[技术]Arizona眼睛模型 [复制链接]

简介 x\2N @*I:  
 R7-+@  
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。 /J`ZO$  
^=gzms  
模型 kmfxk/F}  
>;zQ.2*  
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。 BA cnFO  
/|z_z%=  
<zE~N~;  
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. TBp$S=_**  
1!`B8y)  
光源 @8qo(7<~Q  
;L.RfP"5<  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 z'd*z[L~  
sQ8_j  
-Rz%<`  
Th[Gu8b3  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 ?v$kq}Rg  
VUE6M\&z>  
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。 HtbN7V/  
Q]oCzSi  
U6Ws#e  
)>~d`_$dt  
视网膜的散射 i!9|R)c  
{&Es3+{A  
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。 "T,^>xD  
|37y ="  
]iL>Zxex  
Msea kF  
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。 MY `V0  
yJ!x`RD),w  
)RE~=*?d  
:k*3?*'K  
脚本 &XE eJ  
l9up?opq  
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： K4>nBvZ?v  
AD/7k3:  
F;@A2WD  
cw)'vAE  
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。 4RYvI!
 
余下的脚本计算与屈光度有关的所有参数。 eED@Z/~
6  
loPBHoE3@H  
分析 tQ > IJ  
!tL&Ktoj  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 21
\t2<"  
AECaX4h+_  
$NG|z0  
脚本代码 ahJu+y  
A>dA&'~R  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. g9F4nExo  
Jm(sx'qPx  
Dim entity As T_ENTITY )Ap0" ?q  
Dim op As T_OPERATION OY>0qj  
Dim mat As T_MODELMATERIAL $6 A91|ZSQ  
Dim A As Double A_
vf3 *q  
Dim pupilDiam As Double R?K[O   
Dim eID As Long !e"TWO*X  
Dim parID As Long N=X(G(  
Dim count As Integer S@'yuAe*G  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ^.f`6 6
/  
Dim tlens As Double, nlens As Double mI$3[ #+  
Dim curv As Double, conic As Double 82bOiN15  
Dim ok As Long JG=U@I]  
aAX(M=3  
Sub Main NgXV|)L  
'Oe}Ja  
    '用户输入对话框 !ufSO9eDx"  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ;.g
<u  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Xw2t
CRzD  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 TT0~41&l  
        OKButton 40,91,90,21 ~Uet)y<  
        CancelButton 190,91,90,21 9J!@,Zsh  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 0f<$S$~h  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ,Q5Z<\  
    End Dialog %`~?w'  
    Dim dlg As UserDialog HYkZMVH{  
c!{]Z_d\  
    ok = Dialog (dlg) =H\ig%%E@  
]_ON\v1  
    If ok=0 Then    'cancel button was pressed CAPPOh  
        Print "Execution cancelled." X!w&ib-  
        End z^q ~|7  
    End If 8+irul{H_  
k^ZcgHHgb  
    'Assign accommodation and pupil diameter & use defaults if field left empty qL03iV#h*V  
    If dlg.TextBox1 = "" Then @zHTKi`  
        A = 0           'Default accommodation {U,q!<@mq  
    Else v_zVhEtY  
        A = CDbl(dlg.TextBox1) dt efDsK  
    End If dIUg e`O9  
eI 6G  
    If dlg.TextBox2 = "" Then t*&O*T+fgy  
        pupilDiam = 4   'Default pupil diameter /4R|QD  
    Else :]viLw\&g  
        pupilDiam = CDbl(dlg.TextBox2) $ 4& )  
    End If hu G]kv3F:  
BZP~m=kq  
    Print " " -PI_*  
    Print "Accommodation = " & A & " Diopters" =nmvG%.hd  
    Print "Pupil Diameter = " & pupilDiam & " mm" i8tH0w/(M  
o$=D`B  
    ' Calculate new parameters with accommodation ?1f(@  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 7|"gMw/  
>c~Fgs  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens HZ#<+~J  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens BpGK`0H  
\*C}[D  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens "t{|e6   
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens TzCNY@y  
E_aDkNT  
    tlens = 3.767 + 0.04*A                  'Lens thickness vPV=K+1  
`;@#yyj:_  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction YB}p`b42L  
;JK!dzi}  
    'Adjust parameters to account for accommodation c&Mci"nj0  
(mOUbO8  
    '************************************************************************* Z?vbe}pUM  
    'Aqueous thickness (Position of Lens) FK$?8Jp  
    '************************************************************************* s5s'$|h"  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) g]=w_  
    GetCustomElement eID, entity \eD{bD  
drJ<&1O  
    parID = FindFullName( "Geometry.Arizona Eye" ) 0V5 RZ`.  
