[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 #MbY+[Y@v  
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。 yA7O<p+  
X7gB.=\X  
模型 MOHw{Vw(  
V9%9nR!'  
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。 u;b6uE  
KvI/!hl\  
?zVcP=p@  
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. 8v)HTD/C  
@Y+kg  
光源 ]{I>HA5[  
U@(8)[?nxn  
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。 c)q=il7ef  
uwt29  
{nS(B  
;2^zkmDM  
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。 u!fZ>kS  
W&m3"~BJ  
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。 mXsSOAD<  
x_l8&RIB*  
&?gcnMg$,J  
`[ZA#8Ma  
视网膜的散射 z_8Bl2tl  
'uwq^b_  
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。 "`'+@KlE  
<Zh\6*3:ab  
:73T9/  
]]5(:>l  
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 Z+7S`{  
B E#pHg  
U)3?&9H  
J>nta?/,X  
脚本 h}S2b@e|  
Q1H.2JXr  
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： 3[~LmA  
dO-Zj#%7z8  
]0{,P !  
Z(J 1A x  
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。 |6`7kb;p  
余下的脚本计算与屈光度有关的所有参数。 aQso<oK  
475jmQ{q  
分析 >(sS4_O7N  
viVn  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 6\)u\m`7-l  
UG6\OgkL+  
bnE&-N*  
脚本代码 s2nZW pIy  
u#->?  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. )EN,Ry  
-3XnUGK  
Dim entity As T_ENTITY CT|H1Ry2T  
Dim op As T_OPERATION 3V]psZS  
Dim mat As T_MODELMATERIAL <F|S<\Y.  
Dim A As Double  yT(86#st  
Dim pupilDiam As Double J/[PA[Rf  
Dim eID As Long uHTm  
Dim parID As Long 7[}WvfN8#  
Dim count As Integer >Q)S-4iR  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ;!m_RQPFF  
Dim tlens As Double, nlens As Double TQ5kT?/{  
Dim curv As Double, conic As Double >EgMtZ88.<  
Dim ok As Long Rr\fw'  
ASNo6dP7  
Sub Main A}1:fw\Fn3  
s1T}hp  
    '用户输入对话框 FWS!b!#,N  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 V("T9g  
        TextBox 220,21,40,21,.TextBox1 'default: 0 TI7)yxa=`  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ay=f1<a  
        OKButton 40,91,90,21 wee5Nirw6  
        CancelButton 190,91,90,21  o7AI  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 qmnW  
        TextBox 220,49,40,21,.TextBox2 'default: 4 P{8<U8E  
    End Dialog McvLU+  
    Dim dlg As UserDialog iM]&ryGB#  
-"xC\R  
    ok = Dialog (dlg) I>>X-}  
w1= f\  
    If ok=0 Then    'cancel button was pressed 9O:-q[K**  
        Print "Execution cancelled." f:9qId ;/M  
        End "l6Ob
 
    End If l+O\oD?-  
M5]$w]Ny9  
    'Assign accommodation and pupil diameter & use defaults if field left empty 6x8lnXtA  
    If dlg.TextBox1 = "" Then (HeIO  
        A = 0           'Default accommodation @h7 i;Ok  
    Else #YLI"/Kn  
        A = CDbl(dlg.TextBox1) ;{g>Z|  
    End If SxM5'KQ  
}z2K"eGt  
    If dlg.TextBox2 = "" Then sAPYQ  
        pupilDiam = 4   'Default pupil diameter JRw)~Tg @  
    Else Ly6) ,[q~  
        pupilDiam = CDbl(dlg.TextBox2) &s&Ha{(!w  
    End If "ScY'<  
f<@`{oP@  
    Print " " et6@);F  
    Print "Accommodation = " & A & " Diopters" x4@IK|CE  
    Print "Pupil Diameter = " & pupilDiam & " mm" 0"`|f0}c  
4[K6ZDBU  
    ' Calculate new parameters with accommodation ;3sJ7%`v  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness iIg99c7/&9  
@]%cUjQ  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens g0RfvR  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens `VRt{p  
UC"_#!3  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens +RD{<~i  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens qBWt(jY  
==~ lc;  
    tlens = 3.767 + 0.04*A                  'Lens thickness @X#e  
lQer|?#  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction {+|Em(M  
{hKf 'd9E  
    'Adjust parameters to account for accommodation \H.1I=<  
BoPJ;6?>}  
    '************************************************************************* X1lL@`r.5  
    'Aqueous thickness (Position of Lens) @*~cmf&FIQ  
    '************************************************************************* $:0?"?o);  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) }m-+EUEo9  
    GetCustomElement eID, entity VXu1YxY  
v iM6q<Ht  
    parID = FindFullName( "Geometry.Arizona Eye" ) BO-=X 78f@  
mybjcsV4  
    ' Delete any shift(s) in z OW8"7*irT  
    count = 0 [+4--#&{  
    While GetOperationCount(eID)>count =h}IyY@o  
        GetOperation eID, count, op 8@4)p.{5I  
        If op.Type="ShiftZ" Then 2sXX0kq~V  
            DeleteOperation eID,count MIWI0bnf  
            count=count-1 'B$qq[l]S  
        End If ,W~a%8*  
        count=count+1 NxQ+z^o\  
    Wend v8o{3wJ  
Y,C3E>}Dq  
    'Set new shift in wr;8o*~  
    op.Type = "ShiftZ" 9WsGoZPn  
    op.val1 = taq EX^j^#N  
    op.parent = parID TZ%u;tBH:  
    AddOperation eID, op iKuSk~  
    Print "Set aqueous humor thickness = " & taq-0.55 H-1y2AQ  
Ue)8g#  
    '*************************************************************************
`SO"F,  
    'Radius and conic constant of anterior lens xk8P4`;d$  
    '************************************************************************* 9DP6g<>B  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) X3;|h93.a  
    GetConic eID, entity, curv, conic 7tr;adj
s  
<xQHb^:  
    SetConic eID, entity, 1/Rant, CCant o w<.Dh  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ~Fd<d[b?  
