| infotek |
2023-04-27 08:29 |
Arizona眼睛模型
(H2ylMpQt 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。 _hWuAJ9Qy ?N`qLGRm 模型 '9"%@AFxZ 3? }; 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。 (HPz Table 1. AZ眼睛模型的定义 @wMQC\Z &M$Bt} < 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. Enu!u~1]F [.ey_}X8 光源 %6N)G!P FN>L7
*,0 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 n
3h^VQ*]G ^K"ZJ6?+1 图1. 光源和提示信息使用 }'v{dK %pH)paRAP 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 C/bxfp{? 27Cz1[oX 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 H<$pHyxU 图2. 字母F光源的设定方法光 @K7ebYr? Etw~* 图3. 字母F在视网膜上位置点列图 Q*Y4m8wY J}:&eS 视网膜的散射 D/e&7^iK ; 4l-M2 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。 s:3aRQ% Qg[heND 图4. 视网膜朗伯散射设定 ::v;)VdX+* ^)Smv\Md 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。 7,f:Qi@g Wux 0RF& 图5. 视网膜重点采样规格设定 axOi5 3xP~~j;7 脚本 :-(U%`a[ !X%S)VSMU 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: ES^NBI j5P 图6. 用户对话框的创建与编辑 #]k0Z~Bl 图7. 用户对话框编辑器 dJloH)uJZ> h>~jQ&\M 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。 yq1Gqbh
l 余下的脚本计算与屈光度有关的所有参数。 DE5d]3B p@vpd 分析 AbL5 !' @ <|6{N< 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 :wFb5" 图7. 字母F在视网膜上颜色分析 ejP,29 d:A\<F 脚本代码 H3!,d`D.N pi|\0lH6W Option Explicit 'Remove this to enable non-dimensioned variables to be used. 52da]BW< bh{E&1sLh Dim entity As T_ENTITY f+{c1fb>s Dim op As T_OPERATION 0Wjd-rzc, Dim mat As T_MODELMATERIAL #c6ui0E%;t Dim A As Double @mvIt Dim pupilDiam As Double T@B"BoKU Dim eID As Long ,NjX&A@ Dim parID As Long :8](&B68gE Dim count As Integer #E*@/ p/ Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double F(J\ctha Dim tlens As Double, nlens As Double :uOZjEZi Dim curv As Double, conic As Double &\JK%X.Jlt Dim ok As Long iU.!oeR? SCgyp( Sub Main KX0<j xt?3_?1 '用户输入对话框 sGXp}{E9 Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 fx]\)0n TextBox 220,21,40,21,.TextBox1 'default: 0 OD{5m(JwL Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 P]|J?$1K OKButton 40,91,90,21 QIR4<]/ CancelButton 190,91,90,21 t8L<x Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 K4iI: TextBox 220,49,40,21,.TextBox2 'default: 4 <ED8"~_ End Dialog ~sZqa+jB0 Dim dlg As UserDialog );0<Odw%. GwTT+ ok = Dialog (dlg) lo\: ]/&6 (J6"
; If ok=0 Then 'cancel button was pressed |Dl*w/n
Print "Execution cancelled." !Sh^LYqn End 6Hc H'nmeN End If MDMtOfe| k)?,xY\AV 'Assign accommodation and pupil diameter & use defaults if field left empty \;nD)<)J If dlg.TextBox1 = "" Then 9zXu6<|qrL A = 0 'Default accommodation \pjRv Else 3$GY,B A = CDbl(dlg.TextBox1) r^?)F?n! End If |
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N BV}4 If dlg.TextBox2 = "" Then !7ei1 pupilDiam = 4 'Default pupil diameter >t1_5 Else z7OZ4R: pupilDiam = CDbl(dlg.TextBox2) J xA^DH End If ;X?Ah r]8wOu-' Print " " 0_YxZS\ Print "Accommodation = " & A & " Diopters" y#hga5 Print "Pupil Diameter = " & pupilDiam & " mm" F{#N6,T b:N^Fe ' Calculate new parameters with accommodation ?b!CV
taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness bBkm]
> !!?+M @ Rant = 12.0 - 0.4*A 'Radius of anterior lens \>*MMe CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens 'Qm` A= T0@](g Rpost = -5.224557 + 0.2*A 'Radius of posterior lens @4 zi]v CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens 8>C;
>v />dB%* tlens = 3.767 + 0.04*A 'Lens thickness kx"hWG4 l 'AK nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction 3::3r}g y3
({(URU 'Adjust parameters to account for accommodation ?aK'OIo LK'S)Jk '************************************************************************* 7\7 Brw4 'Aqueous thickness (Position of Lens) m#5|J@] '************************************************************************* *G%1_ eID = FindFullName( "Geometry.Arizona Eye.Lens" ) \_*?R,$3Y, GetCustomElement eID, entity 1g~Dm}m bE7(L
$UF parID = FindFullName( "Geometry.Arizona Eye" ) n/9 LRZD|w JcvHJ0X~a ' Delete any shift(s) in z ]jVIpGM count = 0 R-r+=x& While GetOperationCount(eID)>count KuIt[oM GetOperation eID, count, op g|&.v2 ' If op.Type="ShiftZ" Then M iP[UCh DeleteOperation eID,count SQO>}#qm count=count-1 LY@1@O2@ End If ^@|<'g.R- count=count+1 ,wwU`
