[技术]Arizona眼睛模型 [复制链接]

简介 xnC:?d  
qSDn0^y  
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。 C2aA])7D  
~_hA{$  
模型 Ma'#5)D  
cyLl,OA  
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。 S0Ur{!9\#^  
E/hT/BOPK  
m^\&v0  
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. *;(^)Sj4Q  

J)^F  
光源 2FW"uYA;6  
52 *ii  
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。 ^9`|QF  
+!GJ  
jJaMkF;f  
jXVvVv  
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。 @tJ4^<`P{  
.R@s6}C`}=  
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。 kS35X)-  
s3T7M:DM4  
/k[8xb  
RH:vd|q+  
视网膜的散射 |g>
Q3E  
h-//v~V)  
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。 &qK:LHhj  
u|Oc+qA(  
n!.=05OtX  
Z^}[CQ&Am  
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。 j/_&]6!
  
D^2lb"3  
$hHV Ie]+  
CPL,QVO9  
脚本 b\KbF/T  
mo3A*|U  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： |d z2Drc  
BG8/  
98)C 7N'  
kt0xR)gU  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 ]v0Z[l>yf  
余下的脚本计算与屈光度有关的所有参数。 UM#.`  
yoJ.[M4q  
分析 NM^uP+uS  
Zxd*%v;  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 j:qexhtho  
Mo<q(_ZeRP  
sa&`CEa  
脚本代码 WF-jy7+  
Z:<an+v|5  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. Xt
fs)"  
DRR)mQBb  
Dim entity As T_ENTITY jVLJqWP'!  
Dim op As T_OPERATION %$kd`Rl}  
Dim mat As T_MODELMATERIAL k0O5c[j  
Dim A As Double a??8)=0|}  
Dim pupilDiam As Double a$h^<D ^  
Dim eID As Long G&Dl($  
Dim parID As Long SE43C %hv  
Dim count As Integer 7H?xp_D  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double j
I0gf&v8  
Dim tlens As Double, nlens As Double ~".
@;Q  
Dim curv As Double, conic As Double $|@vmv0  
Dim ok As Long W;cYg.W2  
a;^lOU|L{  
Sub Main |0oaEd^*}  
W7b m}JHn  
    '用户输入对话框 "oNl!<ep  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 |dbKK\ X9  
        TextBox 220,21,40,21,.TextBox1 'default: 0 !zx8I7e4  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 mNacLkh[  
        OKButton 40,91,90,21 AoOA.t6RVo  
        CancelButton 190,91,90,21 0IdA!.|  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 p/RT*?<   
        TextBox 220,49,40,21,.TextBox2 'default: 4 ZZZ9C#hK^9  
    End Dialog ?>7-a~*A@  
    Dim dlg As UserDialog 9M3"'^ {$  
/5/gnpC  
    ok = Dialog (dlg) 3(\D.Z  
G`kz 0Vk  
    If ok=0 Then    'cancel button was pressed YI;iG[T,&  
        Print "Execution cancelled." knYp"<qj  
        End ls&H oJ7  
    End If T}=^D=  
<$zhNu~  
    'Assign accommodation and pupil diameter & use defaults if field left empty !OY}`a(z  
    If dlg.TextBox1 = "" Then Fz,jnV9=j  
        A = 0           'Default accommodation MjQju@  
    Else pvUV5^B(M  
        A = CDbl(dlg.TextBox1) -,b+tC<V)0  
    End If !rr,(!Ip?O  
M*ZN]9{^.  
    If dlg.TextBox2 = "" Then q)Nw$dW<  
        pupilDiam = 4   'Default pupil diameter %+Ze$c}X  
    Else =t)qy5  
        pupilDiam = CDbl(dlg.TextBox2) oPr`SYB  
    End If |k90
aQO  
C$PS@4'U  
    Print " " wB[f%mHs  
    Print "Accommodation = " & A & " Diopters" cPuXye  
    Print "Pupil Diameter = " & pupilDiam & " mm"  jF0"AA  
?YS>_MN  
    ' Calculate new parameters with accommodation +llb{~ZN  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 86 e13MF  
>FwK_Zd'  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Q
Cb%d'_w+  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens QwWd"Of  
QJ4$) Fr(  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens
?@,EGY<  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 6{]F#ig=  
@}g3\xLiK  
    tlens = 3.767 + 0.04*A                  'Lens thickness (~zu4^9w  
`qs}L  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction >h;]rMD!|  
`}#rcDK  
    'Adjust parameters to account for accommodation C&H'?0Y@  
>bze0`}Z  
    '************************************************************************* =3-?$  
    'Aqueous thickness (Position of Lens) s$hO/INr  
    '************************************************************************* rY45.,qWs  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4 O8ct,Y  
    GetCustomElement eID, entity ^ZQMRNP{r  
Z>g>OPu  
    parID = FindFullName( "Geometry.Arizona Eye" ) .
waw=C  
8R3{
YJ6@T  
    ' Delete any shift(s) in z v f{{z%3T  
    count = 0 zG6l8%q'UE  
    While GetOperationCount(eID)>count bc'Io
D/  
        GetOperation eID, count, op s{'Sl{-Eu  
        If op.Type="ShiftZ" Then {sC Ni  
            DeleteOperation eID,count G5/A{1sz&  
            count=count-1 /ki-Tha  
        End If MmjZq  
        count=count+1 ^BA%]pe$I  
    Wend FefroaJ:u  
)&j`5sSXcr  
    'Set new shift in fF0i^E<  
    op.Type = "ShiftZ" ]5f;Kz)  
    op.val1 = taq +mVAmG@  
    op.parent = parID OA3J(4!"W  
    AddOperation eID, op mEd2f^R  
    Print "Set aqueous humor thickness = " & taq-0.55 'l.tV7  
T[|#DMg$F  
    '************************************************************************* tjx8UgSi  
    'Radius and conic constant of anterior lens WDIin6u-  
    '************************************************************************* 2 3PRb<q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) fasWb&~z  
    GetConic eID, entity, curv, conic !\7`I}:  
wg?}c ;  
    SetConic eID, entity, 1/Rant, CCant V'XEz;Ze  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant |?^<=%  
=){G  
    '************************************************************************* eW(pP>@k,  
    'Radius and conic constant of posterior lens }Kgi!$<aQx  
    '************************************************************************* jDY B*Y^
F  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) U~:H>  
    GetConic eID, entity, curv, conic 1PwtzH.w  
b}R_@_<u  
    SetConic eID, entity, 1/Rpost, CCpost >6o <Q  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost DPzW,
aIgv  
rV%68x9  
    '************************************************************************* C{J5:ak  
    'Lens thickness (Position of posterior lens surface) hUlRtt  
    '************************************************************************* gS+X%  
pKc!sdC  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) G7 UUx+X  
AhF@  
    ' Delete any z-shift(s) FLMiW]?x  
    count = 0 tw$EwNI[  
    While GetOperationCount(eID)>count JU>~[yAP  
        GetOperation eID, count, op >j=ZB3yZ  
        If op.Type="ShiftZ" Then ~DK.Y   
            DeleteOperation eID,count uQO5GDuK>  
            count=count-1 oDA'$]UL  
        End If 3HrG^/  
        count=count+1 l7VO8p]y[R  
    Wend 0vqH-)}  
u;q Q/Ftb  
    'Set new z-shift MeBTc&S<  
    op.Type = "ShiftZ" ]vQa~}  
    op.val1 = tlens bPOPoq1#  
    op.parent = parID daKZ*B|  
    AddOperation eID, op #'&-S@/nQs  
    Print "Set lens thickness = " & tlens {A0F/#M]  
#g6_)B=S  
    '************************************************************************* UJ}}H}{  
    'Lens index of refraction W8g13oAu"  
    '************************************************************************* u<:uL  
    eID = FindMaterial( "Lens" ) YdCl  
    GetModelMaterial eID, mat Jq` Dvz  
Eq)b=5qrG?  
    mat.Nd = nlens U%@
PY9#
 
