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2021-10-22 09:55 |
Arizona眼睛模型
简介 iWkWR"ysy _;y9$"A 人眼光学模型可用来设计眼科用设备,光学系统注定了要与人眼一起使用。本文演示了这样一个模型:Arizona眼睛模型,在Jim Schwiegerling教授的书中有详细描述:《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源,并包括一个基于想要的屈光度来调整模型的内嵌脚本。 ]s'as9s9 Bkc4TO 模型 YkSl^j[DHs t{9GVLZ 模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 vI>w e V f&zL
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Table 1. AZ眼睛模型的定义 h(dvZ=
% 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. F/{!tx %[TR^Th6 光源 C{rcs' ? OM!+O 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 ;$|nrwhy 9cF[seE"0 F)QDJE0
图1. 光源和提示信息使用 IEi^kJflU 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。 _TZRVa_ .`eN8Dl1 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。 \}b%E'+_T dZ@63a>>@
图2. 字母F光源的设定方法光 YD6'#( FW4<5~'
图3. 字母F在视网膜上位置点列图 </zEg3F\ 视网膜的散射 \M^bD4';> p6V0`5@t 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。 d7upz]K9g "KpGlY?^ /([kh~a
图4. 视网膜朗伯散射设定 n-;`Cy`k 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。 wP@(?z N4!O.POP H1./x6Hr
图5. 视网膜重点采样规格设定 ZY+qA 脚本 5t]H?b8 T8$y[W-c 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: 73;GW4, u*`GiZAO
图6. 用户对话框的创建与编辑 }Sv:`9=
图7. 用户对话框编辑器 >y3=| 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 0GeTSFj 余下的脚本计算与屈光度有关的所有参数。 kl:Bfs)b onzxx4bax 分析 #"~<HG}bR/ ;e *!S}C, 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 Dp9+HA9t q/,O\,
图7. 字母F在视网膜上颜色分析 "chDg(jMZ 脚本代码 5rik7a)Z] S,he6zS Option Explicit 'Remove this to enable non-dimensioned variables to be used. b]KBgZ \4fQMG Dim entity As T_ENTITY 'H;*W |:-] Dim op As T_OPERATION xA*<0O\V Dim mat As T_MODELMATERIAL Km$\:Xo Dim A As Double
x.$FNt(9 Dim pupilDiam As Double gPPkT" Dim eID As Long k<?b(&`J Dim parID As Long i/Zd8+.n$ Dim count As Integer [7y]n;Fy Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ckCE1e>s Dim tlens As Double, nlens As Double FYQS)s Dim curv As Double, conic As Double WpvhTX Dim ok As Long M_DwUS1? +ZP7{% Sub Main "w<#^d_6 K[YyBEid '用户输入对话框 BI@[\aRLQ Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 w7L)'9 TextBox 220,21,40,21,.TextBox1 'default: 0 $XH^~i; Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 y6BAH OKButton 40,91,90,21 ~k5W@`"W CancelButton 190,91,90,21 @6-jgw>W2 Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 )^hbsMhO TextBox 220,49,40,21,.TextBox2 'default: 4 }jPSUdo End Dialog N;%6:I./ Dim dlg As UserDialog d<Tc7vg4|U !&E-}}< ok = Dialog (dlg) jL}v9$ aN3;`~{9 If ok=0 Then 'cancel button was pressed ]Hv[ IodJ Print "Execution cancelled." owv[M6lbD End ,V}WM%Km End If Tid a a >9J:Uo1z 'Assign accommodation and pupil diameter & use defaults if field left empty rytyw77t( If dlg.TextBox1 = "" Then f|(M.U- A = 0 'Default accommodation )V9bI( v Else N'=gep0V@ A = CDbl(dlg.TextBox1) d0>
zS End If #g!.T g' 2X&qE}%k S If dlg.TextBox2 = "" Then |y!A&d=xYn pupilDiam = 4 'Default pupil diameter *VN6cSq Else q@2siI~W pupilDiam = CDbl(dlg.TextBox2) \'j|BJ~L f End If 8q7b_Pq1U
!}$$: Print " " sDV Q#}a Print "Accommodation = " & A & " Diopters" |4`{]2C Print "Pupil Diameter = " & pupilDiam & " mm" g9F?z2^ \l3h0R ' Calculate new parameters with accommodation apxph2yvS taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness e96k{C`j0 5@W j>:w Rant = 12.0 - 0.4*A 'Radius of anterior lens +"VP-s0 CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens [Vt\$ +ck}l2 Rpost = -5.224557 + 0.2*A 'Radius of posterior lens ;A[Q2(w+ CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens QmIBaMI# *{{89E>wC tlens = 3.767 + 0.04*A 'Lens thickness ~Cjn7 {(}By/_ nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction &kw@,];4Z Aiea\jBv 'Adjust parameters to account for accommodation L/^I*p, <of^AKbt '************************************************************************* "zy7C*)>r 'Aqueous thickness (Position of Lens) 40
0#v|b '************************************************************************* as=LIw}Q4 eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4X|zmr:A GetCustomElement eID, entity t
|oR7qa{w ;*&-C9b parID = FindFullName( "Geometry.Arizona Eye" ) WjqO@]P6 Q NVa?'0"Y ' Delete any shift(s) in z o _H`o&xr count = 0 "