gU
oL8~  
    ' Delete any shift(s) in z BJM_kKH  
    count = 0 v\Y362Xv  
    While GetOperationCount(eID)>count 7h4"5GlO0  
        GetOperation eID, count, op
v$O%U[e<  
        If op.Type="ShiftZ" Then )1>fQ9   
            DeleteOperation eID,count | 'SqG}h  
            count=count-1 fR=B/`  
        End If }NQ{S3JW  
        count=count+1 i#@3\&{J>  
    Wend |kHPk)}I]  
8TK&i,  
    'Set new shift in Yxa
l%  
    op.Type = "ShiftZ" USKa6<:{W  
    op.val1 = taq ;_yp@.,\T  
    op.parent = parID 9`/\|t|V  
    AddOperation eID, op t\hvhcbL  
    Print "Set aqueous humor thickness = " & taq-0.55 Bu ~N)^  
7>g^OE f  
    '************************************************************************* X]?qns7  
    'Radius and conic constant of anterior lens vGK'U*gGD  
    '************************************************************************* (f^K\7HM  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" )  xZ*.@Pkr  
    GetConic eID, entity, curv, conic [jD.l;jF  
`&.]>H)N*  
    SetConic eID, entity, 1/Rant, CCant S$!)Uc\)A  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !H`! KBW  
#6[7q6{4  
    '************************************************************************* !N4?>[E  
    'Radius and conic constant of posterior lens A6APU><dm^  
    '*************************************************************************
=R08B)yR  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) fIo7R-XP  
    GetConic eID, entity, curv, conic 7b,5*]oZ  
y/>]6Pj  
    SetConic eID, entity, 1/Rpost, CCpost KJ Gh)  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost D\~*| J  
6.z8!4fpl  
    '************************************************************************* wG1A]OJl1  
    'Lens thickness (Position of posterior lens surface) C F2*W).+  
    '************************************************************************* *&b~cyC  
dMAd-q5{  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) p{knQ],   
`%lgT+~T  
    ' Delete any z-shift(s) >&0)d7Nu8m  
    count = 0 (fc /"B-  
    While GetOperationCount(eID)>count P +U=/$o  
        GetOperation eID, count, op qB`zyd8yu  
        If op.Type="ShiftZ" Then 3,@I` M  
            DeleteOperation eID,count H7 acT  
            count=count-1 ,Db+c3  
        End If )q?z"F|  
        count=count+1 5>J{JW|  
    Wend <<@vy{*Hg  
^<0u~u)%T  
    'Set new z-shift &J~vXk: !  
    op.Type = "ShiftZ" M<t>jM@'A#  
    op.val1 = tlens WlHw\\ur  
    op.parent = parID o(iN}.c  
    AddOperation eID, op w$~|/UrLf  
    Print "Set lens thickness = " & tlens t'@1FA!)  
0ad
 -4  
    '************************************************************************* g{&a|NU^  
    'Lens index of refraction 4qtjP8Zv[  
    '************************************************************************* zbt>5S_  
    eID = FindMaterial( "Lens" ) ipB*]B F[  
    GetModelMaterial eID, mat r
>N5^  
;m{*iKL6{  
    mat.Nd = nlens =;.#Bds  
    SetModelMaterial eID, mat 9/OB!<*V|  
    Print "Set lens index of refraction = " & nlens U[\aj;g)  
[gZd$9a  
    '************************************************************************* ?MevPy`H  
    'Pupil diameter FL5u68  
    '************************************************************************* `A5^D  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) z= p
b<Y@X  
j_PICv*6  
    'Adjust pupil diameter (trimming volume inner hole) HH[b1z2D  
j%R}  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" FHVZ/ e  
eR.ucTji  
    ' Adjust pupil location to just in front of the lens yZ t}Jnv  
    parID = FindFullName( "Geometry.Arizona Eye" ) 0r=:l/Pz  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) rf"%D<bb  
    count = 0 k36%n
*4  
    While GetOperationCount(eID)>count S_cba(0-|\  
        GetOperation eID, count, op eiB5 8b3  
        If op.Type="ShiftZ" Then 3R%'<MV|  
            DeleteOperation eID,count T"Ph@I<  
            count=count-1 wrq0fHwM  
        End If 7Wg0-{yK4  
        count=count+1 
?C   
    Wend N%{&%C6{  
    op.Type = "ShiftZ" LGq}wxq  
    op.val1 = taq-0.01 BBy"qkTe  
    op.parent = parID mBgMu@zt)  
    AddOperation eID, op ye1kI~LO(  
CK1Xdyf_S  
    Print "Set pupil diameter = " & pupilDiam `INcZr"  
1P&XG@  
    'Update AZ Eye subassembly Description {.2A+JT,  
    eID = FindFullName( "Geometry.Arizona Eye" ) cCN[c)[c|  
    GetEntity eID, entity E<;C@B  
    entity.Description = "Accommodation = " & A & "D" >IO}}USm  
    SetEntity eID, entity 9,y*kC  
F,^Q'$!  
    Update HXF5fs  
    Print "DONE!" ) 'x4#5]  
     ^+cf  
End Sub ETe,RY  
/7
X:=~m  
如果屈光度是4，光瞳直径是4，则会输出如下数据： IGs!SXclCs  
yjZxD[ Z  
Accommodation = 4 Diopters B3u
v>\  
Pupil Diameter = 4 mm &G?b|Tb2  
Set aqueous humor thickness = 2.81 dV#h~  
Set anterior lens radius = 10.4 and conic constant = -2.375869 %\-u&  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 S5]rIcM  
Set lens thickness = 3.927 %^}3:0G  
Set lens index of refraction = 1.42672 dL5u-<y&  
Set pupil diameter = 4 E7^r3#s  
DONE! 6JBE=9d-Q