-
UID:317649
-
- 注册时间2020-06-19
- 最后登录2025-12-12
- 在线时间1894小时
-
-
访问TA的空间加好友用道具
|
简介 M\3!elp2z |zE7W 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。 Tj:F Qnx 9Wn0YIc 模型 RP$A"<goP T5)?6i-N 模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 C{-pVuhK+ c9@* Table 1. AZ眼睛模型的定义 wSDDejg 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. o^D{WH\p 2+HiaYDZ 光源 QB3AL;7 "P~>AXcq 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 y5I7pbe tp"\ .jU9{;[ 图1. 光源和提示信息使用 RA}PM?D/ 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 BKk*<WMD )I@iW\`7 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 i2DR}%U "q8wEu,z[ 图2. 字母F光源的设定方法光 4|qp&%9- G>j/d7 图3. 字母F在视网膜上位置点列图 vs+N{ V 视网膜的散射 hwJ.M4 M6>l%[ 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。
2B#WWb -kO=pYP*O 4'M#m|V 图4. 视网膜朗伯散射设定 7">.{
@S 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 O`eNuQSv 1EN5ZN, |zf||ju 图5. 视网膜重点采样规格设定 .|K5b]na 脚本 u4Sa4o iZUBw 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: f'
eKX7R D~<GVp5T 图6. 用户对话框的创建与编辑 (/^&3xs9 图7. 用户对话框编辑器 DE[y&]/C{ 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 |Z<adOg 余下的脚本计算与屈光度有关的所有参数。 xnArYm Z7 @#0;g{ 分析 ,F1$Of/'@\ `JC!uc 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 WJ%b9{< r=vE0;7 图7. 字母F在视网膜上颜色分析 -Bc.<pFqp 脚本代码 NQb?&.C 9X-DR Option Explicit 'Remove this to enable non-dimensioned variables to be used. = #`FXO1C :sf;Fq Dim entity As T_ENTITY !j(R_wOq Dim op As T_OPERATION GRNH!:e Dim mat As T_MODELMATERIAL /a,q4tD@ Dim A As Double ,yC~{H Dim pupilDiam As Double rkD(KG9E Dim eID As Long te`4*t Dim parID As Long )_BteLo- Dim count As Integer :r\<DVj Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double )TxhJB5| Dim tlens As Double, nlens As Double V; ChrmE Dim curv As Double, conic As Double (Fu9lW}n Dim ok As Long i}Y:o} $HaM,
Oh;i Sub Main ^Tl|v'
@+xQj.jNC '用户输入对话框 I?1^\s#L Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 qU}[(9~Ru TextBox 220,21,40,21,.TextBox1 'default: 0 >yaRz+ Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Dd*C?6 OKButton 40,91,90,21 ].$N@tC CancelButton 190,91,90,21 'rSM6j Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 C 9DRVkjj TextBox 220,49,40,21,.TextBox2 'default: 4 (LnKaf8 End Dialog "Aynt_a. Dim dlg As UserDialog #e=[W)) B${Q Y)t ok = Dialog (dlg) KjhOz%Yt[o a^,Xm(Wb} If ok=0 Then 'cancel button was pressed ETmfy}V8 Print "Execution cancelled." ^mH^cP?/ End Er{yQIi0L End If j_k!9"bt +] FdgmK: 'Assign accommodation and pupil diameter & use defaults if field left empty #
TvY*D, If dlg.TextBox1 = "" Then m~2PpO A = 0 'Default accommodation WXJ%bH Else W &*0F~ A = CDbl(dlg.TextBox1) z+;+c$X End If /:B!hvpw /W fpA\4S If dlg.TextBox2 = "" Then R+P1 +5 pupilDiam = 4 'Default pupil diameter SoCa_9*X Else d^w6_ pupilDiam = CDbl(dlg.TextBox2) /CH*5w)1
End If Z/O5Dear/h Z[ys>\_To Print " " X'O3)Yg Print "Accommodation = " & A & " Diopters" ?v6xaVg: Print "Pupil Diameter = " & pupilDiam & " mm" SDZ/rC!C ,XR1N$LN8_ ' Calculate new parameters with accommodation f`T#=6C4| taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness *M09Y'5] w?Y;pc}1B Rant = 12.0 - 0.4*A 'Radius of anterior lens dtJ?J<m} CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens >Ka}v:E K;Fy&p^d Rpost = -5.224557 + 0.2*A 'Radius of posterior lens l7\Bq+Q CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens L~>pSP^a A3MVNz$wo" tlens = 3.767 + 0.04*A 'Lens thickness x:G uqE 4/cUd=>Z nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction b0t/~]9G T-0fVTeN 'Adjust parameters to account for accommodation %qNT<>c z]K:Amp;Z '************************************************************************* 'V/+v#V+> 'Aqueous thickness (Position of Lens) T=%,^ '************************************************************************* `5:b=^'D/ eID = FindFullName( "Geometry.Arizona Eye.Lens" ) :hC+r=!I GetCustomElement eID, entity ><^
, uS;N&6;: parID = FindFullName( "Geometry.Arizona Eye" ) )k$ +T% t
7 dcaNBZ ' Delete any shift(s) in z Dwn.0|E count = 0 0sIwU!=vm While GetOperationCount(eID)>count h_n`E7&bG GetOperation eID, count, op >We4F2? If op.Type="ShiftZ" Then '| WY 2>/( DeleteOperation eID,count p%[/
_ -7 count=count-1 $9bLD
>. End If fgdqp8~ count=count+1 GUSEbIz): Wend vq=nG]cE) b*(74 >XY 'Set new shift in jnho*,X op.Type = "ShiftZ" q8#zv_>K op.val1 = taq B)*?H=f/ op.parent = parID @~sJ
((G[5 AddOperation eID, op MfNsor Print "Set aqueous humor thickness = " & taq-0.55
>cw%ckE ebfT%_N '************************************************************************* )B)ecJJ_ 'Radius and conic constant of anterior lens u0p[ltJ, '************************************************************************* ^ZP
$(a4 eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) #q?'<''d, GetConic eID, entity, curv, conic ?h\fwF3 e*)*__$O SetConic eID, entity, 1/Rant, CCant UB^OMB-W.m Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Y].,}}9k F#=M$j_ '************************************************************************* ;8m) a 'Radius and conic constant of posterior lens 17la/7l< '************************************************************************* $Y`oqw?g+^ eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) gv\WI4"n GetConic eID, entity, curv, conic bY&!d.
