[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 @b\_696.  
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。 59BHGvaF  
.r%|RWs6W  
模型 <?Izfl6  
~.`r(  
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。 N/{Yi _n  
i=H>D  
^-*Tn  
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. 4qXRDsbCf  
V^/^OR4k  
光源 _m?(O/BTx  
x&oBO{LNK,  
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。 L8xprHgL  
JgKZ;GM:W  
Bp{`%86SE  
C|;Mhe'r=  
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。 3=|2Gs?ut  
}\L!;6oy  
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。 a{Hb7&  
JP,(4h*  
jy@i(@Z  
EQOP?>mWx!  
视网膜的散射 -Dq:Y,%q  
6 %k+
0\d  
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。 +y4AUU:Q  
! }?jCpp  
{r2|fgi  
bd P,Zqd  
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。 !5SQN5K  
<eFAI}=s  
Y{2d4VoW6  
HGQ?(2]8$  
脚本 ck
_fEF  
bb/?02*)H  
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： \pD=Lv9  
J1Ki2I=  
hk!,  
._MAHBx+G  
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。 :Ip:sRz  
余下的脚本计算与屈光度有关的所有参数。 !+DJhw&c,  
<RPoQ'.^  
分析 FJ(B]n[>  
-0VA!3l  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 TFYTvUn  
$K_YC~  
$n#Bi.A j  
脚本代码 LQ(5D_yG.  
-6~y$c&c  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. 'tu@`7*  
waWKpk1Wo  
Dim entity As T_ENTITY #W%)$k
c  
Dim op As T_OPERATION 6;[/9  
Dim mat As T_MODELMATERIAL y-\A@jJC5  
Dim A As Double %V(N U_o  
Dim pupilDiam As Double u|OzW}xb7j  
Dim eID As Long z(` }:t  
Dim parID As Long v]{uxlh  
Dim count As Integer \9(- /rE  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double b~r{J5x@  
Dim tlens As Double, nlens As Double #3Ej0"A@-B  
Dim curv As Double, conic As Double ,c%K)KuPK.  
Dim ok As Long 8
hKP  
$~,}yh;  
Sub Main f7Df %&d  
Q1
nDl  
    '用户输入对话框 :`Uyn!w  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 QSF"8Uk  
        TextBox 220,21,40,21,.TextBox1 'default: 0 C3\E.u?  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 y3cf[Q  
        OKButton 40,91,90,21 M6jp1:ZH2q  
        CancelButton 190,91,90,21 `/w\2n  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 >^yc=mM(g3  
        TextBox 220,49,40,21,.TextBox2 'default: 4 \/*Nf?;  
    End Dialog *m$PH"  
    Dim dlg As UserDialog .;HIEj zq  
mGe|8In  
    ok = Dialog (dlg) :GQIlA8cF$  
C1T=O  
    If ok=0 Then    'cancel button was pressed ,]
Ro',A&  
        Print "Execution cancelled." )>y k-  
        End N~):c2Kp<9  
    End If iIsEQh  
JYwyR++uo  
    'Assign accommodation and pupil diameter & use defaults if field left empty +%Lt".o  
    If dlg.TextBox1 = "" Then j1puB  
        A = 0           'Default accommodation I#U>5"%\a  
    Else Gz>Lqd  
        A = CDbl(dlg.TextBox1) kDzj%sm!  
    End If =2 &hQd   
?wd|G4.Vo  
    If dlg.TextBox2 = "" Then }iilzE4oH#  
        pupilDiam = 4   'Default pupil diameter Mo}H_8y  
    Else L 42|>%uo  
        pupilDiam = CDbl(dlg.TextBox2) 8FzHNG  
    End If e,f ;  
{r={#mO;p  
    Print " " %won=TG8  
    Print "Accommodation = " & A & " Diopters" =-$!:W~  
    Print "Pupil Diameter = " & pupilDiam & " mm" Bx(yu'g|a  
vd}*_d  
    ' Calculate new parameters with accommodation UvkJ?Bu  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ],8;eq%W)  
}A{_L6qx  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens "JkZ
J#  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens $ye^uu;Z  
Kw)KA^KF  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens d,
W/M(S  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens [ S5bj]D  
6wPeb~{  
    tlens = 3.767 + 0.04*A                  'Lens thickness _=ugxL #eB  
wGPotPdE2  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction >):m-I  
8QV t, 'I  
    'Adjust parameters to account for accommodation O -G1})$  
XE9)c
  
    '************************************************************************* Rab#7Q16Q8  
    'Aqueous thickness (Position of Lens) Y2<dM/b/  
    '************************************************************************* tWm>j  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) tJ"az=?  
    GetCustomElement eID, entity `h?LVD'l  
5O&d3;p'  
    parID = FindFullName( "Geometry.Arizona Eye" ) C` pp  
"Nbos.a]5  
    ' Delete any shift(s) in z 'Q5&5UrBr  
    count = 0 lr WLN  
    While GetOperationCount(eID)>count MSl&?}Bj  
        GetOperation eID, count, op ?0{yq>fTu  
        If op.Type="ShiftZ" Then R2l[Q){!  
            DeleteOperation eID,count GR<c=  
            count=count-1 lWbZ=x_0  
        End If (^LS']ybc  
        count=count+1 &&WDo(r3  
    Wend r@iASITX  
x=.tiM{#  
    'Set new shift in 7F9;Su3.  
    op.Type = "ShiftZ" %swR:
B
v  
    op.val1 = taq e&0N
K8&#+  
    op.parent = parID p#bhz5&/  
    AddOperation eID, op ZRnL_z~  
    Print "Set aqueous humor thickness = " & taq-0.55 #4><r.v3  
&'s^nn]  
    '************************************************************************* M ?*Tf&  
    'Radius and conic constant of anterior lens ;|<(9u`  
    '************************************************************************* #|Oj]bd(=  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) O+_N!/  
    GetConic eID, entity, curv, conic 3y ryeS  
)Vg2Jix,]  
    SetConic eID, entity, 1/Rant, CCant If;R?j0;Q  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant :6Pnie
  
