[技术]Arizona眼睛模型 [复制链接]

简介 #@6L|$iX  
otSPi7|k  
人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 E@jl: -*E  
d95N$n   
模型 e-cb?.WU?  
pInWKj[y1  
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。 ;]M67ma7C  
thPH_DW>eb  
px>>]>ZMH  
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. 9BD|uU;0  
*6D%mrK
 
光源 8Qz7uPq  
g**%J Xo  
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\8#Qvghf  
,okJ eZ  
ZU.)K
>'  
x0A%kp&w  
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。 +R#`j r"  
pu$XUt  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ?SOF n  
6>BDA?  
y]YS2^  
Df,VV+  
视网膜的散射 ~<aeA'>OA  
&/hr-5k  
在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 dezL{:Ya  
TnBGMI,g'  
vx5o k1UY  
txfwLqx  
注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ]AC!R{H  
ua|Z`qUyq  
_ K+V?-=  
{.D2ON  
脚本 &]yJCzo]  
%cr]ZR  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： aHPSnB&  
v*'iW
HCl,  
Ul713Bjz  
~\:j9c
C  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 zj$_iB`9  
余下的脚本计算与屈光度有关的所有参数。 dI ZTLb"a  

: 9?Cm`  
分析 Y\g90
  
Xq^y<[  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 z`emKFbv  
Ie G7@  
)K>Eniou  
脚本代码 S3ab0JM  
YVQ_tCC_!  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. a,/M'^YyN  
z+3<$Z  
Dim entity As T_ENTITY YMc8Q\*B  
Dim op As T_OPERATION 
Xt</ -`  
Dim mat As T_MODELMATERIAL xoqiRtlY:  
Dim A As Double "rme~
w Di  
Dim pupilDiam As Double !cq=)xR  
Dim eID As Long |A ;o0pL  
Dim parID As Long 2Pbe~[  
Dim count As Integer t{/hkXq]  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Yw6DJ
Y  
Dim tlens As Double, nlens As Double DJmoW  
Dim curv As Double, conic As Double jP1$qhp  
Dim ok As Long ,\BVV,  
Hze-Ob8  
Sub Main RY9+ 9i  
Ihdu1]~R{  
    '用户输入对话框 1*Sr5N[=  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 sCVI 2S!L  
        TextBox 220,21,40,21,.TextBox1 'default: 0 X Y~;)<s_  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 'I&|1I^  
        OKButton 40,91,90,21 Uh>.v |P6  
        CancelButton 190,91,90,21 q\a[S*  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 sT)6nV  
        TextBox 220,49,40,21,.TextBox2 'default: 4 GtF2@\  
    End Dialog plK=D#)  
    Dim dlg As UserDialog 3@&bxYXm  
_)Qy4[S=d  
    ok = Dialog (dlg) ue@8voZhS/  
mKV'jm0  
    If ok=0 Then    'cancel button was pressed 9ftN8Svw  
        Print "Execution cancelled." ^Z2kq2}a  
        End Xq|nJ|h  
    End If 8 4z6zFv?Q  
[Gh"ojt]w  
    'Assign accommodation and pupil diameter & use defaults if field left empty ^OF5F8Tf/  
    If dlg.TextBox1 = "" Then .8]Y-  
        A = 0           'Default accommodation hm3jpWi8  
    Else e$/&M*0\f  
        A = CDbl(dlg.TextBox1) Yj3P 7k$c  
    End If z5 Bi=~=#  
MD<-w|#8IV  
    If dlg.TextBox2 = "" Then 2/@D7>F&g  
        pupilDiam = 4   'Default pupil diameter 1~'_K9eE  
    Else {]^2R>0Q  
        pupilDiam = CDbl(dlg.TextBox2) kg3ppt  
    End If M/{g(|{  
&8sV o@Pa  
    Print " " O%-h&C3  
    Print "Accommodation = " & A & " Diopters" Sj)}qM-y#  
    Print "Pupil Diameter = " & pupilDiam & " mm" H?uukmZl  
0KAj]5nvb  
    ' Calculate new parameters with accommodation 9cQ_mgch  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness /)9W1U^B  
C c*({  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ]TSg!H  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ioV_oR9I  
$D'^t(  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ,+._;[k  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens v7IzDz6gF  
D|_V<'  
    tlens = 3.767 + 0.04*A                  'Lens thickness zoP%u,XL  
`HW:^T  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction sG,+  
PJgp
+u<  
    'Adjust parameters to account for accommodation j7 d:v7+_  
KrKu7]If6#  
    '************************************************************************* 9`"DFFSMS  
    'Aqueous thickness (Position of Lens) #Qbl=o4  
    '************************************************************************* w#(RW7":F  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) lj2=._@R  
    GetCustomElement eID, entity ksWSMxm  
lKKERO5+  
    parID = FindFullName( "Geometry.Arizona Eye" ) :\yc*OtX  
&uM^0eM  
    ' Delete any shift(s) in z V U~Dk);Bv  
    count = 0 5j^NV&/_  
    While GetOperationCount(eID)>count
Z$'IBv  
        GetOperation eID, count, op H4<Nnd\   
        If op.Type="ShiftZ" Then ?KWj}|%  
            DeleteOperation eID,count M>l^%`  
            count=count-1 Q:Mh
jkOr}  
        End If "5!BU&   
        count=count+1 #^rU x.  
    Wend m)&znLA
 
