[技术]Arizona眼睛模型 [复制链接]

简介 y\@INA^  
^udl&>  
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。 9`Zwa_Tni  
*EllE+M{n  
模型 gvCQ![  
=.\PG[  
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。 ck\TTNA  
vV*i)`IXe  
X6G2$|  
在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. D0VbD" y  
[Nv)37|W  
光源 ..;ep2jSs  
1;"DIsz@d  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 cg).b?g  
]%eyrbU  
Bhg,P.7  
?G<.W
[3  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 N-YCOSUu  
"a=dx| Z  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 e!oL!Zg  
|"i"8~/@<  
3e ?J#;  
EWK?vs  
视网膜的散射 &h'NC%
"v  
MwTouEGGgA  
在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 DT[WO_=  
bA02)?L  
pz ~REsx  
NEW0dF&)  
注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 L17{W4  
8T}Dn\f  
Q=h37]U+  
=i:,")W7=  
脚本 Q3rLCg,;  
c_Jcy  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： Y{g[LG`U  
.tA=5QY,  
d-'BT(@:  
:uB(PeAv*  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 iH>I
V0 <  
余下的脚本计算与屈光度有关的所有参数。 OPJ(ub  
oq[r+E-]$@  
分析 j026CVL  
MN[D)RKh;  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 _@! yj  
<6.?:Jj  
y/;DA=  
脚本代码 Mw|lEctN0  
|>Pz#DCy  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. jKb4d9aX  
FB2{qG3  
Dim entity As T_ENTITY ZwMd 22  
Dim op As T_OPERATION *3rp g  
Dim mat As T_MODELMATERIAL ;^cMP1SH  
Dim A As Double z-^/<u1p  
Dim pupilDiam As Double ;jh.\a_\  
Dim eID As Long  Y}e3:\  
Dim parID As Long uLr-!T  
Dim count As Integer m'WGK`WIm  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double |}Mthj9n  
Dim tlens As Double, nlens As Double &"DD&87N%  
Dim curv As Double, conic As Double g=jB'h?  
Dim ok As Long 85BB{T;  
V$bq|r  
Sub Main ?f:ND1jU  
F%$lcQ04%  
    '用户输入对话框  `l  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 N`O0jH{  
        TextBox 220,21,40,21,.TextBox1 'default: 0 zvwv7JtB  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 qRXHaQi@9  
        OKButton 40,91,90,21 MbeK{8~E%l  
        CancelButton 190,91,90,21 #>2cfZ`6'J  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 \`W8#fob  
        TextBox 220,49,40,21,.TextBox2 'default: 4 s8SCEpz  
    End Dialog c*",AZ>
U  
    Dim dlg As UserDialog 2]}e4@{  
/w2N
O9Q  
    ok = Dialog (dlg) m}t`43}QE  
vj"['6Xa  
    If ok=0 Then    'cancel button was pressed dTqL[?wH?  
        Print "Execution cancelled." W?0u_F  
        End 64D4*GQ  
    End If n1)].`  
lHO.pN`2  
    'Assign accommodation and pupil diameter & use defaults if field left empty 4MRN{W6  
    If dlg.TextBox1 = "" Then 1-PFM-  
        A = 0           'Default accommodation k[\JT[M
p  
    Else !X 0 (4^  
        A = CDbl(dlg.TextBox1) |sBL(9  
    End If |T{ZDJ+  
n"<'F4r  
    If dlg.TextBox2 = "" Then TSj)XU {W  
        pupilDiam = 4   'Default pupil diameter D!D}mPi[  
    Else be'&tsZ9  
        pupilDiam = CDbl(dlg.TextBox2) c3Zwp%  
    End If e r"gPW  
d4o_/[  
    Print " " 1wW4bg 5  
    Print "Accommodation = " & A & " Diopters" r]&&*:  
    Print "Pupil Diameter = " & pupilDiam & " mm" A&_v:z4y/  
9 'IDbe{  
    ' Calculate new parameters with accommodation #Q%0y^s  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness }TU2o3Q  
IXsOTBM  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens a2H_8iQ!  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens )==Qo/N:  
I2C1mV  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens r`C t/]c  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens *'R2Lo<C  
OgkbN`  
    tlens = 3.767 + 0.04*A                  'Lens thickness 2_){4+,fu  
42 Sk`  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction &XSe&1  
OoR0>!x Z  
    'Adjust parameters to account for accommodation k)JwCt.%  
Y'o.`':\~  
    '************************************************************************* (rSBzM]H  
    'Aqueous thickness (Position of Lens) dNz!2mbO  
    '************************************************************************* 92L{be;SY  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Zy >W2(<  
    GetCustomElement eID, entity n:YA4t7S  
&qZ:"k  
    parID = FindFullName( "Geometry.Arizona Eye" ) YQ5d!a.  
YCNpJGM  
    ' Delete any shift(s) in z H/O
v8|  
    count = 0 P4~C0z  
    While GetOperationCount(eID)>count ^v@& q  
        GetOperation eID, count, op vjD||!g'  
        If op.Type="ShiftZ" Then a5%IjgQ&z  
            DeleteOperation eID,count 1 *$-.  
            count=count-1 >]WQ1E[=  
        End If +)TOcxF%  
        count=count+1 Le}-F{~`^  
    Wend 4gK_'b6"  
aD8r:S\  
    'Set new shift in k%lz%r  
    op.Type = "ShiftZ" F#XzhDs  
    op.val1 = taq ,Mw;kevw  
    op.parent = parID 00@y,V_]  
    AddOperation eID, op L<TL6  
    Print "Set aqueous humor thickness = " & taq-0.55 SiSxym  
bn<}  
    '************************************************************************* 1\+d 5Q0  
    'Radius and conic constant of anterior lens 4';(\42  
    '************************************************************************* C\p _  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) n:[GK_  
    GetConic eID, entity, curv, conic 4PAuEM/z  
>pn5nn1a  
    SetConic eID, entity, 1/Rant, CCant j#)K/`  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 4EDwZR>./  
G[5z3  
    '************************************************************************* RP4P"m(
 
