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2021-10-22 09:55 |
Arizona眼睛模型
简介 HxK$ 4I` }U@m*dEG 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。 Li 2Zndp 8#R?]Uwq 模型 @|yeqy_: doHF|<s 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。 Y}6n]n;uR =Nz0.:
Table 1. AZ眼睛模型的定义 T5wjU*=IL 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. r!}al5~& n{*e 9Aw 光源 +@X5!S6 G;gJNK"e 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。 ctQbp~- I
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图1. 光源和提示信息使用 Ql?^
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SqG 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。 6]Q3Yz^h l? #xAZx&_ 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。 -6Tk<W
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图2. 字母F光源的设定方法光 QbYc[8-[ t?;T3k[RM
图3. 字母F在视网膜上位置点列图 31Cq22" 视网膜的散射 Gt9wR &R+#W 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。 EjEFg#q hwnx<f ' JM0I(% Z%
图4. 视网膜朗伯散射设定 L{g E'jCC 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。 Z.&\=qiY ~E4"}n[3A# G,&%VQ3P>
图5. 视网膜重点采样规格设定 NTs;FX~g[ 脚本 8U~.\`H-PT 9T2xU3UyY 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: 0Flu\w/+P pw>m.=9|y
图6. 用户对话框的创建与编辑 Hr;h4J
图7. 用户对话框编辑器 =4C}{IL 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。 x_@i(oQ:_ 余下的脚本计算与屈光度有关的所有参数。 @^nu#R +2cs#i 分析 PW}OU9is kD~uGA 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 #;9H@:N "5DJu~
图7. 字母F在视网膜上颜色分析 ]XUl@Y. 脚本代码 #/J
'P[z vfvlB[ Option Explicit 'Remove this to enable non-dimensioned variables to be used. T!q_/[i~7 ateUpGM QU Dim entity As T_ENTITY fhp)S", Dim op As T_OPERATION 74vmt<Q Dim mat As T_MODELMATERIAL 7-iIay1h" Dim A As Double f%^'P"R Dim pupilDiam As Double <SXZx9A! Dim eID As Long >POO-8Q Dim parID As Long ESQ!@G/n Dim count As Integer f%fa{ Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ft5DU/% Dim tlens As Double, nlens As Double N}/>r D Dim curv As Double, conic As Double -R+zeu(e' Dim ok As Long Y'm=etE DMgBcP Sub Main 10N,?a \tt'm\_ '用户输入对话框 :=g.o;(/N Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 w[fDk1H) TextBox 220,21,40,21,.TextBox1 'default: 0 y]qsyR18i Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 #;j9}N OKButton 40,91,90,21 Z}Cqd?_') CancelButton 190,91,90,21 -Q[g/% Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ~^o=a?L`< TextBox 220,49,40,21,.TextBox2 'default: 4 k'13f,o} End Dialog IvU{Xm"qB Dim dlg As UserDialog 4\Di,PPu s"mFt{Y ok = Dialog (dlg) 1t~({Pl<> ^ "6f\ If ok=0 Then 'cancel button was pressed ~
l )t|'6 Print "Execution cancelled." ]mkJw 3 End R$0U<(/ End If mY2:m(9"5 u^Sv#K X 'Assign accommodation and pupil diameter & use defaults if field left empty ?iz<
If dlg.TextBox1 = "" Then .j 'wQ+_ A = 0 'Default accommodation X\A]"su Else 3ut_Bt\ A = CDbl(dlg.TextBox1) ZJXqCo7O End If JLUms rc~Y=m If dlg.TextBox2 = "" Then 3"i% { pupilDiam = 4 'Default pupil diameter FN{/.?w( Else *FPg#a+ pupilDiam = CDbl(dlg.TextBox2)
_"f<Ol[! End If Q_lu`F| zzJ^x8#R Print " " ~{QEL2 Print "Accommodation = " & A & " Diopters" ;/A}}B]y Print "Pupil Diameter = " & pupilDiam & " mm" 75 Fp[Q- YRa4W.&Yn ' Calculate new parameters with accommodation )
hdgz$cl taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness @a;sV!S{ O]_={% Rant = 12.0 - 0.4*A 'Radius of anterior lens Y@:3 B:m# CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens sFx$>:$ )+B=z}:Nfz Rpost = -5.224557 + 0.2*A 'Radius of posterior lens qRUCnCZs CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens mVrK z @^HwrwRA tlens = 3.767 + 0.04*A 'Lens thickness 24|<<Xn ,?w!5N;iRO nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction _h~p:= Lw*1 .~ 'Adjust parameters to account for accommodation +3?`M<L0 }~GV'7d1 '************************************************************************* TAAR'Jz S 'Aqueous thickness (Position of Lens) >Jiij '************************************************************************* ORtg>az\% eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?1DUNZ6 GetCustomElement eID, entity Ns~g+C9 ;_bq9x parID = FindFullName( "Geometry.Arizona Eye" ) pP
