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2022-02-25 09:52 |
Arizona眼睛模型
简介 *|=D 0 M>i(p% 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。 jg?UwR& DDr\Kv)k( 模型 m ~&
Gk~aTO 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。 9F807G\4Qt Table 1. AZ眼睛模型的定义 [attachment=111140] Q("m*eMRt WkuCnT 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. ^i8,9T'= h*VDd3[# 光源 &|XgWZS5 I#MPJ@*WT 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。 %!\=$ s}g ytY\&m [attachment=111141] 图1. 光源和提示信息使用 ` &A`&-nc= $jMA(e`Ye0 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 ]ltCJq :Vxt2@p{ 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 h A ){>B<; [attachment=111142] 图2. 字母F光源的设定方法光 FXr^ 4B} =Q9^|& 6 [attachment=111143] 图3. 字母F在视网膜上位置点列图 G%s O{k7 a
Y)vi$;] 视网膜的散射
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7SHllZ 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。 >3/mV<g f N 8[rWJ# [attachment=111144] 图4. 视网膜朗伯散射设定 x~5,v5R^] 1vo3aF 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。 C[,h! ahXcQ9jzFi [attachment=111145] 图5. 视网膜重点采样规格设定 ""7H;I& (LK@w9)i; 脚本 D]E=0+ DPf].i# 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: 1vq2`lWpx [attachment=111146] 图6. 用户对话框的创建与编辑 2e\"?y OD [attachment=111147] 图7. 用户对话框编辑器 D N!V".m`J qVh?%c1.Y 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。 M<Bo<,!ua 余下的脚本计算与屈光度有关的所有参数。 1?QVtfwY l0G{{R0Y 分析 P.>fkO1\ -Cvd3%Jje 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 ky|k g@n{ [attachment=111148] 图7. 字母F在视网膜上颜色分析 Z><+4
' fa]8v6 脚本代码 U)'YR$2< uB+#<F/c
- Option Explicit 'Remove this to enable non-dimensioned variables to be used. K_+M?ap_
ulALGzPh Dim entity As T_ENTITY Q.$/I+&j Dim op As T_OPERATION EJ
{vJZO Dim mat As T_MODELMATERIAL C)m@/w Dim A As Double jk`U7G* Dim pupilDiam As Double d1#lC*.Sg Dim eID As Long =eY Dim parID As Long >0SG]er@ Dim count As Integer "zw{m+7f, Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double !QdX+y<re Dim tlens As Double, nlens As Double lFuW8G,-f@ Dim curv As Double, conic As Double n=b!c@f4 Dim ok As Long Pjq9BK9p B[mZQ&Gz`a Sub Main CHS}tCfos> L2Cb/!z`c '用户输入对话框 R}(Rv3>Xx Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 X7*ossv TextBox 220,21,40,21,.TextBox1 'default: 0 j7);N Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 0;a1 0b OKButton 40,91,90,21 _H U>T CancelButton 190,91,90,21 Zah<e6L Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Z wKX$(n TextBox 220,49,40,21,.TextBox2 'default: 4 E
@r &K End Dialog '~yxu$aK Dim dlg As UserDialog :
HU|BJ> uWMSn ok = Dialog (dlg) y+^KVEw 'xuxMav6m If ok=0 Then 'cancel button was pressed CNV^,`FX Print "Execution cancelled." ,4,Bc< End
= <A0; End If "WY5Pzsi: V,Bol(wY 'Assign accommodation and pupil diameter & use defaults if field left empty Z!q$d/1 If dlg.TextBox1 = "" Then \Dr( /n A = 0 'Default accommodation B{`K?e0 Else -m,Y6 A = CDbl(dlg.TextBox1) $2]>{g End If v"Bm4+c&0 18~jUYMV If dlg.TextBox2 = "" Then MYJMZ3qBi pupilDiam = 4 'Default pupil diameter ^[I>#U Else Yx66Xy pupilDiam = CDbl(dlg.TextBox2) |U'` Sc End If <2O#!bX1 Kl ?C[ Print " " D1ik*mDA= Print "Accommodation = " & A & " Diopters" c=-qbG0` Print "Pupil Diameter = " & pupilDiam & " mm" #$ka.Pj $? Z}hU ' Calculate new parameters with accommodation LGtw4'yr taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness g^:`h
VV ifWQwS/,a Rant = 12.0 - 0.4*A 'Radius of anterior lens =^zGn+@z CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens $qpW?<>,0 Z6So5r%wZ Rpost = -5.224557 + 0.2*A 'Radius of posterior lens I(3YXv
VN CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens ~md06"AYJ f6(1jx" tlens = 3.767 + 0.04*A 'Lens thickness wqjR-$c `Y!8,(5# nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction =yRv*C %"#ydOy 'Adjust parameters to account for accommodation <RbsQ^U r|z B?9Q '************************************************************************* 0e:j=kd)NH 'Aqueous thickness (Position of Lens) 0<<ATw$aQ '************************************************************************* @ I&k|\ eID = FindFullName( "Geometry.Arizona Eye.Lens" ) M)JozD% GetCustomElement eID, entity klc$n07 5|}u25J parID = FindFullName( "Geometry.Arizona Eye" ) s[7/w[& 0Bkc93 ' Delete any shift(s) in z `Um-Y'KE count = 0 [tC=P&< While GetOperationCount(eID)>count 2H] 7 =j GetOperation eID, count, op ]R^xO;g' If op.Type="ShiftZ" Then EIpz-"S DeleteOperation eID,count 1(i%nX<U count=count-1 H4wDF:n0H End If RA){\~@wC count=count+1 W8-vF++R Wend dtG>iJ xMpgXB!' 'Set new shift in |~v2~
