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2020-12-09 09:18 |
Arizona眼睛模型
简介 ]Fl+^aLS ^ yH|k@y 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。 =EsKFt" c{rX7+bN 模型 #B)/d?aa' Mwp#.du( 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\sLwLLlG tN";o\!}
Table 1. AZ眼睛模型的定义 v#YO3nD 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. Qf7]t-Kp f(?>z!n0 光源 dSk\J[D wC'KI8- 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。 \TC&/'7} 7b:oz3 ?PI L.l%EcW=,
图1. 光源和提示信息使用 ?ti7iBz? 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。 5j{o0&=_$ m$pXe< 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 4x e:+sA.N !ssE >bDa
图2. 字母F光源的设定方法光 /=,^fCCN !*?&V3!
图3. 字母F在视网膜上位置点列图 u0w2v+ 视网膜的散射 H<X4R REQ2pfk0 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 5}e-\:J>B S;i^ucAF Q:>;d-D|1
图4. 视网膜朗伯散射设定 3f
eI 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 WI[6l6 :4]&R9J>o pc:K5 -Os
图5. 视网膜重点采样规格设定 H6bomp" 脚本 6"-LGK: x #BUIi 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: K)l{3\9l| mrE^D|
图6. 用户对话框的创建与编辑 H Y.,f_m
图7. 用户对话框编辑器 p
Ic;9 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 :NA cad 余下的脚本计算与屈光度有关的所有参数。 k[A=:H1" K34ca-~ 分析 im*QaO%a4 TLPy/, 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 }Jh!B| jEit^5^5|
图7. 字母F在视网膜上颜色分析 T/)$}#w0i 脚本代码 W{1=O)w l
\xIGs Option Explicit 'Remove this to enable non-dimensioned variables to be used. >~>=[M0 rS>njG;R Dim entity As T_ENTITY W_O,Kao Dim op As T_OPERATION aNv6 " Dim mat As T_MODELMATERIAL \P&'4y~PL Dim A As Double #++MoW}'g Dim pupilDiam As Double Uc<B)7{' Dim eID As Long _GI [SzD Dim parID As Long IDdhBdQ Dim count As Integer 1p+2*c Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Fm*n>^P@Y Dim tlens As Double, nlens As Double lOI(+74 Dim curv As Double, conic As Double xfos>|0N Dim ok As Long O0WzDD 67/hhO Sub Main 75Jh(hd( L
a0H '用户输入对话框 /<zBcpVNV Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 vRn^n TextBox 220,21,40,21,.TextBox1 'default: 0 WTY{sq\'
o Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 6LNm>O OKButton 40,91,90,21 7 82NiVed CancelButton 190,91,90,21 k{y@&QNj Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ToDNBt.u{+ TextBox 220,49,40,21,.TextBox2 'default: 4 Z&JW}''n|F End Dialog Zhz.8W Dim dlg As UserDialog 'n)M0e YUM%3 ok = Dialog (dlg) L7q%u.nB1 } Yjic4? If ok=0 Then 'cancel button was pressed
c.KpXY Print "Execution cancelled." ~iEH?J%i1r End ]/bf#&@g`k End If y?CEV-3+ 1 /7H` O? 'Assign accommodation and pupil diameter & use defaults if field left empty E"pq ZP = If dlg.TextBox1 = "" Then VAsaJ`vcb A = 0 'Default accommodation 224I%x., Else kX+y2v(2++ A = CDbl(dlg.TextBox1) ;u!>( QQ End If i7cMe8 ;w}ZI<ou If dlg.TextBox2 = "" Then B=u@u([. pupilDiam = 4 'Default pupil diameter xh_6@}D2J Else S=eY`,'#R pupilDiam = CDbl(dlg.TextBox2) $@}6P,mg End If ?9 :{p r,L#JR w#- Print " " Ia0.I " , Print "Accommodation = " & A & " Diopters" 1;]cYIq Print "Pupil Diameter = " & pupilDiam & " mm" WnvuB.(@3 PG&@.KY ' Calculate new parameters with accommodation 3oE *86 taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness l?pZdAE d]0fgwwGC Rant = 12.0 - 0.4*A 'Radius of anterior lens F1w~f
< CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens F4YCU$V NVcL9"ht*@ Rpost = -5.224557 + 0.2*A 'Radius of posterior lens 'fy1'^VPAV CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens #- f7hg* xzz[!yJjG tlens = 3.767 + 0.04*A 'Lens thickness ]y2(ZTNTs `5=0f}E nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction ncu
&<j }U vd9l1"S 'Adjust parameters to account for accommodation FC.y%P, ?UcW@B{ '************************************************************************* tceQn
^|< 'Aqueous thickness (Position of Lens) ^z"90-V^ '************************************************************************* YB*ZYpRVl eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9"I/jd0B GetCustomElement eID, entity vz#rbBY*; uG${`4 parID = FindFullName( "Geometry.Arizona Eye" ) UpN:F
^7.864 ' Delete any shift(s) in z %a{cJ6P count = 0 &t5pJ`$(Cy While GetOperationCount(eID)>count 600-e;p GetOperation eID, count, op (TVzYm
y If op.Type="ShiftZ" Then ppM d DeleteOperation eID,count oz(<e count=count-1 ,xn+T)2I End If *h-_
