[技术]Arizona眼睛模型 [复制链接]

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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。 t+p-,ey^@  
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模型 IRXpk6|  
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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!K/[p=  
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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. !0E$9Xon  
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光源 p8o%H-Xk
 
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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。 E$*I.i
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 6 3Kec  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 C[<&%=  
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视网膜的散射 F1gDeLmJ  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 W=PDOzB>K  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 SAly
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脚本 ;k(|ynXv  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： Sg')w1  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 sW|u}8`  
余下的脚本计算与屈光度有关的所有参数。 |`_TVzA  
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分析 A3!NEFBK  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Wb/@~!+i`  
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脚本代码 //K]zu  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. =]U[   
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Dim entity As T_ENTITY y#YCc{K [  
Dim op As T_OPERATION |'Ve75 W6u  
Dim mat As T_MODELMATERIAL E5-8tHV   
Dim A As Double ^ chlAQz(  
Dim pupilDiam As Double L$lo5  
Dim eID As Long F2>o"j2  
Dim parID As Long e[>(L%QV+  
Dim count As Integer |I85]'K9a  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 2!{CNt.-  
Dim tlens As Double, nlens As Double 8Bo'0  
Dim curv As Double, conic As Double kX5v!pm[  
Dim ok As Long yd#4b`8U`  
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Sub Main x\I9J4Q  
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    '用户输入对话框 oV,>u5:B  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 _aa3Qwx  
        TextBox 220,21,40,21,.TextBox1 'default: 0 78y4nRQ*  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 pZ OVD%  
        OKButton 40,91,90,21
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        CancelButton 190,91,90,21 ~cU,3g  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 |Z#)1K  
        TextBox 220,49,40,21,.TextBox2 'default: 4 *kZJ  
    End Dialog [4PG_k[uTJ  
    Dim dlg As UserDialog B@.U\.  
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    ok = Dialog (dlg) mZMLDs:  
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    If ok=0 Then    'cancel button was pressed EDL<J1%  
        Print "Execution cancelled." f<0-'fGJd  
        End e,:@c3I  
    End If +#'exgGU^[  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ?Za1  b  
    If dlg.TextBox1 = "" Then .CwMxuW  
        A = 0           'Default accommodation 7}TjOWC  
    Else 0#XZ_(@%  
        A = CDbl(dlg.TextBox1) {IqbO>|"O_  
    End If B5J=q("P  
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    If dlg.TextBox2 = "" Then Ex
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        pupilDiam = 4   'Default pupil diameter .NwHr6/s*  
    Else *8X: fq  
        pupilDiam = CDbl(dlg.TextBox2) FkKx~I:  
    End If nyT
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    Print " " LD]XN'?"W  
    Print "Accommodation = " & A & " Diopters" [A[vR7&S  
    Print "Pupil Diameter = " & pupilDiam & " mm" j.AAY?L  
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    ' Calculate new parameters with accommodation "m/0>U
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness xjv?Z"X  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens M)Ogb'@#  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens s.Yywy  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens V4ayewVX  
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    tlens = 3.767 + 0.04*A                  'Lens thickness gQ
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction mA3C)V  
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    'Adjust parameters to account for accommodation ^EM##Ss_  
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    '************************************************************************* sh E>gTe  
    'Aqueous thickness (Position of Lens) b.;F)(  
    '************************************************************************* ~{RXc+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) M nH4p  
    GetCustomElement eID, entity AGS?<6W-  
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    parID = FindFullName( "Geometry.Arizona Eye" ) G#3 O^,m  
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    ' Delete any shift(s) in z nuhKM.a{  
    count = 0 0.t;i4  
    While GetOperationCount(eID)>count <E!M<!h  
        GetOperation eID, count, op R279=sO,J  
        If op.Type="ShiftZ" Then `?91Cw=`  
            DeleteOperation eID,count l9#M`x9  
            count=count-1 1Cp5a2{  
        End If $WrDZU 2z  
        count=count+1 @ 5|F:J  
    Wend PgxD?Oi8  
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    'Set new shift in /< h~d  
    op.Type = "ShiftZ" $(.[b][S  
    op.val1 = taq h
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    op.parent = parID b":cj:mxL  
    AddOperation eID, op LIirOf~e;!  
    Print "Set aqueous humor thickness = " & taq-0.55 7 45Uo'  
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    '************************************************************************* cZ%weQa#N)  
    'Radius and conic constant of anterior lens ()=  
    '************************************************************************* UR:cBr  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) GC~Tfrf=r  
    GetConic eID, entity, curv, conic jrZM  
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    SetConic eID, entity, 1/Rant, CCant a 0Hzf  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant |SQ5Sb  
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    '*************************************************************************
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    'Radius and conic constant of posterior lens gGH<%nHW1  
    '************************************************************************* G>d@lt  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) >z.o?F  
    GetConic eID, entity, curv, conic ~X*)gS-=  
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    SetConic eID, entity, 1/Rpost, CCpost bL]*K$  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 3?.3Z!H/  
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    '************************************************************************* ZG
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    'Lens thickness (Position of posterior lens surface) al(t-3`<  
    '************************************************************************* A"2k,{d  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) :,]V
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    ' Delete any z-shift(s) jDqe)uVvtV  
    count = 0 q6%jCt2'  
    While GetOperationCount(eID)>count 'Oyz/P(p  
        GetOperation eID, count, op cAC]%~orx  
        If op.Type="ShiftZ" Then hwSn?bkw  
            DeleteOperation eID,count wFnIM2a,  
            count=count-1 R%"wf   
        End If 9EIHcUXe  
        count=count+1 &CV%+  
    Wend [x kbzJ  
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    'Set new z-shift W}50E.\#  
    op.Type = "ShiftZ" {AoH  
    op.val1 = tlens R0B\| O0Uv  
    op.parent = parID yCwBZ/C  
    AddOperation eID, op w[S2
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    Print "Set lens thickness = " & tlens )}0(7z Yu  