U Wend VfL]O 8P> >,w\lf9 'Set new shift in T[Z <bW~0 op.Type = "ShiftZ" rd&*j^? op.val1 = taq VYl_U?D op.parent = parID ,\sR;=svK AddOperation eID, op ZYwBw:y}y Print "Set aqueous humor thickness = " & taq-0.55 ifJv~asp .c=$ bQ>^ '************************************************************************* ^]#Ptoz^(l 'Radius and conic constant of anterior lens p\\P50(- '************************************************************************* 8!`7- eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ,(@Y%UW: GetConic eID, entity, curv, conic ;Zx K3/(7 ?MV[=LPL SetConic eID, entity, 1/Rant, CCant ^F0k2pB Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Gx(K N57D Q{H!s_6iyv '************************************************************************* x*,q
Rew 'Radius and conic constant of posterior lens Ak\D6eHcB '************************************************************************* !^Z[z[ eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) [3{:H"t GetConic eID, entity, curv, conic k=h/i8i2z 7`u A SetConic eID, entity, 1/Rpost, CCpost 2-"Lxe65f Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ),D`ZRXS haEZp6Z '************************************************************************* ohQz%?r 'Lens thickness (Position of posterior lens surface) )RAv[U1 '************************************************************************* mR"2 %T&&x2p^=? parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;3.T* ?|o V',m $ ' Delete any z-shift(s) 4 BE:&A count = 0 YobC'c\~9 While GetOperationCount(eID)>count 0]:*v? GetOperation eID, count, op C)&gL=O*$ If op.Type="ShiftZ" Then ((RpT0rP\ DeleteOperation eID,count YWcui+4p} count=count-1 ,z0~mN End If 1eE]4Z4Q count=count+1 Y-neD?V N Wend ,{`o/F/ X_0{*!v8 'Set new z-shift &|'Kut?8 op.Type = "ShiftZ" 8M3p\}O op.val1 = tlens a!^-~pH: op.parent = parID :r
vO8.\ AddOperation eID, op T_(e(5 Print "Set lens thickness = " & tlens Fu1|b2B-x \0*yxSg,^ '************************************************************************* )'K!)?&d 'Lens index of refraction k<j)?_=` '************************************************************************* -Iruua7b eID = FindMaterial( "Lens" ) Q8gdI GetModelMaterial eID, mat VxPTh\O*[ 8eS@<[[F# mat.Nd = nlens W"}*Q-8W SetModelMaterial eID, mat bb
O;AiHD Print "Set lens index of refraction = " & nlens 7#*CWh1BNO (:k`wh& '************************************************************************* h0QQP 'Pupil diameter FOyfk$ '************************************************************************* aVL%-Il} eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) D4S?bZFHo T1
.@Tbbt 'Adjust pupil diameter (trimming volume inner hole) bv" ({:x .tZ$a_O SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" !Bbwl-e` f3|=T8"t ' Adjust pupil location to just in front of the lens {%}6d~Bg parID = FindFullName( "Geometry.Arizona Eye" ) I9&<:` eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) iJ#oI@s count = 0 {]N?DmF While GetOperationCount(eID)>count $)a5;--W GetOperation eID, count, op vv_?ip:t If op.Type="ShiftZ" Then \zDV|n~{w DeleteOperation eID,count ~&|i'f[ count=count-1 +@v} ( End If A Mfu|%ZL count=count+1 82l";;n4p Wend v)pWx0l= op.Type = "ShiftZ" 1#RA+d( op.val1 = taq-0.01 6%axbB op.parent = parID ?E+XD'~ AddOperation eID, op ee\zU~ K",]_+b Print "Set pupil diameter = " & pupilDiam j* ja) ai2}vR 'Update AZ Eye subassembly Description (acRYv( eID = FindFullName( "Geometry.Arizona Eye" ) 0 ']M,iC/ GetEntity eID, entity %"B$I>h entity.Description = "Accommodation = " & A & "D" {(Z1JoSl SetEntity eID, entity y[eNM6p ovVU%2o1b Update yU`IyaazZ Print "DONE!" 3F3?be 0$
EJ4 End Sub 4K% YS GQ8P}McA 如果屈光度是4,光瞳直径是4,则会输出如下数据: QY!A[!6h ;W:Q}[ Accommodation = 4 Diopters 7MfvU|D[d/ Pupil Diameter = 4 mm Vt>E\{@[t Set aqueous humor thickness = 2.81 #SOe&W5 Set anterior lens radius = 10.4 and conic constant = -2.375869 g9.hR8X Set posterior lens radius = -4.424557 and conic constant = -3.081019 %M:"Ai5: Set lens thickness = 3.927 v<**GW]neD Set lens index of refraction = 1.42672 rkp0ej2- Set pupil diameter = 4 N9Vcp~; DONE! |
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