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2020-12-09 09:18 |
Arizona眼睛模型
简介 u(~( +1W mV|Z5 =f 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。 Yq%r\[%* */j[n$K>~` 模型 &G_XgQsg{ 7upN:7D- 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。 iz2;xa*
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Table 1. AZ眼睛模型的定义 `t2Y IwOK 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. K}tC8D ?S'Wd= 光源 D:XjJMW3r z`!f'I--! 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。 >(Fy6m s\.\z[1 wcL|{rUXba
图1. 光源和提示信息使用 WB\chb%ej# 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。 _^p\
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g 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。
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图2. 字母F光源的设定方法光 1(qL),F; 3u4P
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图3. 字母F在视网膜上位置点列图 _.5ABE 视网膜的散射 QoS]QY'bZ |\N))K-2D 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。 ~y1k2n LuWY}ste J"Nn.iVq
图4. 视网膜朗伯散射设定 ?'^yw C` 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。 -qpe;=g&f 8YO` TgW T<U_Iq
图5. 视网膜重点采样规格设定 9%DLdc\z; 脚本 &W
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R{ YT<(2u#Ng 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: m,r>E%;Cj S~V?Qe@&Z
图6. 用户对话框的创建与编辑 Te H_DVxj
图7. 用户对话框编辑器 $Fv|w9 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 Zi.w+V 余下的脚本计算与屈光度有关的所有参数。 Go PK. E$ 9Qn*frdY, 分析 =]P|!$!}0 g]U!] 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 <Gz* 2i _Q}vPSJviC
图7. 字母F在视网膜上颜色分析 kV$VKag*A 脚本代码 G9h B p *[tLwl. Option Explicit 'Remove this to enable non-dimensioned variables to be used. 1V;,ZGI* 1_z~<d
@?; Dim entity As T_ENTITY #XeabcOQ Dim op As T_OPERATION 2Y%E.){ Dim mat As T_MODELMATERIAL .gA4gI1kH Dim A As Double .>@]Im Dim pupilDiam As Double B2,JfKk/ Dim eID As Long td|O #R Dim parID As Long A<{&?_U Dim count As Integer qoOq47F Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double RNb" O{3 Dim tlens As Double, nlens As Double cT#R B7 Dim curv As Double, conic As Double 8v\^,'@ Dim ok As Long TTz_w-68 >0I\w$L Sub Main "PC9[i F,JqHa9 '用户输入对话框 k
Hh0&~( Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 [\.@,Y0j TextBox 220,21,40,21,.TextBox1 'default: 0 {\ J%i|u Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 og|~:>FmJo OKButton 40,91,90,21 +EM^ CancelButton 190,91,90,21 E~1"Nh Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 'E %+ O TextBox 220,49,40,21,.TextBox2 'default: 4 V)cL=4G End Dialog #)( D_* Dim dlg As UserDialog rF=\H3`p3 MO_;8v~0 ok = Dialog (dlg) _hi8mo nfS.0\z If ok=0 Then 'cancel button was pressed SHN'$f0Mb Print "Execution cancelled." AI2@VvB End Z1oUAzpj4 End If 8J8@0 =Y-mc#{8 'Assign accommodation and pupil diameter & use defaults if field left empty Uw->5 If dlg.TextBox1 = "" Then 1D)=q^\I A = 0 'Default accommodation jCL 1Bj Else f9La79v A = CDbl(dlg.TextBox1) $'Qv
{ End If xRm~a-rp :PQvt/-'(D If dlg.TextBox2 = "" Then _rvO#h pupilDiam = 4 'Default pupil diameter \Wf1b8FW Else a<v!5\dq! pupilDiam = CDbl(dlg.TextBox2)
iKEHwm End If 3ULn ]jA 5U<;6s Print " " Oi\,clR^[o Print "Accommodation = " & A & " Diopters" g)^g_4 Print "Pupil Diameter = " & pupilDiam & " mm" N_f>5uv D'oy%
1Q} ' Calculate new parameters with accommodation Y]H,rO taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness L'<.#(| wak'L5GQE Rant = 12.0 - 0.4*A 'Radius of anterior lens P6u%-# CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens Y%@a~| 9AHxa Rpost = -5.224557 + 0.2*A 'Radius of posterior lens wZKEUJpQ CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens utBKl'` 5ii:93Hlj tlens = 3.767 + 0.04*A 'Lens thickness ?a'P;&@7 a_o99lP nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction (GbZt{. 7aJ:kumDZ 'Adjust parameters to account for accommodation 31~Rs?~f( -*~~00w '************************************************************************* "i~~Q'=7 'Aqueous thickness (Position of Lens) uui3jZ: '************************************************************************* ZoroK.N4A% eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~?uch8H GetCustomElement eID, entity
peGh- tqicyNL parID = FindFullName( "Geometry.Arizona Eye" ) eWTbHF &KVXU0F^z ' Delete any shift(s) in z \Ea(f**2B count = 0 5FwVR3, While GetOperationCount(eID)>count L3y`*&e> GetOperation eID, count, op i=X
B0- If op.Type="ShiftZ" Then
A!^gF~ 5 DeleteOperation eID,count s.XLC43Rs count=count-1 @V qI+5TA End If +~eybm; count=count+1 .|<+-Rsj Wend >0.a#-u^ Pm!/#PtX 'Set new shift in oO][X op.Type = "ShiftZ" Gey j`t op.val1 = taq C!6d`| op.parent = parID :V^|}C# AddOperation eID, op kyu
PN<? Print "Set aqueous humor thickness = " & taq-0.55 A,]%*kg2 Z$:iq '************************************************************************* GNab\M. 'Radius and conic constant of anterior lens T9&bY>f? '************************************************************************* >!%F$$ eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) <^fvTb &* GetConic eID, entity, curv, conic o6A1;e Bf{c4YiF SetConic eID, entity, 1/Rant, CCant xBg.QV Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant AQIBg9y7 @szr '&\%A '************************************************************************* >j_N6B! 'Radius and conic constant of posterior lens %rq/jC '************************************************************************* q@Oe} eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) (V9 ; GetConic eID, entity, curv, conic DBk]2W|i `F4gal^ ^ SetConic eID, entity, 1/Rpost, CCpost 0.
