Arizona眼睛模型
简介 WpTC,~- ocdXzk` 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。 fD,#z& aEZl ICpU7 模型 6K`frt *ArzXhs[ 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。 kZz;l(?0 HD=WHT&
Table 1. AZ眼睛模型的定义 ^4s#nf:} 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. z W+wtYV4 Cc!n`%qc 光源 *:\QD 8 ^ F<'g6f 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。 D#(A?oN %#7M~RB[ '7Te{^<FQ$
图1. 光源和提示信息使用 zKT \i 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。 oWXvkDN
L0+@{GP? 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。 >{m>&u;Cc `uzRHbJ`
图2. 字母F光源的设定方法光 ]j1BEO!Bg G4g},p!
图3. 字母F在视网膜上位置点列图 dZnq 96<:| 视网膜的散射 bE0S)b) X-n'?= 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。 u=ENf1{ $> jRgv
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图4. 视网膜朗伯散射设定 !_x-aro3< 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 BJW;A>@Pj ]t#,{%h 2H]&3kM3X
图5. 视网膜重点采样规格设定 .bpxSU%X 脚本 t$Qav>D `^_.E:f 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@pv c3 Nb B`6@r
图6. 用户对话框的创建与编辑 DVpqm6$Q
图7. 用户对话框编辑器 .5ingB3% 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。 qPzgGbmD9 余下的脚本计算与屈光度有关的所有参数。 !sR`]0 Dj<Vn%d* 分析 t3bN
PK^ NINyg"g< 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 $9hOWti Cu/w><h)
图7. 字母F在视网膜上颜色分析 T_\GvSOI 脚本代码 ,Zs-<e" (a)d7y.oo Option Explicit 'Remove this to enable non-dimensioned variables to be used. h?$4\^/ N2~DxVJ5cT Dim entity As T_ENTITY 8c~b7F
\ Dim op As T_OPERATION M4')gG; Dim mat As T_MODELMATERIAL B d\p!f< Dim A As Double s q :ff Dim pupilDiam As Double S{
*RF) Dim eID As Long u1>| 2D Dim parID As Long meIY00 Dim count As Integer eqjl$QWPJS Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double wcV~z:&^5 Dim tlens As Double, nlens As Double z?E:s.4F Dim curv As Double, conic As Double ]2Lwd@ Dim ok As Long &|gn%<^ wAy;ZNu Sub Main \9D
'7/$I, gv<9XYByt '用户输入对话框 f#mY44:,C Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 vsES` TextBox 220,21,40,21,.TextBox1 'default: 0 <L5[#V_ Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Fdvex$r& OKButton 40,91,90,21 <\yM{
V\ CancelButton 190,91,90,21 8HTV"60hTs Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 w"A'uFXLc TextBox 220,49,40,21,.TextBox2 'default: 4 k*lrE4::a End Dialog (u$Q Dim dlg As UserDialog IURi90Ir %] ok = Dialog (dlg) ZRcY; ? #PtV=Ee1 If ok=0 Then 'cancel button was pressed 6AzH'HF Print "Execution cancelled." rEZa%)XJ End l} h<2 End If RCgs3JIE+2 *S{%+1F 'Assign accommodation and pupil diameter & use defaults if field left empty ;XGG&M%3 If dlg.TextBox1 = "" Then )2FS9h.t A = 0 'Default accommodation 9h~>7VeZ) Else Ku&0bXP A = CDbl(dlg.TextBox1) UyIjM;X End If 3!ulBiMh _RjM . If dlg.TextBox2 = "" Then eGnc6)x@C pupilDiam = 4 'Default pupil diameter cH"M8gP# Else ly6?jVJ pupilDiam = CDbl(dlg.TextBox2) ,R*ru* End If rWSw1(sAA U2+CL)al^ Print " " [)9bR1wh Print "Accommodation = " & A & " Diopters" xae}8E Print "Pupil Diameter = " & pupilDiam & " mm" Yc\;`C l=bB,7gL ' Calculate new parameters with accommodation 1>l{c taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness blxH`O! !]5F2~"v Rant = 12.0 - 0.4*A 'Radius of anterior lens Bz!ddAvlK CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens #p*OLQ3~ '{U56^b] Rpost = -5.224557 + 0.2*A 'Radius of posterior lens N.BD]_C CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens a<c % Xy/ qFf'RgUtP tlens = 3.767 + 0.04*A 'Lens thickness USe"1(|E Y@RPQPmIQ nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction D='/-3f!F] RH>b, 'Adjust parameters to account for accommodation c9iCH~ IN`05 Q '************************************************************************* l0[jepmpiT 'Aqueous thickness (Position of Lens) WynHcxC '************************************************************************* .U9NQwd eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Vx-HW;, GetCustomElement eID, entity QoI@/