6@@J>S>  
    '************************************************************************* rN%aP-sa<  
    'Radius and conic constant of posterior lens 'X(G><R9  
    '************************************************************************* AT4G]pT  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) VXtW{*{"  
    GetConic eID, entity, curv, conic @I^LmB9*  
#x;i R8^
  
    SetConic eID, entity, 1/Rpost, CCpost @SV.F  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost I`e|[k2  
]OKs65  
    '************************************************************************* wx|eO[14  
    'Lens thickness (Position of posterior lens surface) {qHf%
y&[  
    '************************************************************************* GY%48}7  
N\OeWjA F  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~L.)<{?  
^q0Ox&X  
    ' Delete any z-shift(s) A12#v,  
    count = 0 _n;V iQMu  
    While GetOperationCount(eID)>count E#=slj@  
        GetOperation eID, count, op Ph*tZrd*#  
        If op.Type="ShiftZ" Then )q48cQ  
            DeleteOperation eID,count 0oFRcU  
            count=count-1 F(i@Gm=J]  
        End If oX9rpTi  
        count=count+1  vNJ!d  
    Wend yF}l.>7D  
|-c)OS3#D  
    'Set new z-shift ^Fr82rJs  
    op.Type = "ShiftZ" gUoTOA,  
    op.val1 = tlens KXP^F6@l  
    op.parent = parID SBY  
    AddOperation eID, op ` qqUuFMM  
    Print "Set lens thickness = " & tlens 8N|y  
HV^*_  
    '************************************************************************* p9[J9D3~  
    'Lens index of refraction OJUH".o  
    '************************************************************************* 9oL/oL-J/  
    eID = FindMaterial( "Lens" ) d&x1uso%L  
    GetModelMaterial eID, mat )r#^{{6[v  
Ih]'OaE   
    mat.Nd = nlens rQ^$)%uP  
    SetModelMaterial eID, mat 4$oX
,Q`#  
    Print "Set lens index of refraction = " & nlens a~_5N&~pi  
-$#'  
    '************************************************************************* u[_~ !y  
    'Pupil diameter 0\*6UH  
    '************************************************************************* (q!tI*}  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) =Zcbfo_&  
)/u?_)b4"  
    'Adjust pupil diameter (trimming volume inner hole) Jp
<Y2-  
i6p0(OS&D  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" TlD)E  
{]aB3  
    ' Adjust pupil location to just in front of the lens vt3yCS  
    parID = FindFullName( "Geometry.Arizona Eye" ) 1)8;9 Ba:  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Htseu`>_$  
    count = 0 &>I4-D[  
    While GetOperationCount(eID)>count g_\U-pzr  
        GetOperation eID, count, op );*A$C9RA  
        If op.Type="ShiftZ" Then ON{
&-  
            DeleteOperation eID,count R<+K&_  
            count=count-1 Cebl"3Q  
        End If y5L%_ {n  
        count=count+1 aO9a G*9T  
    Wend s
mLXNO  
    op.Type = "ShiftZ" `b^eRnpR  
    op.val1 = taq-0.01 *%^Vq  
    op.parent = parID :?VM1!~ga  
    AddOperation eID, op t0*JinKI  
R&13P&:g  
    Print "Set pupil diameter = " & pupilDiam ^Tbw#x]2  
A`|OPi)  
    'Update AZ Eye subassembly Description $okGqu8z.O  
    eID = FindFullName( "Geometry.Arizona Eye" ) ho#]i$b}f2  
    GetEntity eID, entity L
`%v#R  
    entity.Description = "Accommodation = " & A & "D"
sEj?,1jk  
    SetEntity eID, entity Zk*/~f|\  
IG?044Y  
    Update Re3vW re  
    Print "DONE!" vDgf}  
     LEoL6ga  
End Sub __\Tv>Y  
LHjGlBy  
如果屈光度是4，光瞳直径是4，则会输出如下数据： 6mr5`5~w  
1=x4m=wV  
Accommodation = 4 Diopters /xmUu0H$R  
Pupil Diameter = 4 mm v%|^\A"V  
Set aqueous humor thickness = 2.81 XOQj?Q7)U  
Set anterior lens radius = 10.4 and conic constant = -2.375869 &BnK[Q8X  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 {O-,JCq/  
Set lens thickness = 3.927 #!d@;=[\  
Set lens index of refraction = 1.42672 )K2,h5zU  
Set pupil diameter = 4 T!.6@g`x>  
DONE! (B@:0}>  
{FO>^~>l