[技术]Arizona眼睛模型 [复制链接]

简介 I_<XL
<  
L'e^D|  
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。 /RxP:>hVv  
=EP`,zqn$9  
模型 </{Zb.  
C7FQc{  
模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 jr4xh{Z`  
D=-}&w_T"  
dT|f<E/P  
在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. /h0
bBP  
ZwS:Te9-  
光源 tk%f_"}  
PC_!  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 {h?pvH_>  
Y[6T7eZ0g  
s1D<R,J|H  
etr-\Cp  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 ep"[;$Eb  
_J l(:r\%  
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。 ]nhh|q9r{  
#{8IFA  
ST*h{:u&A  
:5NMgR.d  
视网膜的散射 hpAdoy[  
a;HAuy`M x  
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。 c* {6T}VZr  
_RbfyyaN  
*): |WDR  
(F4e}hr&  
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。 exb} y  
r<UVO$N  
k&dXK  
,MCTb'=G  
脚本 =Zq6iMD  
VsQ|t/|#  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： ~rb0G*R>  
/t0L%jJZ  
aOzIo-  
,9P-<P  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 SyvoN,;Q  
余下的脚本计算与屈光度有关的所有参数。 Bu{Kjv  
{@InOo!4w]  
分析 ]@&X*~c^Z  
+F;2FD$  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 "\b>JV5  
%Rk|B`ST  
BsQ;`2  
脚本代码 \;{ ]YX  
#fuUAbU0X  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. iq; | i!  
{"ST hTZ  
Dim entity As T_ENTITY I=0c\ U}  
Dim op As T_OPERATION 8Qg10Yjy  
Dim mat As T_MODELMATERIAL 54_}9_g  
Dim A As Double *7!MG  
Dim pupilDiam As Double '}Fe&%  
Dim eID As Long NHd@s#@  
Dim parID As Long *g(d}C!  
Dim count As Integer ppAbG,7  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double h*S"]ye5  
Dim tlens As Double, nlens As Double `nP
dZ.  
Dim curv As Double, conic As Double jx}&%p X  
Dim ok As Long ZJ/528Ju  
uavATnGO{B  
Sub Main +A3/^C0  
5|H;%T3_  
    '用户输入对话框 8}'iEj^e  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 $C[z]}iOi  
        TextBox 220,21,40,21,.TextBox1 'default: 0 hi8q?4jE  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 f8Hq&_Pn  
        OKButton 40,91,90,21 u[GZ~L  
        CancelButton 190,91,90,21 ^j<v~GTx+  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 *rq*li;  
        TextBox 220,49,40,21,.TextBox2 'default: 4 =6sP`:  
    End Dialog 7
Lm9I  
    Dim dlg As UserDialog 8+'}`  
'Ea3(OsuXn  
    ok = Dialog (dlg) !l'nX  
m%|\AZBA#  
    If ok=0 Then    'cancel button was pressed C[
^VM$  
        Print "Execution cancelled." `^)`J  
        End _^<vp  
    End If &f.5:u%{b  
u+)!C*ho  
    'Assign accommodation and pupil diameter & use defaults if field left empty KXPCkNIN!  
    If dlg.TextBox1 = "" Then fQoAdw  
        A = 0           'Default accommodation r^,_m,s'<  
    Else K?l|1jez(#  
        A = CDbl(dlg.TextBox1) tV++QC7@L  
    End If /uw@o9`~2-  
yhH2b:nY(9  
    If dlg.TextBox2 = "" Then lS=YnMs6a  
        pupilDiam = 4   'Default pupil diameter ZX_QnSNZ?  
    Else :|j[{;asY  
        pupilDiam = CDbl(dlg.TextBox2) 3!P^?[p3  
    End If ktU:Uq  
| R,dsBd  
    Print " " 8{4'G$6  
    Print "Accommodation = " & A & " Diopters" RRO@r}A!y  
    Print "Pupil Diameter = " & pupilDiam & " mm" >{^_]phlb  

#aqnj+  
    ' Calculate new parameters with accommodation @[^ 3yC#  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness X_PzK'#m  
|r@;ulO  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens =-dnniKW4  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens f}c;s  
Ec7xwPk  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens UN?tn}`!  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens nDkG}JkB!  
G]B0LUT6c  
    tlens = 3.767 + 0.04*A                  'Lens thickness r'i99~  
I gJu/{:y^  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction s.z)l$  
%jAc8~vW?  
    'Adjust parameters to account for accommodation _kD5pC =  
icG 9x  
    '************************************************************************* )QAYjW!Z  
    'Aqueous thickness (Position of Lens) as:=
QMV  
    '************************************************************************* u8"s#%>Ny  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) H;=yR]E  
    GetCustomElement eID, entity hTBJ
\1 -  
;8H&FsR  
    parID = FindFullName( "Geometry.Arizona Eye" ) u/tJ])~@  
yK{P%oh)  
    ' Delete any shift(s) in z :$Cm]RZ  
    count = 0 i%yKyfD  
    While GetOperationCount(eID)>count Nr@,In|JS  
        GetOperation eID, count, op (0`rfYv5.R  
        If op.Type="ShiftZ" Then thPAD+u.3  
            DeleteOperation eID,count -IIrrY O  
            count=count-1 |mhKD#:  
        End If XzAXcxC6G  
        count=count+1 yc0