jLj I+8m1* parID = FindFullName( "Geometry.Arizona Eye" ) ,GZ(>| 56&s' ' Delete any shift(s) in z _W tSZmW? count = 0 >0:h(,?V While GetOperationCount(eID)>count =F8uuYX%m GetOperation eID, count, op (/Z~0hA[Q If op.Type="ShiftZ" Then L=4?vs DeleteOperation eID,count "uqa~R{ count=count-1 6+m) End If #y}@FG count=count+1 /]<0`nI. Wend y.w/7iw: M_$pqVm 'Set new shift in ~>xn9vb= op.Type = "ShiftZ" rm(<?w%'? op.val1 = taq ?i)-K?4Sb op.parent = parID IS]0 3_uQ AddOperation eID, op XC0G5rtB Print "Set aqueous humor thickness = " & taq-0.55 W[j =!o 26.iFt/: '************************************************************************* htlsU*x 'Radius and conic constant of anterior lens BAg*zYV7 '************************************************************************* }B^s!y&b eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) &g.w~KWa GetConic eID, entity, curv, conic E=sBcb/v 4
lJ@qhV SetConic eID, entity, 1/Rant, CCant 9%kY8#%SV Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant B;hc|v{( -(Taj[;[ '************************************************************************* xgsD<3 'Radius and conic constant of posterior lens ~}z p}Pt '************************************************************************* 2,q^O3F eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 1}KNzMHk9 GetConic eID, entity, curv, conic `S{< $:D "{qhk{ SetConic eID, entity, 1/Rpost, CCpost ^?&Jq_oU Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost )|uPCZdLZ dGP*bMCT '************************************************************************* 4UC/pGZY 'Lens thickness (Position of posterior lens surface) \qV5mD]"M '************************************************************************* HBo^8wN '1=/G7g parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4#;rv$
{ IP&En8W+ ' Delete any z-shift(s) CHN!o9f count = 0 V |#B=W While GetOperationCount(eID)>count (RWZ[-;) GetOperation eID, count, op =lr*zeHLC If op.Type="ShiftZ" Then NT= ?@uxD DeleteOperation eID,count 5#$E4k:YV count=count-1 [$8*(d"F' End If ElqHZ$a? count=count+1 |>jlY| Wend Ud`V"X <)?H98S 'Set new z-shift ?n\~&n'C op.Type = "ShiftZ" ~k|~Q\ op.val1 = tlens aE1h0`OT op.parent = parID s3/->1#i AddOperation eID, op QRgWzaI Print "Set lens thickness = " & tlens onG,N1`+ :NA cad '************************************************************************* k[A=:H1" 'Lens index of refraction K34ca-~ '************************************************************************* im*QaO%a4 eID = FindMaterial( "Lens" ) i ,4 GetModelMaterial eID, mat }Jh!B| +qD4`aI mat.Nd = nlens A6q,"BS^d SetModelMaterial eID, mat zu*0uL Print "Set lens index of refraction = " & nlens r_FW)F u^ *)L%pH>` '************************************************************************* RTH dL 'Pupil diameter vyN=X]p '************************************************************************* !i.`m-J* eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) @>(l}5U5 [~f%z(vI 'Adjust pupil diameter (trimming volume inner hole) s/`4]B;2U O 4l[4,` SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" xO"5bj EOVHTDkKf ' Adjust pupil location to just in front of the lens $T1
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?X parID = FindFullName( "Geometry.Arizona Eye" ) ;vQ7[Pv.j eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) B%^B_s count = 0 frc>0\ While GetOperationCount(eID)>count JQQD~J1)E GetOperation eID, count, op :pDw gd If op.Type="ShiftZ" Then |+x;18 DeleteOperation eID,count u2 -%~Rlo count=count-1 '`/1?,= End If /D 2v1 count=count+1 76zi)f1f Wend OHp 121 op.Type = "ShiftZ" `"A\8)6- op.val1 = taq-0.01 '#u|RsZ op.parent = parID ~Jmn?9 3 AddOperation eID, op /_o1b_1U r}D`15IHJ Print "Set pupil diameter = " & pupilDiam } Yjic4? So bK<6 'Update AZ Eye subassembly Description d[-w&[iy eID = FindFullName( "Geometry.Arizona Eye" ) Eq~&d.j GetEntity eID, entity 4q~+K'Z entity.Description = "Accommodation = " & A & "D" gPQ2i])"Q SetEntity eID, entity ~?[%uGI0h Q4CxtY Update FyZw='D Print "DONE!" :E@"4O?<Y) HWVWl~FA End Sub (`!?p ^>A IUbYw~f3 如果屈光度是4,光瞳直径是4,则会输出如下数据: lwQI
9U[O2 $N+a4 Accommodation = 4 Diopters t}_qtO7> Pupil Diameter = 4 mm KosAc'/ M Set aqueous humor thickness = 2.81 l)a]V]oQ Set anterior lens radius = 10.4 and conic constant = -2.375869 .OX.z~":y Set posterior lens radius = -4.424557 and conic constant = -3.081019 gqyQ Zew Set lens thickness = 3.927 7=Ew[MOmM Set lens index of refraction = 1.42672 %89f<F\V Set pupil diameter = 4 7evE;KL DONE! r,L#JR w#-
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