-
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 Je?V']lm Gn_v}31d% 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。 \64(`6> fnXl60C% 模型 }B]FHpi \SMH",u 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。 AV8TP-Ls+ xt`znNN Table 1. AZ眼睛模型的定义 zZE?G:isR 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. 5hDE&hp 1hMk\ -3S 光源 r@n% 7unu-P<C 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。 n*;mFV0s O &X-)g= 9ge$)q@3 图1. 光源和提示信息使用 j}ruXg 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 Wh4lz~D\@ fc\hQXYv 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 Bq2}nDP dm.3. xXq 图2. 字母F光源的设定方法光 :Mt/6} |]B]0J#_ 图3. 字母F在视网膜上位置点列图 I5D\Z 视网膜的散射 lX7#3ti: wicg8[T=B 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 I~mw\K{.3M XM_S" 6!gGWn5>} 图4. 视网膜朗伯散射设定 f|apk,o_ 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 )lW<:?k <4>6k7W N4D_ 43jz 图5. 视网膜重点采样规格设定 nDPfr\\ 脚本 fmSA.z rFmE6{4:p 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: )<~b*^kl\ 3yZ@i<rfH 图6. 用户对话框的创建与编辑 dA_s7), 图7. 用户对话框编辑器 /evh .S 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 oF3#]6`;/ 余下的脚本计算与屈光度有关的所有参数。 %8$wod6 I4");T3 分析 {uhw ^)v Nls|R 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 "%Rx;xw| @cXY"hP` 图7. 字母F在视网膜上颜色分析 T$q]iSgu 脚本代码 D)!k u{_T,k<! Option Explicit 'Remove this to enable non-dimensioned variables to be used. xAoozDj ]#J]f Dim entity As T_ENTITY *.K}`89T Dim op As T_OPERATION c(eu[vj: Dim mat As T_MODELMATERIAL GEvif4 Dim A As Double a-kU?&*
y Dim pupilDiam As Double <vj&e(D^ Dim eID As Long bGSgph Dim parID As Long ;PbyR}s Dim count As Integer QX8N p{g- Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double k r/[|.bq Dim tlens As Double, nlens As Double dFS+O;zE\ Dim curv As Double, conic As Double *D9QwQ
_| Dim ok As Long H-S28%. K1 $Z=]a+ Sub Main a1j6-p &-{4JSII '用户输入对话框 +^%F8GB Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 {X<tUco TextBox 220,21,40,21,.TextBox1 'default: 0 AFY;;_Xks Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 MqNp*n2 OKButton 40,91,90,21 PmTA3aH CancelButton 190,91,90,21
"? R$9i Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 R!- RSkB TextBox 220,49,40,21,.TextBox2 'default: 4 E>7[ti_p5 End Dialog LUCpZ3F1 Dim dlg As UserDialog
^h'
wZ7-\ .]jKuTC\< ok = Dialog (dlg) |w:\fK[ q,m6$\g4 If ok=0 Then 'cancel button was pressed {Ji[d.cY Print "Execution cancelled." UZdpKi@ End [g%oo3`A End If /*8"S mte xvW+;3; 'Assign accommodation and pupil diameter & use defaults if field left empty ty"k If dlg.TextBox1 = "" Then N7[i443a A = 0 'Default accommodation Qg4qjX](? Else ~s
!+9\Fi A = CDbl(dlg.TextBox1) >
^D10Nf* End If A}W&=m8! zfvl<"Rv If dlg.TextBox2 = "" Then 2!l)%F` pupilDiam = 4 'Default pupil diameter PInU-"gG Else SB]|y-su pupilDiam = CDbl(dlg.TextBox2) t\'URpa+5% End If Pxl7zz&pl= `L0}^|`9 Print " " $Y>LUZ)b&8 Print "Accommodation = " & A & " Diopters" y%z$_V] Print "Pupil Diameter = " & pupilDiam & " mm" |2^cPnv?G& 2#p6.4h= ' Calculate new parameters with accommodation TTBl5X taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness #Z8<H |r6<DEg Rant = 12.0 - 0.4*A 'Radius of anterior lens [1l ,I[ CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens v vOG]2z |wWBV{^ Rpost = -5.224557 + 0.2*A 'Radius of posterior lens poQY X5 CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens XlR.Y~ bW[Y:}Hk~ tlens = 3.767 + 0.04*A 'Lens thickness <Ms,0YKx PT|t6V"wd nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction \_0nH` "Bn!<h}mg 'Adjust parameters to account for accommodation >e'6RZRLA B`9'COw '************************************************************************* c]#F^(-A` 'Aqueous thickness (Position of Lens) 11O^)_|c '************************************************************************* 3)p#}_u{ eID = FindFullName( "Geometry.Arizona Eye.Lens" ) a%V6RyT4qW GetCustomElement eID, entity 3~%9;.I3! K+2<{qwh parID = FindFullName( "Geometry.Arizona Eye" ) eG =Hyc w%KU@$ ' Delete any shift(s) in z 4ZSc'9e9 count = 0 k0Rd:DxO While GetOperationCount(eID)>count p^<*v8,~7 GetOperation eID, count, op "NMX>a,( If op.Type="ShiftZ" Then M9M~[[