mS^g,M- Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost C}Ucyzfr,p J `
KyS '************************************************************************* ~9DD=5\ 'Lens thickness (Position of posterior lens surface) p-JGDjR0G '************************************************************************* $#/f+kble L{Kl! parID = FindFullName( "Geometry.Arizona Eye.Lens" ) -&JQdrs yNOoAnGT W ' Delete any z-shift(s) ?OF9{$m3? count = 0 1AAOg+Y@U" While GetOperationCount(eID)>count ^b^}6L'Z GetOperation eID, count, op eq,`T; If op.Type="ShiftZ" Then aDZ] {; DeleteOperation eID,count @"__2\ 0 count=count-1 ,'&H`h54 End If .T\_4C count=count+1 9s&Tv&%VN Wend = ow=3Ku MkX=34oc^ 'Set new z-shift 2./;i>H[u op.Type = "ShiftZ" U*:E|'> op.val1 = tlens ndS8p]P&o( op.parent = parID Usq.'y/o AddOperation eID, op )>I-j$%=2 Print "Set lens thickness = " & tlens *=(vIm[KL _kT{W] '************************************************************************* "? ON0u9 'Lens index of refraction i6 )HC '************************************************************************* :s>x~t8g#n eID = FindMaterial( "Lens" ) ug^esB GetModelMaterial eID, mat ~Aw.=Yi= S pk8u4 mat.Nd = nlens cUC!'+L SetModelMaterial eID, mat .X34[AXd Print "Set lens index of refraction = " & nlens 2B"&WKk l;i/$Yu7 '************************************************************************* 'wni.E& 'Pupil diameter v W4n>h}] '************************************************************************* qylI/,y{ eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ZaF9Q% R*DQLBWc 'Adjust pupil diameter (trimming volume inner hole) hGJANA .FC|~Z1T<F SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" |H.ARLS ziC%Q8 ' Adjust pupil location to just in front of the lens L :Ldk parID = FindFullName( "Geometry.Arizona Eye" ) :*Y2na)qQ eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) V6Y0#sTU count = 0 i>e?$H,/ While GetOperationCount(eID)>count `#"xgOSP> GetOperation eID, count, op Y`rli If op.Type="ShiftZ" Then H{hzw&dZ<P DeleteOperation eID,count _{/[&vJ count=count-1 {r'+icvLX End If EYA=fU count=count+1 U1O8u -X Wend `T{'ufI4B op.Type = "ShiftZ" 0ZJj5<U op.val1 = taq-0.01 n x{MUN7 op.parent = parID PU8dr| ! AddOperation eID, op BhhFij4 B>g(i=E Print "Set pupil diameter = " & pupilDiam JJK-+a6cX Bk[C=< X
'Update AZ Eye subassembly Description QD%!a{I eID = FindFullName( "Geometry.Arizona Eye" ) 2'u% GetEntity eID, entity +t3o5& entity.Description = "Accommodation = " & A & "D" " =6kH, SetEntity eID, entity Xw3j(`w$, o59b#9 Update SEVB.; Print "DONE!" h"nhDART< *wx95?H0Z End Sub Zz"8 <w`EU[y_ 如果屈光度是4,光瞳直径是4,则会输出如下数据: p6!5}dD( PQp/&D4K Accommodation = 4 Diopters w!'y,yb% Pupil Diameter = 4 mm xkv%4H> Set aqueous humor thickness = 2.81 7ug"SV6Hb Set anterior lens radius = 10.4 and conic constant = -2.375869 hQ'W7EF Set posterior lens radius = -4.424557 and conic constant = -3.081019 5z =}o/? Set lens thickness = 3.927 k7j.VpN9 Set lens index of refraction = 1.42672 ln+.=U6Tm Set pupil diameter = 4 t+_\^Oa) DONE! p]ujip {xeJO:M3/ JOJuGB-d QQ:2987619807 ,J,Rup">h
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