-
UID:317649
-
- 注册时间2020-06-19
- 最后登录2026-01-28
- 在线时间1922小时
-
-
访问TA的空间加好友用道具
|
简介 uX5B>32 mjJlXA 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。 qb/!;U_ O8}s*} ] 模型 %li{VDb r-DD*'R 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。 dodz|5o% BqJrL/( Table 1. AZ眼睛模型的定义 (TK
cSVR 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. \V7x3*nA p<.!::* %( 光源 )pj \b[ m>m`aLrnb 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。 tbt9V2U:"n ^{,},
i Y- 9j2.{ 图1. 光源和提示信息使用 cyn]>1ZM 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。 @!tmUme1c &5CeRx7% 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。 w@D@,q'x :=KGQ3V~eK 图2. 字母F光源的设定方法光 t5[JN:an 2yg'?tpj 图3. 字母F在视网膜上位置点列图 fN/KXdAy& 视网膜的散射 .oOt(K+ R(#;yn 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。 nFOG=>c} mTu9'/$( m=b+V#4i( 图4. 视网膜朗伯散射设定 206jeH9 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 #k]0[;1os B,qZwc| S`PSFetC 图5. 视网膜重点采样规格设定 }C1}T}U 脚本 w4/)r-Z4I {;gWn'aq 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: ph. :~n>z 0md{e`'q: 图6. 用户对话框的创建与编辑 *8HxJ+[,[ 图7. 用户对话框编辑器 w9}IM149 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 n_gB#L$ 余下的脚本计算与屈光度有关的所有参数。 @)Y7GM+^ Cd*C^cJU&z 分析 @k;3$ .Zm } 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 Xm+3`$< Y'":OW#oN 图7. 字母F在视网膜上颜色分析 c_=zd6 b$S 脚本代码 &cejy>K 0|k[Wha# Option Explicit 'Remove this to enable non-dimensioned variables to be used. "TCbO`mg U9%nku4 Dim entity As T_ENTITY s_+XSH[=f Dim op As T_OPERATION >}tG^ )os Dim mat As T_MODELMATERIAL \M^4Dd Ay Dim A As Double BAed [ Dim pupilDiam As Double rx)Q] Dim eID As Long SQvB)NOw Dim parID As Long ]zAg6*-/B Dim count As Integer gpl!Iz~5 Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double vUExS Z^ Dim tlens As Double, nlens As Double /v<8x?= Dim curv As Double, conic As Double @AyW9!vV;3 Dim ok As Long 6!m#_z8qG3 Jk{2!uP Sub Main .;Yei6H 09i[2n;O '用户输入对话框 NX/)Z&Fx: Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 @K>Pw arl TextBox 220,21,40,21,.TextBox1 'default: 0 %^A++Z$` Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ~Dh}E9E: OKButton 40,91,90,21 nr6U>
KR^ CancelButton 190,91,90,21 2?&ptN)`N Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 xrd^vE TextBox 220,49,40,21,.TextBox2 'default: 4 J?DyTs3Z End Dialog )^3655mb Dim dlg As UserDialog A>S2BL#= 2sq<"TlQXI ok = Dialog (dlg) breVTY7 S 6f1Y:qK'@ If ok=0 Then 'cancel button was pressed cViCWc2 Print "Execution cancelled." VNfx>&` End ax }Xsk_ End If g_=ZcGC Cl=ExpX/O 'Assign accommodation and pupil diameter & use defaults if field left empty SesO$=y If dlg.TextBox1 = "" Then W;yZ$k#q}( A = 0 'Default accommodation xEqrs6sR Else ^4i3 #} A = CDbl(dlg.TextBox1) S d -+a End If b9jm=U cQb%bmBc5 If dlg.TextBox2 = "" Then /GNYv* pupilDiam = 4 'Default pupil diameter zc5_;!t Else =0|evC pupilDiam = CDbl(dlg.TextBox2) l1-FL-1 End If ggWfk ;anG
F0x Print " " >Li?@+Zl Print "Accommodation = " & A & " Diopters" '-qc\6UY Print "Pupil Diameter = " & pupilDiam & " mm" C7:Ry)8'I
~I74' ' Calculate new parameters with accommodation X8TZePh taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness xR3A4m 4v7RX Rant = 12.0 - 0.4*A 'Radius of anterior lens 9IMcp~zX CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens $fO*229As c{q`uI;O Rpost = -5.224557 + 0.2*A 'Radius of posterior lens Ek6W:Q:@ CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens Dc2eY. oB@C-(M tlens = 3.767 + 0.04*A 'Lens thickness VdgPb ( hJM0A3(Cm nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction wH.'EC 9#7zjrB 'Adjust parameters to account for accommodation >F
v8 - 6fiJ'
j@ '************************************************************************* kp|reKM/ 'Aqueous thickness (Position of Lens) -1:asM7 '************************************************************************* %K4-V5f eID = FindFullName( "Geometry.Arizona Eye.Lens" ) C}Q2UK-: GetCustomElement eID, entity qZ.\GHS L
$~Id parID = FindFullName( "Geometry.Arizona Eye" ) [%pZM.jFO ]SI`fja/ ' Delete any shift(s) in z bYfcn]N count = 0 Syb:i(Y While GetOperationCount(eID)>count idq= US GetOperation eID, count, op TV}SKvu If op.Type="ShiftZ" Then pWqahrWh DeleteOperation eID,count ~F-,Q_|- count=count-1 rm7UFMCR6i End If xnTky1zq count=count+1 s]qfLC Wend Wil+"[Ge n9%rjS$ 'Set new shift in r BL)ct op.Type = "ShiftZ" ~H.;pJ{ 8 op.val1 = taq h
