[技术]Arizona眼睛模型 [复制链接]

简介 Vjp1RWb  
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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。 p&bROuw<T  
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模型 C|).;V&  
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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。 PHXZ=A+  
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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+Kg0:  
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光源 3z)Kz*xr  
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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。 $.PuK~}  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 o-{[|/)Tk  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 7;sj%U^'l  
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视网膜的散射 9S7kUl{  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 jN>{'TqW4  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 z4+k7a@jn  
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脚本 =aj/,Q]  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： W?aI|U1  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 J'fQW<T4wU  
余下的脚本计算与屈光度有关的所有参数。 `'c_=<&n  
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分析 'fF;(?  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ]*FVz$>XM  
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脚本代码 7L@K _ZJ  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Tekfw  
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Dim entity As T_ENTITY H nUYqhZS  
Dim op As T_OPERATION ?)[EO(D  
Dim mat As T_MODELMATERIAL C;`XlQG `  
Dim A As Double w{uuSe  
Dim pupilDiam As Double a,+@|TJ,i  
Dim eID As Long %Gj8F4{  
Dim parID As Long c`WHNky%j  
Dim count As Integer 1~ t{aLPz  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double
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Dim tlens As Double, nlens As Double ;M#_6Hd?qD  
Dim curv As Double, conic As Double @@rEs40  
Dim ok As Long pT1[<X!<s  
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Sub Main vab@-=%k  
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    '用户输入对话框 *U$!I?  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 *gF<m9&  
        TextBox 220,21,40,21,.TextBox1 'default: 0 E)7F\w  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 'd
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        OKButton 40,91,90,21 4e;yG>  
        CancelButton 190,91,90,21 @qjfZH@  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 eKz?"g/j  
        TextBox 220,49,40,21,.TextBox2 'default: 4 HXYRH  
    End Dialog ^Q ps>A(  
    Dim dlg As UserDialog ,4,V4 N  
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    ok = Dialog (dlg) *^wB
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    If ok=0 Then    'cancel button was pressed !\#_Jw%y  
        Print "Execution cancelled." )0e2ic/  
        End _s$_Sa ;  
    End If P<2+L|X?}  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 6uKMCQ=h  
    If dlg.TextBox1 = "" Then -0eq_+oQ  
        A = 0           'Default accommodation npyAJp  
    Else A@D2
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        A = CDbl(dlg.TextBox1) [NIlbjYH  
    End If f%)zg(YlO  
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    If dlg.TextBox2 = "" Then RQB]/D\BO  
        pupilDiam = 4   'Default pupil diameter )VK }m9Ae  
    Else l?DJJ|>O  
        pupilDiam = CDbl(dlg.TextBox2) 7Irau_  
    End If k@D0 {z  
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    Print " " JwRF(1_sM  
    Print "Accommodation = " & A & " Diopters" ?D)<,  
    Print "Pupil Diameter = " & pupilDiam & " mm" :@xm-.D  
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    ' Calculate new parameters with accommodation pdb1GDl0q  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness -l-E_6|/W  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens r-IVb&uFb  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens "ZHtR/;  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens !.<T"8BUpv  
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    tlens = 3.767 + 0.04*A                  'Lens thickness \^K&vW;  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Ei3zBS?J)  
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    'Adjust parameters to account for accommodation Grz 3{U  
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    '************************************************************************* F;!2(sPS  
    'Aqueous thickness (Position of Lens) LsGiu9~S  
    '************************************************************************* o1OBwPj  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) .LRxP#B  
    GetCustomElement eID, entity -g/hAxb5  
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    parID = FindFullName( "Geometry.Arizona Eye" ) x/
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    ' Delete any shift(s) in z PS" .R
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    count = 0 QIn/,Yd  
    While GetOperationCount(eID)>count ?Jusl8Sm  
        GetOperation eID, count, op Ti;Ijcq8  
        If op.Type="ShiftZ" Then Lx U={Y0  
            DeleteOperation eID,count _0 snAt^iC  
            count=count-1 hc$@J}`  
        End If aSYs_?&.  
