[技术]Arizona眼睛模型 [复制链接]

简介 G80d!*7  
'u_'y  
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。 M!!W>A@T[g  
niqiDT/  
模型 HQQc<7c",  
%$!}MxUM  
模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 kTc'k  
bYgrKz@uK  
 p&:RSO  
在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. L$i&>cF\_>  
w<-CKM3qe  
光源 /3'-+bp^=  
G/N'8Q)  
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。 vT\`0di~  
6yv*AmFh  
=NH:/j^  
Mf/zSQk+  
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。 :T5l0h-eC  
[=S@lURzm@  
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。 %89f<F\V  
I$9t^82j  
1ncY"S/VO  
o_bj@X  
视网膜的散射 L*D-RYW  
EoIP#Cnd1  
在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 >9uDY+70I3  
efl6U/'Ij  
+>44'M^Z|(  
najd~%?Rs  
注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 Nyow:7p  
BqCBH!^x  
#wk'&XsC#z  
%
RdCSQ9~  
脚本 UccnQZ7/I  
8`U5/!6fu  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： TL1pv l  
\m*?5]m;  
jF_K*:gQ  
4WzB=C(f  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 ?VC
b@&*  
余下的脚本计算与屈光度有关的所有参数。 kJZBQ<^  
ncu &<j}U  
分析 4F??9o8}  
N&-d8[~  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 x\*`i)su  
LXJ"ct  
^ :6v- Yx  
脚本代码 CsQ}eW8uEf  
Jc-0.^]E}  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. C-@@`EP  
o'D{ql  
Dim entity As T_ENTITY IgG@v9'  
Dim op As T_OPERATION )o SFHf  
Dim mat As T_MODELMATERIAL [JO'ta  
Dim A As Double .px*.e s  
Dim pupilDiam As Double m!$"-nh9  
Dim eID As Long ])7t!<  
Dim parID As Long OzA"i
y  
Dim count As Integer ,fT5I6l  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double H9xxId?3u  
Dim tlens As Double, nlens As Double `Ft.Rwj2:m  
Dim curv As Double, conic As Double cPPE8}PVH  
Dim ok As Long q/6d^&
  
05TZ  
Sub Main u f.Zg;Vc  
|F iL1_  
    '用户输入对话框 6HCP1`gg   
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 zX"@QB3E  
        TextBox 220,21,40,21,.TextBox1 'default: 0 xD8x1-  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 c_yf=  
        OKButton 40,91,90,21 I8Y[d$z  
        CancelButton 190,91,90,21 CGbW]D$@  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 53=VIN]  
        TextBox 220,49,40,21,.TextBox2 'default: 4 V#ZF0a]  
    End Dialog >wNE!Oa*B  
    Dim dlg As UserDialog W&A22jO.1  
F7E#x  
    ok = Dialog (dlg) cZe,l1$  
c#<v:b  
    If ok=0 Then    'cancel button was pressed 3G~ T_J&  
        Print "Execution cancelled." _WVeb}  
        End >Yl?i&3n  
    End If 9} :n  
A%Pjg1(uX  
    'Assign accommodation and pupil diameter & use defaults if field left empty l-Xxur5M'  
    If dlg.TextBox1 = "" Then W=M]1hy  
        A = 0           'Default accommodation pfe9n[  
    Else JY(_}AAu  
        A = CDbl(dlg.TextBox1) Z
oh2m`6  
    End If xm6=l".%z  
G[)Ll=  
    If dlg.TextBox2 = "" Then Q$iYhR  
        pupilDiam = 4   'Default pupil diameter [;7&E{,C  
    Else ?i>.<IPOq  
        pupilDiam = CDbl(dlg.TextBox2) l`:M/z6"  
    End If Q0Y0Zt,h  
x\]%TTps  
    Print " " ^cz#PNB  
    Print "Accommodation = " & A & " Diopters" ]S[M]-I  
    Print "Pupil Diameter = " & pupilDiam & " mm" 7M=LyrO  
+t({:>E  
    ' Calculate new parameters with accommodation q~^Jd=cB\  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness I8d#AVF2  
^8,HJG,!  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ex @e-<  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 9fp1*d  
V*@pmOhz  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens -fI-d1@  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens vrXUS9i.  
@MW
rUx  
    tlens = 3.767 + 0.04*A                  'Lens thickness U;<07 aMj  
T\eOrWt/  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction '2vZ%C$  
qgbp-A!2zF  
    'Adjust parameters to account for accommodation Z 7rVM  
ykrb/j|rK  
    '************************************************************************* HFu#-}iNV  
    'Aqueous thickness (Position of Lens) c|  
    '*************************************************************************
&> tmzlww  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) cs `T7?>  
    GetCustomElement eID, entity k_ 9gMO  
p&/}0eL y  
    parID = FindFullName( "Geometry.Arizona Eye" ) 2 1.;lj  
e|Rd#  
    ' Delete any shift(s) in z :@a8>i1&  
    count = 0 6}
ct{Q  
    While GetOperationCount(eID)>count n dgG1v%  
        GetOperation eID, count, op :8cp]vdW
 
