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2021-10-22 09:55 |
Arizona眼睛模型
简介 VAf1 " )pC fNt`?pWH 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。 8'nVwb8I 7KL v6]b 模型 w6GyBo{2O_ |>27B 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。 1Y@Aixx pDIVZC
Table 1. AZ眼睛模型的定义 tlqiXh< 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. ^,_w$H ;y\IqiA{o 光源 sy"^?th}b orfO^;qTY 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 FUjl8b-| aV?@s4 f[a}aZ9)
图1. 光源和提示信息使用 ,J>5:ht(6 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 J)~L <|+Ex 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 DhT>']Z K4;'/cS
图2. 字母F光源的设定方法光 Ry K\uv yXF?H"h(
图3. 字母F在视网膜上位置点列图 vbBc}G"w 视网膜的散射 cmg^J
!~&R"2/ 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 7-T{a<g r1LViK [[Fx[
图4. 视网膜朗伯散射设定 ;\Y&ce 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 7MHKeLq CS-uNG6 "zRoU$X
图5. 视网膜重点采样规格设定 ^!z[t\$ 脚本 I'iGt~4$ jvFTR'R)= 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: YmgLzGk` ^8Q62
图6. 用户对话框的创建与编辑 ;)e2@'Agl
图7. 用户对话框编辑器 9;Ox;;w 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。 [4C:r! 余下的脚本计算与屈光度有关的所有参数。 !@'6)/ K7W6ZH9; 分析 C{DvD'^ ,o,I5>` 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 \y) cwWodPNm
图7. 字母F在视网膜上颜色分析 R>"OXFaE 脚本代码 !PJ 6%" D]~MC Option Explicit 'Remove this to enable non-dimensioned variables to be used. r*_ZJ*h[ Z%Zd2
v Dim entity As T_ENTITY fasgmi} Dim op As T_OPERATION 5<j%EQN|D Dim mat As T_MODELMATERIAL 5~WGZc Dim A As Double UHxE)]J Dim pupilDiam As Double ,|plWIl~ Dim eID As Long [$"n^5_~ Dim parID As Long )
^3avRsC Dim count As Integer %\r!7@Q Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double c#]q^L\x Dim tlens As Double, nlens As Double <xC#@OZ Dim curv As Double, conic As Double HcV"X,7S Dim ok As Long wz.6du6- Zg`Mz
_? Sub Main IGFR4+ _}VloiY '用户输入对话框 ZMLg;-T.&4 Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 i?:_:"^x TextBox 220,21,40,21,.TextBox1 'default: 0 YH_7=0EJ Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 %ck]S!}6 OKButton 40,91,90,21 OdY=z!Fls CancelButton 190,91,90,21 g
HbxgeL Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 `z )N,fF TextBox 220,49,40,21,.TextBox2 'default: 4 %T9 sz4V End Dialog 1`9xIm*9w Dim dlg As UserDialog ]mXLg:3B BC;: ok = Dialog (dlg) e$uiJNS2 @L:>!< If ok=0 Then 'cancel button was pressed JA_BKA Print "Execution cancelled." h=_0+\% End 0Ir<y End If [mr9(m[F ;h" P{fF 'Assign accommodation and pupil diameter & use defaults if field left empty +@K09ge If dlg.TextBox1 = "" Then dG71*)<)t A = 0 'Default accommodation 8Bq!4uq\5| Else ?EK?b
s A = CDbl(dlg.TextBox1) 5W@jfh) End If f5==";eP H'UR8% If dlg.TextBox2 = "" Then t/PlcV_M" pupilDiam = 4 'Default pupil diameter g@Qgxsyk> Else <ExZ:ip pupilDiam = CDbl(dlg.TextBox2) I]y.8~xs End If 'vaLUy9] "AhTH.ZP Print " " !GQ\"Ufs> Print "Accommodation = " & A & " Diopters" l?)ZJ3]a Print "Pupil Diameter = " & pupilDiam & " mm" n%\
/J K[7EOXLy ' Calculate new parameters with accommodation ^p/Ob'! taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness z5X~3s\dP .+([ Rant = 12.0 - 0.4*A 'Radius of anterior lens 3TZ*RPmFRm CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens tDCw- ~b|`'kU Rpost = -5.224557 + 0.2*A 'Radius of posterior lens
E|$Oha[ CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens FHPXu59u Y05P'Q tlens = 3.767 + 0.04*A 'Lens thickness o(Cey7 A=-F,=k(!/ nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction OcSEo7W hwDbs[: 'Adjust parameters to account for accommodation F("#^$ @&hnL9D8lL '************************************************************************* rqlc2m,<-p 'Aqueous thickness (Position of Lens) @i3bgx>_o '************************************************************************* vkRi5!bR eID = FindFullName( "Geometry.Arizona Eye.Lens" ) R,
