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2021-10-22 09:55 |
Arizona眼睛模型
简介 ~oh=QakW @!&\Z[", 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。 IM}T2\tZ} &C<B=T"I 模型 b40zYH`'{ CE:TQzg 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。 ' D+h_*H 5zX;/n~
Table 1. AZ眼睛模型的定义 @;M( oFS9 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. G*ZHLLO4S\ K_',Gd4L 光源 5bR;R{:x )V%xbDd S 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。 G eN('0 |S|0'C* UMuqdLaT9
图1. 光源和提示信息使用 /Ou`$2H87 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 oJbD|m *<#jr 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 n;)!N _ro^<V$%
图2. 字母F光源的设定方法光 R_:47.qq h.ojj$f,
图3. 字母F在视网膜上位置点列图 I.A7H'j 视网膜的散射 *g]q~\b/; wGD".CS0 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 T~7i:<E^ X90VJb] A1zM$
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图4. 视网膜朗伯散射设定 QpwOrxI} 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。 uA7~`78 2i*-ET p<*3mbgGO
图5. 视网膜重点采样规格设定 +',[q 脚本 4=td}% &duWV6Acw 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: YwyP+Sr\ $As;Tvw.
图6. 用户对话框的创建与编辑 ,y>,?6:>
图7. 用户对话框编辑器 l^w=b~|7= 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。 :oYu+cQ 余下的脚本计算与屈光度有关的所有参数。 #\[h.4i T_|%nF-+ 分析 wv>*g:El' eRc+.m[ 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 3
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图7. 字母F在视网膜上颜色分析 <|[G=GA\S! 脚本代码 x1</%y5ev Ppi/`X Option Explicit 'Remove this to enable non-dimensioned variables to be used. je@F:5 5wYYYo= Dim entity As T_ENTITY hJ$o+sl Dim op As T_OPERATION : kz*.1 Dim mat As T_MODELMATERIAL +>h}Uz Dim A As Double YyEW}2 Dim pupilDiam As Double }kzGuNj Dim eID As Long u+%Ca,6 Dim parID As Long B,@geJ Dim count As Integer 0YK`wuZGS Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double g"aWt%
P Dim tlens As Double, nlens As Double {q
fgvu Dim curv As Double, conic As Double =&G<^7 Dim ok As Long P1KXvc}JGe I[,tf! Sub Main DKw%z8ft| 3fPd|F.kF '用户输入对话框 idW= Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Agt6G\n TextBox 220,21,40,21,.TextBox1 'default: 0 vFKX@wV S Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 81Ixs
Qt OKButton 40,91,90,21 jej|B#?` CancelButton 190,91,90,21 M &`ZF Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 vM )2F TextBox 220,49,40,21,.TextBox2 'default: 4 z{XN1'/V End Dialog "c5C0 pK0 Dim dlg As UserDialog -}avH
!kCMw%[ ok = Dialog (dlg) {p3VHd# xuBXOr4"P If ok=0 Then 'cancel button was pressed &D@/_m $ Print "Execution cancelled." GP=i6I6C End ZccQ{$0H End If dQP7CP _
nFsC 'Assign accommodation and pupil diameter & use defaults if field left empty PL vz1}ts If dlg.TextBox1 = "" Then }#0MJ6L A = 0 'Default accommodation Gt;@.jY& Else eyq\a'tyB A = CDbl(dlg.TextBox1) '2)c;/-E End If 1$S;#9PQ S}fU2Wi If dlg.TextBox2 = "" Then fDe4 [QQ8 pupilDiam = 4 'Default pupil diameter 5WhR| Else yLv jfP1 pupilDiam = CDbl(dlg.TextBox2) 2K >tI9); End If ifA=qn0=} Qdepzo>E Print " " j5hM|\] Print "Accommodation = " & A & " Diopters" 85;hs Print "Pupil Diameter = " & pupilDiam & " mm" Jt-s6-2 YA(_*h
' Calculate new parameters with accommodation VjZ_L_U} taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness VrG4wLpLs $E=t6WvA Rant = 12.0 - 0.4*A 'Radius of anterior lens ;VQFz&Q$u CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens MYVUOd, >y
P`8Oq[ Rpost = -5.224557 + 0.2*A 'Radius of posterior lens 31BN ?q CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens ?gZJ v 5<0d2bK$ tlens = 3.767 + 0.04*A 'Lens thickness lo }[o0X _W@SCV)yH nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction Y-8qAF?SJ] iC U[X& 'Adjust parameters to account for accommodation JGmW>mH WW.\5kBl8 '************************************************************************* TF\<`}akX 'Aqueous thickness (Position of Lens) b0\'JZ '************************************************************************* {HgW9N( eID = FindFullName( "Geometry.Arizona Eye.Lens" ) `i{k^Q GetCustomElement eID, entity d<*4)MRN m~K[+P parID = FindFullName( "Geometry.Arizona Eye" ) {d|R67~V doR'E=Z4h ' Delete any shift(s) in z Salu[)+? count = 0 apW0(&\ While GetOperationCount(eID)>count vBUl6EmWu GetOperation eID, count, op wp/u*g If op.Type="ShiftZ" Then C:tA|<b| DeleteOperation eID,count +B*8$^,V) count=count-1 uj.~/W1,! End If TO\%F}m( count=count+1 =k4yWC5- Wend !g? ~<` \!UNale 'Set new shift in -t9oL3J op.Type = "ShiftZ" D\Y)E#%, op.val1 = taq 1SBc:!2 op.parent = parID CK
