Arizona眼睛模型
简介 v]BN. SHE_ @hp@*$#& 9 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。 qXgg"k%A\ 7D<M\l8G 模型 PXWBc\ |GLa`2q| 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。 yy@g=<okt\ Table 1. AZ眼睛模型的定义 [attachment=111140] c&ymVB?G:1 VXQ~PF]z0 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. +eQg+@u uN2Ck 光源 jCkYzQUPz f/aSqhAW 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。 ;>bcI). ZJ1% [attachment=111141] 图1. 光源和提示信息使用 ar }F^8Ku )V7bi^r 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。 7xqTTN6h Z)?B5FF 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。 #A+ dj|
b [attachment=111142] 图2. 字母F光源的设定方法光 26?yEd6^Z N2WQrTA:S+ [attachment=111143] 图3. 字母F在视网膜上位置点列图 Eu2@%2}P bejvw?)S. 视网膜的散射 w,n&K6< Dm2&}{&K 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。 qf-0 | w )cxLpTr [attachment=111144] 图4. 视网膜朗伯散射设定 ')zdI]@M _NA[g:DZ&O 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。 llN#4D9s Y
{a#2(xn [attachment=111145] 图5. 视网膜重点采样规格设定 EVX*YGxx6 6B'd]Fe 脚本 9l<f?OzAO >|IUjv2L 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: Pv@Lx+k [attachment=111146] 图6. 用户对话框的创建与编辑 {B+|",O5) [attachment=111147] 图7. 用户对话框编辑器 <A"[Wk "k&QS@l 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。 m`_s_# 余下的脚本计算与屈光度有关的所有参数。 j6}/pe*;;T A0JlQE&U 分析 dz_~_| u)J&3Ah% 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 ()%NotN; [attachment=111148] 图7. 字母F在视网膜上颜色分析 eb10=Lmj ufq9+} 脚本代码 O(pa;&" F)XO5CBK
- Option Explicit 'Remove this to enable non-dimensioned variables to be used. ,%Sf,h?"^
TuR.'kE@ Dim entity As T_ENTITY w\SfzJN Dim op As T_OPERATION .Aj4?AXWc Dim mat As T_MODELMATERIAL cqXP} 5 Dim A As Double 6)5Akyz4V Dim pupilDiam As Double pQ2'0u5w5 Dim eID As Long D6z*J?3^#& Dim parID As Long *{TB<^ * Dim count As Integer pT ]: TRPS Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 8p"R4 Dim tlens As Double, nlens As Double ~&{LMf Dim curv As Double, conic As Double q#pD}Xe$ Dim ok As Long -0P(lkylf wB%N}bi! Sub Main :9?y-X ZF@T,i9 '用户输入对话框 V\|V1c Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 uz
U2)n3y TextBox 220,21,40,21,.TextBox1 'default: 0 Q&\(m[:) Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 >tGl7Ov OKButton 40,91,90,21 KdN+$fe*g CancelButton 190,91,90,21 RZ+SOZs7H Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 7^bde<0 TextBox 220,49,40,21,.TextBox2 'default: 4 *gGL5<%T: End Dialog 4C]>{osv Dim dlg As UserDialog SobOUly5{ <?h,;]U ok = Dialog (dlg) BU;o$"L tMbracm If ok=0 Then 'cancel button was pressed e]5
n4"]D) Print "Execution cancelled." qL;u59 End sW#OA\i& End If 'cgB$:T}., I
l2`c}9 'Assign accommodation and pupil diameter & use defaults if field left empty {>r56\!F If dlg.TextBox1 = "" Then OK8|w]-A A = 0 'Default accommodation JnodDH ? Else 5yl[#>qt A = CDbl(dlg.TextBox1) e<Bwduy End If Lnk(l2~U u*"mdL2 If dlg.TextBox2 = "" Then <<vT"2Q] pupilDiam = 4 'Default pupil diameter G_1`NyI Else z\g6E/ %% pupilDiam = CDbl(dlg.TextBox2) f5tkv<) % End If .S{>?2 ]:g;S,{ Print " " EEI!pi Print "Accommodation = " & A & " Diopters" rb_FBa% Print "Pupil Diameter = " & pupilDiam & " mm" 0YsBAfRG HzdyfZ!jR ' Calculate new parameters with accommodation mN^/ taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness MGbl-,] + 7~u_J Rant = 12.0 - 0.4*A 'Radius of anterior lens u&-Zh@;Q7 CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens RX\l4H5; u6#FG9W7 Rpost = -5.224557 + 0.2*A 'Radius of posterior lens LkK# =v CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens 2N/4. n`TXmg tlens = 3.767 + 0.04*A 'Lens thickness &Cykw$s vQ_D%f4; nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction K (!+l ^1 U<,< 'Adjust parameters to account for accommodation j-}WA" VdC,M;/=Z '************************************************************************* #)7THx/= 'Aqueous thickness (Position of Lens) &:@)roCR '************************************************************************* |A/)b78'u eID = FindFullName( "Geometry.Arizona Eye.Lens" ) )}|b6{{< GetCustomElement eID, entity r@)_>( V/,@hv`+ parID = FindFullName( "Geometry.Arizona Eye" ) &ZR} Z7E*= Bsc ' Delete any shift(s) in z j~;kh_ count = 0 @o/126(k While GetOperationCount(eID)>count [+8in\T i GetOperation eID, count, op EmFL