z>lIZ} SetConic eID, entity, 1/Rpost, CCpost :<gC7UW Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [] cF*en h(C@IIO^;G '************************************************************************* V$0mcwH 'Lens thickness (Position of posterior lens surface) P_}wjz}9ZX '************************************************************************* 4Dy|YH$>S x/NjdK parID = FindFullName( "Geometry.Arizona Eye.Lens" ) i/|}#yw8A sD#*W< ' Delete any z-shift(s) /Ixv{H)H count = 0 hU'h78bt( While GetOperationCount(eID)>count {f"oqry_g GetOperation eID, count, op YC[cQX If op.Type="ShiftZ" Then Q%r KKOX8 DeleteOperation eID,count @B\$
me count=count-1 q{Ao
j End If 9$f% count=count+1 ij5|P4Eka Wend 4ibOVBG:*, CFXr=.yz 'Set new z-shift ;&c9!LfP op.Type = "ShiftZ" (h"-#q8$ op.val1 = tlens UMUG~P&@ op.parent = parID G,!{Q''w AddOperation eID, op \&/V p` Print "Set lens thickness = " & tlens 'pj*6t1~ @)XR '*************************************************************************
SwE bVwB 'Lens index of refraction C <Pd_& '************************************************************************* (}m2} eID = FindMaterial( "Lens" ) %/oeV;D GetModelMaterial eID, mat i0nu5kD+d @.)WS\Cv#E mat.Nd = nlens ]w0_!Z& SetModelMaterial eID, mat sm Kp3_r Print "Set lens index of refraction = " & nlens 8 qlQC.VA[ &6e A. '************************************************************************* yXQ 28A 'Pupil diameter `*WzHDv5p '************************************************************************* ]TVc 'G; eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) #+&"m7
s 'i<%kL@ 'Adjust pupil diameter (trimming volume inner hole) m
yy*rt v,|jmv+: SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" \1sWmN6 oT0:Ny ' Adjust pupil location to just in front of the lens Q[Gs%/> parID = FindFullName( "Geometry.Arizona Eye" ) cs9"0&JX eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) kho$At)V count = 0 {>UT'fa- While GetOperationCount(eID)>count l}@C'Np GetOperation eID, count, op NvvD~Bb If op.Type="ShiftZ" Then h t3P@; DeleteOperation eID,count |?v .5|1 count=count-1 &PPYxg< End If b#-=Dbe count=count+1 r:M0#
2 Wend JFdMYb op.Type = "ShiftZ" .P#t"oW} op.val1 = taq-0.01 i0u`J op.parent = parID {A~3/M%74; AddOperation eID, op *B)10R yU>ucuF Print "Set pupil diameter = " & pupilDiam q'9; H#M;TjR 'Update AZ Eye subassembly Description [HhaBy9 eID = FindFullName( "Geometry.Arizona Eye" ) %%9T-+T GetEntity eID, entity m2HO .ljc entity.Description = "Accommodation = " & A & "D" Y() ZM SetEntity eID, entity Ej $.x6: \0K&2' Update +TAyCxfmt
Print "DONE!" HQSFl=Q sf
O{.#5< End Sub p+228K ;H `_sKR,LhB 如果屈光度是4,光瞳直径是4,则会输出如下数据: cqaq~ )X3
|[4R Accommodation = 4 Diopters cd`P'GDF Pupil Diameter = 4 mm X/buz Set aqueous humor thickness = 2.81 2UopGxrPKw Set anterior lens radius = 10.4 and conic constant = -2.375869 )Fw#]~Z Set posterior lens radius = -4.424557 and conic constant = -3.081019 +i[@+`
Set lens thickness = 3.927 7[0<,O6Q Set lens index of refraction = 1.42672 dkW7k^g Set pupil diameter = 4 pd|l&xvka DONE! &UVqFo QRx9;!~b} OKAmw>{ QQ:2987619807 gH.$B'
|