count=count+1 u;F++$= Wend '2WYbcU hE/gul?|_ 'Set new shift in s~Ni\SF op.Type = "ShiftZ" oi::/W|A+ op.val1 = taq |GA4fFE= op.parent = parID 7M<7^)9 AddOperation eID, op )z=`,\&p: Print "Set aqueous humor thickness = " & taq-0.55 f]h99T TMhUo#`I|
'************************************************************************* _o8il3 'Radius and conic constant of anterior lens s4@AK48 '************************************************************************* VWI|`O.w eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ZcYxH|Gn GetConic eID, entity, curv, conic (=j]fnH? q-KN{y/ SetConic eID, entity, 1/Rant, CCant 3R
!Mfz* Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 7;dV]N DQ?'f@I&* '************************************************************************* @-NdgM< 'Radius and conic constant of posterior lens #c5G"^)z '************************************************************************* ^}ngbDn eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) zF>|
9JU GetConic eID, entity, curv, conic vnw83a%3 `jSxq66L p SetConic eID, entity, 1/Rpost, CCpost KA0Ui,q3 Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost LR@rn2Z 2ZNTj u7h '************************************************************************* ^+Ie 'Lens thickness (Position of posterior lens surface) G[)Ll= '************************************************************************* Q$iYhR 'ZgrN14 parID = FindFullName( "Geometry.Arizona Eye.Lens" ) .8<bz4 ]uI#4t~ ' Delete any z-shift(s) SaH0YxnY+ count = 0 iN %kF'&9 While GetOperationCount(eID)>count po}Jwx! GetOperation eID, count, op DBWe>Ef( If op.Type="ShiftZ" Then 4N[8LC;MH DeleteOperation eID,count yEJ}!/ count=count-1 ]E .+)> End If ytf.$P count=count+1 Q mT L- Wend ?\L@Pr|=Dr Du k v[/60 'Set new z-shift YLVIn_\} op.Type = "ShiftZ" @MWrUx op.val1 = tlens Qr6[h! op.parent = parID Smzy EMT AddOperation eID, op ;f:}gMK Print "Set lens thickness = " & tlens x{`>Il {9q~bt '************************************************************************* y m<3 'Lens index of refraction )@Fuw* '************************************************************************* 1@JAY!yoo_ eID = FindMaterial( "Lens" ) 3Kc GetModelMaterial eID, mat 8
;y N v}XMFC ! mat.Nd = nlens -/*-e
/+b SetModelMaterial eID, mat d[;S n:B Print "Set lens index of refraction = " & nlens h[b;_>7 ^a#Vp '************************************************************************* 4:GVZR|- 'Pupil diameter sPuNwVX>}I '************************************************************************* "q5Tw+KCfu eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) `bw>.Ay y=_8ae}aD~ 'Adjust pupil diameter (trimming volume inner hole) (%=[J/F/ U6;,<-bL SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" I&^B?"Y 8Ux3,X= ' Adjust pupil location to just in front of the lens O>9+tQ parID = FindFullName( "Geometry.Arizona Eye" ) pJ!:mt eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) G[z!;Zuf count = 0 N=]2vyh While GetOperationCount(eID)>count l ?RsXC GetOperation eID, count, op dr#g[}l'H If op.Type="ShiftZ" Then H g(%gT DeleteOperation eID,count 6}zargu(; count=count-1 V+j58Wuf End If
#/a>dK count=count+1 `./$hh Wend = s^KZV op.Type = "ShiftZ" CBz$N) f op.val1 = taq-0.01 EUZ#o\6 op.parent = parID ?UCK AddOperation eID, op \6~(#y e=S51q_0 Print "Set pupil diameter = " & pupilDiam ,$BbJQ5 n\Y{?x 'Update AZ Eye subassembly Description YBb%D eID = FindFullName( "Geometry.Arizona Eye" ) VL4ErOoZ GetEntity eID, entity >Z@^R7_W entity.Description = "Accommodation = " & A & "D" I*8i=O@0T SetEntity eID, entity WfYu-TK* X/Umfci Update =g)|g+[H Print "DONE!" F*Lm=^: &}%rZU End Sub #;,dk(URo ,ND}T#yTR 如果屈光度是4,光瞳直径是4,则会输出如下数据: T v2d?y }Fy~DsQ Accommodation = 4 Diopters }@JPvIE Pupil Diameter = 4 mm P(B:tg Set aqueous humor thickness = 2.81 GR6BpV7 Set anterior lens radius = 10.4 and conic constant = -2.375869 $]O;D~ Set posterior lens radius = -4.424557 and conic constant = -3.081019 :ZrE/3_S Set lens thickness = 3.927 VE3,k'^v Set lens index of refraction = 1.42672 x`:zC# Set pupil diameter = 4 #J&45 DONE! Reci:T(_ DPIIE2X rZ}y'A QQ:2987619807 E2J.t`H
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