%++V If op.Type="ShiftZ" Then ==XO:P DeleteOperation eID,count 8~@?cy1j! count=count-1 !kG 2$/lR End If a 9H^e<g count=count+1 E(p*B8d Wend WUfPLY_c( W!=X_ 'Set new shift in -qW[.B op.Type = "ShiftZ" FbU98n+z op.val1 = taq 81jVjf?` op.parent = parID -#agWqUM|T AddOperation eID, op B K/_hNz Print "Set aqueous humor thickness = " & taq-0.55 Ng 3r`S"_<
|08'd5 '************************************************************************* 7,BULs\g 'Radius and conic constant of anterior lens W[4 V#&Z '************************************************************************* m6 V L eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) vlSSw+r9 GetConic eID, entity, curv, conic ymo]. (;6vT'hE SetConic eID, entity, 1/Rant, CCant &4}Uaxt) Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant /Y_)dz^@ w;=g$Bn '************************************************************************* T-)lnrs^ 'Radius and conic constant of posterior lens o-7,P
RmKN '************************************************************************* 8nKb
mjM eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) q1_iV.G< GetConic eID, entity, curv, conic appWq}db .d?2Kc)SV\ SetConic eID, entity, 1/Rpost, CCpost 57~/QEdy Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost -qNun3 2M$^|j:[ '************************************************************************* Gw@]w;ed 'Lens thickness (Position of posterior lens surface) tmVGJ+gz '************************************************************************* }T1.~E 29tih{xx parID = FindFullName( "Geometry.Arizona Eye.Lens" ) FzM<0FJRX I;GbS` ' Delete any z-shift(s) O;8 3A count = 0 >p?Vv0* While GetOperationCount(eID)>count 8m"(T-wb6{ GetOperation eID, count, op Y:#nk.}> If op.Type="ShiftZ" Then -POsbb> DeleteOperation eID,count P,W(9&KM count=count-1 _/[}PQC6G End If :c}"a(| count=count+1 :N#8|;J1Fl Wend E
E^lw61
H_vGa!_ 'Set new z-shift g|=1U op.Type = "ShiftZ" .9VhDrCK op.val1 = tlens h,@tfd U^ op.parent = parID \ Dccf_(Pb AddOperation eID, op cP2n,>: Print "Set lens thickness = " & tlens \PL0-.t, CAbR+y '************************************************************************* Y{D?&x%yq 'Lens index of refraction q~6a$8+t '************************************************************************* Lc! t eID = FindMaterial( "Lens" ) &1Cif$Y4w GetModelMaterial eID, mat kps}i~Jb lEXI<b'2 mat.Nd = nlens K)N'~jCG SetModelMaterial eID, mat B1 Y
Print "Set lens index of refraction = " & nlens Ev]oPCeA (MzThGJK_ '************************************************************************* /C6$B)w_*{ 'Pupil diameter )'i n}M '************************************************************************* ]QSQr* eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) #7Jvk_r9Y .g>0FP 'Adjust pupil diameter (trimming volume inner hole) ,Fzuo:{uy 4L<;z' SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 7Sl"q=> z`:tl7 ' Adjust pupil location to just in front of the lens 5gKXe4}\/| parID = FindFullName( "Geometry.Arizona Eye" ) ,Q,3^v- eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) *3# RS count = 0 MmH(dp+ While GetOperationCount(eID)>count _jM+;=f GetOperation eID, count, op -7u_ \XFk If op.Type="ShiftZ" Then %0q)PT\ DeleteOperation eID,count R/P9 =yvg0 count=count-1 8SOfX^;o End If 7bL48W<QD count=count+1 x\b+B
Wend "sJ@_lp op.Type = "ShiftZ" %@^9(xTE op.val1 = taq-0.01 4vyJ<b
op.parent = parID F5
7Kr5X AddOperation eID, op yC\!6pg 2Q)pT$ Print "Set pupil diameter = " & pupilDiam UL0n>Wa5 '<1Q;3Ho 'Update AZ Eye subassembly Description f{+X0Oj eID = FindFullName( "Geometry.Arizona Eye" ) 51'{Jx8 GetEntity eID, entity 6ANAoWg* entity.Description = "Accommodation = " & A & "D" [/Xc},HbMe SetEntity eID, entity Sh(XFUJ GzjC;+W Update %ZTI ?a Print "DONE!" g?{7DI` kb[+II End Sub C
j: 17[vq!x6 如果屈光度是4,光瞳直径是4,则会输出如下数据: -?1ed|I8 ofuQ`g1hb Accommodation = 4 Diopters p!7(ayu Pupil Diameter = 4 mm cv9-ZOxJ Set aqueous humor thickness = 2.81 CO{AC~ Set anterior lens radius = 10.4 and conic constant = -2.375869 cB_3~=fV Set posterior lens radius = -4.424557 and conic constant = -3.081019 lin Set lens thickness = 3.927 7'RU\0QG Set lens index of refraction = 1.42672 K}8wCS F Set pupil diameter = 4 9M7Wlx2 DONE!
|