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2020-12-09 09:18 |
Arizona眼睛模型
简介 @h>#cwhU %bDd 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。 e!tgWYN ?=r!b{9 模型 j@GMZz< 1Y}gki^F 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。 R3?~+y& R&ou4Y:DG
Table 1. AZ眼睛模型的定义 GdG%=+ 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. k\ I$ve"* Gk[P-%%b / 光源 a Q`a>&R0 Z"Et]xSU%$ 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。 Mh~T.;f.qq F<V
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图1. 光源和提示信息使用 !c SD9q* 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。 mG?a)P {H])Fob 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。 zE<vFP-1v ]\#RsVX
图2. 字母F光源的设定方法光 ~Rv U+D {F@;45)o
图3. 字母F在视网膜上位置点列图 & RROra 视网膜的散射 }Ecm ;A-Ef 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。 ~-W.yg6D{ *,'"\n LR9'BUfFv
图4. 视网膜朗伯散射设定 cq[}>5*k 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。 ?7G[`@^Y
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图5. 视网膜重点采样规格设定 ?[m5|ty# 脚本 OVj,qL) k?J}-+Bm[| 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: X,y$!2QI NoKYHN^*w
图6. 用户对话框的创建与编辑 C{2UPG4 x
图7. 用户对话框编辑器 2ZE4^j| 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 JBoo7a1 余下的脚本计算与屈光度有关的所有参数。 X0!48fL* {|rwIRe 分析 7kJ,;30) Q45rP4mQ 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 .Dx]wv S:1! )7
图7. 字母F在视网膜上颜色分析 \{UiGCK 脚本代码 rcyH2)Y/e Q2fa]*Z5 Option Explicit 'Remove this to enable non-dimensioned variables to be used. GGLVv) wkIH<w|jb Dim entity As T_ENTITY w6wXe_N+M Dim op As T_OPERATION /5=A#G Dim mat As T_MODELMATERIAL #a .aD+d' Dim A As Double ;- cq#8S Dim pupilDiam As Double l|uN-{w Dim eID As Long Y:byb68 Dim parID As Long -7pZRnv Dim count As Integer L3kms6ch Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 5|>jz ` Dim tlens As Double, nlens As Double "arbUX~d Dim curv As Double, conic As Double W0nRUAo[ Dim ok As Long 9JUlu = j}00,WH Sub Main .79'c%3} `[:f;2(@ '用户输入对话框 sxuYwQ Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 6~2!ZU TextBox 220,21,40,21,.TextBox1 'default: 0 1= <Qnmw Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 9xWeVlfQ OKButton 40,91,90,21 z{%G CancelButton 190,91,90,21 e8gD(T Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 #cmj?y() TextBox 220,49,40,21,.TextBox2 'default: 4 ^c!Hur6) End Dialog CF$^we Dim dlg As UserDialog YL{LdM-xM Y]Xal
ok = Dialog (dlg) VvPTL8Z dwmj*+ If ok=0 Then 'cancel button was pressed $MP'j9-S? Print "Execution cancelled." QU\|RX End py,z7_Nuh End If #PFf`7b,z >Ks| yNJ 'Assign accommodation and pupil diameter & use defaults if field left empty W/&cnp\ If dlg.TextBox1 = "" Then 0_%u(? A = 0 'Default accommodation yuhSP{pv' Else Z$+0gm\Cnw A = CDbl(dlg.TextBox1) J.*dA j End If m+V'*[O{ //AS44^IS If dlg.TextBox2 = "" Then NB>fr#pb pupilDiam = 4 'Default pupil diameter =m1B1St 2 Else {E!$<A9 pupilDiam = CDbl(dlg.TextBox2) :PjHs Np;^ End If 0A|.ch :GO}G`jY Print " " ^S[Mg6J Print "Accommodation = " & A & " Diopters" Pirc49c Print "Pupil Diameter = " & pupilDiam & " mm" nKV1F0- #,$d!l @ ' Calculate new parameters with accommodation Q;`#ujxL taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness NPKRX Li% +e4o~p Rant = 12.0 - 0.4*A 'Radius of anterior lens ]3C7guWz CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens UB=I> &grT} Rpost = -5.224557 + 0.2*A 'Radius of posterior lens Q7f\ 5QjT CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens Bm.%bA>
LL.YkYu tlens = 3.767 + 0.04*A 'Lens thickness elw<(<u` @@_f''f$ nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction 3C2L _ K3 *y
F 9_\n 'Adjust parameters to account for accommodation rFdovfb
mVW:]|!s '************************************************************************* $I+QyKO9k
'Aqueous thickness (Position of Lens) n|3ENN '************************************************************************* >8HcCG eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Qnph?t> GetCustomElement eID, entity <+pwGKtD EubF`w$KWX parID = FindFullName( "Geometry.Arizona Eye" ) I=|b3- leX&py ' Delete any shift(s) in z jj.i W@m count = 0 X>=`{JS1 While GetOperationCount(eID)>count <<Ut@243\ GetOperation eID, count, op xR\$2( If op.Type="ShiftZ" Then i5q