    'Radius and conic constant of posterior lens " )_-L8  
    '************************************************************************* j-j,0!T~b  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) "kT?9&  
    GetConic eID, entity, curv, conic IF$*6 ,v.z  
*(sFr E  
    SetConic eID, entity, 1/Rpost, CCpost H '(Ky  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 1Qz1 Ehz>  
s
>^$: wzu  
    '************************************************************************* OwM.N+z#T  
    'Lens thickness (Position of posterior lens surface) oaJnLd90W  
    '************************************************************************* ESAFsJ$r;  
c
oQ>CbHg  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Iib39?D W  
 rVo?I  
    ' Delete any z-shift(s) kX^Y{73  
    count = 0 #ig* !  
    While GetOperationCount(eID)>count L4L[@tMPmY  
        GetOperation eID, count, op `upxM0gc  
        If op.Type="ShiftZ" Then 1v^eXvY  
            DeleteOperation eID,count .;xt{kK  
            count=count-1 =whYo?cE(  
        End If y=)xo7(  
        count=count+1 zU)Ib<$  
    Wend H_CX5=Nq^  
y.:Z:w6$  
    'Set new z-shift EecV%E  
    op.Type = "ShiftZ" x)<Hr,wd  
    op.val1 = tlens KLn.v
A.  
    op.parent = parID 8XUm.nV  
    AddOperation eID, op 'sCj|=y2Qc  
    Print "Set lens thickness = " & tlens pjP R3 r  
CF:s@Z+  
    '************************************************************************* j%qBNoT~  
    'Lens index of refraction 9 ZD4Gv   
    '************************************************************************* 1/H9(2{L  
    eID = FindMaterial( "Lens" ) yfd$T}WW6  
    GetModelMaterial eID, mat &~xzp^&  
wA#w]8SM  
    mat.Nd = nlens -3fzDxD  
    SetModelMaterial eID, mat #H@rb  
    Print "Set lens index of refraction = " & nlens VkNg Vjg  

^U`Bj*"2  
    '*************************************************************************  0"VL6$  
    'Pupil diameter H^c8r^#
 
    '************************************************************************* ;=FSpZ@  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) dt -=7mz#  
bH-QF\>  
    'Adjust pupil diameter (trimming volume inner hole) n8.W$&-ia  
QD}'2{M!  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" >2[\WF*"X  
"0(H! }D  
    ' Adjust pupil location to just in front of the lens <&+\X6w[  
    parID = FindFullName( "Geometry.Arizona Eye" ) SGd[cA Ko  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) fU )@Lj1Wo  
    count = 0 a}Dx"zl;  
    While GetOperationCount(eID)>count bk-veJR  
        GetOperation eID, count, op S<f]Y4A&  
        If op.Type="ShiftZ" Then 3Vu_-.ID  
            DeleteOperation eID,count Vg6/1I  
            count=count-1 INd:_cT4l  
        End If VuOZZ7y  
        count=count+1 ^*{:;F@  
    Wend 't+ J7  
    op.Type = "ShiftZ" `FjU2 O  
    op.val1 = taq-0.01 <]~FX25  
    op.parent = parID yZ_6yJw3}  
    AddOperation eID, op Pp*:rA"N  
[O"9OW'2!B  
    Print "Set pupil diameter = " & pupilDiam gH+s)6  
/Ria"lLv  
    'Update AZ Eye subassembly Description /E/Z0<l7  
    eID = FindFullName( "Geometry.Arizona Eye" ) ~]MACG:'  
    GetEntity eID, entity 59Lv/Mfy  
    entity.Description = "Accommodation = " & A & "D" qHZ!~Kq,"'  
    SetEntity eID, entity w)#Lu/  
ZU=omRh5  
    Update 9;\a|8O  
    Print "DONE!" (R.l{(A  
     kBh*@gf  
End Sub lUL6L4m  
pk%%}tP<  
如果屈光度是4，光瞳直径是4，则会输出如下数据： #-]!;sY>  
sew0n`d1  
Accommodation = 4 Diopters 6n|R<DO%\  
Pupil Diameter = 4 mm BHNcE*U}@?  
Set aqueous humor thickness = 2.81 6T?$m7c  
Set anterior lens radius = 10.4 and conic constant = -2.375869 }{R?i,j(  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 c#ahFpsnlw  
Set lens thickness = 3.927 5~,/VV  
Set lens index of refraction = 1.42672 ?~%Go  
Set pupil diameter = 4 0^0Q0A  
DONE! TrYt(F{t