[技术]Arizona眼睛模型 [复制链接]

简介 >m$ 1+30X  
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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。 5bgs*.s  
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模型 ^t#&@-'(d  
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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。 c(~[$)i6  
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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. N=7pK&NHSG  
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光源 _+E5T*dk  
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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。 1waTTT?"Ho  
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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。 =7m)sxj]w  
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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。 Z'7
 
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视网膜的散射 !*B'?|a<\  
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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。 {C N~S*m  
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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。 %_%Q8,W  
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脚本 aGtf z)  
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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： Vg>dI&O  
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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。 Pama#6?OPh  
余下的脚本计算与屈光度有关的所有参数。 DN-+o
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分析 lvBx\e;7P  
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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。 ;RC{<wBTx  
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脚本代码 [S9K6%w_!  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 7byK{{/
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Dim entity As T_ENTITY {GK;63`1  
Dim op As T_OPERATION e.7EU  
Dim mat As T_MODELMATERIAL 59Xi3KY  
Dim A As Double @"Fme-~
 
Dim pupilDiam As Double )U7t  
Dim eID As Long Z<1FSk,[  
Dim parID As Long v&Yi  
Dim count As Integer r~jm`y  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double }Gz~nf%  
Dim tlens As Double, nlens As Double 1PVtxL?1P  
Dim curv As Double, conic As Double 7~^GA.92  
Dim ok As Long Fq~yL!#!  
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Sub Main 9YIM'q>`v  
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    '用户输入对话框 DBW[{DE  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 m4hX 'F  
        TextBox 220,21,40,21,.TextBox1 'default: 0 "CSsCA$/  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 xu/cq9  
        OKButton 40,91,90,21 &zl|87M  
        CancelButton 190,91,90,21 >Ea8G,  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 q8X feoUV  
        TextBox 220,49,40,21,.TextBox2 'default: 4 rq8K_zp  
    End Dialog nrL9 E'F'  
    Dim dlg As UserDialog B8.P
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    ok = Dialog (dlg) {C 6=[  
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    If ok=0 Then    'cancel button was pressed fM]+SMZy  
        Print "Execution cancelled." f/ ?_  
        End $? m9")  
    End If 0t^M3+nc  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 1t:Q_j0Ym  
    If dlg.TextBox1 = "" Then :#LLo}LKp  
        A = 0           'Default accommodation ;+W#5<i  
    Else ^!<U_;+  
        A = CDbl(dlg.TextBox1) F|d\k Q
 
    End If fV &KM*W*@  
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    If dlg.TextBox2 = "" Then ZOft.P O  
        pupilDiam = 4   'Default pupil diameter TC@s  
    Else #^`4DhQ/ 1  
        pupilDiam = CDbl(dlg.TextBox2) X^T:8npxt  
    End If W^0w  
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    Print " " 4iqoR$3Fc  
    Print "Accommodation = " & A & " Diopters" UR%/MV  
    Print "Pupil Diameter = " & pupilDiam & " mm" Lrta/SU*  
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    ' Calculate new parameters with accommodation I3=%h  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Z,RzN5eN  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens &qMPq->  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens k&&2Tq
  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens dq7x3v^"ZG  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens = 6tHsN23  
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    tlens = 3.767 + 0.04*A                  'Lens thickness fdxLAC  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction TMAJb+@l:  
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    'Adjust parameters to account for accommodation ?5U2D%t  
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    '************************************************************************* |M>eEE*F<  
    'Aqueous thickness (Position of Lens)  :l~ I  
    '************************************************************************* Vx(B{5>Vu  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) BHd&yIyI  
    GetCustomElement eID, entity V_>\9m  
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    parID = FindFullName( "Geometry.Arizona Eye" ) /d0K7F  
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    ' Delete any shift(s) in z QZ4v/
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    count = 0 $iI]MV%
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    While GetOperationCount(eID)>count DamCF  
        GetOperation eID, count, op cnSJ{T  
        If op.Type="ShiftZ" Then &yGaCq;0  
            DeleteOperation eID,count @'YS1N<  
            count=count-1 3Th'paMG  
        End If 0FGe=$vD  
        count=count+1 cYFiJJLG]  
    Wend |w_7_J2
 
