Arizona眼睛模型
简介 `a:@[0r0U ? $pGG 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。 xpFu$2T6P. 1SkGG0
W 模型 .)})8csl.d H1|X0a(j 模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 ix^:qw; Table 1. AZ眼睛模型的定义 [attachment=111140] `(=)8>|e 0$&Z_oJ 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~ v<Z/gm G#duZNBdc 光源 /.05rTpp gbr|0h> 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。 x:;8U i"&B ~n]:f7?I [attachment=111141] 图1. 光源和提示信息使用 F#4?@W <3HW!7Ad1 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。 lZ^XZjwoM %Iv+Y$'3B 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 n5S$Dl [attachment=111142] 图2. 字母F光源的设定方法光 \R&`bAd k 4OCz:t [attachment=111143] 图3. 字母F在视网膜上位置点列图 /RmLV 6$SsdT|8B 视网膜的散射 }5OlX S?hM 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 }'kk}2ej` #k)G1Y[c [attachment=111144] 图4. 视网膜朗伯散射设定 ?xK9 *KxV;H8/ 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 !bH-(K{S6 N
Ja]UZx [attachment=111145] 图5. 视网膜重点采样规格设定 ,PRM(n - CNbrXN 脚本 M%&`&{ U <4<8' 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: _PNU*E%s< [attachment=111146] 图6. 用户对话框的创建与编辑 BT d$n!'$n [attachment=111147] 图7. 用户对话框编辑器 |[!xLqG c)@M7UK[ 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 jE2ziK 余下的脚本计算与屈光度有关的所有参数。 s.zH.q, MrOW&7 分析 J>hl&J aM? 7'8/ 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 @!%<JZEz3 [attachment=111148] 图7. 字母F在视网膜上颜色分析 =5dv38 * +A!12s@ 脚本代码 vU{ZB^+&6o .s7/bF
- Option Explicit 'Remove this to enable non-dimensioned variables to be used. 1Lj\"+.
#J2856bzS Dim entity As T_ENTITY Ks7s2 vK^ Dim op As T_OPERATION qf24l&} Dim mat As T_MODELMATERIAL q;kMeE* Dim A As Double 4D\_[(P Dim pupilDiam As Double *#UDMoz< Dim eID As Long |C>Yd*E,C Dim parID As Long 0pkU1t~9 Dim count As Integer cO(|>&tJ Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double rX;(48Y Dim tlens As Double, nlens As Double y0(k7D|\ Dim curv As Double, conic As Double 8{?Oi'-|0 Dim ok As Long %HYC-TF# i7 p#%2 Sub Main Zls4@/\Q X/gh>MJJ< '用户输入对话框 !7%L%~z^ Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 qY14LdC}~ TextBox 220,21,40,21,.TextBox1 'default: 0 CUxSmN2[ Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 7;|6g8= OKButton 40,91,90,21 S'3l<sY CancelButton 190,91,90,21 ;Kkn7&'F Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 {_(;&\5 TextBox 220,49,40,21,.TextBox2 'default: 4 ? `FI!3j End Dialog /tt Dim dlg As UserDialog % j^= @*%.V. ok = Dialog (dlg)
ZfvFs Hk6Dwe[y If ok=0 Then 'cancel button was pressed zhN'@Wj'_ Print "Execution cancelled." MHxv@1)K|Y End [xI@)5Xk End If l'3NiIX t}'Oh}CG 'Assign accommodation and pupil diameter & use defaults if field left empty [ HNGTde& If dlg.TextBox1 = "" Then L}:u9$w A = 0 'Default accommodation kv(N/G Else _|6{( A = CDbl(dlg.TextBox1) G e~&Ble End If |n6nRE wW evszfCH'J If dlg.TextBox2 = "" Then $orhY D3gv pupilDiam = 4 'Default pupil diameter 25YJH1x Else 37lmB
'~ pupilDiam = CDbl(dlg.TextBox2) u[d8)+VX
End If X0U{9zP vZXyc* Print " " t5eux&C Print "Accommodation = " & A & " Diopters" vn,L),"= Print "Pupil Diameter = " & pupilDiam & " mm" @@# G. Q*KEODR8\ ' Calculate new parameters with accommodation oPWvZI(\& taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness urog.Q -{L[Wt{1 Rant = 12.0 - 0.4*A 'Radius of anterior lens $fC= v CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens >#0yd7BST {kZhje^$vi Rpost = -5.224557 + 0.2*A 'Radius of posterior lens x%x[5.CT CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens 5RlJybN"o J@yy2AZnO tlens = 3.767 + 0.04*A 'Lens thickness wF38c]r`\< 0V`/oaW; nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction ^QFjBQ-Hai 6o,,w^ 'Adjust parameters to account for accommodation 1~5={eI 7i/?+| '************************************************************************* 0Y"==g+>f 'Aqueous thickness (Position of Lens) U15Hq*8Z '************************************************************************* dmE-WS eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5IMh$!/uc GetCustomElement eID, entity ^M?uv{354 GbNVcP.ocP parID = FindFullName( "Geometry.Arizona Eye" ) <y`yKXzBUV 6= 9 ' Delete any shift(s) in z Ye(0'*-jyc count = 0 Lw!@[;2 While GetOperationCount(eID)>count v3aiX GetOperation eID, count, op ^. Pn)J If op.Type="ShiftZ" Then '5[L []A DeleteOperation eID,count wmT3 > count=count-1 !^\|r<2M End If u2U@Qrs2 count=count+1 h!)(R< Wend q .?D{[2 y)(@ 'Set new shift in Dy8Go4 op.Type = "ShiftZ" w@oq.K op.val1 = taq y8,es$ op.parent = parID &O!d!Pf AddOperation eID, op %*r Pd>* Print "Set aqueous humor thickness = " & taq-0.55 @];Xbbw+c uswz@