        If op.Type="ShiftZ" Then x9)^0Hbo  
            DeleteOperation eID,count Tp2`eY5  
            count=count-1 'te4mY}  
        End If ~:~-AXaMT  
        count=count+1 AC;ja$A#  
    Wend T$RVz   
M >#kfSF+  
    'Set new shift in *Hx{eqC  
    op.Type = "ShiftZ" )F Q '^  
    op.val1 = taq 49q\/  
    op.parent = parID tu8n1W  
    AddOperation eID, op P~/Glak  
    Print "Set aqueous humor thickness = " & taq-0.55 ?s/]k#H  
%;$zR}  
    '************************************************************************* ,)^4H>~V  
    'Radius and conic constant of anterior lens 'o;>6u<u  
    '************************************************************************* lcR53X  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 3@P 2]Q~D  
    GetConic eID, entity, curv, conic Goa0OC,  
]f#1G$  
    SetConic eID, entity, 1/Rant, CCant OPHf9T3H  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant f}
Mx\dc  
7<;87t]]  
    '************************************************************************* I/:M~ b  
    'Radius and conic constant of posterior lens .21[3.bp/q  
    '************************************************************************* %2>ya>/M  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) &Jw]3U5J  
    GetConic eID, entity, curv, conic OIPJN8V  
?hu}wl)  
    SetConic eID, entity, 1/Rpost, CCpost QS.t_5<U  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Q'
xZ\t  
?Ho~6q8O@  
    '************************************************************************* r/E'#5 Q  
    'Lens thickness (Position of posterior lens surface) F*Lm=^:  
    '************************************************************************* &}%rZU  
ig|ol*~  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) E{+V_.tlu  
cYHHCaCS  
    ' Delete any z-shift(s) &cy@Be}|T  
    count = 0 5H8]N#Y&  
    While GetOperationCount(eID)>count y!JZWq%=  
        GetOperation eID, count, op sswYwU  
        If op.Type="ShiftZ" Then )1f8 H,q^  
            DeleteOperation eID,count ea
Sf[!24"  
            count=count-1 F#d`nZ=M  
        End If {Yp>h5nwM_  
        count=count+1 :rr;9nMR[  
    Wend (prqo1e@  
5y3V duE  
    'Set new z-shift "W!Uxc  
    op.Type = "ShiftZ" rq=D[vX\N(  
    op.val1 = tlens ^0"W/  
    op.parent = parID ';<gc5EK  
    AddOperation eID, op H
jG!pO{  
    Print "Set lens thickness = " & tlens i%RN0
UO^  
gG5@ KD6k  
    '*************************************************************************
8&T6  
    'Lens index of refraction L O)&|9xw  
    '************************************************************************* 8)n799<.  
    eID = FindMaterial( "Lens" ) kC~\D?8E=  
    GetModelMaterial eID, mat R Ptc \4  
k4WUfL d  
    mat.Nd = nlens g?Jx99c;  
    SetModelMaterial eID, mat dG5p`N%  
    Print "Set lens index of refraction = " & nlens :v-&}?  
9em?2'ysa  
    '************************************************************************* }\+7*|  
    'Pupil diameter GI:
J9TS  
    '************************************************************************* E"8cB]`|8  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) "zpc)'$L=  
M3>c?,O)J  
    'Adjust pupil diameter (trimming volume inner hole) i n}N[  
e6O+hC]:  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" e}V3dC^pU  
ib$_x:OO"  
    ' Adjust pupil location to just in front of the lens hRKAs ]^j  
    parID = FindFullName( "Geometry.Arizona Eye" ) /"$A?}V  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) +OGa}9j-  
    count = 0 Zp:(U3%  
    While GetOperationCount(eID)>count %OS}BAh^i  
        GetOperation eID, count, op iIZDtZFF  
        If op.Type="ShiftZ" Then J-Xw}|>@  
            DeleteOperation eID,count d5aG6/  
            count=count-1 Q:U^):~  
        End If 53vnON#{*  
        count=count+1 70sb{)  
    Wend Rwu y!F  
    op.Type = "ShiftZ" *CsRO  
    op.val1 = taq-0.01 xV]eEOiL
M  
    op.parent = parID AC`4n|,zJ;  
    AddOperation eID, op os<YfMM<:/  
I.V?O}   
    Print "Set pupil diameter = " & pupilDiam QOb+6qy:3  
SEf:u  
    'Update AZ Eye subassembly Description *RPdU.  
    eID = FindFullName( "Geometry.Arizona Eye" ) (+M]C]  
    GetEntity eID, entity }cl~Vo-mp  
    entity.Description = "Accommodation = " & A & "D" kX0hRX  
    SetEntity eID, entity .TI=3*`G  
12W`7  
    Update ! };OLQ  
    Print "DONE!" u1@&o9  
     /&PRw<}>_o  
End Sub ar+ j`QIe  
pb>TUKvT&  
如果屈光度是4，光瞳直径是4，则会输出如下数据： *<.{sx^Gk  
+>v3&[lGv  
Accommodation = 4 Diopters gd#j{yI/Xf  
Pupil Diameter = 4 mm BYhF?  
Set aqueous humor thickness = 2.81 Nn`l+WA3  
Set anterior lens radius = 10.4 and conic constant = -2.375869 w+,Kpb<x[0  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 7FQ&LF46  
Set lens thickness = 3.927 .?<M$38fv  
Set lens index of refraction = 1.42672 gL)l)}#  
Set pupil diameter = 4 `a$c6^a  
DONE! )qyJwN .D