oxVvG{ C zpsqTQ ' Delete any shift(s) in z wLSjXpP8 count = 0 "o<D;lO While GetOperationCount(eID)>count g1dmkX GetOperation eID, count, op xO gq-@` If op.Type="ShiftZ" Then a[JZ5D DeleteOperation eID,count SNxz*`@4 count=count-1 7(5]Ry: End If X@eg<]'m count=count+1 KMe.i' Wend e18T(g_i F]Pul|.l 'Set new shift in A'b<?)Y7_ op.Type = "ShiftZ" 3li q9P_ op.val1 = taq {'&8`d op.parent = parID \|Y{jG<cu AddOperation eID, op mR6E]TuM Print "Set aqueous humor thickness = " & taq-0.55 y,1S&k }o{!}g9 '************************************************************************* y#nSk%"t" 'Radius and conic constant of anterior lens r5Wkc$ '************************************************************************* MsSoX9A{D eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 'bG1U`v=3 GetConic eID, entity, curv, conic kU>#1He AV9:O{ SetConic eID, entity, 1/Rant, CCant ?Ip$;s Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant =cknE= AwA1&mh '************************************************************************* ?<g|.HY/ 'Radius and conic constant of posterior lens '|J) ds '************************************************************************* f};!m=b eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) #Xj;f^}/ GetConic eID, entity, curv, conic 37,L**Dgs J~fuW?a]r SetConic eID, entity, 1/Rpost, CCpost +0SW ?#% Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 9k*^\@\\x ho(5r5SNE '************************************************************************* es{cn=\s 'Lens thickness (Position of posterior lens surface) 8x`Kl( '************************************************************************* ]kzv8# 77 *v-8c parID = FindFullName( "Geometry.Arizona Eye.Lens" ) k`{RXx <tGI]@Nwk ' Delete any z-shift(s) #R5we3&p count = 0 4|I7:~ While GetOperationCount(eID)>count i=x.tsJ:hB GetOperation eID, count, op Dg1kbO=2 If op.Type="ShiftZ" Then b*@&c9I;q DeleteOperation eID,count 7j4ej|Fjo count=count-1 QZ6[*_Z6 End If 6sO count=count+1 Ks9FnDm8 Wend s0_-1VU ^mS.HT=X 'Set new z-shift (9Fabo\SH op.Type = "ShiftZ" L?AM&w-cg9 op.val1 = tlens tCd{G
c op.parent = parID \Ac}R' AddOperation eID, op 8Pl+yiB/o` Print "Set lens thickness = " & tlens jdV .{8@ *1 n;p)K '************************************************************************* A73V6" 'Lens index of refraction ]J8KCjq@ '************************************************************************* |G|* eID = FindMaterial( "Lens" ) }wa}hIqx GetModelMaterial eID, mat V:nMo2'hb GhSL%y mat.Nd = nlens m~Kch~~] SetModelMaterial eID, mat !N@S^JD6 Print "Set lens index of refraction = " & nlens JUe K"|fA yEMX ` '************************************************************************* /k4^& 'Pupil diameter .E?bH V '************************************************************************* lGD%R'} eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Td["l!-fe vkDZv@ 'Adjust pupil diameter (trimming volume inner hole) Zj%B7s1A 4GMa5]Ft SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" -6hu31W 7/5NaUmPTt ' Adjust pupil location to just in front of the lens "ZA$"^ parID = FindFullName( "Geometry.Arizona Eye" ) &KOG[tv eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) _WRR
3 count = 0 1kz9>;Ud6 While GetOperationCount(eID)>count /8P4%[\ GetOperation eID, count, op gQ[] If op.Type="ShiftZ" Then glOqft&>` DeleteOperation eID,count ;PP_3` count=count-1 pXpLL_ End If twYB=68 count=count+1 CP F>^Mp# Wend c5T~0 'n op.Type = "ShiftZ" LV[66<T op.val1 = taq-0.01 I>YtWY|ed op.parent = parID Z=e[
!c AddOperation eID, op Qwp\)jVi YYZs#_ Print "Set pupil diameter = " & pupilDiam gLXvw] *783xEF>f 'Update AZ Eye subassembly Description Q%X:5G? eID = FindFullName( "Geometry.Arizona Eye" ) eCPKpVhP GetEntity eID, entity
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pe[V~F entity.Description = "Accommodation = " & A & "D" 6,V.j>z SetEntity eID, entity A|`Joxr #G[
*2h~99 Update OTNZ!U/)j Print "DONE!" X1
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vue@ End Sub 8a":[Q[ : e0R7sj 如果屈光度是4,光瞳直径是4,则会输出如下数据: K&\BwBU +_-)0[+p Accommodation = 4 Diopters @>
+^< Pupil Diameter = 4 mm ;*j6d3E Set aqueous humor thickness = 2.81 k
Nf!j Set anterior lens radius = 10.4 and conic constant = -2.375869 R.T?ZF Set posterior lens radius = -4.424557 and conic constant = -3.081019 v4,syd*3|V Set lens thickness = 3.927 Us@ {w`T Set lens index of refraction = 1.42672 1S)0
23N Set pupil diameter = 4 y ? {PoNI DONE! mNBpb}
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