    SetModelMaterial eID, mat QIkF
X.^  
    Print "Set lens index of refraction = " & nlens s1_Y~<yX  
\ZcI{t'a  
    '************************************************************************* "Y+VNS  
    'Pupil diameter d8: $ll  
    '************************************************************************* QwhO/  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) rB+ (  
KJT N"hF   
    'Adjust pupil diameter (trimming volume inner hole) oi0O4J%H  
wetu.aMp  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" B@-\.m  
zRjbEL  
    ' Adjust pupil location to just in front of the lens = cxO@Fu  
    parID = FindFullName( "Geometry.Arizona Eye" ) ti+e U$  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) K;"H$0!9  
    count = 0 R WY>`.su  
    While GetOperationCount(eID)>count =r/K#hOR\J  
        GetOperation eID, count, op ??nT[bhQ  
        If op.Type="ShiftZ" Then 3/vtx9D  
            DeleteOperation eID,count LBG`DYR@  
            count=count-1 9q?knMt  
        End If qOG@MR(5  
        count=count+1 AIOGa<^  
    Wend |i
Jz[%  
    op.Type = "ShiftZ" Kc]cJ`P4.  
    op.val1 = taq-0.01 w-WAgAch  
    op.parent = parID vltE2mb  
    AddOperation eID, op RbUir185Y  
-aJ(-Np$f  
    Print "Set pupil diameter = " & pupilDiam )b nGZ8h99  
^kNVQJiZyG  
    'Update AZ Eye subassembly Description x%X3FbF]  
    eID = FindFullName( "Geometry.Arizona Eye" ) E~q3o*  
    GetEntity eID, entity \_.'/<aQ  
    entity.Description = "Accommodation = " & A & "D" a)2l9  
    SetEntity eID, entity 7x`$A  
?:vg`m!*  
    Update 'dwsm7Xd  
    Print "DONE!" `GqF/?i  
     |u`YT;`!"-  
End Sub [uqr  
u*l>)_HD  
如果屈光度是4，光瞳直径是4，则会输出如下数据： '*Y mYU  
&S.p%Qe"  
Accommodation = 4 Diopters w#9.U7@.  
Pupil Diameter = 4 mm >;G_o="X  
Set aqueous humor thickness = 2.81 wa[J\lW  
Set anterior lens radius = 10.4 and conic constant = -2.375869 1Mq"f7X8  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ;Uch  
Set lens thickness = 3.927 ?z)
2\D  
Set lens index of refraction = 1.42672 ,?U(PEO\f  
Set pupil diameter = 4 5Zc  
DONE! hK4ww"-