[技术]Arizona眼睛模型 [复制链接]

简介 c
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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。 ;l?(VqX_E  
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模型 \)uad5`N  
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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。 0U*"OSpF  
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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. IEf^.Z
 
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光源 G.e\#_RR?  
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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。 Z[bC@y[Wb  
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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。 k ,(:[3J  
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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。 ADz|Y~V!  
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视网膜的散射 }TL"v|ny6;  
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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。 dS=,. }  
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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。 dD<kNa}2  
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脚本 59 Y=VS
 
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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： b;l%1x9r  
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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。 0eP~F2<bC  
余下的脚本计算与屈光度有关的所有参数。 R"([Y#>m  
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分析 v4aGL<SO  
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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。 ,-kZ5&r  
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脚本代码 E5Jk+6EcMa  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. )wd~639U  
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Dim entity As T_ENTITY <~w#sIh  
Dim op As T_OPERATION =x>k:l~s  
Dim mat As T_MODELMATERIAL 0in6z  
Dim A As Double WpZ^R;eK  
Dim pupilDiam As Double (p!AX
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Dim eID As Long 7Y:s6R|  
Dim parID As Long Rby7X*.-v  
Dim count As Integer ]S ,GHPEN  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ?]N&H90^5  
Dim tlens As Double, nlens As Double FG\?_G  
Dim curv As Double, conic As Double C:{'0m*jKs  
Dim ok As Long ,#loVLy  
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Sub Main [4yQ-L)]e  
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    '用户输入对话框 (eP)>G]  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Nl _Jp:8s  
        TextBox 220,21,40,21,.TextBox1 'default: 0 e>.xXg6Zn  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ta(x
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        OKButton 40,91,90,21 + aFjtb  
        CancelButton 190,91,90,21 ps{(UYM=b  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 r_m&Jl@4  
        TextBox 220,49,40,21,.TextBox2 'default: 4 3RUB2c4  
    End Dialog z16++LKmM  
    Dim dlg As UserDialog [-ecKPx  
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    ok = Dialog (dlg) FC#Qtu~J  
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    If ok=0 Then    'cancel button was pressed j;.&+.  
        Print "Execution cancelled." oP6G2@3P/  
        End f9$q.a*  
    End If ):@B1 yR  
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    'Assign accommodation and pupil diameter & use defaults if field left empty qxx.f58H  
    If dlg.TextBox1 = "" Then RP9||PFS~~  
        A = 0           'Default accommodation 8J0tya"z  
    Else =[&Jxy>Y  
        A = CDbl(dlg.TextBox1) p\K5B,  
    End If i747( ^  
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    If dlg.TextBox2 = "" Then p pq#5t^[)  
        pupilDiam = 4   'Default pupil diameter u[DV{o  
    Else -E1}mL}I`  
        pupilDiam = CDbl(dlg.TextBox2) &AVi4zV  
    End If B|&<  
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    Print " " ITV}f#  
    Print "Accommodation = " & A & " Diopters" q'q{M-U<  
    Print "Pupil Diameter = " & pupilDiam & " mm" Fwr,e;Z  
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    ' Calculate new parameters with accommodation W=*\4B]  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness X)~-MY*p  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens j
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens xjYFTb}!  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens EA\~m*k  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens w'!gLta  
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    tlens = 3.767 + 0.04*A                  'Lens thickness yT4|eHl  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction &}r932  
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    'Adjust parameters to account for accommodation lQzrf"N'  
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    '************************************************************************* =Z
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    'Aqueous thickness (Position of Lens) n!p&.Mt  
    '************************************************************************* s5.2gu|"%  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) T1E=<q4  
    GetCustomElement eID, entity Z&%61jGK  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 5>HI/QG  
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    ' Delete any shift(s) in z 8Y9mB#X  
    count = 0 TsQMwV_h  
    While GetOperationCount(eID)>count G4i&:0  
        GetOperation eID, count, op M@8(h=  
        If op.Type="ShiftZ" Then }7V/(K  
            DeleteOperation eID,count Buo1o&&  
            count=count-1 {9)f~EbM!  
        End If xiI!_0'  
        count=count+1 jHd~yCq  
    Wend G`pI{_-e  
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    'Set new shift in w*+rBp,f  
    op.Type = "ShiftZ" {XVSHUtw  
    op.val1 = taq Ul=`]@]]  
    op.parent = parID Y4_i=}\*vf  
    AddOperation eID, op g%Z;rDfi  
    Print "Set aqueous humor thickness = " & taq-0.55 &"BKue~q@p  
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    '************************************************************************* it.l;L_nW  
    'Radius and conic constant of anterior lens V{n
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    '************************************************************************* dG| iA]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) G/y< bPQ  
    GetConic eID, entity, curv, conic &(K*TB|Om  
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    SetConic eID, entity, 1/Rant, CCant 7(jt:V6V  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant cIgF]My*D@  
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    '************************************************************************* .JzO f[g5  
    'Radius and conic constant of posterior lens .(sT?M`\J  
    '************************************************************************* lY~xoHT;[  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) \
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    GetConic eID, entity, curv, conic HJ2]xe09  
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    SetConic eID, entity, 1/Rpost, CCpost h\1_$ac  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost QKVZ![Y!s  
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    '************************************************************************* gAE}3//  
    'Lens thickness (Position of posterior lens surface) htaB!Q?V  
    '************************************************************************* Q>.-u6(&  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) NE(6`Wq`  
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    ' Delete any z-shift(s) x>t:&Y M  
    count = 0 _+UD>u{  
    While GetOperationCount(eID)>count 
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        GetOperation eID, count, op 'Ct+0X:D  
        If op.Type="ShiftZ" Then Tj>~#~  
            DeleteOperation eID,count pdE=9l'  
            count=count-1 ?-(E$ll  
        End If >iq^Ts  
        count=count+1 hX;xbl  
    Wend 4b4nFRnH  
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    'Set new z-shift #Z
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    op.Type = "ShiftZ" d/;oNC+  
    op.val1 = tlens zRB1V99k  
    op.parent = parID Gs-'  
    AddOperation eID, op s,0,w--=  
    Print "Set lens thickness = " & tlens w7O(I"  
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    '************************************************************************* =6? 3
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    'Lens index of refraction 5:O"T  
    '************************************************************************* ]e+S~me  
    eID = FindMaterial( "Lens" ) {4#'`Eejj  
    GetModelMaterial eID, mat 4).q+{#k  
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    mat.Nd = nlens h8nJ$jg  
    SetModelMaterial eID, mat KSLyU1W  
    Print "Set lens index of refraction = " & nlens C7PHZ`<  
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    '************************************************************************* NC0x!tJ#7  
    'Pupil diameter C,K
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    '************************************************************************* 3C.bzw^  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) nE,"3X"  
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    'Adjust pupil diameter (trimming volume inner hole) Vk[m$  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" C#(4>'  
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    ' Adjust pupil location to just in front of the lens c>I^SY(r%  
    parID = FindFullName( "Geometry.Arizona Eye" ) 3pm;?6i6  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) BjJ+~R  
    count = 0 rlW
  
