[技术]Arizona眼睛模型 [复制链接]

简介 fhC=MJ @  
N>/U%01a  
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。 2]7nw1&  
kqyY:J  
模型 CV`  I.  
XW1
9hG  
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。 q3;HfZ  
$FAl9  
0$UE|yDs>  
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. # OJD<=")  
eVy,7goh  
光源 / og'W j  
ICGBU>Db  
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。 +pE-Yn`YS  
8\[6z0+;  
s^6S
{XJ  
ON$u581 y  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 E)`+1j  
WUHijHo5(8  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 I|p(8R!  
SnVnC09y  
* @oAM,@  
X&K1>dgWP  
视网膜的散射 HK}C<gg  
|=SaI%%Be  
在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 _xbV
AI4  
lc*<UZR  
#t;@x_2yD\  
/N~.,vf  
注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 E")82I  
.~Td/o7  
VPf=LSxJe  
.aNy)Yu8  
脚本 b,I$.&BD  
fu33wz1$}B  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： GUMO;rZs  
b,s T[!X[  
f 1]1ZOb  
;Lz96R@}  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 0kmZO"K#e  
余下的脚本计算与屈光度有关的所有参数。 CY9`ztO*  
wVp  
分析 G!wFG-Y}  
6VIi nuOW  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 40mgB4I  
@'dtlY5;  
6tj
+  
脚本代码 yw2sK
7  
IRD?.K]*  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. W*N^Gp@  
 z7>  
Dim entity As T_ENTITY .]P@{T||Y  
Dim op As T_OPERATION o AvX(  
Dim mat As T_MODELMATERIAL HPT$)NeNc  
Dim A As Double V D-,)f  
Dim pupilDiam As Double -FdhV%5]  
Dim eID As Long 8eQ 4[wJY  
Dim parID As Long tKu'Q;J  
Dim count As Integer Y=\;$:L[  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double !5&% P b  
Dim tlens As Double, nlens As Double h9$Ov`N(%  
Dim curv As Double, conic As Double $fL2w^ @  
Dim ok As Long Qn6'E  
SCZtHEl9  
Sub Main qE!.C}L+  
^pIT,|myY7  
    '用户输入对话框 ~}PB&`%7  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 \= =rdW-  
        TextBox 220,21,40,21,.TextBox1 'default: 0 tWT@%(2~0  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 -ich N/U]s  
        OKButton 40,91,90,21 CWHTDao  
        CancelButton 190,91,90,21 r< sx On  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 )w=ehjV^m  
        TextBox 220,49,40,21,.TextBox2 'default: 4 1>|2B&_^  
    End Dialog 09HlL=0q  
    Dim dlg As UserDialog J{`G=  
aOIE9wO  
    ok = Dialog (dlg) $GB/}$fd&  
~QQi{92  
    If ok=0 Then    'cancel button was pressed \c(R#*0,  
        Print "Execution cancelled." +O8rjVg)  
        End T5$db-^  
    End If Y`.FSs  
Xz4T_-X8d  
    'Assign accommodation and pupil diameter & use defaults if field left empty HN?NY  
    If dlg.TextBox1 = "" Then t4X:I&l-M:  
        A = 0           'Default accommodation -
C1,$mkj  
    Else j]~;|V5Z  
        A = CDbl(dlg.TextBox1) INt]OPD  
    End If W"MwpV  
gE;r;#Jt4  
    If dlg.TextBox2 = "" Then `v) :|Q  
        pupilDiam = 4   'Default pupil diameter }]V
FLBl`w  
    Else FX}kH]  
        pupilDiam = CDbl(dlg.TextBox2) LpN_s#  
    End If ROq
z$yY  
,aq0Q<}~lc  
    Print " " jJc:%h$|2  
    Print "Accommodation = " & A & " Diopters" )i|0Ubn[|  
    Print "Pupil Diameter = " & pupilDiam & " mm" aGSix}b1P  
X2\1OWR0  
    ' Calculate new parameters with accommodation m?*}yM  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness kn9ul3c  
gn,D9d+  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens =cz^g^
7  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ;=r_R!
d@  
bYt[/K,  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens #s%_ L  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Fp=O:]  
0Ez(;4]3  
    tlens = 3.767 + 0.04*A                  'Lens thickness ZMa@/\pf1  
;xqN#mqq  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction (t[sSl  
FglW|Hwy  
    'Adjust parameters to account for accommodation Es]:-TR  
3&`LVhx  
    '************************************************************************* ;[)O{%s  
    'Aqueous thickness (Position of Lens) b}<?& @  
    '************************************************************************* !DU4iq_.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) skeH~-`M@  
    GetCustomElement eID, entity n[+$a)$8  
|[./jg"  
    parID = FindFullName( "Geometry.Arizona Eye" ) V$o]}|  
1|bg;X9+  
    ' Delete any shift(s) in z %7}ibz4iF  
    count = 0 6~b)Hc/  
    While GetOperationCount(eID)>count -HQ(t  
        GetOperation eID, count, op C"7-lz  
        If op.Type="ShiftZ" Then L*(Sh2=_  
            DeleteOperation eID,count Te d1Ky2O  
            count=count-1 ^]n:/kZ5"[  
        End If u7(<
YSOs  
        count=count+1 CNMcQP  
    Wend -_[ZRf?^  
^jYE4gHM  
    'Set new shift in i(O+XQ}Fyx  
    op.Type = "ShiftZ" |&u4Q /0  
    op.val1 = taq @h=r;N#/`P  
    op.parent = parID ,azBk`$iQr  
    AddOperation eID, op vCX
54  
    Print "Set aqueous humor thickness = " & taq-0.55 5.M82rR;~  
yt+d f0l  
    '************************************************************************* jCp^CNbA  
    'Radius and conic constant of anterior lens BG/Q7s-?K  
    '************************************************************************* .(g"(fgF  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) %n B}Hq ;  
    GetConic eID, entity, curv, conic P1G;JK  
&iI5^b-P  
    SetConic eID, entity, 1/Rant, CCant )=TS)C4  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant *e,GXU@  
O_4j"0  
    '************************************************************************* /0 2-0mNv  
    'Radius and conic constant of posterior lens .dPy<6E  
    '************************************************************************* Q ym=L(X  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) T|^KG<uPV!  
