[技术]Arizona眼睛模型 [复制链接]

简介 E ?2O(  
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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。 c"YXxAJ  
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模型 &Y|Xd4:  
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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[xkSF^)  
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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. 6@;ha=[+  
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光源 jX=lAs~6  
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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。 l'4AF| p
 
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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。 vvu<:16  
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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。  GrJ#.  
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视网膜的散射 l?N`{,1^  
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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。 f*((;*n;  
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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。 JV"NZvjN7d  
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脚本 _"f :`  
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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： y%BX]~  
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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。 #Fd W/y5  
余下的脚本计算与屈光度有关的所有参数。 ^tAO_~4  
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分析 60B-ay0e$b  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 97~K!'/^+y  
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脚本代码 T{MC-j _T9  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ksI>IW  
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Dim entity As T_ENTITY I lG:X)V%  
Dim op As T_OPERATION crmUrF#  
Dim mat As T_MODELMATERIAL aO1IVESr$  
Dim A As Double BA+_C]%ZJ  
Dim pupilDiam As Double ," R>}kPli  
Dim eID As Long Lyoor1   
Dim parID As Long ?C;JJ#Ho  
Dim count As Integer rg&+  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double B4W\ t{  
Dim tlens As Double, nlens As Double (Pi-uL<[a  
Dim curv As Double, conic As Double av'*u  
Dim ok As Long UmP'L!  
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Sub Main #s"B-sWE  
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    '用户输入对话框 T0|H9>M  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 uEd,rEB>  
        TextBox 220,21,40,21,.TextBox1 'default: 0 xPQL?.  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 zXre~b03ZS  
        OKButton 40,91,90,21 s44iEh=V(I  
        CancelButton 190,91,90,21 9N Le&o  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 qi=3L  
        TextBox 220,49,40,21,.TextBox2 'default: 4 <MZi<Z`  
    End Dialog HHS45kg[c  
    Dim dlg As UserDialog 'DAltr<  
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    ok = Dialog (dlg) 31XU7
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    If ok=0 Then    'cancel button was pressed LM1b
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        Print "Execution cancelled." j[DIz@^  
        End Nlt4)  
    End If FMS2.E  
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    'Assign accommodation and pupil diameter & use defaults if field left empty p.Y$A if.  
    If dlg.TextBox1 = "" Then z\}!RBOq  
        A = 0           'Default accommodation @d)a~[pm  
    Else 5-'vB  
        A = CDbl(dlg.TextBox1) Y><(?  
    End If @hT;Bo2G]  
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    If dlg.TextBox2 = "" Then `pYE[y+  
        pupilDiam = 4   'Default pupil diameter FmA-OqEpA  
    Else lG]GlgSs  
        pupilDiam = CDbl(dlg.TextBox2) 7Po/_%  
    End If 
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    Print " " faVS2TN4  
    Print "Accommodation = " & A & " Diopters" V_]-`?S  
    Print "Pupil Diameter = " & pupilDiam & " mm" {HuLuP0t  
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    ' Calculate new parameters with accommodation Ihef$,  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness E& ]_U$  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens -A@U0=o  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens I"V3+2e  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens w4}(Ab<Y  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens R6Pz#`n  
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    tlens = 3.767 + 0.04*A                  'Lens thickness V'yxqI?  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction qS82/e)7  
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    'Adjust parameters to account for accommodation 4`0;^K.  
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    '************************************************************************* &|] Fg5  
    'Aqueous thickness (Position of Lens) },3R%?89%  
    '************************************************************************* ]Hj`2\KD.d  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) fW[.r==Kf  
    GetCustomElement eID, entity YD+QX@  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ~p!QSRu~,b  
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    ' Delete any shift(s) in z 9;:7e*x]lc  
    count = 0 RA~_
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    While GetOperationCount(eID)>count c=<v.J@K  
        GetOperation eID, count, op Q,TaJ]  
        If op.Type="ShiftZ" Then &`5 :GLV  
            DeleteOperation eID,count ~pwY6Q  
            count=count-1 D2-O7e  
        End If T/3;NXe6E  
        count=count+1 8Nv-/VQ/b  
    Wend t9n'!  
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    'Set new shift in .Px,=56$X  
    op.Type = "ShiftZ" otZ JY)  
    op.val1 = taq ri;r7Y9V9`  
    op.parent = parID 1 pYsjo~  
    AddOperation eID, op PE +qYCpP9  
    Print "Set aqueous humor thickness = " & taq-0.55 a\|X^%2g  
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    '************************************************************************* zkvH=wL  
    'Radius and conic constant of anterior lens JG1
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    '************************************************************************* Is~yVB02  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) fjG/dhr  
    GetConic eID, entity, curv, conic lHRK'?Q  
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    SetConic eID, entity, 1/Rant, CCant 7{8)ykBU^  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 5"]aZMua  
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    '************************************************************************* lK 9s0t'  
    'Radius and conic constant of posterior lens ec,z6v^9  
    '************************************************************************* HKT{IP+7(L  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ZW`HDrP`  
    GetConic eID, entity, curv, conic 96k(XLR  
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    SetConic eID, entity, 1/Rpost, CCpost +2f> M4q  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost +# A|Zp<  
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    '************************************************************************* ],WwqD=  
    'Lens thickness (Position of posterior lens surface) il<gjlyR]L  
    '************************************************************************* d u_O}x  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) N>h]mX6  
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    ' Delete any z-shift(s) p` ^:Q*C"  
    count = 0 nT(!HD
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    While GetOperationCount(eID)>count jAsh   
        GetOperation eID, count, op 6!i( \Q*  
        If op.Type="ShiftZ" Then /<Gyg7o0  
            DeleteOperation eID,count K>`m_M"LA  
            count=count-1 s$eK66H  
        End If 4d,qXSKty  
        count=count+1 MX%|hIOpr  
    Wend zV9 =  
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    'Set new z-shift 1j_aH#Fz:  
    op.Type = "ShiftZ" %!1@aL]pQ  
    op.val1 = tlens 1KNkl,E  
    op.parent = parID @D(KuF  
    AddOperation eID, op C8O7i[uc  
    Print "Set lens thickness = " & tlens gogl[gHO  
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    '************************************************************************* gt(X!iN]  
    'Lens index of refraction ) >-D={
 
