[技术]Arizona眼睛模型 [复制链接]

简介 fx_#3=bXi  
aP  
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。 WMa0L&C~v  
N2}SR|.  
模型 S"Cz. bv  
QE(.w dHP  
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。 7a'yO+7-)  
A ]A{HEX  
#4'wF4DR@  
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. ls 5iE  
yv[j Pbe  
光源 ! dzgi:  
>s{I@#9  
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。 .r<aPy$  
I
y9hBAg\y  
|qUGB.Q  
nTqU~'d'  
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。 s7 "xDDV  
yXR1NYg  
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。 MuY:(zC%  
'K,\
  
yV{B,T`W  
c1'@_Is  
视网膜的散射 
o]e,5]  
wGAr
R7r  
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。 |RiJ>/MK\  
QO'Hyf t  
i?6&4  
uDDa>Ka#+  
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。 i<Vc~!pT  
+FTc/r  
9*)&hhBs,  
6Xvpk1
  
脚本 _ >OP  
RPz[3y  
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： \HeJc:^  
d/7fJ8y8  
Pp8S\%z~h  
+vh|m5"7I7  
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。 S>yiD`v  
余下的脚本计算与屈光度有关的所有参数。 n$/|r  
&K9;GZS?  
分析 v"bWVc~H  
7*5B  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 jdxHWkQ  
iE~!?N|a3  
+K4XMf  
脚本代码 bwsKdh  
hw DxGiU  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. O*xx63%jR  
')uYI;h9  
Dim entity As T_ENTITY TjW!-s?S  
Dim op As T_OPERATION uwNJM  
Dim mat As T_MODELMATERIAL ]&*POri&  
Dim A As Double Ds`e-X)O;\  
Dim pupilDiam As Double -H-U8/WC  
Dim eID As Long )pWgt5:7~  
Dim parID As Long !7N:cx'Qy  
Dim count As Integer E'QAsU8pP  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double FOTe,F.8  
Dim tlens As Double, nlens As Double KYFKH+d>m  
Dim curv As Double, conic As Double kuEXNi1l  
Dim ok As Long UUt"8]@[  
F\:
~^`  
Sub Main 37U8<  
p*g Fr hm  
    '用户输入对话框 ='7m$,{(Q[  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 y~9wxK  
        TextBox 220,21,40,21,.TextBox1 'default: 0 )@g[aRFa  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 b;i*}4h!  
        OKButton 40,91,90,21 8em'7hR9  
        CancelButton 190,91,90,21 72<9xNcB!}  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 wLV,E,gM  
        TextBox 220,49,40,21,.TextBox2 'default: 4 RNT9M:w  
    End Dialog Za|7gt];l  
    Dim dlg As UserDialog QK-aH1r  
|+cz\+  
    ok = Dialog (dlg) k6tCfq;  
@cDB 7w\  
    If ok=0 Then    'cancel button was pressed Etz#+R&*  
        Print "Execution cancelled." >F$9&s&  
        End {*_Ln  
    End If aHhLz>H'  
y1V}c,  
    'Assign accommodation and pupil diameter & use defaults if field left empty TFSdb\g  
    If dlg.TextBox1 = "" Then &h5Vhzq(<  
        A = 0           'Default accommodation VUP|j/qD  
    Else A*h8 o9M  
        A = CDbl(dlg.TextBox1) b_x!m{  
    End If E?w#$HS  
8FsQLeOE  
    If dlg.TextBox2 = "" Then ndSu-8?L  
        pupilDiam = 4   'Default pupil diameter RD`|Z~:q:K  
    Else Ac_P^  
        pupilDiam = CDbl(dlg.TextBox2) 3D|Lb]=  
    End If x\yM|WGL  
> X~\(|EM  
    Print " " _}{KS, f]0  
    Print "Accommodation = " & A & " Diopters" ZU\$x<,  
    Print "Pupil Diameter = " & pupilDiam & " mm" WIWo4[(  
]3,'U(!+  
    ' Calculate new parameters with accommodation !r/i<~'Bx  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness i\xs!QU  
#$WnMJ@  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens re/-Yu$'  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens &8VH m?h  
%JeNDXbI4  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 6#=Iv X4  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens htB2?%S=T  
]OpGD5jZ  
    tlens = 3.767 + 0.04*A                  'Lens thickness HNZ$CaJh  
z%}"=  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 7gX32r$%V  
M6-uTmN:d  
    'Adjust parameters to account for accommodation ]}`t~#Irz  
D0J{pAJ  
    '************************************************************************* B)q}]Qn  
    'Aqueous thickness (Position of Lens) 9SC1A-nF  
    '************************************************************************* ruaZ(R[  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,2AulX1  
    GetCustomElement eID, entity $1=7^v[U  
+*.*bo  
    parID = FindFullName( "Geometry.Arizona Eye" ) g$Tsht(rHD  
,ei9 ?9J1  
    ' Delete any shift(s) in z ~&:-c v  
    count = 0 fw%p_Cm  
    While GetOperationCount(eID)>count Q<>u)%92@  
        GetOperation eID, count, op 'DW|a  
        If op.Type="ShiftZ" Then ivo3pibk%  
            DeleteOperation eID,count $HwF:L)*  
            count=count-1 d.}65{F,x  
        End If 9fp"r,aHN&  
        count=count+1 -zECxHjx  
    Wend \J:+Wl.9A  
Rk9n,"xpv  
    'Set new shift in CC^D4]ug  
    op.Type = "ShiftZ" \d
:Q%S  
    op.val1 = taq xxGm T.&  
    op.parent = parID yBK$2to~  
    AddOperation eID, op s:{[Y7\?  
    Print "Set aqueous humor thickness = " & taq-0.55 zFOtOz`9H  
WvU[9ME^)  
    '************************************************************************* b GSj?t9/  
    'Radius and conic constant of anterior lens aPJTH0u  
    '************************************************************************* Xau%v5r  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) YusmMsN?  
    GetConic eID, entity, curv, conic D[^K0<-Z  
9>{ml&$  
    SetConic eID, entity, 1/Rant, CCant )d[n-Si  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Jk{SlH3'  
)pI( <  
    '************************************************************************* 3MX#}_7A  
    'Radius and conic constant of posterior lens @zGF9O<3,@  
    '************************************************************************* 5CnNp?.t^  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) S^R dj ]  
    GetConic eID, entity, curv, conic h]@'M1D%  
C32*RNG?U  
    SetConic eID, entity, 1/Rpost, CCpost [( xPX  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost sssw(F  
}^I3
6$\  
    '************************************************************************* -sHX  
    'Lens thickness (Position of posterior lens surface) %nJo:/  
    '************************************************************************* UR'v;V&Cb\  
9@qkj 4w  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) / 8O=3  
8XVRRk  
    ' Delete any z-shift(s) NvzPZ9=@-  
    count = 0 5XT^K)'  
    While GetOperationCount(eID)>count 7j|CWurvq  
        GetOperation eID, count, op 2KO`+
  
