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2020-12-09 09:18 |
Arizona眼睛模型
简介 `@i!'h KfLp cV 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。 <o\I C?A sMAu* 模型 $Z^HI $F86Dwd 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。 VBI~U?0 $v+t~b
Table 1. AZ眼睛模型的定义 ~@bh[o~rF 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. <f`G@ giz#(61j^ 光源 |0/~7l @I|gA 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 +eD+Z.{ 3.s.&^ y2,M9
图1. 光源和提示信息使用 7q[a8rUdh 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 -?68%[4lm_ -V)DKf"f 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 Q'S"$^~{ DJf!{:b)
图2. 字母F光源的设定方法光 ];1Mg J -g<-!>RM
图3. 字母F在视网膜上位置点列图 _}-Ed,.= 视网膜的散射 vmZyvJSE &*N;yW""f 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。 m|w-}s, S(
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图4. 视网膜朗伯散射设定 %Cz&7 qf" 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。 7U\GX >FabmIcC cRhu]fv()
图5. 视网膜重点采样规格设定 xMu[#\Vc 脚本 %nfaU~IqK ]V K%6PQ0 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: o1kY|cnGH [_h/DhC:+
图6. 用户对话框的创建与编辑 ]e+88eQ
图7. 用户对话框编辑器 Y[ciT) 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。 $ RDwy)9 余下的脚本计算与屈光度有关的所有参数。 M &g1'zv?/ x4C}AyR 分析 i/%+x-# `i,l)X] 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 Io81zA ?2#MU
图7. 字母F在视网膜上颜色分析 )E.!jL:g 脚本代码 <!s+X_^ +q/ j Option Explicit 'Remove this to enable non-dimensioned variables to be used. As;@T$G D 1Q@4
g Dim entity As T_ENTITY \qAg]- Dim op As T_OPERATION Is $I;` Dim mat As T_MODELMATERIAL ;ctJ9"_g Dim A As Double YnzhvE Dim pupilDiam As Double %&RF;qa2xu Dim eID As Long 5mxYzu;#] Dim parID As Long axSJ:j8 Dim count As Integer mu[:b Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ,u1Yn} Dim tlens As Double, nlens As Double 75+#)hNa!P Dim curv As Double, conic As Double 0'IV"eH2 Dim ok As Long :QGd/JX$n` t0 1@h_WS Sub Main *,:>EcDr wsnR$FhQ` '用户输入对话框 IezOal Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 PtUea
TextBox 220,21,40,21,.TextBox1 'default: 0 WPmH4L>T Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 qW1d;pt OKButton 40,91,90,21 D+Ke)-/ CancelButton 190,91,90,21 jIMT&5k Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 xpWx6 TextBox 220,49,40,21,.TextBox2 'default: 4 G^`IfF-j End Dialog >VQP,J{ Dim dlg As UserDialog *v}8n95*2 mIK-a{?G ok = Dialog (dlg) "B~c/%#PH ADTx _tE If ok=0 Then 'cancel button was pressed 7*9a`p3w Print "Execution cancelled." <QlpIgr End -bN;nSgb End If 8
z) K 2qw -: 'Assign accommodation and pupil diameter & use defaults if field left empty Aj854 L(! If dlg.TextBox1 = "" Then A{[joo A = 0 'Default accommodation 3C,G~)=
x Else $)1i)/]9U A = CDbl(dlg.TextBox1) yJCqP= End If 66P'87G WF)(Q~op0U If dlg.TextBox2 = "" Then 0Jz5i4B pupilDiam = 4 'Default pupil diameter 4GA9oLl Else 3@qy}Nm pupilDiam = CDbl(dlg.TextBox2) SXYH#p End If CFm(
yFk gRnn}LL^ Print " " fgiOYvIS2m Print "Accommodation = " & A & " Diopters" Tz\ PQ)! Print "Pupil Diameter = " & pupilDiam & " mm" DChqcdx~~ TzaR{0
1 ' Calculate new parameters with accommodation XX85]49`% taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness UlG8c~p z n,y'}, Rant = 12.0 - 0.4*A 'Radius of anterior lens E[:eMJR CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens y /$Q5P+o <G9HVMiP Rpost = -5.224557 + 0.2*A 'Radius of posterior lens |K|[>[?Z/ CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens (=2-*((&(A WpPm|h tlens = 3.767 + 0.04*A 'Lens thickness z%)~s/2Rs rq>}]
U nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction <>n-+Kr 9H~2
iW,Q; 'Adjust parameters to account for accommodation mH1T|UI 6:fHPlqW '************************************************************************* Dq [f 'Aqueous thickness (Position of Lens) ;6 ?a8t@ '************************************************************************* _d|CO eID = FindFullName( "Geometry.Arizona Eye.Lens" ) s6q6)RD" GetCustomElement eID, entity %DK0s(*w0 [@VM'@e7 parID = FindFullName( "Geometry.Arizona Eye" ) jW,b"[ &d%\&fCm( ' Delete any shift(s) in z x7<2K( count = 0 jmp0 %:+L While GetOperationCount(eID)>count "QKCZ8_C GetOperation eID, count, op N)I9NM[ If op.Type="ShiftZ" Then TANv)&,|9 DeleteOperation eID,count AiP#wK; count=count-1 6`PQP;