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    '************************************************************************* "M3R}<Vt  
    'Lens index of refraction t,gKN^P_  
    '************************************************************************* <7~HG(ks  
    eID = FindMaterial( "Lens" ) )+'FTz` c  
    GetModelMaterial eID, mat /59jkcA+  
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    mat.Nd = nlens "7(2m  
    SetModelMaterial eID, mat qL/4mM0  
    Print "Set lens index of refraction = " & nlens rwWs\~.H  
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    '************************************************************************* k1e0kxn  
    'Pupil diameter -NHA{?6r  
    '************************************************************************* Rq-BsMX!A  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) (j@3=-%6G  
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    'Adjust pupil diameter (trimming volume inner hole) <7NY.zvwk]  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" /o Q^j'v  
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    ' Adjust pupil location to just in front of the lens 80TSE*  
    parID = FindFullName( "Geometry.Arizona Eye" ) .bE+dA6:v  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) />=)=CGv;  
    count = 0 %JF.m$-  
    While GetOperationCount(eID)>count iG()"^G  
        GetOperation eID, count, op aKkL0D  
        If op.Type="ShiftZ" Then Q(=}
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            DeleteOperation eID,count i0; p?4`m  
            count=count-1
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        End If ZCsL%(  
        count=count+1 ZV=O oLt,  
    Wend $lz\te  
    op.Type = "ShiftZ" wl|cipy"  
    op.val1 = taq-0.01 `a2%U/U  
    op.parent = parID puEuv6F  
    AddOperation eID, op BQmH
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    Print "Set pupil diameter = " & pupilDiam JR>#PJ,N-  
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    'Update AZ Eye subassembly Description -T3 z@k  
    eID = FindFullName( "Geometry.Arizona Eye" ) \Jq$!foYx  
    GetEntity eID, entity pxy=edd  
    entity.Description = "Accommodation = " & A & "D" T
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    SetEntity eID, entity 0/z=G!z\  
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    Update O75^(keW  
    Print "DONE!" E_k<EQ%r  
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End Sub M+4>l\  
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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： 4&]Sb}  
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Accommodation = 4 Diopters O1!hSu&  
Pupil Diameter = 4 mm Jse;@K5y  
Set aqueous humor thickness = 2.81 3Run.Gv\  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Y7{|iw(#  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ]
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Set lens thickness = 3.927 k<xPg5  
Set lens index of refraction = 1.42672 b'F#Y9  
Set pupil diameter = 4 {BB#Bh[  
DONE! _gDEIoBp