op.Type = "ShiftZ" WFmW[< g op.val1 = taq 6@:<62!; op.parent = parID DHvZ:)aT} AddOperation eID, op 3_&s'sG5 Print "Set aqueous humor thickness = " & taq-0.55 F[B=sI 8h=K S '************************************************************************* yYTOp^ 'Radius and conic constant of anterior lens L|'B* '************************************************************************* (BK_A{5 eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) m3(p7Z^Bq GetConic eID, entity, curv, conic fCX8s(|F "d0D8B7HI@ SetConic eID, entity, 1/Rant, CCant s=K?-O Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant tHM0]Gb} `O%O[ '************************************************************************* k2#|^N 'Radius and conic constant of posterior lens \nTV;@F '************************************************************************* ^ME'D eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) xbCQ^W2YU| GetConic eID, entity, curv, conic ]T.+(\I X<v1ES$ SetConic eID, entity, 1/Rpost, CCpost r&F
6ZCw Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 9.9B#? 4l>d^L '************************************************************************* ~g@}A 'Lens thickness (Position of posterior lens surface) uA t{WDHm '************************************************************************* }Q6o#oZ Bf[`o<c parID = FindFullName( "Geometry.Arizona Eye.Lens" ) {DUtdu[
<LJb,l" ' Delete any z-shift(s) Bob-qCBV count = 0 mO8/eVws[M While GetOperationCount(eID)>count bFH`wLW GetOperation eID, count, op E},zB*5TH If op.Type="ShiftZ" Then p3T:Y_ DeleteOperation eID,count L7.SH#m count=count-1 7y.iXe!P End If QTN'yd?WE count=count+1 43O5|8o Wend $(*>]PC+) Tgbq4xR( 'Set new z-shift *!dA/sid op.Type = "ShiftZ" %E [HMq<H op.val1 = tlens cVr+Wp7K#| op.parent = parID :s-9@Yl| AddOperation eID, op zW)Wt.svP Print "Set lens thickness = " & tlens :V_UJ3xf |TR
+Wn '************************************************************************* $>+g) 'Lens index of refraction N8J(RR9O '************************************************************************* OF-VVIS eID = FindMaterial( "Lens" ) YPCitGBl GetModelMaterial eID, mat v?%vB#A^ [r'A8!/|[ mat.Nd = nlens Oi-%6&}J SetModelMaterial eID, mat Qam48XZ > Print "Set lens index of refraction = " & nlens (qz)3Fa roBb8M|q '************************************************************************* >6)|>#Wi 'Pupil diameter TgHUH>k '************************************************************************* #5{BxX&\ eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) IcGX~zWr K%Bz6 ~ 'Adjust pupil diameter (trimming volume inner hole) i` ay9J8N O}}rosA SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" |f.,fVVV; ( 5uSqw&U ' Adjust pupil location to just in front of the lens a(ml#-M parID = FindFullName( "Geometry.Arizona Eye" ) l(@c eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) aeAx0yE[p count = 0 wkV'']= Xg While GetOperationCount(eID)>count Q(e GetOperation eID, count, op -*Th=B- If op.Type="ShiftZ" Then GS}JyU DeleteOperation eID,count nb6Y/`G count=count-1 SQ/HZ End If )OVa7[-T count=count+1 l\uNh~\ Wend ErQ6a%~, op.Type = "ShiftZ" c&
bms)Jwa op.val1 = taq-0.01 Fmz+ Xb op.parent = parID )}t't" AddOperation eID, op (mKH,r a;M{-G Print "Set pupil diameter = " & pupilDiam =2ED
w_5E ,|.}6\zl*{ 'Update AZ Eye subassembly Description NK(_ &.F
eID = FindFullName( "Geometry.Arizona Eye" ) ~!cxRd5;F GetEntity eID, entity fGRV]6?V entity.Description = "Accommodation = " & A & "D" \k{[HfVvn SetEntity eID, entity D{[{ &1\)r B;W%P.<. Update rPqM&&+ Print "DONE!" %H2ios[UO lBAu@M
End Sub =9,^Tu| F[`dX 如果屈光度是4,光瞳直径是4,则会输出如下数据: = dM P'Vnfj Accommodation = 4 Diopters 4RYH^9;>K Pupil Diameter = 4 mm 4l68+ Set aqueous humor thickness = 2.81 n;Q8Gg2U Set anterior lens radius = 10.4 and conic constant = -2.375869 QG2 Zh9R Set posterior lens radius = -4.424557 and conic constant = -3.081019 D}j`T Set lens thickness = 3.927 \g
h |G Set lens index of refraction = 1.42672 ;ko6igx)+ Set pupil diameter = 4 FF!PmfF' DONE!
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