@Doyt{|T  
    'Set new shift in NZXjE$<Vr  
    op.Type = "ShiftZ" X-JV'KE}^z  
    op.val1 = taq TGV  
    op.parent = parID p!W[X%`)  
    AddOperation eID, op c[cAUsk i  
    Print "Set aqueous humor thickness = " & taq-0.55 >n
nY:7m  
#DI$
Oc  
    '************************************************************************* OXhAha`R  
    'Radius and conic constant of anterior lens '$m7ft}  
    '************************************************************************* J7&DR^.Sw  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) +=3CL2{An  
    GetConic eID, entity, curv, conic 4$"D
baC  
Vk}49O<K/  
    SetConic eID, entity, 1/Rant, CCant JW+*d`8Z[  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ]/dVRkZeAE  
RtV.d\  
    '************************************************************************* )]Ti>RO7  
    'Radius and conic constant of posterior lens B~gV'(9g  
    '************************************************************************* $H2GbZ-I  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 4%ZM:/  
    GetConic eID, entity, curv, conic _p}xZD\?,  
jBtj+TL8  
    SetConic eID, entity, 1/Rpost, CCpost t#b0H)  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 3<(q }  
\8b6\qF/\  
    '************************************************************************* %w"nDu2Gcv  
    'Lens thickness (Position of posterior lens surface) Omyt2`q  
    '************************************************************************* :#X[%"g.  
!,&yyx.  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) "'tRfB  
Dgi~rr1`'s  
    ' Delete any z-shift(s) H7&xLYQ2  
    count = 0 +1`t}hO  
    While GetOperationCount(eID)>count Wd 2sh  
        GetOperation eID, count, op 5vOCCW  
        If op.Type="ShiftZ" Then i^2IW&+}e}  
            DeleteOperation eID,count H5xzD9K;/C  
            count=count-1 \U
@3`  
        End If $:vkX   
        count=count+1 [_!O<z_sB  
    Wend a39hP*  
8tc*.H{^+  
    'Set new z-shift VXKT\9g3A  
    op.Type = "ShiftZ" ">90E^  
    op.val1 = tlens 3N4.$#>#9@  
    op.parent = parID 284zmZZ  
    AddOperation eID, op h4`9Cfrq,  
    Print "Set lens thickness = " & tlens %}qbkkZ  
.iv3q?8.b  
    '************************************************************************* @.$MzPQQI  
    'Lens index of refraction ?U9/fl  
    '************************************************************************* 

Pl  
    eID = FindMaterial( "Lens" ) |4>:M\h  
    GetModelMaterial eID, mat sdr.u  
2$0)?ZC?=  
    mat.Nd = nlens >Y&KTSD"  
    SetModelMaterial eID, mat ]PX}b  
    Print "Set lens index of refraction = " & nlens }~I|t!GL  
ElR)Gd_8  
    '************************************************************************* +zO]N&  
    'Pupil diameter DeQDH5X"  
    '************************************************************************* )%j"  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) v\0^mp  
+R\~3uj[7  
    'Adjust pupil diameter (trimming volume inner hole) ;Bs^iL  
|]ucHV  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" dY'Y5Th~  
F`&>NQb  
    ' Adjust pupil location to just in front of the lens \Jpw1,6  
    parID = FindFullName( "Geometry.Arizona Eye" ) QJXdb]Y^;  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) U[fSQ`&D  
    count = 0 UR:n5V4  
    While GetOperationCount(eID)>count hqW$kw  
        GetOperation eID, count, op +by|  
        If op.Type="ShiftZ" Then C*pLq5s  
            DeleteOperation eID,count </ZHa:=7  
            count=count-1 :,YLx9i>  
        End If l<N?'
&  
        count=count+1 CWMlZVG  
    Wend (Y;'[.  
    op.Type = "ShiftZ" { _X#f
q0}  
    op.val1 = taq-0.01 "m>};.lj  
    op.parent = parID cVg$dt  
    AddOperation eID, op 8A_TIyh?  
4K #^dJnC  
    Print "Set pupil diameter = " & pupilDiam  >fwlg-  
Te}IMi:  
    'Update AZ Eye subassembly Description ,O9`X6rh'  
    eID = FindFullName( "Geometry.Arizona Eye" ) ZjavD^ky  
    GetEntity eID, entity 2K~tDNv7  
    entity.Description = "Accommodation = " & A & "D" 6\mC$:F  
    SetEntity eID, entity ds')PIj  
1Kc{#+a^  
    Update >rRjm+vg  
    Print "DONE!" qIk )'!Vk  
     J ZNyC!u  
End Sub  l58l  
wEv*1y4  
如果屈光度是4，光瞳直径是4，则会输出如下数据： ls]Elo8h1f  
 nFVbQa~  
Accommodation = 4 Diopters BiI{8`M!$x  
Pupil Diameter = 4 mm ur`}v|ZY  
Set aqueous humor thickness = 2.81 @]<DR*<  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ap{{(y&R  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 w7Pe  
Set lens thickness = 3.927 [lrmuf  
Set lens index of refraction = 1.42672 r)(i{:@r`  
Set pupil diameter = 4 #SK#k<&P  
DONE! $o
{F