[pa '************************************************************************* Vxk0oIk` 'Radius and conic constant of anterior lens H[6d@m- Z '************************************************************************* + ^~n09 eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) W 6jB!W GetConic eID, entity, curv, conic {O!fV<Vx 9 (T`x-wTl SetConic eID, entity, 1/Rant, CCant &f!!UZMt) Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant dn5T7a~
KXdls(ROP '************************************************************************* bg 7b!t1F 'Radius and conic constant of posterior lens Ya,>E@oc '************************************************************************* ]n!pn#Q eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) guf+AVPno GetConic eID, entity, curv, conic I@x*> }RM?gE SetConic eID, entity, 1/Rpost, CCpost NP|U
|zn Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost l?#([(WM E7j]"\~ i '************************************************************************* SUvHLOA 'Lens thickness (Position of posterior lens surface) 3 #jPQ[+ '************************************************************************* [9$>N XFM6.ye parID = FindFullName( "Geometry.Arizona Eye.Lens" ) &Cdd s[Njk@y, ' Delete any z-shift(s) Ak4iG2 count = 0 W]reQ&<Z While GetOperationCount(eID)>count KXR GetOperation eID, count, op ;,9|;)U?u If op.Type="ShiftZ" Then BeplS DeleteOperation eID,count !m^WtF count=count-1 WxIP~ End If &;C|=8eB count=count+1 ^yBx.GrQc Wend ,9q5jOnk z+wBZn{0I 'Set new z-shift ^>]p4Q3 6 op.Type = "ShiftZ" =k0l>) op.val1 = tlens 0R*!o\y op.parent = parID iUSs) []H> AddOperation eID, op Z/a]oR@ Print "Set lens thickness = " & tlens rsiG]o=8 jQ`cfE$sV '************************************************************************* kbOo;<X9A 'Lens index of refraction vbh\uv& '************************************************************************* T#h`BtET[ eID = FindMaterial( "Lens" ) *y.KD4@{ GetModelMaterial eID, mat ;:'A{&0N 2uqdx'^" mat.Nd = nlens ucB< SetModelMaterial eID, mat H?O* Print "Set lens index of refraction = " & nlens |-Y,:sY: , gz:2UY# '************************************************************************* uv._N6mj 'Pupil diameter @'~v~3
$S '************************************************************************* V=1Y&y eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) et)A$'Q {wCQ#V 'Adjust pupil diameter (trimming volume inner hole) M-0BQs`N *Q5/d9B8TN SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" cojuU=i &e2") 4oh ' Adjust pupil location to just in front of the lens &K|CH?
D parID = FindFullName( "Geometry.Arizona Eye" ) ~FDJKGK eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Z
wIsEJz count = 0 *`mwm:4 While GetOperationCount(eID)>count Fe`$mtPu . GetOperation eID, count, op +=;F vb If op.Type="ShiftZ" Then +dIg&}Tr DeleteOperation eID,count _[IN9ZC 2G count=count-1 5f}wQ End If aq[kKS` count=count+1 @K2q*d Wend F&I^bkvh op.Type = "ShiftZ" 8"RX~Igf op.val1 = taq-0.01 LXfDXXF op.parent = parID q=g;TAXZl AddOperation eID, op :C>slxY 'TezUBRAz Print "Set pupil diameter = " & pupilDiam q[7C,o>/ f~8Xue,l" 'Update AZ Eye subassembly Description $Jx]
FZDQ eID = FindFullName( "Geometry.Arizona Eye" ) BWz*!( GetEntity eID, entity B-'Xk{ entity.Description = "Accommodation = " & A & "D" BTGPP@p4 SetEntity eID, entity @
L?7`VoE |a/"7B|?\ Update ,Cde5A{K Print "DONE!" W
4~a`D7 n$B=Vt, End Sub :J}L| `U9 M|7xI 如果屈光度是4,光瞳直径是4,则会输出如下数据: ')+'m1N x4R[Q&:M Accommodation = 4 Diopters jQ(qaX&
Pupil Diameter = 4 mm qeHb0G Set aqueous humor thickness = 2.81 op/|&H' Set anterior lens radius = 10.4 and conic constant = -2.375869 U''/y\Z Set posterior lens radius = -4.424557 and conic constant = -3.081019 qAHQZKk Set lens thickness = 3.927 UC\CCDV#^ Set lens index of refraction = 1.42672 .$L'Jt2X Set pupil diameter = 4 fg^$F9@ DONE!
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