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2021-10-22 09:55 |
Arizona眼睛模型
简介 Qf"gH<vT 4bmpMF- 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。 \jC}>9 Ek84yme# 模型 ' e-FJ')| hhwV)Z 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。 !X8:#a( K'y;j~`-
Table 1. AZ眼睛模型的定义 *@/!h2 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*|h G/{ CFVe0!\ 光源 8c#u"qF {>Zc#U' 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。 $ U<xrN>O BK,=(;d3 D=e&"V a
图1. 光源和提示信息使用 '9-8_; 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。 "= HCP, =6/0=a[ 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。 i_V~SC` <s
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图2. 字母F光源的设定方法光 c8#A^q} "GgK,d}%
图3. 字母F在视网膜上位置点列图 }9jy)gF*e 视网膜的散射 i9_ZK/* nx=Zl:Q} 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。 'a*tee ^RS 5PG%)xff* <kt,aMw[*
图4. 视网膜朗伯散射设定 S's\M5 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。 *l^h;RSx ?> }bg nxCwg>
图5. 视网膜重点采样规格设定 y$7<ZBG 脚本 YcT!`B )9,9yd~SI 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: 0d~>zKho jCxw|tmgq
图6. 用户对话框的创建与编辑 Ar N *9
图7. 用户对话框编辑器 7$k[cL1 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。 ]_@5LvI 余下的脚本计算与屈光度有关的所有参数。 tGe|@.! IZoa7S&t 分析 R6*:Us0\FJ t=Tu-2,k 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 pS;jrq
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图7. 字母F在视网膜上颜色分析 D^$Nn*i;U 脚本代码 tUH#% yuWoz*:t Option Explicit 'Remove this to enable non-dimensioned variables to be used. H"6Sj-<= XTyJ*`> Dim entity As T_ENTITY YD 1u Dim op As T_OPERATION +v{<< Dim mat As T_MODELMATERIAL aHvTbpJ Dim A As Double \E5%.KR Dim pupilDiam As Double uAwT)km
{ Dim eID As Long QG$LbuZ` Dim parID As Long d~u+:[\=/ Dim count As Integer 0ZlF#PJA Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double y".uu+hL` Dim tlens As Double, nlens As Double *2Il{KOA^ Dim curv As Double, conic As Double 17
Hdj Dim ok As Long JL=MlZ bzz=8n Sub Main FhVi|Va wK!4:]rhG '用户输入对话框 LzEs_B=9 Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 1-!u=]JDE TextBox 220,21,40,21,.TextBox1 'default: 0 3@f@4t@5V Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 0.Pd,L( OKButton 40,91,90,21 sluR@[l CancelButton 190,91,90,21 <nOK#;O) Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 O'a
Srjl TextBox 220,49,40,21,.TextBox2 'default: 4 ZnVi.s~1V End Dialog BrcT`MM[(= Dim dlg As UserDialog /~Zxx}<; zc%#7"FM ok = Dialog (dlg) { AdPC?R` ),1MR= If ok=0 Then 'cancel button was pressed c4E=qgP Print "Execution cancelled." j?K]0j; End ()i8 Qepo} End If BuII|j YtI2Vr/9 'Assign accommodation and pupil diameter & use defaults if field left empty /"Ws3.p If dlg.TextBox1 = "" Then {B8W>>E A = 0 'Default accommodation u|t<f`ze Else A6v<+`? A = CDbl(dlg.TextBox1) $\h\,N$y End If rP Wn a/Z >- If dlg.TextBox2 = "" Then fS+Ga1CsH pupilDiam = 4 'Default pupil diameter ,g\%P5 Else |7KW'=O pupilDiam = CDbl(dlg.TextBox2) Pi7vuOJr8 End If })f4`$qf +MU|XT_5|6 Print " " 0 UdAF Print "Accommodation = " & A & " Diopters" \}[{q Print "Pupil Diameter = " & pupilDiam & " mm" )D?\ru H qP@d)XRQ ' Calculate new parameters with accommodation MM8@0t'E taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness h.+{cOA;n tCH4-~,# Rant = 12.0 - 0.4*A 'Radius of anterior lens "5Orj*{ CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens X+2 aP'D Qvo(2( Rpost = -5.224557 + 0.2*A 'Radius of posterior lens 2~[f<N CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens /cM< *;b.x" tlens = 3.767 + 0.04*A 'Lens thickness @=4K%SCw 8G@I e nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction FaS}$-0 ClZ:#uMbN 'Adjust parameters to account for accommodation v%N/mL+5L Uv|z
c '************************************************************************* xDv5'IGBb 'Aqueous thickness (Position of Lens) el
GP2x#: '************************************************************************* M\\t)=q eID = FindFullName( "Geometry.Arizona Eye.Lens" ) pt[H5 GetCustomElement eID, entity R(_UR)G0 @ pd2Lc
$O@ parID = FindFullName( "Geometry.Arizona Eye" ) &-^|n*=g6 .PjJ g^^ ' Delete any shift(s) in z hwgLJY? count = 0 `\!oY;jk While GetOperationCount(eID)>count Q(Q.( GetOperation eID, count, op L,G{ t^j If op.Type="ShiftZ" Then /HCd52 DeleteOperation eID,count =fk+"!-i%" count=count-1 H{}0-0o End If ukM11LD5x count=count+1 mY[s2t Wend [>+}2-# m?LnO5Vs 'Set new shift in Np$peT[ op.Type = "ShiftZ" l"9.zPvT< op.val1 = taq FnkB