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    'Set new shift in `%CtWJ(e  
    op.Type = "ShiftZ" anI
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    op.val1 = taq h lkn%  
    op.parent = parID SPN5dE.@  
    AddOperation eID, op I3 .x9  
    Print "Set aqueous humor thickness = " & taq-0.55 {88)~  
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    '*************************************************************************
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    'Radius and conic constant of anterior lens xB_!>SqF1U  
    '************************************************************************* #~SP)Ukp  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) cU0s p  
    GetConic eID, entity, curv, conic ]GN7+8l  
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    SetConic eID, entity, 1/Rant, CCant |o,8V p  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ul
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    '************************************************************************* jZh';M8"  
    'Radius and conic constant of posterior lens hfnN@Kg?B}  
    '************************************************************************* >2~+.WePu  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ktj]:rCkF  
    GetConic eID, entity, curv, conic K)qF+Vb^j  
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    SetConic eID, entity, 1/Rpost, CCpost mocI&=EF2X  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost HFwN  
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    '************************************************************************* ,Vh.T&X5  
    'Lens thickness (Position of posterior lens surface) p[<Dk$7K  
    '************************************************************************* Vy*:ne  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) YhOlxON
 
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    ' Delete any z-shift(s) T%6&PrQ7  
    count = 0 Eq$&qV-?(  
    While GetOperationCount(eID)>count Y^ kXSU  
        GetOperation eID, count, op 1QmH{jM  
        If op.Type="ShiftZ" Then .q[SI$qO/  
            DeleteOperation eID,count ?*?RP)V  
            count=count-1 OR}c)|1  
        End If X5X?&* %{  
        count=count+1 [%9noB  
    Wend qHNE8\9  
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    'Set new z-shift DA2}{  
    op.Type = "ShiftZ" kGd<5vCs  
    op.val1 = tlens ;QW3CEaUq  
    op.parent = parID Pcu#lWC$  
    AddOperation eID, op ,WJH}(h"D  
    Print "Set lens thickness = " & tlens {"&SJ
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    '************************************************************************* d?:=PH  
    'Lens index of refraction <Q?a=4  
    '************************************************************************* |1ST=O7.LH  
    eID = FindMaterial( "Lens" ) u0#}9UKQ  
    GetModelMaterial eID, mat DyQM>xw)t  
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    mat.Nd = nlens V5GW:QT  
    SetModelMaterial eID, mat lu#LCG-.  
    Print "Set lens index of refraction = " & nlens rAs,X  
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    '************************************************************************* jCrpL~tWT  
    'Pupil diameter :=8t"rO=W  
    '************************************************************************* # eCj
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) `5~ +,/Ys  
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    'Adjust pupil diameter (trimming volume inner hole) +,yK;^b  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" -0_d/'d  
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    ' Adjust pupil location to just in front of the lens .[Ap=UYI>  
    parID = FindFullName( "Geometry.Arizona Eye" ) cuK,X!O  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) hUD7_arKF  
    count = 0 <)\y#N  
    While GetOperationCount(eID)>count ~}!3G  
        GetOperation eID, count, op = <j"M85.  
        If op.Type="ShiftZ" Then Iw<jT|y)  
            DeleteOperation eID,count m$9w"8R  
            count=count-1 M@3"<[g  
        End If ;L|uIg;.s  
        count=count+1 *loOiM\5a  
    Wend /s-A?lw^2  
    op.Type = "ShiftZ" UG'bOF4  
    op.val1 = taq-0.01 ?-tVSRKQ  
    op.parent = parID $2<d<Um~z  
    AddOperation eID, op d/}SAvtt  
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    Print "Set pupil diameter = " & pupilDiam oW^*l#v  
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    'Update AZ Eye subassembly Description k"g._|G  
    eID = FindFullName( "Geometry.Arizona Eye" ) gr-fXZO  
    GetEntity eID, entity u
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    entity.Description = "Accommodation = " & A & "D" PlYm&  
    SetEntity eID, entity kNT}dv]<  
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    Update 4CQ"8k(S"  
    Print "DONE!" %+ FG,d  
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End Sub `xiCm':  
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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： q~L^au8  
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Accommodation = 4 Diopters ^FZ^6*
 
Pupil Diameter = 4 mm @\w,otT  
Set aqueous humor thickness = 2.81 l%Gw_0.?e  
Set anterior lens radius = 10.4 and conic constant = -2.375869 +3i7D  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 N$TL;T>  
Set lens thickness = 3.927 u*7Z~R  
Set lens index of refraction = 1.42672 w[_x(Ojq;  
Set pupil diameter = 4 CC;! <km  
DONE! ]O{u tm