        count=count+1 ]Lqt(c  
    Wend rn:!dV[  
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    'Set new shift in i~{ _eQV  
    op.Type = "ShiftZ" 5lJ)(|_  
    op.val1 = taq W;Jx<-#1  
    op.parent = parID L1)@z8]
 
    AddOperation eID, op 8Chu"PM%-J  
    Print "Set aqueous humor thickness = " & taq-0.55 V5GkP1L  
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    '************************************************************************* dYojm1MQ  
    'Radius and conic constant of anterior lens \H5Jk$*  
    '************************************************************************* N<_Ko+VF  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 2#/p|$;Ec'  
    GetConic eID, entity, curv, conic <<|H=![  
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    SetConic eID, entity, 1/Rant, CCant w.+Eyu_I\  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant lZt(
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    '************************************************************************* ;ggy5?>Qu  
    'Radius and conic constant of posterior lens v
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    '************************************************************************* bYh9sO/l  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) g.#+z'l  
    GetConic eID, entity, curv, conic |AH@ EI>  
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    SetConic eID, entity, 1/Rpost, CCpost _NdLcpBT?  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost JK~ m(oQ  
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    '************************************************************************* bn 4 &O  
    'Lens thickness (Position of posterior lens surface) 4W\,y_Qo  
    '************************************************************************* 8!h'j  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^,2c-  
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    ' Delete any z-shift(s) 0%)5.=6  
    count = 0 ]s|lxqP  
    While GetOperationCount(eID)>count CYB=Uq,  
        GetOperation eID, count, op `:
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        If op.Type="ShiftZ" Then H]qq ~bO[  
            DeleteOperation eID,count %f[Ep 3D  
            count=count-1 ?:|YGLaB  
        End If R~B0+:6  
        count=count+1 I Ru$oF}  
    Wend bGh0<r7
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    'Set new z-shift 1BD6l2y  
    op.Type = "ShiftZ" ^w6eWzI  
    op.val1 = tlens ,p,Du F  
    op.parent = parID A"/aGCG0z  
    AddOperation eID, op WhUa^  
    Print "Set lens thickness = " & tlens X
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    '************************************************************************* D$_8rHc\A  
    'Lens index of refraction q?VVYZXP  
    '************************************************************************* .wFU:y4r  
    eID = FindMaterial( "Lens" ) ?2~U2Ir]:  
    GetModelMaterial eID, mat oa9)Dv  
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    mat.Nd = nlens $ WFhBak8  
    SetModelMaterial eID, mat 
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    Print "Set lens index of refraction = " & nlens tmxPOe  
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    '************************************************************************* Nz]aaoO4  
    'Pupil diameter ti;%BS  
    '************************************************************************* S_!R^^ySG9  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) *Pb.f  
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    'Adjust pupil diameter (trimming volume inner hole)
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" mahi7eU P  
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    ' Adjust pupil location to just in front of the lens !\w\ ]7ls  
    parID = FindFullName( "Geometry.Arizona Eye" ) #6FaIq92V  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) z`9l<Q/  
    count = 0 :Ba-u  
    While GetOperationCount(eID)>count c
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        GetOperation eID, count, op  ,(hY%M&\  
        If op.Type="ShiftZ" Then u-/3(dKt  
            DeleteOperation eID,count er\:U0fr#@  
            count=count-1 `
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        End If `1p?*9Ssn  
        count=count+1 }@4|7  
    Wend vj@V !j?  
    op.Type = "ShiftZ" >\-3P$  
    op.val1 = taq-0.01 y%g`FC   
    op.parent = parID ,yi2O]5e>!  
    AddOperation eID, op 9t\ [N/  
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    Print "Set pupil diameter = " & pupilDiam o;'4c  
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    'Update AZ Eye subassembly Description j)<[j&OWw  
    eID = FindFullName( "Geometry.Arizona Eye" ) ]J~g'">  
    GetEntity eID, entity 7#/|VQX<A  
    entity.Description = "Accommodation = " & A & "D" [b pwg&Oo  
    SetEntity eID, entity W)  
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    Update Bzm.X=U:  
    Print "DONE!" k%a?SU<f  
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End Sub {
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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： Uc>LFX& -B  
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Accommodation = 4 Diopters 4]M =q{  
Pupil Diameter = 4 mm vD"_X"v  
Set aqueous humor thickness = 2.81 A9.;>8!u  
Set anterior lens radius = 10.4 and conic constant = -2.375869 +"G(  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 BfEx'C  
Set lens thickness = 3.927 i&B?4J)  
Set lens index of refraction = 1.42672 .k|-Ks|d|  
Set pupil diameter = 4 A<1l^%i  
DONE! >fhSaeN