-
UID:317649
-
- 注册时间2020-06-19
- 最后登录2025-12-04
- 在线时间1893小时
-
-
访问TA的空间加好友用道具
|
简介 ePdzQsnVe "E#%x{d 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。 .<hv&t
xSZw, 模型 <h0ptCB /m:}rD 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。 ypVr"fWB $nWmoe) Table 1. AZ眼睛模型的定义 ]B[Qdn 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. FA,CBn5%
=B2=UF 光源 L}nc'smvM #k, kpL<a 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 b2H6}s"=w n_hD d~%Rnic6* 图1. 光源和提示信息使用 ;rbn/6 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 y0^FTSQ| I}x*AM 7+ 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 6 h):o "m5ZZG#R` 图2. 字母F光源的设定方法光 ]T`qPIf;yJ hG]20n2 图3. 字母F在视网膜上位置点列图 p6*D^- 视网膜的散射 (re D |n/id(R+ 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ~ME=!;<_ h Bw~l?G ( d.i np( 图4. 视网膜朗伯散射设定 @hv]
[(< 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 m? hX= 75u*ZMK @P>@;S 图5. 视网膜重点采样规格设定 4g9VE;Gd 脚本 &gfQZxT <j'#mUzd 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: gS ]'^Sr }, H,ky 图6. 用户对话框的创建与编辑 b04~z&Xv 图7. 用户对话框编辑器 2}AV_]] 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 {iv=KF_S_ 余下的脚本计算与屈光度有关的所有参数。 B#}RMFIj vPi+8) 分析 '7^_$M3$\ A(B2XBS!? 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 CpXv?uU 7E'C o| 图7. 字母F在视网膜上颜色分析 (;h\)B!o 脚本代码 *`W82V f &|SGD* Option Explicit 'Remove this to enable non-dimensioned variables to be used. f$L5=V lbY>R@5 Dim entity As T_ENTITY |(N4x(xl Dim op As T_OPERATION _)Ms9RN Dim mat As T_MODELMATERIAL Z3d&I]Tf Dim A As Double {*m?t 7 Dim pupilDiam As Double Q=[&~^Y) Dim eID As Long mAMKCxz, Dim parID As Long lF<(yF5 Dim count As Integer q$K~BgFzpZ Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double q0}LfXql8 Dim tlens As Double, nlens As Double 0=04:.%D Dim curv As Double, conic As Double bCsQWsj^NW Dim ok As Long c-,/qn/ 1JM~Ls%Z Sub Main Nuj%8om6 p0/I}n4<5n '用户输入对话框 lk}x;4]Z Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 @ 9uwcM1F TextBox 220,21,40,21,.TextBox1 'default: 0 2yNlQP8% Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 lL?;?V~ OKButton 40,91,90,21 t|//oEY CancelButton 190,91,90,21 &lD4-_2J Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 O/-xkzR* TextBox 220,49,40,21,.TextBox2 'default: 4 B:l(`G End Dialog 4-o$OI> Dim dlg As UserDialog Sb<=ROCg@ opBvx>S ok = Dialog (dlg) "371`!% #f[yp=uI: If ok=0 Then 'cancel button was pressed y ^YrGz. Print "Execution cancelled." e2;">tp6? End g+f{I'j End If jE{z4en A;kB"Tx 'Assign accommodation and pupil diameter & use defaults if field left empty (Az^st/_ If dlg.TextBox1 = "" Then IJ!UKa*o% A = 0 'Default accommodation a*=e 3nS Else 9i"3R0HN A = CDbl(dlg.TextBox1) Yy&0b(m U End If `jJb) z3D nX If dlg.TextBox2 = "" Then dM
QnN[d6 pupilDiam = 4 'Default pupil diameter cu
Nwv(P Else ,[A} 86 pupilDiam = CDbl(dlg.TextBox2) iVFnt! End If sh0O~%]g %j=7e@ Print " " +q3W t| Print "Accommodation = " & A & " Diopters" {MIs%w.G Print "Pupil Diameter = " & pupilDiam & " mm" NY_Oo!)3 S"lcePN ' Calculate new parameters with accommodation cewQQ& taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness ': HV9]k }JI5,d Rant = 12.0 - 0.4*A 'Radius of anterior lens HGPbx$! CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens ,7eN m>$ >~6
;9{@ Rpost = -5.224557 + 0.2*A 'Radius of posterior lens 1[!Idl ?m CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens bO-8<IjC_3 BKN]DxJ6 tlens = 3.767 + 0.04*A 'Lens thickness pPh$Jvo] &4]%&mX)- nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction B64%|
S g|W~0A@D 'Adjust parameters to account for accommodation ;]p#PNQ0 nHA2p`T '************************************************************************* 0O[q6!&] 'Aqueous thickness (Position of Lens) n] &fod '************************************************************************* ] $5r h8 eID = FindFullName( "Geometry.Arizona Eye.Lens" ) z2-=fIr.h GetCustomElement eID, entity ?L|@{RS{| *@n%K,$v parID = FindFullName( "Geometry.Arizona Eye" ) !I:6L7HdwB !]W6i]p ' Delete any shift(s) in z xe}"0'g count = 0 w^dB1Y7c(W While GetOperationCount(eID)>count U,)+wZJ GetOperation eID, count, op dlyE2MiL: If op.Type="ShiftZ" Then Ff|?<\x0}A DeleteOperation eID,count ~aBALD0D; count=count-1 sjztT<{Q^- End If o6'`W2P count=count+1 &bTadd%0 Wend