    '************************************************************************* %>oT7|x  
    eID = FindMaterial( "Lens" ) Vw6>:l<+<  
    GetModelMaterial eID, mat +^o3}`  
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    mat.Nd = nlens fwz5{>ON
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    SetModelMaterial eID, mat O#<|[Dzw  
    Print "Set lens index of refraction = " & nlens 96^1Ivd  
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    '************************************************************************* )4VLm  
    'Pupil diameter W,L>'$#pM  
    '************************************************************************* aH~x7N6!  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) W_Ws3L1;N  

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    'Adjust pupil diameter (trimming volume inner hole) }-k_?2"A  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ;+#za?w  
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    ' Adjust pupil location to just in front of the lens |R:v<  
    parID = FindFullName( "Geometry.Arizona Eye" ) xP|%rl4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]-+.lR%vd9  
    count = 0 o>QFdx  
    While GetOperationCount(eID)>count N23+1h  
        GetOperation eID, count, op >"m@qkh  
        If op.Type="ShiftZ" Then Oa3=+_C~$1  
            DeleteOperation eID,count 96([V|5K  
            count=count-1 9, sCJ5bb"  
        End If 3e!a>Gl*  
        count=count+1 HquB*=^xh  
    Wend e{#a{`?Uez  
    op.Type = "ShiftZ" O_%PBgcJr  
    op.val1 = taq-0.01 8{U]ATx'(  
    op.parent = parID u:qD*zOq  
    AddOperation eID, op -sGWSC  
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    Print "Set pupil diameter = " & pupilDiam eO[Cb]Dy:  
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    'Update AZ Eye subassembly Description C$Hl`>?$  
    eID = FindFullName( "Geometry.Arizona Eye" ) OL6xMToP  
    GetEntity eID, entity /^es0$Co.  
    entity.Description = "Accommodation = " & A & "D" '"G %0y  
    SetEntity eID, entity Z1MJ!{@6  
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    Update 8=zM~v)   
    Print "DONE!" `mHOgS>|  
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End Sub `!>dbR&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： j@_) F^12  
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Accommodation = 4 Diopters zi DlJ3]^  
Pupil Diameter = 4 mm o\:f9JL  
Set aqueous humor thickness = 2.81 spoWdRM2  
Set anterior lens radius = 10.4 and conic constant = -2.375869 9OO_Hp#|9  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 $'mB8 S  
Set lens thickness = 3.927 KE)D =P  
Set lens index of refraction = 1.42672 B$[%pm`'2  
Set pupil diameter = 4
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DONE! TF iM[