    While GetOperationCount(eID)>count !30BZM^  
        GetOperation eID, count, op xez~Yw2  
        If op.Type="ShiftZ" Then J8(v65  
            DeleteOperation eID,count {ImZ><xe/  
            count=count-1 ~g)gXPjke  
        End If Ao 1*a%-.  
        count=count+1 7+@:wX\  
    Wend RBiDU}j  
    op.Type = "ShiftZ" 3%'$AM}+s  
    op.val1 = taq-0.01 }F**!%4d  
    op.parent = parID s4t>/.;x  
    AddOperation eID, op Vhv<w O Ct  
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    Print "Set pupil diameter = " & pupilDiam 2,'m]`;GNr  
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    'Update AZ Eye subassembly Description }7k+tJ<   
    eID = FindFullName( "Geometry.Arizona Eye" ) I%;xMtY1o  
    GetEntity eID, entity b=.Ikt+y  
    entity.Description = "Accommodation = " & A & "D" u9QvcD^'z  
    SetEntity eID, entity b?qtTce  
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    Update ABB4(_3E  
    Print "DONE!" :Q"]W!kCs  
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End Sub $ ^m_M.1  
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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： U!TFFkX[  
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Accommodation = 4 Diopters &p`RKD  
Pupil Diameter = 4 mm }n oI2.-#  
Set aqueous humor thickness = 2.81 ~M2w&g;1  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ;)~loa1\  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 %jim] ]<S[  
Set lens thickness = 3.927 RT4ns+J1  
Set lens index of refraction = 1.42672 f_7a) 'V4  
Set pupil diameter = 4 *EvnN:  
DONE! 5L%A5C&|