2Dngw While GetOperationCount(eID)>count mj@13$= GetOperation eID, count, op N}YkMJy If op.Type="ShiftZ" Then !{41!O,K# DeleteOperation eID,count t&DEb_"De count=count-1 WMg~Y"W End If KY]C6kh count=count+1 ^sg,\zD 'X Wend b>9>uC@J15 6S\8$ 'Set new shift in tklH@'q op.Type = "ShiftZ" ws^ np op.val1 = taq ~^b/( op.parent = parID BFW&2 AddOperation eID, op Zj4Uak Print "Set aqueous humor thickness = " & taq-0.55 ;6hOx(>`= ,,|^%Ct'] '************************************************************************* H 7
^/q7 'Radius and conic constant of anterior lens =E{`^IT'R '************************************************************************* k-""_WJ~^ eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Pr,q*_Yy GetConic eID, entity, curv, conic NW)1#]gg% r!{Up7uL SetConic eID, entity, 1/Rant, CCant .w,q0<} Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant /|&*QLy :p6M= '************************************************************************* G 9vpt M 'Radius and conic constant of posterior lens IdxzE_@ '************************************************************************* pFz`}?c0 eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) BDZ?Ez\Sg GetConic eID, entity, curv, conic 9JKEw eQvg7aO; SetConic eID, entity, 1/Rpost, CCpost gbagi+8s`% Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost e64 ^ChCoV h3@v+Z<} '************************************************************************* ROZF)|l 'Lens thickness (Position of posterior lens surface) 7i1q wRv '************************************************************************* uhutg,[ $]2vvr parID = FindFullName( "Geometry.Arizona Eye.Lens" ) O!bOp= -;k+GrLr^ ' Delete any z-shift(s) *siFj
CN< count = 0 N=g"(% While GetOperationCount(eID)>count &XUiKnNW GetOperation eID, count, op [;myHI`tw If op.Type="ShiftZ" Then Ef13Q]9| DeleteOperation eID,count K)k<Rh[< count=count-1 TrR8?- End If (0kK_k'T count=count+1 2jCf T>`3 Wend QoH6 9490o:s 'Set new z-shift DrK{}uM op.Type = "ShiftZ" 'a.qu9PJ op.val1 = tlens \:F_xq op.parent = parID ^@NU}S):yN AddOperation eID, op V,N%;iB} Print "Set lens thickness = " & tlens ! #2{hQRu GF=g<H
M '************************************************************************* uOdl*| T? 'Lens index of refraction [Cv/{f3]u{ '************************************************************************* )p%E%6p eID = FindMaterial( "Lens" ) `%WU8Yv GetModelMaterial eID, mat ijx0gh`~ 6<(.4a? mat.Nd = nlens n#_$\
p>Yd SetModelMaterial eID, mat Vj>8a)"B5a Print "Set lens index of refraction = " & nlens UU0,!?o4 wZZ t '************************************************************************* Hc(OI|z~ 'Pupil diameter q;)JISf. '************************************************************************* %z4Nl$\ eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ,:\|7 F WaR`Kp+> 'Adjust pupil diameter (trimming volume inner hole) SS.dY""89 /J6rv(( SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" #|PS&}6wU !f&g-V ' Adjust pupil location to just in front of the lens ^eYVWQ' parID = FindFullName( "Geometry.Arizona Eye" ) &H:(z4/ eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) t |A-9^t'! count = 0 )U{Qj5W+F While GetOperationCount(eID)>count y;@:ulv[ GetOperation eID, count, op m5Di=8 If op.Type="ShiftZ" Then P1' al DeleteOperation eID,count pr UM-u8 count=count-1 ]yPqLJ End If O55 xS+3^k count=count+1 D]Xsvv
# Wend $43qME op.Type = "ShiftZ" HBx=\%;n op.val1 = taq-0.01 .z}~4BY op.parent = parID <1\Nb{5 AddOperation eID, op agW@{c AoL2@C.C%D Print "Set pupil diameter = " & pupilDiam +@iA;2& j
Dv{/) 'Update AZ Eye subassembly Description @A^;jk eID = FindFullName( "Geometry.Arizona Eye" ) H-f X(9 GetEntity eID, entity LvUj9eVb/L entity.Description = "Accommodation = " & A & "D" Is?La SetEntity eID, entity ':m,)G5& HYSIN^<oy Update oJ|j#+Ft Print "DONE!" 2n"V}p>8i# j*TYoH1 End Sub ptxbDzOz LsS
如果屈光度是4,光瞳直径是4,则会输出如下数据: i|*)I:SHU %
0+j?>#X Accommodation = 4 Diopters VrQmP Pupil Diameter = 4 mm \%N!5>cZ{ Set aqueous humor thickness = 2.81 g:Xhw$x9 Set anterior lens radius = 10.4 and conic constant = -2.375869 ILShd)]Rw Set posterior lens radius = -4.424557 and conic constant = -3.081019 j@uOOhy Set lens thickness = 3.927 dZ0vA\z| Set lens index of refraction = 1.42672 o@i#|kx, Set pupil diameter = 4 bsA-2*Q+ DONE! @;?p&.W`D
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