? M0@Z op.parent = parID u|C9[( AddOperation eID, op 7%tn+ Print "Set aqueous humor thickness = " & taq-0.55 ]KmYPrCl0 NTC,Vr\A '************************************************************************* z'm;H{xf 'Radius and conic constant of anterior lens bF.Aj8ZQ '************************************************************************* k`d eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) A8?>V%b[Y GetConic eID, entity, curv, conic >HDK<1 > eP)RP6ON{ SetConic eID, entity, 1/Rant, CCant |7 argk+ Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant vc<8ApK3V 9}=Fdt '************************************************************************* eNNK;xXe# 'Radius and conic constant of posterior lens Je/R'QP^8 '************************************************************************* /#a$4 }2L eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) <D__17W:; GetConic eID, entity, curv, conic h(9K7 <K43f#% SetConic eID, entity, 1/Rpost, CCpost >,[(icyzn Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost T|u)5ww% }\@*A1*X2 '************************************************************************* "}n]0 >J 'Lens thickness (Position of posterior lens surface) m4EkL '************************************************************************* 5b&'gd^d TCVJ[LbJ parID = FindFullName( "Geometry.Arizona Eye.Lens" ) \oi=fu=}* yk=H@`~! ' Delete any z-shift(s) pCq{F*; count = 0 vm(% u!_P While GetOperationCount(eID)>count milU,!7J GetOperation eID, count, op .e6 :/x~p* If op.Type="ShiftZ" Then ]!/1qF DeleteOperation eID,count mGIS[_dcs count=count-1 Zffzyh End If H*Yyo? count=count+1 {h2D}F Wend _^KD&t%!+y ^P[-HA| 'Set new z-shift VL\6U05Z op.Type = "ShiftZ" qLR)>$ op.val1 = tlens yPL@uCzA@ op.parent = parID kWgxswl7H AddOperation eID, op NEX\+dtE~0 Print "Set lens thickness = " & tlens v8LKv`I's mF
"ctxE '************************************************************************* B$fL);l- 'Lens index of refraction $ED<:[3N '************************************************************************* +Ta7b) eID = FindMaterial( "Lens" ) wqw$6"~ GetModelMaterial eID, mat -Z @cj oM< 9]jK} mat.Nd = nlens X@TQD SetModelMaterial eID, mat n#4Ra+dD Print "Set lens index of refraction = " & nlens BsxQW`>^y *r%=p/oQ}B '************************************************************************* (|S e+Y#e, 'Pupil diameter 'E6)6N '************************************************************************* E}~GX G eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ^)X^Pcx KX{ S8_ 'Adjust pupil diameter (trimming volume inner hole) <CeDIX t ZMbv1*Vt SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" (}'0K? pZXva9bE ' Adjust pupil location to just in front of the lens `/"TYR% parID = FindFullName( "Geometry.Arizona Eye" ) 6%:N^B=%} eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) z55P~p count = 0 wL~
dZ!,J While GetOperationCount(eID)>count p!173y,nL GetOperation eID, count, op NKO5c?ds If op.Type="ShiftZ" Then r6"t`M DeleteOperation eID,count H$Q_K<V count=count-1 9"&HxyOfX End If Tf` ~=fg% count=count+1 7GpSWM6 Wend y;uk|#qnPS op.Type = "ShiftZ" [5>0om5 op.val1 = taq-0.01 `*N2x\+X op.parent = parID !x[+rf AddOperation eID, op 9^XT,2Wwf YYN=`ST Print "Set pupil diameter = " & pupilDiam dKhDO`.s {R\ "x| 'Update AZ Eye subassembly Description "QA!z\0\ eID = FindFullName( "Geometry.Arizona Eye" ) AfyEFnY GetEntity eID, entity 0Bb amU entity.Description = "Accommodation = " & A & "D" s<tdn[d SetEntity eID, entity >{V]q*[/;Q n hS=t8H Update VcA87*pel Print "DONE!" yPKeatH] ^~?VD End Sub .pK_j~}P q8`JRmt)H 如果屈光度是4,光瞳直径是4,则会输出如下数据: \ c9EE- MYDAS- Accommodation = 4 Diopters [.;VCk)0x Pupil Diameter = 4 mm %\2
ll=p1 Set aqueous humor thickness = 2.81 }"E?#&^ Set anterior lens radius = 10.4 and conic constant = -2.375869 Ub%5# <k|- Set posterior lens radius = -4.424557 and conic constant = -3.081019 zq8LQ4@ay Set lens thickness = 3.927 ?FxxH*>" Set lens index of refraction = 1.42672 BNnGtVAbZ Set pupil diameter = 4 ,a_\o&V DONE! H4MFTnJ{ hVd%
jU: fMy7pXa_ QQ:2987619807 )L<NW{
|