        If op.Type="ShiftZ" Then x7B;\D#`i/  
            DeleteOperation eID,count jhRr!  
            count=count-1 ['>ZC3?"h  
        End If ^coCsV^CW"  
        count=count+1 NJJ=c
h  
    Wend zw'%n+5m  
= y^5PjN  
    'Set new z-shift 3LyNi$`f  
    op.Type = "ShiftZ" Z|KDi `S  
    op.val1 = tlens XFTqt]
 
    op.parent = parID DhxS@/  
    AddOperation eID, op xi"ff.  
    Print "Set lens thickness = " & tlens NPv.7,  
#P!<u Lc%  
    '************************************************************************* lpPPI+|4N  
    'Lens index of refraction \v+>qY<q  
    '************************************************************************* 6RI
bsy  
    eID = FindMaterial( "Lens" ) N, u]2,E  
    GetModelMaterial eID, mat z3[J sE%  
{tYY _BI<  
    mat.Nd = nlens f>xi(0  
    SetModelMaterial eID, mat D,*|:i  
    Print "Set lens index of refraction = " & nlens .~ uKr^%  
NHUJ:j@  
    '************************************************************************* &b>&XMIK  
    'Pupil diameter l(x0d  
    '************************************************************************* }>y!I5O  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 3ouy-SQ  
x?A<X2  
    'Adjust pupil diameter (trimming volume inner hole) AEM;ZQU  
aZo}Ix:/  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" k:7Gb7\  
bD/ZKvg  
    ' Adjust pupil location to just in front of the lens PN99 R]K0g  
    parID = FindFullName( "Geometry.Arizona Eye" ) a Z)1SX`D  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) W=g'Xu!|!2  
    count = 0 2aR9vmR  
    While GetOperationCount(eID)>count \^pc"?Rc  
        GetOperation eID, count, op U<F|A!Fg  
        If op.Type="ShiftZ" Then [< g9jX5  
            DeleteOperation eID,count @x*xgf  
            count=count-1 =!DX,S7  
        End If Q)XH5C2X  
        count=count+1 iEI#J!
~  
    Wend zC:Pg4=w]  
    op.Type = "ShiftZ" |_g7k2oLY  
    op.val1 = taq-0.01 sk07|9nU  
    op.parent = parID &=S:I!9;;  
    AddOperation eID, op OpazWcMoo  
ab9ecZ  
    Print "Set pupil diameter = " & pupilDiam `zq+Xl  
^B%ki  
    'Update AZ Eye subassembly Description |Wa.W0A  
    eID = FindFullName( "Geometry.Arizona Eye" ) 'aV'Am+:  
    GetEntity eID, entity H}_R`S  
    entity.Description = "Accommodation = " & A & "D" cGm?F,/`  
    SetEntity eID, entity V=&M\58  
czT2f  
    Update ?vbAaRg50s  
    Print "DONE!" yaG:}=.3  
     ]zAwKuIK  
End Sub jPo,mz&^  
:J@3:+sr  
如果屈光度是4，光瞳直径是4，则会输出如下数据： kf<c[su  
s8's(*]  
Accommodation = 4 Diopters h|PC?@jp  
Pupil Diameter = 4 mm w2s06`g  
Set aqueous humor thickness = 2.81 wC%qSy'  
Set anterior lens radius = 10.4 and conic constant = -2.375869 vw:GNpg'R6  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 WC=d@d)M  
Set lens thickness = 3.927 %rhZH^2  
Set lens index of refraction = 1.42672 f34/whD65  
Set pupil diameter = 4 }%PK %/ zI  
DONE! J,?F+Qji&=