Arizona眼睛模型

>\ :kP>U   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。 _$?SKid|o   /gKX%`ZF/r   模型 ["\Y-6"l   iC`K$LY4W   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。 RAQi&?Ko   Table 1. AZ眼睛模型的定义 [g:ZIl4p\P   z5v)~+"1   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. io$!z=W   h$FpH\-   光源 ~g+?]Lk}   N4Z%8:"pj   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。 nxP>IfSA   T,,,+gPx   图1. 光源和提示信息使用 7W6tz\Y   gjJ?*N[   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ckWBL   R;gN^Yjk:   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。 < 6[XE   图2. 字母F光源的设定方法光 Tt.wY=,K   fYR*B0tu   图3. 字母F在视网膜上位置点列图 A7|!&fi   p*8LS7UT   视网膜的散射 Lmx95[#@a   F`;oe[wfk   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。 `Pv[A   y1!c:&   图4. 视网膜朗伯散射设定 +^ n\?!   ]VY}VALZ   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。 v_PhJKE   Rw\ LVRd A   图5. 视网膜重点采样规格设定 E-_FxBw   oO-kO!59y   脚本 ^<#08L;   7yLO<o?9w   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： 8S[`(] )   图6. 用户对话框的创建与编辑 G/Nb@pAy[   图7. 用户对话框编辑器 - ckk2D?   9pD=E>4?#   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。 445}Yw5;9   余下的脚本计算与屈光度有关的所有参数。 FWv-_    &y/   分析 8r7~ >p~   \Jr ta   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Nh7+Vl   图7. 字母F在视网膜上颜色分析 y-qbK0=X4   {#aW")x^#   脚本代码 i>w'$ {   ORhe?E]   Option Explicit     'Remove this to enable non-dimensioned variables to be used. C~Fdo0D   B>}=x4-8   Dim entity As T_ENTITY ;ZMm6o   Dim op As T_OPERATION B:om61Dn   Dim mat As T_MODELMATERIAL 47b=>D8   Dim A As Double fX=o,=-f   Dim pupilDiam As Double Sdl1k+u   Dim eID As Long :|3n`,   Dim parID As Long C=&7V   Dim count As Integer j]\3>.   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double j^ VAA\   Dim tlens As Double, nlens As Double :uE:mY%R   Dim curv As Double, conic As Double &L[7jA'[J   Dim ok As Long s*<\mwB   5|>FM&   Sub Main (he cvJ   ;Ll/rJ:*       '用户输入对话框 Nf(Np1?;c       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 bM[!E8dF           TextBox 220,21,40,21,.TextBox1 'default: 0 c+:LDc3!Gb           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 fG2 hCP+           OKButton 40,91,90,21 t .*z)N           CancelButton 190,91,90,21 Ffxf!zS           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 5 Z +2            TextBox 220,49,40,21,.TextBox2 'default: 4 cn1UFmT       End Dialog ?;Ck]l#5ys       Dim dlg As UserDialog B]Vnu7   byz2u       ok = Dialog (dlg) ))Ws{   ZPHiR4fQli       If ok=0 Then    'cancel button was pressed EHk(\1!V           Print "Execution cancelled." #-b0U[,.           End GORu*[U8       End If T=6fZ;7   P%`|Tu!B       'Assign accommodation and pupil diameter & use defaults if field left empty +X )n}jh       If dlg.TextBox1 = "" Then :<$B o           A = 0           'Default accommodation 4 [2^#t[       Else !QK~l           A = CDbl(dlg.TextBox1) h/u>F$}c       End If X2>qx^jT   T~B'- >O       If dlg.TextBox2 = "" Then VJ1(|v{D4[           pupilDiam = 4   'Default pupil diameter KLqn`m`O;       Else 1<Fh aK           pupilDiam = CDbl(dlg.TextBox2) QJ{to%       End If .kO!8Q-;%   kkfwICBI       Print " " ^+Ho#]       Print "Accommodation = " & A & " Diopters" }1<_       Print "Pupil Diameter = " & pupilDiam & " mm" H"hL+F^   &w@~@]       ' Calculate new parameters with accommodation Xq"@Z       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness =Kdd+g!   A#&Q(g\YE       Rant = 12.0 - 0.4*A                     'Radius of anterior lens tEEeek(!       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens o(iv=(o   Ta;'f7Oz       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens b"x[+&%i       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens TE+d?   rG7S^,5o       tlens = 3.767 + 0.04*A                  'Lens thickness C~\/FrO?   {4u8~whLp       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction X ?p_O2#k   9$0-UUCk       'Adjust parameters to account for accommodation -]=-IiC#   V&)lS Qw       '************************************************************************* XAN{uD^3\%       'Aqueous thickness (Position of Lens) Vg1! u+`<       '************************************************************************* ppcuMcR{       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) PVBf'       GetCustomElement eID, entity C4V#qhj   hR;J#w       parID = FindFullName( "Geometry.Arizona Eye" ) ['F,   7/c[ f       ' Delete any shift(s) in z $,+'|_0yM       count = 0 /($!