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2020-12-09 09:18 |
Arizona眼睛模型
简介 AG"l1wz E,G<_40 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。 OTvROJP Ry;$^.7% 模型 hAR?
t5c ,+/zH'U} 模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 sPYX~G&T D=?{8 'R'
Table 1. AZ眼睛模型的定义 =6nD0i9+ 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. ^t.W|teD I?Y d
光源 3*S[eqMJc uF(k[[qaiN 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 x2wg^$F*oO '8`T|2 Z_z#QX>=D
图1. 光源和提示信息使用 0A$SYF$O+[ 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。 B+VuUt{S "X1vZwK8N 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。 60B-ay0e$b mMw;0/n
图2. 字母F光源的设定方法光 V2znU 4Kp L>'Q=
图3. 字母F在视网膜上位置点列图 y0q#R.TOm 视网膜的散射 Z[#IfbYt O&?.&h 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。 jp<VK<s] [,f)9v) Q|hm1q
图4. 视网膜朗伯散射设定 ;b~~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。 crmUrF# L@)&vn] q(]f]Vl|0
图5. 视网膜重点采样规格设定 `| 9K u 脚本 O]=C#E{ Ek .3 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:
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图6. 用户对话框的创建与编辑 (O5)wej
图7. 用户对话框编辑器 c?6d2jH. 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。 ?b$3ob" 余下的脚本计算与屈光度有关的所有参数。 Ti= 3y497S }=@zj6AC 分析 i ^|@"+ X ,
ZeD 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 tHI*, Vewzo1G2
图7. 字母F在视网膜上颜色分析 =7jEz+w# 脚本代码 R2^iSl%pj 7kz-V. Option Explicit 'Remove this to enable non-dimensioned variables to be used. pCt}66k} P^IY:
-s Dim entity As T_ENTITY 1j3=o }m Dim op As T_OPERATION ki4f*Ej Dim mat As T_MODELMATERIAL )!-S|s' Dim A As Double ROoE%%8I Dim pupilDiam As Double hZuYdV{'h Dim eID As Long o/JPYBhdl Dim parID As Long rx:lKoOnB Dim count As Integer 'Z[d7P Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double nFXAF!,jj Dim tlens As Double, nlens As Double YvTA+yL Dim curv As Double, conic As Double {
/<4'B Dim ok As Long S}gD,7@ dF,DiRD Sub Main 2LhE]O(_" < l[`"0 '用户输入对话框 )BLmoJOf Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 FmA-OqEpA TextBox 220,21,40,21,.TextBox1 'default: 0 lG]GlgSs Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 k,]{NO
OKButton 40,91,90,21 .
bG{T| CancelButton 190,91,90,21 A?Sm-#n{ Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 kPJ~X0Fr{t TextBox 220,49,40,21,.TextBox2 'default: 4 b\L)m ( End Dialog (46U|P(v Dim dlg As UserDialog s1=u{ET LXxl ?D ok = Dialog (dlg) ^
wQcB r,nn~ If ok=0 Then 'cancel button was pressed 2{};6{yz Print "Execution cancelled." XI
g|G}i. End ;U7t End If R6Pz#`n }}s)
+d 'Assign accommodation and pupil diameter & use defaults if field left empty YHh u^}|jQ If dlg.TextBox1 = "" Then r %xB8e9 A = 0 'Default accommodation Ph\F'xROe Else [NR1d-Wg A = CDbl(dlg.TextBox1) N[{]iQ End If ~[;{ 2o}8W7y If dlg.TextBox2 = "" Then )fR1n}# pupilDiam = 4 'Default pupil diameter bVOO) Else nK:`e9ES pupilDiam = CDbl(dlg.TextBox2) EQ~I'#m7 End If tQnJS2V"{u A?V<l<EAm Print " " cFxSDTR Print "Accommodation = " & A & " Diopters" B2"+Hwbk Print "Pupil Diameter = " & pupilDiam & " mm" /
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}8C ' Calculate new parameters with accommodation &@Yoj %% taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness [M2Dy{dh +{bh Rant = 12.0 - 0.4*A 'Radius of anterior lens 6KBHRt CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens N>T=L0` vev8l\ Rpost = -5.224557 + 0.2*A 'Radius of posterior lens ^)'||Ly CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens kjfxjAS=m L/%xbm~ tlens = 3.767 + 0.04*A 'Lens thickness $q=hcu |W/Hi^YE2 nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction -y<rM0"NE ,P1G?,y 'Adjust parameters to account for accommodation -hm9sNox [/n'@cjNZ '************************************************************************* 5vl2yN 'Aqueous thickness (Position of Lens) F.&*D~f '************************************************************************* PK9Qm'W b eID = FindFullName( "Geometry.Arizona Eye.Lens" ) *+# k{D, GetCustomElement eID, entity Xek E#?. DwQp$l'NfW parID = FindFullName( "Geometry.Arizona Eye" ) $jDD0<F.# O/'f$ Zj36 ' Delete any shift(s) in z X]>[Qz)K^ count = 0 lp3(&p<: While GetOperationCount(eID)>count o<Ke3?J\ GetOperation eID, count, op ook' u}h If op.Type="ShiftZ" Then rUhWZta DeleteOperation eID,count ],WwqD= count=count-1 il<gjlyR]L End If -U&098}<K count=count+1 _LLW{^V Wend ggzAU6J !G@V<'F 'Set new shift in %Gnd"SGs op.Type = "ShiftZ" DB!uv[c op.val1 = taq (p}9^Y op.parent = parID K4BTk! AddOperation eID, op 3Bu D/bs Print "Set aqueous humor thickness = " & taq-0.55 kvY}
