[技术]Arizona眼睛模型 [复制链接]

简介 Nx z ,/d  
IQY#EyTb  
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。 <QLj6#d7Y  
S]@iS[|?  
模型 v3#47F)  
I@v.Hqg+7  
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。 Yr0i9Qow  

sRI8znus  
:\We =oX  
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. cu|q&  
e$I:[>  
光源 :PkSX*E[q  
@cNI|T  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 !XceiQu  
6 VDF@V$E  
]^%3Y  

/tP  
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。 K*RRbtb  
Ut@)<N  
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。 ^T>.04";x  
?q`mr_x%?  
u
S.a9 Q(  
ga%77t|jm3  
视网膜的散射 l).Ijl}AH;  
%&GQ]pmcY  
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。 {+}Lc$O#C  
Os+=}  
%)]RM/e8  
a)b@en;v  
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。 |V]E8Qt  
$nWmoe)  
]
B[Qdn  
FA,CBn5%  
脚本 G9Ezm*I;:  
x$sQ .aT  
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： H&+s&F{%  
4 -W?u51"  
~o$=(EC  
['j,S<Bu~  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 y0^FTSQ|  
余下的脚本计算与屈光度有关的所有参数。 I}x*AM 7+  
Ho|n\7$  
分析 "m5ZZG#R`
 
]T`qPIf;yJ  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 hG]20n2  
4mg&H0 !  
'@bA_F(  
脚本代码 2{\Y<%.  
%yVZ|d*Q  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. llJ)u!=5  
__[q`  
Dim entity As T_ENTITY L3\{{QOA  
Dim op As T_OPERATION F9" K  
Dim mat As T_MODELMATERIAL q\<vCKI-^  
Dim A As Double d=XhOC$  
Dim pupilDiam As Double 6dp~19T^  
Dim eID As Long 6(=:j"w0  
Dim parID As Long ~x+w@4)a>  
Dim count As Integer `P~RG.HO  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ),eiJblH  
Dim tlens As Double, nlens As Double Fk:(%ci  
Dim curv As Double, conic As Double V{r@D!}  
Dim ok As Long .^,vK7  
ub%q<sE*  
Sub Main +TX]~k79Oq  
/k,p]/e  
    '用户输入对话框 VTdZ&%@  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 a@./e @
p  
        TextBox 220,21,40,21,.TextBox1 'default: 0 H#D=vx'  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 qeYr=%)c  
        OKButton 40,91,90,21 rv%Xvs B  
        CancelButton 190,91,90,21 KqQrxi?f-  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 !p2&$s"N.  
        TextBox 220,49,40,21,.TextBox2 'default: 4 |bh:x{h  
    End Dialog FoLwS%+yO  
    Dim dlg As UserDialog Sn]A0J_  
RK0IkRXQd  
    ok = Dialog (dlg) y? g7sLDc  
WJ@,f%=<~  
    If ok=0 Then    'cancel button was pressed sC j3h  
        Print "Execution cancelled." (|-/S0
AV  
        End .B@;ch,  
    End If MX34qJ9k  
=uH`EkY:  
    'Assign accommodation and pupil diameter & use defaults if field left empty %K%z<R8  
    If dlg.TextBox1 = "" Then %`~8j H@  
        A = 0           'Default accommodation <8Ad\MU  
    Else bm^ou#]|  
        A = CDbl(dlg.TextBox1)
9Y(<W_{/  
    End If VybiuP  
b4Z#]o  
    If dlg.TextBox2 = "" Then f%af.cR*  
        pupilDiam = 4   'Default pupil diameter 3yQ(,k#  
    Else ~I'hiV^-  
        pupilDiam = CDbl(dlg.TextBox2) E5rNC/Ul$$  
    End If {5*5tCIt  
k$zDofdfp  
    Print " " ,70|I{,Km  
    Print "Accommodation = " & A & " Diopters" Y9C]-zEv  
    Print "Pupil Diameter = " & pupilDiam & " mm" k~H-:@  
s=q}XIWK  
    ' Calculate new parameters with accommodation jooh`| `P  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness w/R^Vwq  
-V\33cA  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens cNHNh[ C  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens :Q%&:[2  
kAqk~.  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 5<u+2x8|  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens a*=e 3nS  
9i"3R0HN  
    tlens = 3.767 + 0.04*A                  'Lens thickness Yy&0b(m U  
`jJb) z3D  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction i"-j:b:c<  
9:P)@UF  
    'Adjust parameters to account for accommodation X:DHz0S  
A2B&X}K|U  
    '************************************************************************* /HLQ  
    'Aqueous thickness (Position of Lens) )/BKN`,  
    '************************************************************************* J%nJO3,  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) #pf}q+A  
    GetCustomElement eID, entity 4X^0:.bT&  
3
M^ /  
    parID = FindFullName( "Geometry.Arizona Eye" ) fUa`YryQ  
(bXCc  
    ' Delete any shift(s) in z 5ewQjwW0  
    count = 0 <)M?qkjb  
    While GetOperationCount(eID)>count X[VQ 1  
        GetOperation eID, count, op "zr%Q'Ky  
        If op.Type="ShiftZ" Then PoC24#vS  
            DeleteOperation eID,count }ts?ZR^V,  
            count=count-1 Rq;R{a  
        End If p{.EFa>H  
        count=count+1 %bddR;c  
    Wend KxY|:-"Tt  
fz:F*zT1  
    'Set new shift in ek.L(n,J|  
    op.Type = "ShiftZ" r8@:Ko= a  
    op.val1 = taq :qI myaGQ  
    op.parent = parID #u#s'W  
    AddOperation eID, op :^l`m9  
    Print "Set aqueous humor thickness = " & taq-0.55 @%RDw*L(  
@~zhAU!  
    '************************************************************************* 7^S&g.A  
    'Radius and conic constant of anterior lens K~[/n<ks  
    '************************************************************************* gbo{Zgf<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) (!;4Y82#  
    GetConic eID, entity, curv, conic I5  
X\M0Q%8  
    SetConic eID, entity, 1/Rant, CCant HgbJsv$  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 7pkc*@t  
yfYAA*S!z  
    '************************************************************************* 5Pn$@3  
    'Radius and conic constant of posterior lens R D)dw  
    '************************************************************************* #*?a"  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ~bgFU  
    GetConic eID, entity, curv, conic SdN|-'qf  
Dj?95Z,r  
    SetConic eID, entity, 1/Rpost, CCpost HAP9XC(F]  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost qxk1Rzm?x  
D_'Zucq  
    '************************************************************************* aY6]NpT  
    'Lens thickness (Position of posterior lens surface) bD=_44
I  
    '************************************************************************* aMT&}3  
KrG$W/<tg  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 'j>Q7M7q{  
GT`:3L  
    ' Delete any z-shift(s) CI ~+(+q  
    count = 0 6D) vY  
    While GetOperationCount(eID)>count :*Sl\:_X)  
        GetOperation eID, count, op J/=b1{d"n  
        If op.Type="ShiftZ" Then  gryC#  
            DeleteOperation eID,count ix,5-j  
            count=count-1 9CW .xX8  
        End If t hTY('m  
        count=count+1 e>X&[\T  
    Wend J/WPffqD  
qJUu9[3'm  
    'Set new z-shift Bz]j&`  
    op.Type = "ShiftZ" WY #pzBA  
    op.val1 = tlens fk;39$[  
    op.parent = parID BPtU]Bv-  
    AddOperation eID, op vxY7/_]  
    Print "Set lens thickness = " & tlens HSq&'V  
6imDA]5N&
 