VQo DeleteOperation eID,count fD]}&xc count=count-1 U c$RYPq End If ,;hIyT count=count+1 ?nCG:\&;'= Wend 8?h-H#h @9-z8PyF 'Set new shift in gI<TfcC op.Type = "ShiftZ" iLNKC' op.val1 = taq x{j|Tf3,G op.parent = parID vc5g4ud AddOperation eID, op m "h{HgJd Print "Set aqueous humor thickness = " & taq-0.55 "i(k 8+iK G!uoKiL '************************************************************************* tc.R(F96 'Radius and conic constant of anterior lens r|:i: ii '************************************************************************* E~3wdOZv1 eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) X@2[!%nm GetConic eID, entity, curv, conic n0:'h}^ HSE9-c= SetConic eID, entity, 1/Rant, CCant ,dLh`t<\ Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant K}L-$B*i ~q5" ' '************************************************************************* n&jfJgD&g 'Radius and conic constant of posterior lens W
MU9tq[ '************************************************************************* Oca_1dlx eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) z}&?^YU*)` GetConic eID, entity, curv, conic b*\K I 4siNY4i" SetConic eID, entity, 1/Rpost, CCpost MuQyHEDF Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost c,:xm=& P4-`<i]!S '************************************************************************* \!Cix}}1 'Lens thickness (Position of posterior lens surface) l\I#^N '************************************************************************* N.vt5WP $e)d!m. parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7F!_gj p 3Un
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9 ' Delete any z-shift(s) M_<O'Ii3 count = 0 d[9c6C:<q While GetOperationCount(eID)>count $6kVhE!; GetOperation eID, count, op ^mz&L|h If op.Type="ShiftZ" Then p%pM3<p DeleteOperation eID,count O0`sg90,C count=count-1 a;WRTV End If
G?AZ%Yx count=count+1 [p^N].K$ Wend iZ} w>1 =ZR9zL=h 'Set new z-shift GVP"~I~/: op.Type = "ShiftZ" (n_lu=E70 op.val1 = tlens ~8L*N>Y op.parent = parID e[.c^Hw AddOperation eID, op bi;?)7p&ZY Print "Set lens thickness = " & tlens SAMP,un7 'Alt+O_ '************************************************************************* #Mkwd5S|L 'Lens index of refraction MB06=N '************************************************************************* 3z';Zwz &X eID = FindMaterial( "Lens" ) V3DXoRE-8i GetModelMaterial eID, mat Q\|72NWS ufyqfID mat.Nd = nlens _H@Y%"ZHJ6 SetModelMaterial eID, mat yr?*{; Print "Set lens index of refraction = " & nlens ^}7iouE C \n$s5i- '************************************************************************* #-*7<wN 'Pupil diameter $N4%I4 '************************************************************************* =oQw?,eY
eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) o8Vtxnkg 3NAU|//J 'Adjust pupil diameter (trimming volume inner hole) |U)m'W-(q })RT2zw} SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" BB@I|)9O( ~'>RK ' Adjust pupil location to just in front of the lens S81Z\=eK parID = FindFullName( "Geometry.Arizona Eye" ) 4gbi?UAmX eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) q/w<>u count = 0 hiO:VA While GetOperationCount(eID)>count e&%m[:W:< GetOperation eID, count, op {uH
4j4)2 If op.Type="ShiftZ" Then E`s9SE DeleteOperation eID,count x dDR/KS count=count-1 l}odW End If k.=67L count=count+1 =+;1^sZ Wend -wv5c op.Type = "ShiftZ"
Z)}q=NjA op.val1 = taq-0.01 =Lx*TbsFYt op.parent = parID dayp1%d AddOperation eID, op mw0#Dhyy1= *%<Ku&C Print "Set pupil diameter = " & pupilDiam EXn$ [K; *AX)QKQ@ 'Update AZ Eye subassembly Description uX_A4ht* eID = FindFullName( "Geometry.Arizona Eye" ) %~%1Is`4J GetEntity eID, entity 3S='/^l entity.Description = "Accommodation = " & A & "D" B198_T! SetEntity eID, entity n.zVCKNH !#cZ! Update xHEkmL`)4 Print "DONE!" Y^5X> 2_Me
4 End Sub 8qwc]f$.w r"#h6lYK& 如果屈光度是4,光瞳直径是4,则会输出如下数据: Q|eRek #:Z"V8n' Accommodation = 4 Diopters [P#^nyOh( Pupil Diameter = 4 mm R:=C Set aqueous humor thickness = 2.81 . 2_t/2 Set anterior lens radius = 10.4 and conic constant = -2.375869 {MX_t/o=f Set posterior lens radius = -4.424557 and conic constant = -3.081019 _YF~DU Set lens thickness = 3.927 )US|&>
o8 Set lens index of refraction = 1.42672 CORX .PQ Set pupil diameter = 4 ?3
J DONE! f:iK5g -f?Rr:# =uKGh`^[ QQ:2987619807 <()xO(
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