DeleteOperation eID,count #J#x,BLI count=count-1 1T!(M"'Ij End If v[A)r]"j"M count=count+1 Hj2E -RwG Wend JPRo<jt= M4~^tML>Ey 'Set new shift in s\@RJ[(<
op.Type = "ShiftZ" g\ilK:r} op.val1 = taq 7A<X!a op.parent = parID x2%xrlv<J/ AddOperation eID, op a9}7K/Y=d Print "Set aqueous humor thickness = " & taq-0.55 I($0&Y\De Na=.LW-ma= '************************************************************************* /m"O.17N 'Radius and conic constant of anterior lens 6QO[!^lY '************************************************************************* N`,ppj eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) J2W#vFe\ GetConic eID, entity, curv, conic BE>^;` K mmRxs1 0$ SetConic eID, entity, 1/Rant, CCant bys5IOP{]o Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant (_1(<Jw __LR!F]=i '************************************************************************* UNY
O
P{ 'Radius and conic constant of posterior lens v,,
.2UR4 '************************************************************************* 57@6O-t- eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) N5_` GetConic eID, entity, curv, conic >oh7f| pUF$Nq>og SetConic eID, entity, 1/Rpost, CCpost @ @uKOFA? Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost bAOL<0RS9` (`'(`x# '************************************************************************* _?~EWT 'Lens thickness (Position of posterior lens surface) ^`iqa-1 '************************************************************************* &"lSq2 KJ (|skO parID = FindFullName( "Geometry.Arizona Eye.Lens" ) )@(IhU) l;7T.2J'Z ' Delete any z-shift(s) [Z]%jABR count = 0 !1m7^3l7j While GetOperationCount(eID)>count 10}<n_I GetOperation eID, count, op Dm{9;Abs% If op.Type="ShiftZ" Then 9u?[{h.`B DeleteOperation eID,count ?COLjk count=count-1 #|j8vmfn$e End If NdxPC~Z+ count=count+1 .o#A(3&n Wend Dbl3ef Wr+/9 'Set new z-shift SL[ EOz# op.Type = "ShiftZ" 9z#z9|hj)3 op.val1 = tlens @oKW$\ op.parent = parID GHWt3K:*w AddOperation eID, op W*;r}!ro Print "Set lens thickness = " & tlens A'6-E{ >BWe"{ ; '************************************************************************* EQ [K 'Lens index of refraction ^#gJf*'UE '************************************************************************* h~pQ eID = FindMaterial( "Lens" ) 9y}/ G GetModelMaterial eID, mat ;:
xE'- V7<w9MM mat.Nd = nlens NG5k9pJ SetModelMaterial eID, mat ~F"w Print "Set lens index of refraction = " & nlens 1<G, 0Lt >PYc57S1c '************************************************************************* 0e +Qn&$#4 'Pupil diameter qDS~|<Y5 '************************************************************************* A'aY H`j eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 1lYQR`Uh P"{yV?CNg 'Adjust pupil diameter (trimming volume inner hole)
CH$K_\ LGh# SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" )mH(Hx )8E[xBaO ' Adjust pupil location to just in front of the lens K BlJJH`z{ parID = FindFullName( "Geometry.Arizona Eye" ) :#OaE, eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) tISb' ^T count = 0 4(? Z1S While GetOperationCount(eID)>count /H*[~b GetOperation eID, count, op G%fXHAs .+ If op.Type="ShiftZ" Then ]tNB^ DeleteOperation eID,count [(; .D count=count-1 XMF#l]P End If BPSie0 count=count+1 -amNz.`[PR Wend zmg
:Z p= op.Type = "ShiftZ" oXQI"?^+ op.val1 = taq-0.01 Y,m=&U op.parent = parID 8&:dzS AddOperation eID, op !jR 1!i z
$iI Print "Set pupil diameter = " & pupilDiam _ xM}*_<VP ]P2Wa
'Update AZ Eye subassembly Description /~{fPS eID = FindFullName( "Geometry.Arizona Eye" ) YRu/KUT$ 7 GetEntity eID, entity -n:;/ere7- entity.Description = "Accommodation = " & A & "D" *-3*51 jW SetEntity eID, entity Iv{uk$^7S $\aJ.N6rb Update IK,aA;d Print "DONE!" })?KpYk K8uqLSP ' End Sub
uyoV) cS>xT cj 如果屈光度是4,光瞳直径是4,则会输出如下数据: }-@h H( >&JS-jFg Accommodation = 4 Diopters POQ4&ChA Pupil Diameter = 4 mm c^~R%Bx Set aqueous humor thickness = 2.81 ^@$T>SB1 Set anterior lens radius = 10.4 and conic constant = -2.375869 gb26Y!7% Set posterior lens radius = -4.424557 and conic constant = -3.081019 ;Ouu+#s Set lens thickness = 3.927 ]YUst]gu3 Set lens index of refraction = 1.42672 d z\yP
v~ Set pupil diameter = 4 xgIb4Y% DONE! *X2dS
{
|