[技术]Arizona眼睛模型 [复制链接]

简介 6<$.Z-,  
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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。 q4&! mDU  
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模型 ES AX}uF  
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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。 5RFro^S9E  
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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. U|V,&RlbR  
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光源 Mms|jFoQ  
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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。 jwa6`u  
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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。 \<*F#3U1  
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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。 n]`]gLF\i  
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视网膜的散射 "aF2: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。 dGm%If9P  
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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`":Q1n  
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脚本 1F,U^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： :_6o|9J\t  
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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。 9 da=q  
余下的脚本计算与屈光度有关的所有参数。 QUn!&55  
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分析 pNOE KiJ  
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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。 jH9PD8D\  
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脚本代码 +bLP+]7oZ  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. "h_f-vP  
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Dim entity As T_ENTITY eLPtdP5k  
Dim op As T_OPERATION ygnZ9ikh<-  
Dim mat As T_MODELMATERIAL ejZ-A?f-K  
Dim A As Double dY&v(~&;]  
Dim pupilDiam As Double ,.p 36ZLP  
Dim eID As Long 5X)QW5A  
Dim parID As Long l+F29_o#  
Dim count As Integer -%M
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double M?sax+'  
Dim tlens As Double, nlens As Double x)dLY.'|  
Dim curv As Double, conic As Double 8QJr!#u  
Dim ok As Long _lkVT']  
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Sub Main &?bsBqpN  
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    '用户输入对话框 #~-Xt!I  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 *W\3cS  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ,4xNW:!j  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 i*N2@Z[  
        OKButton 40,91,90,21 'uL$j
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        CancelButton 190,91,90,21 @
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 |e@1@q(a[]  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ,dQ*0XO!  
    End Dialog }C_g;7*  
    Dim dlg As UserDialog a%m )8N;C  
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    ok = Dialog (dlg) '6qH@r4Z<  
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    If ok=0 Then    'cancel button was pressed qzxWv5UH  
        Print "Execution cancelled." J[6/dM  
        End 
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    End If p1niS:}j  
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    'Assign accommodation and pupil diameter & use defaults if field left empty @JhkUGG]p  
    If dlg.TextBox1 = "" Then YX,;z/Jw2  
        A = 0           'Default accommodation Z72%Bv  
    Else qpe9?`vVX  
        A = CDbl(dlg.TextBox1) Uz_ob9l<#H  
    End If y
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    If dlg.TextBox2 = "" Then A}9^,C$#  
        pupilDiam = 4   'Default pupil diameter {ObY1Y`ea  
    Else [rcM32  
        pupilDiam = CDbl(dlg.TextBox2) !O!:=wq  
    End If s-Gd{=%/q  
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    Print " " 2(GYk
 
    Print "Accommodation = " & A & " Diopters" `Z>=5:+G@2  
    Print "Pupil Diameter = " & pupilDiam & " mm" 4uO88[=  
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    ' Calculate new parameters with accommodation B^TgEr  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 0AWxU?$A4  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens IxWi>8  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens tE-bHu370  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ?H_@/?  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens /!Ag/SmS!9  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 09vVCM;DY  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 6bj77CoB  
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    'Adjust parameters to account for accommodation (kX:@9Pn  
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    '************************************************************************* cy6YajOk7  
    'Aqueous thickness (Position of Lens) 
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    '************************************************************************* l=P)$O|=w  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3%9XJ]Qao  
    GetCustomElement eID, entity F#9^RA)9  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Xl<*Fn?  
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    ' Delete any shift(s) in z )Dhx6xM[a  
    count = 0 Qo3Enwap=  
    While GetOperationCount(eID)>count t 4M-;y  
        GetOperation eID, count, op
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        If op.Type="ShiftZ" Then <6.`(isph  
            DeleteOperation eID,count n|H
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            count=count-1 /: -&b#+  
        End If HI:
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        count=count+1 //r)dN^  
    Wend \ 6taC  
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    'Set new shift in 6j1C=O@S  
    op.Type = "ShiftZ" -0`
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    op.val1 = taq \goiW;b  
    op.parent = parID ]!"7k_  
    AddOperation eID, op "-:g.x*d  
    Print "Set aqueous humor thickness = " & taq-0.55 QaE!?R  
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    '************************************************************************* WyB^b-QmDh  
    'Radius and conic constant of anterior lens @6!Myez'  
    '************************************************************************* <i
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) op-\|<i  
    GetConic eID, entity, curv, conic ql5&&e=-  
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    SetConic eID, entity, 1/Rant, CCant hD
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 'bH~KK5  
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    '************************************************************************* _ A{F2M  
    'Radius and conic constant of posterior lens A^hafBa  
    '************************************************************************* )iC@n8f7o  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) k=p[Mlic/  
    GetConic eID, entity, curv, conic b ~]v'|5[  

