[技术]Arizona眼睛模型 [复制链接]

简介 v0EF?$Wo  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 . C_\xb  
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模型 Q"
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 @* a'B=7  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. =Kdd+g!  
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光源 tEEeek(!  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 |~Q`DdkX  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 C~\/FrO?  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 X ?p_O2#k  
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视网膜的散射 F$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。 nsChNwPX  
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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。 #@h3#IC  
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脚本 @D.]PZf  
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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： _;*|"e@^  
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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。 .;gK*`G2W)  
余下的脚本计算与屈光度有关的所有参数。 ^Pc>/lY$Q%  
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分析 $#V^CmW.  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 @ucN|r}=R  
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脚本代码 yK"OZ2Mv  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 2i);2>HLG  
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Dim entity As T_ENTITY QC:/xP  
Dim op As T_OPERATION B7Um G)C  
Dim mat As T_MODELMATERIAL  )]2yTG[  
Dim A As Double =2%EIZ0oW  
Dim pupilDiam As Double F\.n42Tz  
Dim eID As Long [,_M@g3  
Dim parID As Long gIA{6,A  
Dim count As Integer K`PmWxNPh  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Ov{f
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Dim tlens As Double, nlens As Double v2<roG6.V  
Dim curv As Double, conic As Double g%w@v$  
Dim ok As Long (]BZ8GOx  
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Sub Main \mZ\1wzn'{  
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    '用户输入对话框 ]y6`9p  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 M%7H-^{  
        TextBox 220,21,40,21,.TextBox1 'default: 0 \~xOdqF/  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ?v2OoNQ   
        OKButton 40,91,90,21 J.x>*3<l  
        CancelButton 190,91,90,21 t/cjz/]  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ?V_Qa0k  
        TextBox 220,49,40,21,.TextBox2 'default: 4 LX.1]T*m`  
    End Dialog /p') u3  
    Dim dlg As UserDialog &/lJ7=Nq  
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    ok = Dialog (dlg) '3uj6Wq2  
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    If ok=0 Then    'cancel button was pressed 8|[\Tp:;  
        Print "Execution cancelled." |dNtM^  
        End  l;>#O  
    End If Pf oAg*  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ' U(v  
    If dlg.TextBox1 = "" Then 5|1&s3/f  
        A = 0           'Default accommodation z)5n&w S  
    Else [Dq7mqr$  
        A = CDbl(dlg.TextBox1) #&">x7?5  
    End If A"Rzn1/  
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    If dlg.TextBox2 = "" Then ovCk:Vz  
        pupilDiam = 4   'Default pupil diameter a<Pi J?  
    Else sTqy-^e7  
        pupilDiam = CDbl(dlg.TextBox2) 1G|Q~%cv  
    End If W0$G7s  
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    Print " " K_nN|'R-  
    Print "Accommodation = " & A & " Diopters" !mL,Ue3/  
    Print "Pupil Diameter = " & pupilDiam & " mm" C5Q|3d  
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    ' Calculate new parameters with accommodation ~0?p @8  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness &RXd1>|c2  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 6f=/vRAh$  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 8BNsh[+  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens xpyb&A  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens %R;cXs4r  
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    tlens = 3.767 + 0.04*A                  'Lens thickness LF%1)x  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L5yxaF{]  
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    'Adjust parameters to account for accommodation 1:7>Em<s  
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    '************************************************************************* }p t
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    'Aqueous thickness (Position of Lens) '*>LZo4  
    '************************************************************************* &X+V}
 
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) =&"Vf!7YR7  
    GetCustomElement eID, entity ^yK94U;<Gy  
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    parID = FindFullName( "Geometry.Arizona Eye" ) W~k!qy `  
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    ' Delete any shift(s) in z <zZAVGb4I  
    count = 0 'n:Ft  
    While GetOperationCount(eID)>count j)-D.bY0  
        GetOperation eID, count, op @+1E|4L1vf  
        If op.Type="ShiftZ" Then 9b]U&A$  
            DeleteOperation eID,count no?)GQ  
            count=count-1 }C*o;'o5G  
        End If 0y;&L63>T  
        count=count+1 ? |8&!F  
    Wend `8FC&%X_  
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    'Set new shift in &K>]!yn   
    op.Type = "ShiftZ" 9^a>U
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    op.val1 = taq YfMe69/0I  
    op.parent = parID y^@%Xrs  
    AddOperation eID, op XOqpys
 