1\o  
    Wend #mH28UT  
ejg!1*H@n  
    'Set new shift in |(~IfSE2  
    op.Type = "ShiftZ" 7:~3B-Tb  
    op.val1 = taq `y'%dY}$n  
    op.parent = parID _~Lu%  
    AddOperation eID, op z7fX!'3V  
    Print "Set aqueous humor thickness = " & taq-0.55 1drg5  
6X ]I`e  
    '************************************************************************* [<+T
@"y  
    'Radius and conic constant of anterior lens ~U<j_j)z4.  
    '************************************************************************* Fmn_fW6  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" )
UHJro9  
    GetConic eID, entity, curv, conic qA}l[:F+#  
T c-fO /0  
    SetConic eID, entity, 1/Rant, CCant w[2E:Nj  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant _WV13pnRu  
m<Gd 6V5  
    '************************************************************************* C4E*q3[Y  
    'Radius and conic constant of posterior lens QP%AJ[3ea%  
    '************************************************************************* .yDR2sW  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Njo.-k  
    GetConic eID, entity, curv, conic u}'m7|)8  
dnANlNMk?  
    SetConic eID, entity, 1/Rpost, CCpost >>=zkPy  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 9'X"a  
8U#14U5rS  
    '************************************************************************* }T%E;m-  
    'Lens thickness (Position of posterior lens surface) p+I`xyk  
    '************************************************************************* <MxA;A  
a;i}<n7  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) P EzT|uY  
&~"N/o  
    ' Delete any z-shift(s) 7WV"Wrl]  
    count = 0 "97sH_ ,  
    While GetOperationCount(eID)>count mv<cyWp  
        GetOperation eID, count, op fN`Prs A  
        If op.Type="ShiftZ" Then U
SE!  
            DeleteOperation eID,count (>Sy,  
            count=count-1 T+V:vuK  
        End If 45+kwo0  
        count=count+1 8yr-X!eF  
    Wend n`Ypv{+ {%  
} BP.t$_  
    'Set new z-shift @ /e{-Q  
    op.Type = "ShiftZ" .j!:Hp(z}  
    op.val1 = tlens &sq q+&ao  
    op.parent = parID Dmtsu2o  
    AddOperation eID, op RZvRV?<bR  
    Print "Set lens thickness = " & tlens ylmVmHmc  
p=Qo92 NH  
    '************************************************************************* @M*5q# s  
    'Lens index of refraction 2J(,Xf  
    '************************************************************************* .>5E 4^$%  
    eID = FindMaterial( "Lens" ) >wV2` 6  
    GetModelMaterial eID, mat NS4W!o;"  
5t-(MY  
    mat.Nd = nlens %e: hVU  
    SetModelMaterial eID, mat P\X$fD  
    Print "Set lens index of refraction = " & nlens G!GGT?J  
o`jVd,aj  
    '************************************************************************* YZ0Q?7l7  
    'Pupil diameter P; =,Q$e8  
    '************************************************************************* :JxuaM8  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) A*{V%7hs&  
K?wo AuY  
    'Adjust pupil diameter (trimming volume inner hole) EU7mP MxJ  
U_0"1+j
bq  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ]gb?3a}A  
B?XqH_=0L  
    ' Adjust pupil location to just in front of the lens -1F
+,+m  
    parID = FindFullName( "Geometry.Arizona Eye" ) j&?@:Zg v  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) xirZ.wjW  
    count = 0 &W y9%  
    While GetOperationCount(eID)>count cZ/VMQEr  
        GetOperation eID, count, op mVyF M -`  
        If op.Type="ShiftZ" Then 3}?]G8iL?L  
            DeleteOperation eID,count LwCf}4u"  
            count=count-1 1`&"U[{  
        End If sU?%"q  
        count=count+1 SR'u*u!  
    Wend JLxAk14lc  
    op.Type = "ShiftZ"  cCy*?P@  
    op.val1 = taq-0.01 .ktyA+r8v  
    op.parent = parID [tz}H&  
    AddOperation eID, op x_KJCU  
&FzZpH  
    Print "Set pupil diameter = " & pupilDiam 8<g9 ~L  
X[iQ%Y$/n  
    'Update AZ Eye subassembly Description xcl8q:  
    eID = FindFullName( "Geometry.Arizona Eye" ) dxeLu  
    GetEntity eID, entity #ruL+-8!<  
    entity.Description = "Accommodation = " & A & "D" n#5%{e>  
    SetEntity eID, entity "PY&NL?  
1O;q|p'9  
    Update ^5*9BwH`  
    Print "DONE!" w'D=K_h  
     fnO>v/&B  
End Sub |`6*~ciUV  
Ut^ {4_EC  
如果屈光度是4，光瞳直径是4，则会输出如下数据： 9rhl2E  
KdtQJ:_`k  
Accommodation = 4 Diopters t=(CCq_N,  
Pupil Diameter = 4 mm >a2i%j/T  
Set aqueous humor thickness = 2.81 L,wEUI  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ]PjJy/vkjj  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 iwnFCZVS  
Set lens thickness = 3.927 3N5b3F  
Set lens index of refraction = 1.42672 ;V\l, u  
Set pupil diameter = 4 qm=N@@R&  
DONE! UB1/0o