Arizona眼睛模型

dK#:io[Nz   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。 2LiJ IO8N   [as\>@o   模型 'hf#Q9W5   \@N8[   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。 f2`[skNj   Table 1. AZ眼睛模型的定义 _<+!   N41)?-7F   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. &j<B22t!   ?R(fxx   光源 %u,H2*   ;*BG{rkr   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。 f1rP+l-C<   }G]6Rip3   图1. 光源和提示信息使用 `% ZM(9T   F *=>=   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。 `1=n H/E   _s[ohMlh   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。 .D(H@3qA@   图2. 字母F光源的设定方法光 I%ivY   o+*YX!]#L   图3. 字母F在视网膜上位置点列图 XT9]+b8(M   }Y[xj{2$O   视网膜的散射 W;4rhZEgd   4QARrG%   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 _/;vsQB   fa//~$#"{L   图4. 视网膜朗伯散射设定 i+ ]3J/J   7?9QlUO   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。 C< 3`]l   tBd-?+~7   图5. 视网膜重点采样规格设定 $M5iU@A   +DmfqKKbd   脚本 2F%2K?$`Ej   JfGU3d*c   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： mEeD[dMN   图6. 用户对话框的创建与编辑 o%;R4 s,   图7. 用户对话框编辑器 H*51GxK   R.@I}>   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。 Hb55RilC   余下的脚本计算与屈光度有关的所有参数。 rE$0a-d2B   !w2J*E\   分析 uH="l.u   ^SM>bJ1Z_   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 |L[/]@|   图7. 字母F在视网膜上颜色分析 <|8N\FU{   p{X?_F   脚本代码 :d}I`)&   f8E,.$>   Option Explicit     'Remove this to enable non-dimensioned variables to be used. `v?XFwnV`   Of0(.-Q w   Dim entity As T_ENTITY )-VpDW!%_   Dim op As T_OPERATION ]dIcW9a   Dim mat As T_MODELMATERIAL r&+8\/{   Dim A As Double (SGX|,5X7   Dim pupilDiam As Double i]x_W@h   Dim eID As Long 3w!8PPl   Dim parID As Long RT`.S uN   Dim count As Integer zW#P ~zS   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double v+d} _rCT   Dim tlens As Double, nlens As Double uaghB,i'n   Dim curv As Double, conic As Double A\ARjSdb   Dim ok As Long {6Y|Z>   ;$,b w5   Sub Main [GQn1ZLc   7}#zF]vHNi       '用户输入对话框 M5 \flE2       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 jKr\mb           TextBox 220,21,40,21,.TextBox1 'default: 0 4N6JKS           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 wtM1gYl^           OKButton 40,91,90,21 >|zMN$:           CancelButton 190,91,90,21 (;VlK#rnC           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ES,T[           TextBox 220,49,40,21,.TextBox2 'default: 4 sU Er?TZ       End Dialog B']-4X{SGa       Dim dlg As UserDialog EDAtC   8ShIn@|32       ok = Dialog (dlg) FQTAkkA_!   1A%0y)]       If ok=0 Then    'cancel button was pressed 6mV-+CnYC           Print "Execution cancelled." :'`y}'           End ?_ 476A       End If moS0y?N   0\zY?UUww       'Assign accommodation and pupil diameter & use defaults if field left empty sGFvSW       If dlg.TextBox1 = "" Then S^s|/!>           A = 0           'Default accommodation 9$k0       Else S5o,\wT           A = CDbl(dlg.TextBox1) uwl_TDc>%       End If %lq[,6?>5   7+9o<j@@o       If dlg.TextBox2 = "" Then &R5zt]4d&           pupilDiam = 4   'Default pupil diameter ONVhB       Else TB}6iIe           pupilDiam = CDbl(dlg.TextBox2) { x{~%)-       End If igx~6G*   = U7P\sw2       Print " " ) >te|@}o       Print "Accommodation = " & A & " Diopters" "7q!u,u       Print "Pupil Diameter = " & pupilDiam & " mm" u i RO,B}z   : &bJMzB       ' Calculate new parameters with accommodation \VpN:RI       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness EDT9O   GXaPfC0-y       Rant = 12.0 - 0.4*A                     'Radius of anterior lens o_8Wnx^       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ?lE&ow   \5|MW)x       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 3{)!T;Wd       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens fUMjLA|*I<   !\VzX       tlens = 3.767 + 0.04*A                  'Lens thickness e@Mg9VwDc   w_h{6Kc<       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction B"YN+S o   9(3]t}J5 d       'Adjust parameters to account for accommodation 4VF4 8   8WE@ X)e       '************************************************************************* 7KesfH?       'Aqueous thickness (Position of Lens) !(Ymc_s       '************************************************************************* 5S <Rz)1r       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) JC0#pU;       GetCustomElement eID, entity >AFQm   wBDHhXi0       parID = FindFullName( "Geometry.Arizona Eye" )  !2kM    5tyA{&Ao       ' Delete any shift(s) in z 5vFM0       count = 0 IL go:xQ       While GetOperationCount(eID)>count f&j\gYWq           GetOperation eID, count, op 3! #|hI>f           If op.Type="ShiftZ" Then }uNj#Uf               DeleteOperation eID,count 3[j,d]\|               count=count-1 jzJQ/ZFS           End If Iprt ZqiL           count=count+1 IsmZEVuC       Wend _aYhW{wW   L3w.