e AddOperation eID, op -`e=u<Y9@ Print "Set aqueous humor thickness = " & taq-0.55 MDkIaz\U l3aG#4jj '************************************************************************* lY}mrb 'Radius and conic constant of anterior lens }?P~qJ|1 '************************************************************************* =q|fe%# eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) R|Ft@]
GetConic eID, entity, curv, conic oeXNb4; 4 &%pB; dk SetConic eID, entity, 1/Rant, CCant X$JO<@x Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant dE5DH~ldV H+zn:j@~L '************************************************************************* f{e*R#+& 'Radius and conic constant of posterior lens IidZ-Il '************************************************************************* \h^bOxh eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) a@@!Eg
A GetConic eID, entity, curv, conic ;U<)$5 tC+9W1o SetConic eID, entity, 1/Rpost, CCpost .Jdw: Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost MW9B
-x ej,MmLu~^ '************************************************************************* yZ:|wxVY 'Lens thickness (Position of posterior lens surface) -b@E@uAX/ '************************************************************************* :Puv8[1i >Z^7=5K"O parID = FindFullName( "Geometry.Arizona Eye.Lens" ) yh_s(>sh ~4}m'#! ' Delete any z-shift(s) #},]`"n\ count = 0 ZNB*Azi While GetOperationCount(eID)>count 89l_%To GetOperation eID, count, op F dv&kK! If op.Type="ShiftZ" Then ~E^EF{h
DeleteOperation eID,count NQfIY`lt' count=count-1 se_zCS4Y End If *Oz5I count=count+1 17D167\X Wend VhSKtD1 va8:QHdU 'Set new z-shift |iM*}Ix- op.Type = "ShiftZ" -lL*WA` op.val1 = tlens +:&(Ag op.parent = parID pq5)Ug AddOperation eID, op H@IX$+;z Print "Set lens thickness = " & tlens l%Sz6 @7lZ{jV$ '************************************************************************* *ep!gT*4 'Lens index of refraction $
O!f*lG '************************************************************************* &s/aJgJhp eID = FindMaterial( "Lens" ) ZJ=C[s!wu GetModelMaterial eID, mat RAE|eTnna 6}NvVolr mat.Nd = nlens dc&Qi_W SetModelMaterial eID, mat P>N\q Print "Set lens index of refraction = " & nlens n^Z?u9VR !W$Br\< '************************************************************************* !hH6!G 'Pupil diameter ObM5v rEk| '************************************************************************* cJ8*[H<NV eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) !y] Y'j b}"/K$`Fd 'Adjust pupil diameter (trimming volume inner hole) [q.W!l4E
l3g6y9; SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Jy|Mfl%d ;
wHuL\ ' Adjust pupil location to just in front of the lens #-lk=> parID = FindFullName( "Geometry.Arizona Eye" ) wFqz.HoB eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) j|aT`UH03 count = 0 }= <!j5: While GetOperationCount(eID)>count t1Jz?Ix6% GetOperation eID, count, op D[-Ct If op.Type="ShiftZ" Then 8%xtb6#7M DeleteOperation eID,count zV80r+y count=count-1 JAiV7v4&R End If S?3{G@!
count=count+1 ;,4J:zvZdQ Wend Y#t"..mc' op.Type = "ShiftZ" Z#J{tXZc op.val1 = taq-0.01 9hguC yr@h op.parent = parID #&8Opo( AddOperation eID, op WG}QLcP 9MYt4 Print "Set pupil diameter = " & pupilDiam *(k=!`4( fglZjT 'Update AZ Eye subassembly Description PRah?|*0s eID = FindFullName( "Geometry.Arizona Eye" ) =p7W^/c GetEntity eID, entity |y=gp entity.Description = "Accommodation = " & A & "D" WI~%n
SetEntity eID, entity Ol-'2l ih;TQ!c+b Update T ]zjJwa Print "DONE!" <1LuYEDq -"nYCF End Sub sO6t8)$b z`2d(KE? 如果屈光度是4,光瞳直径是4,则会输出如下数据: CKR9APkv T
a[74;VO Accommodation = 4 Diopters :|A db\b Pupil Diameter = 4 mm >5gzo6j/ Set aqueous humor thickness = 2.81 U D(#u3z Set anterior lens radius = 10.4 and conic constant = -2.375869 2bC%P})m Set posterior lens radius = -4.424557 and conic constant = -3.081019 _k@l-Bj Set lens thickness = 3.927 V9bLm,DtT Set lens index of refraction = 1.42672 ^R$dG[Qf Set pupil diameter = 4 bbM
!<&F DONE! A3$b_i @P
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