[技术]Arizona眼睛模型 [复制链接]

简介 xm~`7~nFR  
-d/ =5yxL  
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。 o5PO=AN  
Q&tG4f<  
模型 o:'MpKm  
JyK3{wYS  
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。 )2o?#8J  
{dlXLx!B  
f'RX6$}\1X  
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. ^[`%&uj!g  
h,N?Ab'S  
光源 V1zmGy  
Dx?,=~W9  
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。 `$9x1dx  
khxnlry  
&6!)jIWJ  
*N<]Xy@  
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。 g:@#@1rB6  
BDDlQci38  
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。 sll\g  
h;"4+uw  

|HQW0  
2F.;;A
b  
视网膜的散射 <'oQ \eB  
Wn2NMXK  
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。 >tr}|>  
q3!bky\  
C}Cs8eUn  
C<tl/NC  
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。 CAhXQ7w'Z  
+O{*M9B  
2/^3WY1U  
$s:aW^k  
脚本 wn%A4-%{  

U8?mc  
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： f$$/H>MJ  
TD0 B%  
;6$jf:2m  
C1)!f j=  
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。 ^yp
{32  
余下的脚本计算与屈光度有关的所有参数。 6bC3O4Rw  

2[W&s&  
分析 ZY+qA  
v!5 `|\  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 lymCH  
u6JM]kR
  
7?_CcRe  
脚本代码 &h/Xku&0  
wc4=VC"y  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. PJH&  
g2_"zDiw2  
Dim entity As T_ENTITY #*
Ctwl,T  
Dim op As T_OPERATION VTE .^EK!  
Dim mat As T_MODELMATERIAL F JyT+  
Dim A As Double 57c8xk[.2  
Dim pupilDiam As Double 4tBYR9|  
Dim eID As Long :vbW  
Dim parID As Long e\L8oOk#r  
Dim count As Integer ^1.By^ $  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double .ioEIsg  
Dim tlens As Double, nlens As Double rx|pOz,:  
Dim curv As Double, conic As Double 5$k:t  
Dim ok As Long ;i+jJ4  
&^jXEz;  
Sub Main L!xi  
KZf+MSq? B  
    '用户输入对话框 bk[!8-b/a  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ;4\;mmLVk  
        TextBox 220,21,40,21,.TextBox1 'default: 0 i/Zd8+.n$  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 <e6#lF
QqK  
        OKButton 40,91,90,21 ckCE1e>s  
        CancelButton 190,91,90,21 FYQS)s  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 WpvhTX  
        TextBox 220,49,40,21,.TextBox2 'default: 4 M_DwUS1?  
    End Dialog +ZP7{%  
    Dim dlg As UserDialog t?FBG4  
K[YyBEid  
    ok = Dialog (dlg) sW\!hW1*x  
>m\(6x8RE  
    If ok=0 Then    'cancel button was pressed p!%pP}I  
        Print "Execution cancelled." FS.L\MjV]U  
        End xAm6BB c  
    End If YoFxW5by  
VIf.q)_k  
    'Assign accommodation and pupil diameter & use defaults if field left empty ?S=mybp  
    If dlg.TextBox1 = "" Then X:{!n({r=  
        A = 0           'Default accommodation f$QNg0v  
    Else _+MJ%'>S
 
        A = CDbl(dlg.TextBox1) :ShT|n7  
    End If 8&dF  
hDGF
7  
    If dlg.TextBox2 = "" Then )4;`^]F  
        pupilDiam = 4   'Default pupil diameter Fsg*FH7J  
    Else lyhiFkO iH  
        pupilDiam = CDbl(dlg.TextBox2) u*9V&>o  
    End If 'J|_2*  
.=; ;  
    Print " "
Iq.*8Oc  
    Print "Accommodation = " & A & " Diopters" \~wMfP8  
    Print "Pupil Diameter = " & pupilDiam & " mm" @C aG9]  
#g!.T g'  
    ' Calculate new parameters with accommodation 2Tppcj v  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness |y!A&d=xYn  
*VN6cSq  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens q@2siI~W  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \'j|BJ~L f  
8q7
b_Pq1U  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 69.NPy@  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens sDV Q#}a  
,
R|BG  
    tlens = 3.767 + 0.04*A                  'Lens thickness /qw.p#  
7K:PdF>/  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction apxph2yvS  
9N3eN  
    'Adjust parameters to account for accommodation Rf1x`wml  
Xn ;AZu^'R  
    '************************************************************************* kU`r)=1"  
    'Aqueous thickness (Position of Lens) 8dhUBJ0_  
    '************************************************************************* xkAK!uVy  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) $ME)#(  
    GetCustomElement eID, entity a'IdYW0  
U/BR*Zn]*  
    parID = FindFullName( "Geometry.Arizona Eye" ) #e5\j\#.  
4KrL{Z+}  
    ' Delete any shift(s) in z 9_s`{(0?  
    count = 0 rrv%~giU  
    While GetOperationCount(eID)>count <9 ;!3xG  
        GetOperation eID, count, op HpnWoDM  
        If op.Type="ShiftZ" Then KK &?gTa  
            DeleteOperation eID,count qIqM{#' ^  
            count=count-1 40 0#v|b  
        End If NaCy@  
        count=count+1 `P ,d$H "  
    Wend xN%K^Tree  
CJI~_3+K  
    'Set new shift in Wv/=
O}  
    op.Type = "ShiftZ" >F&47Yn  
    op.val1 = taq sp`Dvqx0  
    op.parent = parID S21,VpW\  
    AddOperation eID, op ~u+9J}  
    Print "Set aqueous humor thickness = " & taq-0.55 *uvQ\.  
\nqS+on]  
    '************************************************************************* t&DEb_"De  
    'Radius and conic constant of anterior lens wec)Ctj+  
    '************************************************************************* KY
]C6kh  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ^sg,\zD 'X  
    GetConic eID, entity, curv, conic b>9>uC@J15  
O|UC ?]6  
    SetConic eID, entity, 1/Rant, CCant &iVs0R  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant HUOj0T  
]M
'=^32  
    '************************************************************************* M& CqSd  
    'Radius and conic constant of posterior lens +d-NL?c  
    '************************************************************************* BL58] P84  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Dn}Jxu'(  
    GetConic eID, entity, curv, conic ei5~&  
D|#E9OQzs  
    SetConic eID, entity, 1/Rpost, CCpost da~],MN  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 9]@!S|1  
1g~R/*Jo  
    '************************************************************************* ^y4Z+Gu[  
    'Lens thickness (Position of posterior lens surface) dGTsc/$  
    '************************************************************************* v74&BL]a
 