ZQ@^(64 F+9|D 'Set new shift in $lUZm\R|k op.Type = "ShiftZ" ,VbP$1t op.val1 = taq Pf]L`haGN op.parent = parID ?9/%K45 AddOperation eID, op @aI`ru+a Print "Set aqueous humor thickness = " & taq-0.55 C}wmoYikV 1Hzj-u&N/ '************************************************************************* }&ZO
q'B 'Radius and conic constant of anterior lens .{~ygHQ`f '************************************************************************* CI
~+(+q eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6D)
vY GetConic eID, entity, curv, conic :*Sl\:_X) 2g|+*.*` SetConic eID, entity, 1/Rant, CCant }[?X%= Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant . [*6W.X "c=\? '************************************************************************* pM.>u/=X 'Radius and conic constant of posterior lens ,f4Hl%T; '************************************************************************* ?2QssfB eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) gy,B+~p GetConic eID, entity, curv, conic Z-Zox-I1}- 9^>nZ6 SetConic eID, entity, 1/Rpost, CCpost "rBo?%: Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost -k")#1 XP~4jOL] '************************************************************************* n`;=^^ B 'Lens thickness (Position of posterior lens surface) /zM '************************************************************************* UjUDP>iz.> Tj@s \@hv parID = FindFullName( "Geometry.Arizona Eye.Lens" ) {
+MqXeq ;}WdxWw4 ' Delete any z-shift(s) 2Q0fgH2 count = 0 |-=^5q5 While GetOperationCount(eID)>count !/sXG\ GetOperation eID, count, op
:p5V5iG If op.Type="ShiftZ" Then ^0c:ro DeleteOperation eID,count JM@MNS_||( count=count-1 @'jC>BS8` End If ?kISAA4x count=count+1 gVEW*8 Wend [$
vAjP `pOiv&> 'Set new z-shift
ze{ op.Type = "ShiftZ" ="JLUq*]s op.val1 = tlens CZuV{Oh}? op.parent = parID X70G@-w AddOperation eID, op d>VerZZU Print "Set lens thickness = " & tlens *C}vy`X R 6ca; '************************************************************************* cEhwv0f!qS 'Lens index of refraction ?1JS*LQ$ '************************************************************************* ,=.& eID = FindMaterial( "Lens" ) VMe~aUd GetModelMaterial eID, mat &Vd,{JU i9 8T+{4 mat.Nd = nlens 2<y!3OeN SetModelMaterial eID, mat ZEiW\ V Print "Set lens index of refraction = " & nlens @Q
8E)k@ vdyLwBz: '************************************************************************* G n>#Mvq 'Pupil diameter g!,>. '************************************************************************* y_;LTCj? eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) MDM/~Qpj_ I&,gCZ# 'Adjust pupil diameter (trimming volume inner hole) )`, Bt %ZDo;l+<F6 SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 7`9J.L&,; R/VrBiw ' Adjust pupil location to just in front of the lens TO ^}z parID = FindFullName( "Geometry.Arizona Eye" ) pdUrVmW "' eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 7Y"CeU-S count = 0 URz$hcI8 While GetOperationCount(eID)>count 4Z.G GetOperation eID, count, op eZ'J,; If op.Type="ShiftZ" Then -]C3_ve DeleteOperation eID,count ]2`PS<a2 count=count-1 tsaf|xe End If 0pYO-@E count=count+1 :OT~xU==H Wend 6nRXRO op.Type = "ShiftZ" .KSPr op.val1 = taq-0.01 Oc8]A=M12 op.parent = parID |]kcgLqj AddOperation eID, op v1*Lf/ G}<%%U D Print "Set pupil diameter = " & pupilDiam I<PKwT/? V<A_c^unO 'Update AZ Eye subassembly Description !#wd~: H eID = FindFullName( "Geometry.Arizona Eye" ) #+I)<a7\ GetEntity eID, entity ^@5#jS2 entity.Description = "Accommodation = " & A & "D" 5Arx"=c SetEntity eID, entity vN'Y);$ c'ExZ)RJ Update
)GhMM Print "DONE!" |E/U(VS3l~ t6V@00M@ End Sub sq1Z;l31" _?$P? 如果屈光度是4,光瞳直径是4,则会输出如下数据: 1n|)05p [}-CXB Accommodation = 4 Diopters P4@<`Eb Pupil Diameter = 4 mm &.~Xl:lq Set aqueous humor thickness = 2.81 O%?noW Set anterior lens radius = 10.4 and conic constant = -2.375869 $Pv;>fHu Set posterior lens radius = -4.424557 and conic constant = -3.081019 =iF}41a
Set lens thickness = 3.927 CvDy;'{y1 Set lens index of refraction = 1.42672 EA_6L\+8& Set pupil diameter = 4 'Pyeb`AXE9 DONE! z'FD{xdf ,QU2xw D[ lt%bGjk QQ:2987619807 l;_zXN
|