yw7 r< N-A?a '************************************************************************* ,<IL*=a 'Radius and conic constant of anterior lens 4"rb&$E '************************************************************************* )2
eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) &n,xGIG GetConic eID, entity, curv, conic z0FR33- +<vqkc SetConic eID, entity, 1/Rant, CCant Vu^Q4Z Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant k|)^!BdO w`w `q' '************************************************************************* :"h
Pg]' 'Radius and conic constant of posterior lens b*9m2=6 '************************************************************************* #h}IUR eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) O p! GetConic eID, entity, curv, conic YLr%vnO*NS hPNQGVv SetConic eID, entity, 1/Rpost, CCpost T(t
<Ay?c Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost exGhkt~ F='jmiVJ '************************************************************************* c9>8IW 'Lens thickness (Position of posterior lens surface) 7cJO)cm0' '************************************************************************* Rq~
>h99M 7l4InR] parID = FindFullName( "Geometry.Arizona Eye.Lens" ) @8}-0c MV:<w3! ' Delete any z-shift(s) Z &ua,:5 count = 0 wt3Z?Pb While GetOperationCount(eID)>count ?ZD{e|:u GetOperation eID, count, op S0X.8Bq If op.Type="ShiftZ" Then Q)7L^ DeleteOperation eID,count ZKiL-^dob count=count-1 wjw<@A9 End If ]-+.lR%vd9 count=count+1 D:S6Mu Wend gXJ19zB+ Gh chfI. 'Set new z-shift +)''l op.Type = "ShiftZ"
.jrR4@ op.val1 = tlens @8x6#|D op.parent = parID %$!R] B) AddOperation eID, op &,6y(- Print "Set lens thickness = " & tlens 0|*UeM HCn]# '************************************************************************* Z1qATXXf 'Lens index of refraction 7o 83|s.Bm '************************************************************************* )e <! =S eID = FindMaterial( "Lens" ) HnYFE@Nl:U GetModelMaterial eID, mat H8Z Z@@ qm >(1_Dn\ mat.Nd = nlens e
P,XH{s SetModelMaterial eID, mat Q'%5"&XFD Print "Set lens index of refraction = " & nlens R)DNFc: WP#_qqO '************************************************************************* ?AM8*w 'Pupil diameter UHsrZgIRYT '************************************************************************* ]R3pBC"Jv eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) o sgS?=8 _|5FrN 'Adjust pupil diameter (trimming volume inner hole) S<bz7
k9 j@_) F^12 SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ^|hRu{QW %N AFU/& ' Adjust pupil location to just in front of the lens r&l*.C* parID = FindFullName( "Geometry.Arizona Eye" ) 8BoT%kVeJv eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) eL$U M count = 0 I}]@e^ ~ While GetOperationCount(eID)>count 3I{ta/( GetOperation eID, count, op $y]||tX If op.Type="ShiftZ" Then [C~)&2wh> DeleteOperation eID,count ba)YbP[ count=count-1 g cK" End If ws=9u- count=count+1 h/+I-],RF Wend ,B/p1^;. op.Type = "ShiftZ" :pF]TY"K. op.val1 = taq-0.01 F~rYjAFTi op.parent = parID 0)] C&;}_M AddOperation eID, op re 1k] hhgz=7Y Print "Set pupil diameter = " & pupilDiam meVVRFQ2+ ("M#R!3 'Update AZ Eye subassembly Description 6x zR*~7 eID = FindFullName( "Geometry.Arizona Eye" ) LK-6z w5=( GetEntity eID, entity _*?"[TYfX entity.Description = "Accommodation = " & A & "D" _I}L$ SetEntity eID, entity V]PhXVJ L)nVpqm Update UE$[;Zg Print "DONE!" 'V9aB5O&
_>)"+z^r End Sub m+8b2H:V s2v#evI`+ 如果屈光度是4,光瞳直径是4,则会输出如下数据: 2Q'XB 9xS`@ "` Accommodation = 4 Diopters U.j\u>a Pupil Diameter = 4 mm pZJQKTCG Set aqueous humor thickness = 2.81 3L%r_N*a Set anterior lens radius = 10.4 and conic constant = -2.375869 G mUs U{ Set posterior lens radius = -4.424557 and conic constant = -3.081019 YU0HySP: Set lens thickness = 3.927 ;gu>;_ Set lens index of refraction = 1.42672 }GNH)-AG)$ Set pupil diameter = 4 EKS<s82hF& DONE! {F9Qy0.*u =O:ek#Bp ht)*Ync QQ:2987619807 P;o>~Y>x
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