[技术]Arizona眼睛模型 [复制链接]

简介 7vO3+lT/Y;  
]yI~S(  
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。 50h?#u6?  
z0|%h?N  
模型 3H"bivK
 
j`tBki:  
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。 0}v_usP  
_voU^-  
sg0HYb%_E  
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. Q#!|h:K  
N~Zcrt_D  
光源 <g9@iUOI  
h2~b%|Pv  
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。 t$+[(}@+  
QE8;Jk-  
*O6q=yg;K:  
N;N,5rxV  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 BO]}E:C9  
R;D|To!  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 <;)qyP  
a(cZ]`s]*  
-hv<8bC~4  
Ew
.a*[W''  
视网膜的散射 HYqDaRn  
Ek#?B6s  
在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 {jVEstP  
:x*#RnRr.  
&.D#OnRh9  
ZDffR:An  
注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 DX|yL!4[  
>2kjd  
_pZ
2^OO@  
b@
9>1d$  
脚本 [&_c.ti  
(Qf"|3R4  
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： t^ax:6;"|  
w&U>w@H^  
U_\3preF  
bIs@CDB  
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。 pXL@&]U
+  
余下的脚本计算与屈光度有关的所有参数。 DMeP9D  
QVEGd"WvvO  
分析 svT1b'=\$I  
)TH~Tq:  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 83~9Xb=!\  
-XcX1_  
s01W_P.@R  
脚本代码 @)h
rj2Jw  
I{rW+<)QGC  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. >n!,KUu]  
|~V`Es +j  
Dim entity As T_ENTITY WJXQM[  
Dim op As T_OPERATION I[td:9+hK@  
Dim mat As T_MODELMATERIAL (=de#wh2]  
Dim A As Double )'pc1I  
Dim pupilDiam As Double +xGz~~iNh  
Dim eID As Long 97XGJ1HI  
Dim parID As Long zLeId83>  
Dim count As Integer vbn'CY]QU  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double qYi<GI*|@  
Dim tlens As Double, nlens As Double 
Q|3SYJf  
Dim curv As Double, conic As Double ~C;1}P%9x  
Dim ok As Long F~qiNV  
cag9f?w@V  
Sub Main O7KR~d  
gJn_Z7MgJ  
    '用户输入对话框 JE
[+  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 $hCPmiI  
        TextBox 220,21,40,21,.TextBox1 'default: 0 71$MhPvd<  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 pN]$|#%q(  
        OKButton 40,91,90,21 slV7,4S&!  
        CancelButton 190,91,90,21 MZ/PXY  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 x?|C-v  
        TextBox 220,49,40,21,.TextBox2 'default: 4 +ISXyGu  
    End Dialog -4}I02  
    Dim dlg As UserDialog Z T5p
 
nV$ctdusQ  
    ok = Dialog (dlg) ":o1g5?  
-_>g=a@&  
    If ok=0 Then    'cancel button was pressed $1(FN+ Mb  
        Print "Execution cancelled." ;4g_~fB  
        End x:Nd>Fb  
    End If IdvBQ [Gj  
@|2}*_3\  
    'Assign accommodation and pupil diameter & use defaults if field left empty SdI/  
    If dlg.TextBox1 = "" Then E\%'/3o
 
        A = 0           'Default accommodation k*;2QED  
    Else N%2UL&w#B  
        A = CDbl(dlg.TextBox1)
+]!`>  
    End If jE&Onzc  
te+5@k#t  
    If dlg.TextBox2 = "" Then .QhH!#Y2D  
        pupilDiam = 4   'Default pupil diameter gw1| ?C  
    Else
R+s_uwS  
        pupilDiam = CDbl(dlg.TextBox2) X> *o\   
    End If &M,"%w!  
SwDUg
}M~  
    Print " " >VAZ^kgi  
    Print "Accommodation = " & A & " Diopters" MKuy?mri~  
    Print "Pupil Diameter = " & pupilDiam & " mm" 7 -(LWH  
OoFQ@zE7%  
    ' Calculate new parameters with accommodation (5"BKu1t  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness <N{pMz  
Wv  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Oc]&1>M  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens |sw&sfH[FD  
D4"](RXH  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens biFN]D  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens F7(~v2|  
}}GBCXAf_  
    tlens = 3.767 + 0.04*A                  'Lens thickness ]Mh7;&<6[  
]c8$%  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction jH*+\:UP-  
JuGQS24  
    'Adjust parameters to account for accommodation 6]|NB&  
EO|r  
    '************************************************************************* !d1}IU-h  
    'Aqueous thickness (Position of Lens) r: _-Cj  
    '************************************************************************* %qzpt{'?<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) _+,2b:D:  
    GetCustomElement eID, entity ifu"e_^  
F:/R'0  
    parID = FindFullName( "Geometry.Arizona Eye" ) cLQvzd:h=  
y*M
,&,$  
    ' Delete any shift(s) in z ;+-$=l3[a  
    count = 0 ;y#6Nx,:  
    While GetOperationCount(eID)>count Po[u6K2&  
        GetOperation eID, count, op h(;qnV'c  
        If op.Type="ShiftZ" Then b'$j* N  
            DeleteOperation eID,count XR^VRn6O  
            count=count-1 /$hfd?L  
        End If &
)vX7*j  
        count=count+1 (n-8p6x(  
    Wend dXh@E7
 
