P} 0%-JC  
            count=count+1 w8U&ls1b  
        Wend |4B:<x   
        op.Type = "ShiftZ" BT}!W`  
        op.val1 = taq-0.01 >pp5;h8!  
        op.parent = parID *7ZN]/VRT  
        AddOperation eID, op X]wRwG  
    DXJ`oh  
        Print "Set pupil diameter = " & pupilDiam Y8-86 *zC  
    ;\14b?TUH  
        'Update AZ Eye subassembly Description FVaQEMZ^  
        eID = FindFullName( "Geometry.Arizona Eye" ) J&.{7YF  
        GetEntity eID, entity 5h Q E4/hH  
        entity.Description = "Accommodation = " & A & "D" -o $QS,  
        SetEntity eID, entity M$/|)U'W  
    u>kN1kQ8  
        Update G!>z;5KuS  
        Print "DONE!" gm igsXQ  
         e=B|==E10M  
    End Sub 8~J(](QA  
    j g8fU  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: , udTvI  
    ABD)}n=%c  
    Accommodation = 4 Diopters CGY]r.O*  
    Pupil Diameter = 4 mm ms*(9l.hOK  
    Set aqueous humor thickness = 2.81 $a ]_w.@  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 +l9!Fl{MK\  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 amOnqH-(  
    Set lens thickness = 3.927 G9xmmc  
    Set lens index of refraction = 1.42672 s$Z _48  
    Set pupil diameter = 4 Gd-'Z_b  
    DONE! YjxF}VI~<  
     
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