    '************************************************************************* rC$ckug  
    'Lens index of refraction 0vf2wBK'T  
    '************************************************************************* sYgpK92  
    eID = FindMaterial( "Lens" ) N'3Vt8o,  
    GetModelMaterial eID, mat 7l%O:M(\  
' !ZFK}  
    mat.Nd = nlens ^DM^HSm  
    SetModelMaterial eID, mat tBp dKJn##  
    Print "Set lens index of refraction = " & nlens J_<ENs-  
6xvyhg#B  
    '************************************************************************* _.yBX\tf[  
    'Pupil diameter 8?J\  
    '************************************************************************* Q3'\Vj,S&  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) `pOiv&>  
ze{  
    'Adjust pupil diameter (trimming volume inner hole) -}4<P}.5T  
VYMs`d[  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 4F^(3RKZ|  
rK9X68)  
    ' Adjust pupil location to just in front of the lens ,FlF.pt  
    parID = FindFullName( "Geometry.Arizona Eye" ) 1-Sc@WXd  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) XSkx<"U*  
    count = 0 UW88JA0  
    While GetOperationCount(eID)>count o!dTB,Molr  
        GetOperation eID, count, op m?`U;R[  
        If op.Type="ShiftZ" Then E}00y%@*J  
            DeleteOperation eID,count \J.PrE'(}  
            count=count-1 DfXXN  
        End If (ylpH`  
        count=count+1 ^~E?7{BL  
    Wend \,+act"v  
    op.Type = "ShiftZ" 4U(W~O  
    op.val1 = taq-0.01 NffZttN  
    op.parent = parID Zx@/5!_n.  
    AddOperation eID, op @rB!47!  
z GhJ  
    Print "Set pupil diameter = " & pupilDiam E%FCOKw_  
Xb@lKX5Re  
    'Update AZ Eye subassembly Description |kB1>$  
    eID = FindFullName( "Geometry.Arizona Eye" ) 2WE_NEpJI  
    GetEntity eID, entity 07:CcT  
    entity.Description = "Accommodation = " & A & "D" G];5'd~C;d  
    SetEntity eID, entity WPPz/c|j  
A'^y+42jY  
    Update .v?Ir)  
    Print "DONE!" 8!(4;fN$j.  
     c*sK| U7)  
End Sub
Vcm9:,Xlw  
+] s"*'V$  
如果屈光度是4，光瞳直径是4，则会输出如下数据： iaPrkMhd  
n}P

z:  
Accommodation = 4 Diopters qq9fZZb  
Pupil Diameter = 4 mm # xx{}g]%  
Set aqueous humor thickness = 2.81 sN]O]qYXJ  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Lf`LFPKb  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 3GqvL_  
Set lens thickness = 3.927 -HutEbkjx  
Set lens index of refraction = 1.42672 EdbLAagI6  
Set pupil diameter = 4 x%Ivd  
DONE! %eW[`uyV