End If WE{fu{x count=count+1 w#XD4kwQG Wend ]C;X/8'Jf5 kB)u@`</mV 'Set new shift in diz=|g=w op.Type = "ShiftZ" a2!U9->! op.val1 = taq J~]Y op.parent = parID Silh[8 AddOperation eID, op (-no`j Print "Set aqueous humor thickness = " & taq-0.55 ?XlPKY afw`Heaa2( '************************************************************************* _o52#Q4 'Radius and conic constant of anterior lens u?-|sv* '************************************************************************* HBdZE7.x)3 eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) &KYPi'C9!z GetConic eID, entity, curv, conic ;u8a%h! 5%_aN_1?ef SetConic eID, entity, 1/Rant, CCant Y&XO:jB Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant VMee"'08 hCOCX_ '************************************************************************* `<Q[$z 'Radius and conic constant of posterior lens ^ Fnag]qQ '************************************************************************* ~Ydm"G eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) :MP*Xy\7&J GetConic eID, entity, curv, conic BXb=NE j|KjQ'9 SetConic eID, entity, 1/Rpost, CCpost 1KUM!DUD Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost /fSsh;F )n&6= Li '************************************************************************* sTxgU !_ 'Lens thickness (Position of posterior lens surface) g8SVuG<DI\ '************************************************************************* j S4\; y;if+ parID = FindFullName( "Geometry.Arizona Eye.Lens" ) `53S[8 O**~ Tj ' Delete any z-shift(s) *mJ\Tzc) count = 0 #z1/VZ While GetOperationCount(eID)>count ~n~j2OE GetOperation eID, count, op U2Tw_ If op.Type="ShiftZ" Then S\SYFXUl DeleteOperation eID,count
`-!kqJ count=count-1 UQg_y3
#V End If A+MG?k>yg count=count+1 |ms. Wend HU/2P` DGP cy(4g-b]@e 'Set new z-shift r;9 V7C op.Type = "ShiftZ" ;nx.:f op.val1 = tlens @#p6C op.parent = parID I
6'!b/ AddOperation eID, op [}=a6Q>) Print "Set lens thickness = " & tlens ' Tk4P{ %g~&$oZmq '************************************************************************* R/xT.EQ(N 'Lens index of refraction ' GUCXx '************************************************************************* 8OMMV,QF eID = FindMaterial( "Lens" ) :}R,a=N GetModelMaterial eID, mat m5o$Dus+?' kWacc&*| mat.Nd = nlens t2iQ[`/?~ SetModelMaterial eID, mat r8tW)"? Print "Set lens index of refraction = " & nlens c*y*UG H_JE)a:+ '************************************************************************* XtQwLH+F
'Pupil diameter ~z\a:+ '************************************************************************* &Hyy .a eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) }U(bMo@; Na4O( d` 'Adjust pupil diameter (trimming volume inner hole) FUXJy{n6"2 D59q/@ SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" (<
>L fn k 1a?yH)= ' Adjust pupil location to just in front of the lens |@~_&g parID = FindFullName( "Geometry.Arizona Eye" ) zBK"k]rz eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 4TI` count = 0 )4h|7^6ji While GetOperationCount(eID)>count $@vB<(sk GetOperation eID, count, op L/E7xLz If op.Type="ShiftZ" Then wwRPfr[ DeleteOperation eID,count V c;g$Xr[ count=count-1 NJSbS<O End If bIlNA )g count=count+1 p>i8aN Wend q{_ f" op.Type = "ShiftZ" 0y t36Du op.val1 = taq-0.01 X- X`Z`o op.parent = parID 5JEOLPS AddOperation eID, op 2
6DX4 JS/ChoU Print "Set pupil diameter = " & pupilDiam HI{h>g T 6"+9$nFyW 'Update AZ Eye subassembly Description ^eyVEN eID = FindFullName( "Geometry.Arizona Eye" ) eEfGH GetEntity eID, entity Sa%%3_& entity.Description = "Accommodation = " & A & "D" .jg@UAK SetEntity eID, entity 'sXrtl7{^ 5Po:$( Update b`$qKO Print "DONE!" 5|~nX8> gaxM# End Sub Mtv{37k~ b !y 如果屈光度是4,光瞳直径是4,则会输出如下数据: !*L)v 4F9!3[}qF Accommodation = 4 Diopters t)Cf]]dV Pupil Diameter = 4 mm M 87CP=yc Set aqueous humor thickness = 2.81 ,Jh#$mil Set anterior lens radius = 10.4 and conic constant = -2.375869 .>#O'Z&q9 Set posterior lens radius = -4.424557 and conic constant = -3.081019 X(eW+,H Set lens thickness = 3.927 9a=>gEF],@ Set lens index of refraction = 1.42672 7G^Q2w Set pupil diameter = 4 >e&
L" DONE! 1x=x,lcL `"[qb ?z VBix8| QQ:2987619807 j{r@>g;3
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