("b       While GetOperationCount(eID)>count o* qF"xG           GetOperation eID, count, op IEb"tsel           If op.Type="ShiftZ" Then }Ip"j]h               DeleteOperation eID,count **I9Nw!IH               count=count-1 RfPRCIo           End If QInow2/u           count=count+1 >patv       Wend gR `:)>   0(9]m)e       'Set new shift in !6:q#B*       op.Type = "ShiftZ" %\=oy=f       op.val1 = taq p_hljgOV       op.parent = parID s }P-4Sg       AddOperation eID, op %y zFWDg       Print "Set aqueous humor thickness = " & taq-0.55 ag6hhkjA   ZB-+bY       '************************************************************************* %SV"iXxY       'Radius and conic constant of anterior lens g*9jPwdG       '************************************************************************* QC:/xP       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) \Fhk>       GetConic eID, entity, curv, conic  )]2yTG[   H!dUQ       SetConic eID, entity, 1/Rant, CCant h3^ &,U       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant zdA:K25"   K`PmWxNPh       '************************************************************************* Ov{f O       'Radius and conic constant of posterior lens v2<roG6.V       '************************************************************************* g%w@v$       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) (]BZ8GOx       GetConic eID, entity, curv, conic "4FL<6   EXz5Rue LV       SetConic eID, entity, 1/Rpost, CCpost tK&.0)*=       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 8QYG"CA6/   *Kt7"J       '************************************************************************* UQ>GAzh       'Lens thickness (Position of posterior lens surface) bWv6gOPR3       '************************************************************************* -mZo`   8 Oeg"d       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) CTtF=\   h`%K\C       ' Delete any z-shift(s) L&ws[8-       count = 0 \{da|n-       While GetOperationCount(eID)>count f7X#cs)a           GetOperation eID, count, op ;-=y}DK           If op.Type="ShiftZ" Then #s1M>M)               DeleteOperation eID,count @Risabn               count=count-1 sVkR7 ^KsG           End If S^)r,cC           count=count+1 GMU<$x8o       Wend <X y8}Z`s   !U>"H8}dv       'Set new z-shift Kggf!\MR8       op.Type = "ShiftZ" J+\F)k>r       op.val1 = tlens O) Nt"k7 b       op.parent = parID sNvT0       AddOperation eID, op B\|>i~u(       Print "Set lens thickness = " & tlens joDfvY*[   `P/*x[?       '************************************************************************* j`BFk>       'Lens index of refraction kRiWNEw       '************************************************************************* W~k!qy `       eID = FindMaterial( "Lens" ) e%bERds       GetModelMaterial eID, mat [tMf KO   LEhku4U.       mat.Nd = nlens e+y< a~N       SetModelMaterial eID, mat )[oU| !@       Print "Set lens index of refraction = " & nlens E f,@}S   +7 F7Kh       '************************************************************************* 8<n8joO0       'Pupil diameter 42p6l       '************************************************************************* (dMFYL>YP       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) />ob*sk/Y   %hrv~=       'Adjust pupil diameter (trimming volume inner hole) X""'}X|O   k|A!5A2       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" hQL 9 Zl~   i qy}|xAU       ' Adjust pupil location to just in front of the lens h!K B%4V       parID = FindFullName( "Geometry.Arizona Eye" ) LOnh FX        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 8~HC0o\2       count = 0 iLmU|jdE       While GetOperationCount(eID)>count FG#j0#|*           GetOperation eID, count, op p~8~EQFj           If op.Type="ShiftZ" Then n[4Nu`E9               DeleteOperation eID,count a|nlmH"l               count=count-1 \=N tbBL$[           End If ~Y'e1w$`           count=count+1 2jhVmK       Wend ik$wS#1+L       op.Type = "ShiftZ" !'{j"tv       op.val1 = taq-0.01 :ZL>JVk       op.parent = parID l*v([@A\       AddOperation eID, op k5/nAaiVE   ^7"%eWT`       Print "Set pupil diameter = " & pupilDiam 'oT}jI   Ep?a>\       'Update AZ Eye subassembly Description 0'py7       eID = FindFullName( "Geometry.Arizona Eye" ) awkVjyqX       GetEntity eID, entity V)@MM2,       entity.Description = "Accommodation = " & A & "D" (VOKa       SetEntity eID, entity =k$d8g ez   WHNb.>       Update _O!D*=I       Print "DONE!" Q ,;x;QR4        Nb];LCx   End Sub c%Gz{':+   \s+MHa&   如果屈光度是4，光瞳直径是4，则会输出如下数据： p +T&9   1)YFEU&]   Accommodation = 4 Diopters ;! 9_5Ar%   Pupil Diameter = 4 mm ! 4o Ix`   Set aqueous humor thickness = 2.81 z=K5~nU   Set anterior lens radius = 10.4 and conic constant = -2.375869 D{ loX6   Set posterior lens radius = -4.424557 and conic constant = -3.081019 6sZRR{'   Set lens thickness = 3.927 ttsB'|ps   Set lens index of refraction = 1.42672 jSVO$AW~C   Set pupil diameter = 4 ^&6NB)6   DONE!

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