8s_jN GetCustomElement eID, entity <p?&udqD 7gS1~Q4\V2 parID = FindFullName( "Geometry.Arizona Eye" ) VNtPKtx\ {3Vk p5%l ' Delete any shift(s) in z ='E$-_ count = 0 Sm2>'C While GetOperationCount(eID)>count kV Rn`n0 GetOperation eID, count, op ^-M^gYBR If op.Type="ShiftZ" Then \ M/6m^zS DeleteOperation eID,count jUqy8q& count=count-1 "XLe3n End If sF+=KH count=count+1 da$BUAqU Wend &wetzC) @lUlY2 'Set new shift in xDO7A5 op.Type = "ShiftZ" k 2%S`/: op.val1 = taq qUF1XJZ}z op.parent = parID 0%;146.p AddOperation eID, op L {ymI)Y^ Print "Set aqueous humor thickness = " & taq-0.55 mEuHl> Yp4c'Zk '************************************************************************* })IO#, 'Radius and conic constant of anterior lens 7>
Pgc '************************************************************************* RX2{g^V7 eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) wp.TfKxw GetConic eID, entity, curv, conic !=*.$4 HpexH{.u) SetConic eID, entity, 1/Rant, CCant fj'jNE Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant IGAzE( `$z)$VuP '************************************************************************* i`OrMzL 'Radius and conic constant of posterior lens r5/R5Ga^ '************************************************************************* y^FOsr eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) S C_|A9 GetConic eID, entity, curv, conic a1MFjmq 5QWNZJ&}d SetConic eID, entity, 1/Rpost, CCpost =<<3Pkv7@ Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost `HX3|w6W; ev>oC~>s '************************************************************************* ZcryAm:I 'Lens thickness (Position of posterior lens surface) M}.b"
ljZ '************************************************************************* xNN@ 1P[* n!N\zx8 parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;~sr$6 hPufzhT ' Delete any z-shift(s) RFG$X-.e count = 0 w&lZ42(mF While GetOperationCount(eID)>count xKJ>gr"w# GetOperation eID, count, op Z-|li}lDr If op.Type="ShiftZ" Then F1A1@{8bN DeleteOperation eID,count >v0 :qN7| count=count-1 BGjb`U#%3 End If _JOP[KHb count=count+1 h}=M^SL Wend Z%v6xP. hswTn`f 'Set new z-shift A'"-m)1P op.Type = "ShiftZ" P&t;WPZ op.val1 = tlens WaYO1*= op.parent = parID Y5jYmP< AddOperation eID, op "oE* 9J?e Print "Set lens thickness = " & tlens _@ i>s, !.+"4TF '************************************************************************* _IYY08&(r 'Lens index of refraction lvufk VG| '************************************************************************* \X@IkL$r eID = FindMaterial( "Lens" ) -fux2?8M GetModelMaterial eID, mat [(cL/_ iUNnPJh mat.Nd = nlens dB`b9)Tk0z SetModelMaterial eID, mat KF{a$d Print "Set lens index of refraction = " & nlens w<d*#$[,* g[!Cj, '************************************************************************* Jf+7"![| 'Pupil diameter uJPH~mdW '************************************************************************* %\yK5V5 eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) /w~C~6z
@! >0T3'/k<H 'Adjust pupil diameter (trimming volume inner hole) om7`w
] MYTS3( SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"
z^~U]S3 zH+<bEo=1= ' Adjust pupil location to just in front of the lens =8S}Iat parID = FindFullName( "Geometry.Arizona Eye" ) b]dxlj}
< eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) \UtS>4w\ count = 0 X RRJ)}P While GetOperationCount(eID)>count 4qBY%1 GetOperation eID, count, op qP`?M\!O If op.Type="ShiftZ" Then ;qT5faKB3J DeleteOperation eID,count gX"T*d>y count=count-1 &enlAV'#)O End If e3rfXhp count=count+1 -wIM0YJ Wend QX/]gX op.Type = "ShiftZ" ]n1D1 op.val1 = taq-0.01 `1_FQnm) op.parent = parID WH;xq^ AddOperation eID, op s7Qyfe&> YlB["@\[B Print "Set pupil diameter = " & pupilDiam *cy.*@d Hf.xd.Yw 'Update AZ Eye subassembly Description T Xl\hL\+ eID = FindFullName( "Geometry.Arizona Eye" ) q @*UUj@ GetEntity eID, entity 9!S^^;PN& entity.Description = "Accommodation = " & A & "D" Fi k@hu SetEntity eID, entity U;>B7X;`E4 _6J<YQK Update |3|wdzV Print "DONE!" ;<VR2U` aZC*7AK
End Sub }9FD/ EUXV/QV{ 如果屈光度是4,光瞳直径是4,则会输出如下数据: k2wBy'M.' ~W/}:;
Accommodation = 4 Diopters ?PYNE Pupil Diameter = 4 mm 2:n|x5\H Set aqueous humor thickness = 2.81 T*p|'Q` Set anterior lens radius = 10.4 and conic constant = -2.375869 K9LEIby Set posterior lens radius = -4.424557 and conic constant = -3.081019 &?v#| qIh Set lens thickness = 3.927 n=r=u'oi Set lens index of refraction = 1.42672 `-5cQ2>" Set pupil diameter = 4 H7J`]nr6 DONE! *+&z|Pwv[^
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