XM/P2=;  
    'Set new shift in {rWu`QT  
    op.Type = "ShiftZ" _%s_w)  
    op.val1 = taq *@Z/L26s;=  
    op.parent = parID DPnKr/  
    AddOperation eID, op s,^?|Eo;0  
    Print "Set aqueous humor thickness = " & taq-0.55 `hM:U  
XN"V{;OP1  
    '************************************************************************* SVp]}!jI  
    'Radius and conic constant of anterior lens
US)wr  
    '************************************************************************* KQ/v](
77  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) E{r_CR+8  
    GetConic eID, entity, curv, conic VEd#LSh  
~(B\X?v  
    SetConic eID, entity, 1/Rant, CCant &Ko}Pv  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant {e2 (  
a#1LGH7E8  
    '************************************************************************* =&,zWNz)  
    'Radius and conic constant of posterior lens @2 dp5  
    '************************************************************************* pFSVSSQRV|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @+}Q<  
    GetConic eID, entity, curv, conic ?ZSG4La\  
Be2@9  
    SetConic eID, entity, 1/Rpost, CCpost `QR2!W70o3  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost +[r%y,
k  
b]s=Uv#)  
    '************************************************************************* ja~b5Tf9  
    'Lens thickness (Position of posterior lens surface) +D4Nu+~BSN  
    '************************************************************************* /-$`GT?l  
/,5`#Gte_  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) N|Ua|^  
 | qHWM  
    ' Delete any z-shift(s) V#!ypX]AB[  
    count = 0 rK~362|mo  
    While GetOperationCount(eID)>count AnPm5i.  
        GetOperation eID, count, op xn@?CP`-y  
        If op.Type="ShiftZ" Then CBSJY&:K  
            DeleteOperation eID,count %@Ks<"9  
            count=count-1 .,,?[TI  
        End If +M@G 8l  
        count=count+1 5]; 8
 
    Wend *@G4i  
`+B+RQl}[  
    'Set new z-shift g$dL5N7  
    op.Type = "ShiftZ" /^uvY  
    op.val1 = tlens |gxU;"2`5~  
    op.parent = parID ~<v.WP<:  
    AddOperation eID, op \\hZlCV,  
    Print "Set lens thickness = " & tlens p>K'6lCa  
[p!C+|rro  
    '************************************************************************* 35RH|ci&  
    'Lens index of refraction P xpz7He  
    '************************************************************************* 2t
[c^J  
    eID = FindMaterial( "Lens" ) =]xNpX)  
    GetModelMaterial eID, mat l(=#c
/f  
q9WdJ!-^X  
    mat.Nd = nlens ADv a@P  
    SetModelMaterial eID, mat NFLmM  
    Print "Set lens index of refraction = " & nlens < q;]  
6{lWUr  
    '************************************************************************* c#"\&~. P  
    'Pupil diameter r-N2*uYtu  
    '************************************************************************* -ZQ3^'f:0J  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ZFW}Vnl  
jI;bVG  
    'Adjust pupil diameter (trimming volume inner hole) YXIDqTA+  
f[.hN  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ?]9uHrdsN}  
2z0HB+Y}x  
    ' Adjust pupil location to just in front of the lens ;S?1E
:\av  
    parID = FindFullName( "Geometry.Arizona Eye" ) kP;:s  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) :jp?FF^j;  
    count = 0 K:y q^T7  
    While GetOperationCount(eID)>count ]; ^OY\,  
        GetOperation eID, count, op =53LapTPJ  
        If op.Type="ShiftZ" Then i+&="Z@  
            DeleteOperation eID,count /=e[(5X|O  
            count=count-1 F|P2\SPL  
        End If oSa FmP  
        count=count+1 bq(*r:`"  
    Wend lmmyDg1R  
    op.Type = "ShiftZ" ljt1:@SN(  
    op.val1 = taq-0.01 pHg8(ru|  
    op.parent = parID sM5 w~R>Y  
    AddOperation eID, op ?sS'T7r v  
M\v4{\2l0  
    Print "Set pupil diameter = " & pupilDiam "apv)xdW  
[tD*\\IA  
    'Update AZ Eye subassembly Description .k*2T<p$rC  
    eID = FindFullName( "Geometry.Arizona Eye" ) (ZEVbAY?i  
    GetEntity eID, entity !zJ.rYZ=g`  
    entity.Description = "Accommodation = " & A & "D" M;iaNL(  
    SetEntity eID, entity iT5H<uS  
#[KwR\b{:+  
    Update X!2|_  
    Print "DONE!" <BU|?T6~  
     $s]@%6f  
End Sub +] 5a(/m.~  
\3LD^[qi  
如果屈光度是4，光瞳直径是4，则会输出如下数据： >8JvnBFx=  
rk. UW  
Accommodation = 4 Diopters !k s<VJh  
Pupil Diameter = 4 mm %[Ds-my2  
Set aqueous humor thickness = 2.81 $1dI  
Set anterior lens radius = 10.4 and conic constant = -2.375869 [Thz
Lk#m  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 CqX%V":2  
Set lens thickness = 3.927 /uyQ>Y*-\Y  
Set lens index of refraction = 1.42672 @B^'W'&C  
Set pupil diameter = 4 F Qk;  
DONE! @2$8o]et