kh3<V'k]  
    '************************************************************************* zI^Da!r.  
    'Radius and conic constant of posterior lens i?;R}%~  
    '************************************************************************* e0 u,zg+m  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) \, 8p1$G  
    GetConic eID, entity, curv, conic Ql &0O27  
03([@d6<
E  
    SetConic eID, entity, 1/Rpost, CCpost  / +1{  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost XX2h(-  
-f?Ah  
    '*************************************************************************  F~6#LT  
    'Lens thickness (Position of posterior lens surface) i)8N(HN  
    '************************************************************************* +{$QAjW(/  
@*(4dt:V  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZYcd.?:6  
/ZW&0E  
    ' Delete any z-shift(s) j
)by}}  
    count = 0 ?gSSli[  
    While GetOperationCount(eID)>count -Wc~B3E|  
        GetOperation eID, count, op 7J|&U2}c  
        If op.Type="ShiftZ" Then FRZs[\I|iT  
            DeleteOperation eID,count ``u:l
L  
            count=count-1 rwSbqL^eM  
        End If d"ZU y!a  
        count=count+1
*5OCqU+g  
    Wend u1Ek y/e-  
so+4B1$)q  
    'Set new z-shift ghAi{@s$)  
    op.Type = "ShiftZ" P=`1rjPE  
    op.val1 = tlens O'$K],=BS  
    op.parent = parID 7NL%$Vf  
    AddOperation eID, op bA@P}M)X  
    Print "Set lens thickness = " & tlens P`jL]x  
uLk]LT
 
    '*************************************************************************
" xR[mJ@U  
    'Lens index of refraction = 96P7#%  
    '************************************************************************* g5S?nHS}  
    eID = FindMaterial( "Lens" ) HjA_g0u  
    GetModelMaterial eID, mat BFVAw  
347eis'  
    mat.Nd = nlens LA%bq_>f  
    SetModelMaterial eID, mat l! v!hUb+  
    Print "Set lens index of refraction = " & nlens {6G?[ `&ca  
y(a!YicA?  
    '************************************************************************* ~n?>[88"  
    'Pupil diameter aWy]9F&C:  
    '************************************************************************* *5VXyt2  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) /nZ;v4  
@Uo6>-WF  
    'Adjust pupil diameter (trimming volume inner hole) "i&"* ~  
z42
F,4Gk  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" =IjQ40W  
+4qU>  
    ' Adjust pupil location to just in front of the lens @=Fi7M  
    parID = FindFullName( "Geometry.Arizona Eye" ) . +  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) .*YD&(  
    count = 0 }uY!(4Rw  
    While GetOperationCount(eID)>count 6l\FIah@  
        GetOperation eID, count, op )]43R   
        If op.Type="ShiftZ" Then qO@@8/l  
            DeleteOperation eID,count atF?OP|{,w  
            count=count-1 Sr_VL:Gg  
        End If #1.YKo  
        count=count+1 {ZsdLF#  
    Wend T=Z.TG|lIx  
    op.Type = "ShiftZ" l2jF#<S@  
    op.val1 = taq-0.01 D y-S98Y  
    op.parent = parID I?Aj.{{$G%  
    AddOperation eID, op nV_8Ke  
5nlMrK  
    Print "Set pupil diameter = " & pupilDiam [I;^^#'P  
I+(/TP  
    'Update AZ Eye subassembly Description 58tVx'1y  
    eID = FindFullName( "Geometry.Arizona Eye" ) H%F>@(U  
    GetEntity eID, entity EZD
y+6b  
    entity.Description = "Accommodation = " & A & "D" od' /%  
    SetEntity eID, entity %G3(,Qz  
I5m][~6.?  
    Update .dMVoG5  
    Print "DONE!" q'Wr[A40j  
     K(}AX+rIg  
End Sub e8=YGx^o`  
`D$JvN  
如果屈光度是4，光瞳直径是4，则会输出如下数据： ^P'{U26  
{a(&J6$VE  
Accommodation = 4 Diopters mTNB88p8^D  
Pupil Diameter = 4 mm "es?=  
Set aqueous humor thickness = 2.81 cTTW06^  
Set anterior lens radius = 10.4 and conic constant = -2.375869 j
=?'4sF  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 8T)&`dM6P~  
Set lens thickness = 3.927 :#~U<C@o  
Set lens index of refraction = 1.42672 .xhK'}l[  
Set pupil diameter = 4 _5 ^I.5Z3  
DONE! }Ew hj>w  
NEt1[2X%