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    SetConic eID, entity, 1/Rpost, CCpost D8*6h)~  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost u^'X>n)oL#  
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    '************************************************************************* aS>cXJ;=  
    'Lens thickness (Position of posterior lens surface) >bmdu\j5R  
    '************************************************************************* i;qij[W.z  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4kV$JV.l  
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    ' Delete any z-shift(s) kbH@h2Ww  
    count = 0 N3
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    While GetOperationCount(eID)>count G|t0no\f  
        GetOperation eID, count, op ;5T}@4m|r  
        If op.Type="ShiftZ" Then nu|,
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            DeleteOperation eID,count .*+jD^Gr  
            count=count-1 N<KsQsy=  
        End If NTCFmdbs 6  
        count=count+1 `d/* sX?k  
    Wend !"E/6z2&(k  
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    'Set new z-shift eQ[}ALIq  
    op.Type = "ShiftZ" ;/ |tU o$  
    op.val1 = tlens OYmutq  
    op.parent = parID sUiO~<Ozpk  
    AddOperation eID, op {7$jwk  
    Print "Set lens thickness = " & tlens g{>0Pa1?C  
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    '************************************************************************* ,5T1QWn^f  
    'Lens index of refraction .>}Z3jUrf  
    '************************************************************************* y GmFi  
    eID = FindMaterial( "Lens" ) m' |wlI[lq  
    GetModelMaterial eID, mat `q |
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    mat.Nd = nlens MlS5/9m@^  
    SetModelMaterial eID, mat N<Ym&
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    Print "Set lens index of refraction = " & nlens W|sU[dxZ  
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    '************************************************************************* "HH<5
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    'Pupil diameter t-}IKrbv  
    '************************************************************************* ?Ycl!0m  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) oxI?7dy5  
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    'Adjust pupil diameter (trimming volume inner hole) (KPD`l8.  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" JIYzk]Tj  
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    ' Adjust pupil location to just in front of the lens mxpw4  
    parID = FindFullName( "Geometry.Arizona Eye" ) 7@k3-?q  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) !4Sd^"  
    count = 0 H,7!"!?@N  
    While GetOperationCount(eID)>count s bR*[2  
        GetOperation eID, count, op  #3RElI  
        If op.Type="ShiftZ" Then udc9KuR@  
            DeleteOperation eID,count )7#3n(_np  
            count=count-1 '0o^T 7C  
        End If cT&lkS  
        count=count+1 }1CvbB%,A  
    Wend 0xvSi9  
    op.Type = "ShiftZ" xwHE,ykE  
    op.val1 = taq-0.01 @~5Fcfmm  
    op.parent = parID $S2 /*  
    AddOperation eID, op #i*PwgC%_  
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    Print "Set pupil diameter = " & pupilDiam -Edi"B4K  
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    'Update AZ Eye subassembly Description -r~9'aEs  
    eID = FindFullName( "Geometry.Arizona Eye" ) <F-IF7>a  
    GetEntity eID, entity qwn EVjf  
    entity.Description = "Accommodation = " & A & "D" [a~@6*=  
    SetEntity eID, entity 4N3O<)C)@  
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    Update &t!f dti  
    Print "DONE!" RjrQDh|((  
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End Sub @$%.iQ7A;  
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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： vD/l`Ib:  
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Accommodation = 4 Diopters fwUF5Y  
Pupil Diameter = 4 mm ^R(=4%8%"  
Set aqueous humor thickness = 2.81 z?UEn#E2
 
Set anterior lens radius = 10.4 and conic constant = -2.375869 _c:th{*  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ;/IXw>O(/  
Set lens thickness = 3.927 G<`(d@g  
Set lens index of refraction = 1.42672 X_Pbbx_j  
Set pupil diameter = 4 IEkbVIA(  
DONE! G$CSZrP.