    Print "Set aqueous humor thickness = " & taq-0.55 LOnh
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    '************************************************************************* 6S6nE%.3  
    'Radius and conic constant of anterior lens >.{ ..~"K  
    '************************************************************************* {Y/|7Cl0  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Ka_UVKwMro  
    GetConic eID, entity, curv, conic _D,8`na>K  
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    SetConic eID, entity, 1/Rant, CCant $#RD3#=?u  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant do[K-r  
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    '************************************************************************* cJA:vHyw  
    'Radius and conic constant of posterior lens &V=54n=O?  
    '************************************************************************* J.<eX=<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) i[\[xfk  
    GetConic eID, entity, curv, conic xh-[]Jz(
 
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    SetConic eID, entity, 1/Rpost, CCpost _5`M( ;hL2  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost :W1,s53  
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    '************************************************************************* )
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    'Lens thickness (Position of posterior lens surface) V)@MM2,  
    '************************************************************************* (VOKa  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) WHNb.>  
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    ' Delete any z-shift(s) h[Iu_#HMa  
    count = 0 N!h>fE`  
    While GetOperationCount(eID)>count Ro<!n>
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        GetOperation eID, count, op PzV(e)~7  
        If op.Type="ShiftZ" Then }TF<C!]  
            DeleteOperation eID,count /vPb
 
            count=count-1 6~!YEuA  
        End If `S~u4+y]  
        count=count+1 5t<]|-i!  
    Wend i*^K)SI8  
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    'Set new z-shift i3%~G
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    op.Type = "ShiftZ" &U=f,9H  
    op.val1 = tlens +%<Jr<~W  
    op.parent = parID /7lkbL  
    AddOperation eID, op eXOFAd]>u  
    Print "Set lens thickness = " & tlens E{fnh50^Q.  
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    '************************************************************************* * QR7t:([  
    'Lens index of refraction e`~q;?:  
    '************************************************************************* Z~c7r n  
    eID = FindMaterial( "Lens" ) yBe/UFp+  
    GetModelMaterial eID, mat Z|/):nVP7  
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    mat.Nd = nlens E{6}'FG+A  
    SetModelMaterial eID, mat A;|DQR()  
    Print "Set lens index of refraction = " & nlens .lFSFJ??  
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    '************************************************************************* |M?HdxPa  
    'Pupil diameter !<LS4s;  
    '************************************************************************* qnS7z%H8  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ;VuB8cnL`  
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    'Adjust pupil diameter (trimming volume inner hole) *Qf}4a0  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"  vXvV5Oq  
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    ' Adjust pupil location to just in front of the lens < 5PeI  
    parID = FindFullName( "Geometry.Arizona Eye" ) Jzdc'3dq  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) p)jxqg
 
    count = 0 /iN\)y#u1  
    While GetOperationCount(eID)>count z K(5&u  
        GetOperation eID, count, op ?
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        If op.Type="ShiftZ" Then 3?XLHMxW  
            DeleteOperation eID,count bT8UmR98  
            count=count-1 I;v`o{  
        End If V[mQ;:=  
        count=count+1 :A'!u r=\  
    Wend 0?7uqS#L  
    op.Type = "ShiftZ" )2$_:Ek  
    op.val1 = taq-0.01 o{he)r6)_  
    op.parent = parID {_~G+rqY  
    AddOperation eID, op %:,=J  

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    Print "Set pupil diameter = " & pupilDiam _UBI,Dg]  
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    'Update AZ Eye subassembly Description J:u|8>;  
    eID = FindFullName( "Geometry.Arizona Eye" ) ) G{v>Z,  
    GetEntity eID, entity DPwSg\*)  
    entity.Description = "Accommodation = " & A & "D" f3N:MH-c  
    SetEntity eID, entity zEB1Br,  
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    Update :#/bA&  
    Print "DONE!" E5(Y*m!  
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End Sub .vv*bx   
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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： XOCau.#  
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Accommodation = 4 Diopters 8UIL_nPO  
Pupil Diameter = 4 mm [&CM-` N  
Set aqueous humor thickness = 2.81 MuobMD}jqe  
Set anterior lens radius = 10.4 and conic constant = -2.375869 5u46Vl{  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 j
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Set lens thickness = 3.927 E(tBN]W.  
Set lens index of refraction = 1.42672 NXBOo  
Set pupil diameter = 4 32iI :u  
DONE! Nd_@J&