Ld-_,-n  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?Pc'C  
Q)z8PQl O  
    ' Delete any z-shift(s) S>; 5[l 4  
    count = 0 eKqk= (  
    While GetOperationCount(eID)>count $,fX:x  
        GetOperation eID, count, op
f'3$9x  
        If op.Type="ShiftZ" Then -o EW:~y  
            DeleteOperation eID,count $ o#V#  
            count=count-1 y$R_.KbO  
        End If vgN&K@hJ  
        count=count+1 $7A8/#  
    Wend -RK- Fu<e  
efE.&]  
    'Set new z-shift U|j`e5)  
    op.Type = "ShiftZ" ?5 [=(\/.  
    op.val1 = tlens `x%>8/  
    op.parent = parID *siFj CN<  
    AddOperation eID, op '>C5-R:O  
    Print "Set lens thickness = " & tlens S?BG_J6A7  
tIS<U(N;  
    '************************************************************************* Nu~lsWyRI5  
    'Lens index of refraction &UlWCOo8  
    '************************************************************************* VTHH&$ZNq  
    eID = FindMaterial( "Lens" ) _/<x  
    GetModelMaterial eID, mat @2v_pJy^  
KdbHyg<4  
    mat.Nd = nlens @49S`  
    SetModelMaterial eID, mat X+]G-  
    Print "Set lens index of refraction = " & nlens QUQ'3  
('p5:d  
    '************************************************************************* y Fq&8 x<X  
    'Pupil diameter LC!bIm5'  
    '************************************************************************* {3vNPQJ  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) x# 5A(g  
cDkf qcC  
    'Adjust pupil diameter (trimming volume inner hole) D*|Bb?  
_ZkI)o
 
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" K8Y=S12Ti  
\mlqO[ S  
    ' Adjust pupil location to just in front of the lens ,L'zRyP  
    parID = FindFullName( "Geometry.Arizona Eye" ) OJy#w{4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) cq4Ipe  
    count = 0 g_COp"!~9  
    While GetOperationCount(eID)>count ~z;FP$U  
        GetOperation eID, count, op As<bL:>dE  
        If op.Type="ShiftZ" Then &W6^sj*k5U  
            DeleteOperation eID,count gEE\y{y  
            count=count-1 RhLVg~x  
        End If L5:$U>H(  
        count=count+1 ZbAcO/  
    Wend Gjo`&#  
    op.Type = "ShiftZ" B~Xw[q  
    op.val1 = taq-0.01 8 uwq-/$  
    op.parent = parID hODWB&b  
    AddOperation eID, op iTU5l5Uz  
x5*!Wx   
    Print "Set pupil diameter = " & pupilDiam Q^txVUL  
m$T-s|SY  
    'Update AZ Eye subassembly Description fNZ__gO!%  
    eID = FindFullName( "Geometry.Arizona Eye" ) \.#>=!Ie  
    GetEntity eID, entity Czu\RXJR  
    entity.Description = "Accommodation = " & A & "D" oIj#>1~c%  
    SetEntity eID, entity = 6\^%  
ChXq4]  
    Update 7g}w+p>  
    Print "DONE!" (,Df^4%7  
     LOV)3{m  
End Sub .];=Pu^  
D]Xsvv
#  
如果屈光度是4，光瞳直径是4，则会输出如下数据： $43qME  
HBx=\%;n  
Accommodation = 4 Diopters |64~K\X  
Pupil Diameter = 4 mm <1\Nb
{5  
Set aqueous humor thickness = 2.81 0T5L_%c  
Set anterior lens radius = 10.4 and conic constant = -2.375869 L AA
HEv  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ?zHPJLv|Y  
Set lens thickness = 3.927 ~|xA4u5LG  
Set lens index of refraction = 1.42672 ut/=R !(K  
Set pupil diameter = 4 pOG1jI5<{8  
DONE! ]G< Vg5