<h       'Set new shift in A!,c@Kv 3       op.Type = "ShiftZ" 0BNH~,0u       op.val1 = taq {yv_Ni*6!       op.parent = parID Tdade+       AddOperation eID, op Siq]Ii0F;>       Print "Set aqueous humor thickness = " & taq-0.55 0cSm^a   XD?Lu _.       '*************************************************************************  V~VUl)       'Radius and conic constant of anterior lens _CPj]m{       '************************************************************************* gg.]\#3g       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) @<3E`j'p       GetConic eID, entity, curv, conic L pq)TE#   dG7d}0Ou'       SetConic eID, entity, 1/Rant, CCant Z^]jy>dj       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 5kGQf   9 Jw,ls       '************************************************************************* =@ acg0       'Radius and conic constant of posterior lens e]nP 7TIU       '************************************************************************* T;5VNRgpI       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) rrR"2WuGO       GetConic eID, entity, curv, conic l 9C `:g   3$xpZm60       SetConic eID, entity, 1/Rpost, CCpost |fywqQFq       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost cHt4L]n8n   i6P}MtC1       '************************************************************************* 4evNZ Q       'Lens thickness (Position of posterior lens surface) 0J^Z)U>j       '************************************************************************* ysZ(*K n(?   $K+|bb       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) wm^1Fn--   VXiU5n^       ' Delete any z-shift(s) c]Gs{V]\       count = 0  pdm(7^       While GetOperationCount(eID)>count Xq )7Im}?           GetOperation eID, count, op )^BZ,e           If op.Type="ShiftZ" Then +pq) 7               DeleteOperation eID,count ?A;RTM               count=count-1 k-a1^K3           End If G6 2;p#           count=count+1 rHjDf[5+       Wend Op8Gj `   >]anTF`d       'Set new z-shift p2Gd6v.t       op.Type = "ShiftZ" f[D%(       op.val1 = tlens %E/#h8oN{       op.parent = parID &OZx!G^Z       AddOperation eID, op \pkK >R       Print "Set lens thickness = " & tlens y\j[\UZKO   nTc#I~\       '************************************************************************* C$K?4$       'Lens index of refraction JBA{i45x       '************************************************************************* 7D,nxx(`       eID = FindMaterial( "Lens" ) A4|7^Ay       GetModelMaterial eID, mat u$[&'D6   FX9WXb4w       mat.Nd = nlens (SQGl!Lai0       SetModelMaterial eID, mat b$0;fEvIJn       Print "Set lens index of refraction = " & nlens X.>~DT%0Lm   jbq x7x       '************************************************************************* "=K3sk       'Pupil diameter J/D~]U       '************************************************************************* =BN<)f^*s       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Xs|d#WbX    9{U@s       'Adjust pupil diameter (trimming volume inner hole) -(e=S^36   TghT{h@       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" wLiPkW   6W       ' Adjust pupil location to just in front of the lens E k_&E7       parID = FindFullName( "Geometry.Arizona Eye" ) !<=(/4o&P       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) {`k&Q +gY       count = 0 k"%JyO8Y       While GetOperationCount(eID)>count ^`M%g2x           GetOperation eID, count, op N.+A-[7,W           If op.Type="ShiftZ" Then Ct?xTFb               DeleteOperation eID,count j@#RfVx               count=count-1 cUP1Uolvn           End If \!jz1`]&{           count=count+1 -hfkF+=U'       Wend g"Hl 30o       op.Type = "ShiftZ" ?D7zty+}^       op.val1 = taq-0.01 B5+Q%)52       op.parent = parID 5(\/ b<#       AddOperation eID, op AxH`4=3<   \v+c.       Print "Set pupil diameter = " & pupilDiam UroC8Tm   J!RRG~       'Update AZ Eye subassembly Description {S-M]LE       eID = FindFullName( "Geometry.Arizona Eye" ) 'LuxF1>       GetEntity eID, entity ^K::g)       entity.Description = "Accommodation = " & A & "D" vol (%wB       SetEntity eID, entity 9@lG{9id?   3!cenyE       Update wj0_X;L       Print "DONE!" I(kEvfxc"        6C<GYzzo   End Sub w;(=wN\   c;]^aaQ+>   如果屈光度是4，光瞳直径是4，则会输出如下数据： b;*'j9ly   _<2{8>EVf   Accommodation = 4 Diopters ;5 $ GJu(   Pupil Diameter = 4 mm of7p~{3H   Set aqueous humor thickness = 2.81 uVhz Ju.   Set anterior lens radius = 10.4 and conic constant = -2.375869 nO'C2)bBSG   Set posterior lens radius = -4.424557 and conic constant = -3.081019 YMNLn9   Set lens thickness = 3.927 FIAmAZH}_   Set lens index of refraction = 1.42672   u+z   Set pupil diameter = 4 ^*UtF9~%n   DONE!

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