z5D op.parent = parID 0a<:.} AddOperation eID, op $@]tTz;b Print "Set aqueous humor thickness = " & taq-0.55 cTpmklq v4_p3&aj '************************************************************************* .-Y3oWV 'Radius and conic constant of anterior lens 7+^9"k7 '************************************************************************* cspO5S># eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 7kDX_,i GetConic eID, entity, curv, conic 5:[<pY!s# 8j~:p!@
SetConic eID, entity, 1/Rant, CCant V/%tFd1 Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 00s&<EM 2de[ yz '************************************************************************* #'"zyidu 'Radius and conic constant of posterior lens hCXSC*; '************************************************************************* }~gBnq_DDU eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Z:F5cXt< GetConic eID, entity, curv, conic d GEMrjx UuDT=_1Sh SetConic eID, entity, 1/Rpost, CCpost |a!AgvNF Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost _"BYnPq@wb kaSi sjd '************************************************************************* MF+J3) 'Lens thickness (Position of posterior lens surface) N^,@s"g '************************************************************************* P}=u8(u v=n'#:k parID = FindFullName( "Geometry.Arizona Eye.Lens" ) R7'a/ bcgh}D ' Delete any z-shift(s) Z0yy<9q]2 count = 0 Bvbv~7g( While GetOperationCount(eID)>count w-~u[c GetOperation eID, count, op \W^Mo>l If op.Type="ShiftZ" Then Ie 3
F DeleteOperation eID,count pz'l9Gp;@ count=count-1 $i#
1<Qj End If fBgW0o.Bu count=count+1 S;0,UgB1 Wend RRYm.dMIw UclQo~3 'Set new z-shift NZUQ
R`5 op.Type = "ShiftZ" 6U{&`8C op.val1 = tlens Z#8O)GK op.parent = parID vj?v7 AddOperation eID, op :H}a/ x*ur Print "Set lens thickness = " & tlens qw]:oh&G B~p` 3rC '************************************************************************* ppv/A4Kv 'Lens index of refraction eUiJl6^x '************************************************************************* 5)=XzO0 eID = FindMaterial( "Lens" ) Vf
Jpiv1 GetModelMaterial eID, mat $@8$_g|Wz FScE3~R mat.Nd = nlens B?}ZAw> SetModelMaterial eID, mat caA>; +aBH Print "Set lens index of refraction = " & nlens eK
}AVz}k l.tNq$3pS '************************************************************************* n0o'ns 'Pupil diameter g.CUo:c '************************************************************************* .(!> *ka| eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) P#`Mg@. A0x"Etbw) 'Adjust pupil diameter (trimming volume inner hole) ,TuDG*YA &w{""' SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 9v7l@2/ }m6zu'CV ' Adjust pupil location to just in front of the lens aL63=y parID = FindFullName( "Geometry.Arizona Eye" ) 5w: eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) oH/6 count = 0 <|= UrG While GetOperationCount(eID)>count 7%aaqQ1T GetOperation eID, count, op eT??F If op.Type="ShiftZ" Then x"kc:F DeleteOperation eID,count kj(Ko{ count=count-1 @^Tof5?F? End If fFG, ^;7-O count=count+1 Qz*!jwg Wend Z
P\A op.Type = "ShiftZ" chjXsq#Q^ op.val1 = taq-0.01 %vPs38Fks op.parent = parID e/@t U'$ AddOperation eID, op F<8Rr#Z 1( V>8}zn Print "Set pupil diameter = " & pupilDiam &V;^xMO! d/>owCwQ 'Update AZ Eye subassembly Description cnm&oC 6 eID = FindFullName( "Geometry.Arizona Eye" ) r3a$n$Qw GetEntity eID, entity "eWN52 entity.Description = "Accommodation = " & A & "D" voRr9E*n SetEntity eID, entity m&)5QX pDr%uL Update 2mVcT3 Print "DONE!" &
[)1LRt_ w9D<^(_}/ End Sub J(*QtF x\ieWF1 如果屈光度是4,光瞳直径是4,则会输出如下数据: 2ye^mJ17 tB"amv Accommodation = 4 Diopters D3#/*Ky Pupil Diameter = 4 mm e%VJ:Dj Set aqueous humor thickness = 2.81 +^% y&8e Set anterior lens radius = 10.4 and conic constant = -2.375869 Uf^zA/33 Set posterior lens radius = -4.424557 and conic constant = -3.081019 !a&@y#x Set lens thickness = 3.927 dI!x Ai Set lens index of refraction = 1.42672 X#9}|rT56 Set pupil diameter = 4 p8<Y5:` DONE! FY%v \`@1*
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