    GetConic eID, entity, curv, conic X+KQ%Efo  
q=x1:^rVH  
    SetConic eID, entity, 1/Rpost, CCpost 2A&Y})D  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost #Y<QEGb(  
B`w@Xk'D  
    '************************************************************************* lvp8{]I<  
    'Lens thickness (Position of posterior lens surface) ;&9wG`  
    '************************************************************************* @:w[(K[^b/  
]@A31P4t|  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) *f-8egt-  
68QA%m'J  
    ' Delete any z-shift(s) _Gtq]`y  
    count = 0 {?uG] G7  
    While GetOperationCount(eID)>count `xsU'Wd^<  
        GetOperation eID, count, op |2!cPf^8  
        If op.Type="ShiftZ" Then |R3A$r#-  
            DeleteOperation eID,count } m&La4E  
            count=count-1 >A.m`w  
        End If I*4g ;1x  
        count=count+1 ? t_$C,A+  
    Wend pxV@fH+`  
=z4kK_?F,  
    'Set new z-shift ~]78R!HJ  
    op.Type = "ShiftZ" 9jf2b  
    op.val1 = tlens /SKgN{tWe  
    op.parent = parID wS;hC&~2  
    AddOperation eID, op ><w=  
    Print "Set lens thickness = " & tlens Evt&N)l!^  
wvz_)bN~A  
    '************************************************************************* @QbTO'UzK`  
    'Lens index of refraction u(C?\HaH  
    '************************************************************************* JW9U&Bj
{  
    eID = FindMaterial( "Lens" ) ;@s'JSPt  
    GetModelMaterial eID, mat d)'J:  
l'FNp  
    mat.Nd = nlens 7q@>d(xho  
    SetModelMaterial eID, mat f0ME$:2  
    Print "Set lens index of refraction = " & nlens /2Qgg`^)  
EL:Az~]V  
    '************************************************************************* hngdeGa  
    'Pupil diameter %y[ t+)!E  
    '************************************************************************* f[+
N=vr  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) {wCzm  
\{{i:&] H  
    'Adjust pupil diameter (trimming volume inner hole) aP`V  
CAtdx!  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" <?Y.w1  
+^<-;/FZue  
    ' Adjust pupil location to just in front of the lens &k@r23V7r  
    parID = FindFullName( "Geometry.Arizona Eye" ) +&qj`hA-b  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) l
Ql
  
    count = 0 Wer.VL  
    While GetOperationCount(eID)>count "2>_eZ#b  
        GetOperation eID, count, op W8Aii'Q8C/  
        If op.Type="ShiftZ" Then {N`<THPP  
            DeleteOperation eID,count u 4$$0 `  
            count=count-1 qV7nF }V{  
        End If /5r!Fhx  
        count=count+1 HK4 *+  
    Wend ]`u_d}`  
    op.Type = "ShiftZ" U`)o$4Bq  
    op.val1 = taq-0.01 1%k$9[!l%  
    op.parent = parID gFAtIx4  
    AddOperation eID, op ~spfQV~  
zMbz_22*  
    Print "Set pupil diameter = " & pupilDiam 'bx$}w N  
G !;
<#|a  
    'Update AZ Eye subassembly Description |^T?5=&Kt  
    eID = FindFullName( "Geometry.Arizona Eye" ) f) @-X!  
    GetEntity eID, entity !F[^?:pK  
    entity.Description = "Accommodation = " & A & "D" KV]8o
'  
    SetEntity eID, entity k \V6q9*  
IHStN,QD  
    Update _H)>U[  
    Print "DONE!" $|n#L6k  
     <ecif_a=m  
End Sub 25m!Bf  
JVt(!%K}&  
如果屈光度是4，光瞳直径是4，则会输出如下数据： * vW#XDx  
%2z]2@  
Accommodation = 4 Diopters :vRUb>z  
Pupil Diameter = 4 mm 5@
< D6>6  
Set aqueous humor thickness = 2.81 VtzX I2.2  
Set anterior lens radius = 10.4 and conic constant = -2.375869 :8jaW?~  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ~|.vz!A  
Set lens thickness = 3.927 1Aw/-FxJ  
Set lens index of refraction = 1.42672 VmTPE5d  
Set pupil diameter = 4 PHv0^l]B  
DONE! gbL!8Z1
h