[技术]Arizona眼睛模型 [复制链接]

简介 {srP3ll P  
fu5L)P^T  
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。 ?9~^QRLT  
m Q9
dF,  
模型 HA,o2jZ?In  
q}LDFsU  
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。 G=:/v  
I\mF dE  
oqJYbim  
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. +hN>Q$E  
cw<
IL  
光源 i;O_B5 d  
*{ rorir  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 :c/54Ss~  
|&#N&t  
? "I %K%  
2{=]Pf  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 Bv<gVt  
L8`v  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ,:t,$A  
^^b'tP1>  
$*0-+h  
.iy4 (P4  
视网膜的散射  V9) /  
q<:8{Y|  
在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 OijuOLt  
|3]/CrR_  
F vkyp"W3  
jqaX|)8|$  
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;R~!3f./b  
3F;C{P!  
$?56 i4  
16L YVvmW  
脚本 &>\;4E.O5  
;\pVc)\4"  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： Q a (Sb  
roQI;gq^  
.y s_'F-]0  
E f\|3D_  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 +YvF+E  
余下的脚本计算与屈光度有关的所有参数。 E;a,].  
CP7Fe{P  
分析 =o9s?vOJ  
>?@5>wF  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ;^ME  
jSp&\Wjb  
H7+"BWc  
脚本代码 => (g_\  
dL0Q8d\^T  
Option Explicit     'Remove this to enable non-dimensioned variables to be used.  FSMM  
H\>{<`sD;f  
Dim entity As T_ENTITY <odi>!ViH  
Dim op As T_OPERATION FOG{dio  
Dim mat As T_MODELMATERIAL T1d@=&0
"  
Dim A As Double )V1xL_hx/  
Dim pupilDiam As Double d'';0[W)  
Dim eID As Long 9Vt ^q%DC  
Dim parID As Long G=cRdiy`C  
Dim count As Integer x {NBhq(4  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double PLz{EQ[cV  
Dim tlens As Double, nlens As Double hQ|mow@Zmz  
Dim curv As Double, conic As Double 1K9.3n   
Dim ok As Long zQ=b|p]|W  
AY52j  
Sub Main <MS>7Fd2  
?,$:~O*w  
    '用户输入对话框 !P{ /;Q  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 O<$w-(  
        TextBox 220,21,40,21,.TextBox1 'default: 0 .:?v;rYk{  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 -YQh F;/  
        OKButton 40,91,90,21 }eLApFHEDg  
        CancelButton 190,91,90,21 x:)H Ii q/  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1  qraXAQ  
        TextBox 220,49,40,21,.TextBox2 'default: 4 'UX^]  
    End Dialog No7-fX1B  
    Dim dlg As UserDialog R[m-jUL  
s&E,$|80  
    ok = Dialog (dlg) 0cmd +`  
-- %XkO  
    If ok=0 Then    'cancel button was pressed 5ngs1ZF@  
        Print "Execution cancelled." A-r;5?S  
        End =aVvv+T
 
    End If 9?\cm}^?  
&oG>Rqkm  
    'Assign accommodation and pupil diameter & use defaults if field left empty k1z`92"  
    If dlg.TextBox1 = "" Then )x!q;^Js9A  
        A = 0           'Default accommodation `<tRfl}qs  
    Else h{)m}"n<R  
        A = CDbl(dlg.TextBox1) ->I.D?p  
    End If }[eUAGhDU  
b]u=Iza  
    If dlg.TextBox2 = "" Then ~3s?.[}d  
        pupilDiam = 4   'Default pupil diameter sK%b16#  
    Else nq_$!aB_K  
        pupilDiam = CDbl(dlg.TextBox2) RJ?)O#}  
    End If .f$2-5q  
 C O6}D  
    Print " " 7FH-l(W  
    Print "Accommodation = " & A & " Diopters" .gy:Pl]w  
    Print "Pupil Diameter = " & pupilDiam & " mm" m@<,bZkl  
&W>\Vl1  
    ' Calculate new parameters with accommodation HW[&q  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness j*QdD\)  
:?f+*  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 8~T}BC  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens |r+ x/,2-  
BZ\="N#f  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens wbWC &X.  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens J;>;K6pW  
rTR$\ [C  
    tlens = 3.767 + 0.04*A                  'Lens thickness V~PGmn[V  
?J$k 5;  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction {EZR}N  
FtJaX])b  
    'Adjust parameters to account for accommodation #eYYu2ND  
EC\@$Fg  
    '************************************************************************* E0qJ.v  
    'Aqueous thickness (Position of Lens) Z+V%~C1  
    '************************************************************************* 3\Amj}RJ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) FqJd  
    GetCustomElement eID, entity kVLZdXn,q2  
Dh^l:q+c  
    parID = FindFullName( "Geometry.Arizona Eye" ) 6c+29@  
JA{kifu0+  
    ' Delete any shift(s) in z d%}?%VH  
    count = 0 "L5w]6C4  
    While GetOperationCount(eID)>count Vw;iE=L  
        GetOperation eID, count, op 1[
OY-G  
        If op.Type="ShiftZ" Then C+\z$/q  
            DeleteOperation eID,count ^%*qe5J  
            count=count-1 _*}D@yy&  
        End If +_ehzo97  
        count=count+1 `/1rZ#  
    Wend Y
AR$6&  
#_\**%,<  
    'Set new shift in ,w"cY?~<  
    op.Type = "ShiftZ" e3n^$'/\r  
    op.val1 = taq zecM|S_  
    op.parent = parID kPOk.F%)  
    AddOperation eID, op ZWGelZP~  
    Print "Set aqueous humor thickness = " & taq-0.55 XSx!11  
Z3o HOy  
    '************************************************************************* G l/3*J  
    'Radius and conic constant of anterior lens H5]q*D2  
    '************************************************************************* euY+jc%  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) w*'DlP<7  
    GetConic eID, entity, curv, conic v$`3}<3-  
"LYhYkI  
    SetConic eID, entity, 1/Rant, CCant @<P;F  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 8Ud.t=2  
,h5 FX^  
    '************************************************************************* f`vWCb  
    'Radius and conic constant of posterior lens 1grcCL q  
    '************************************************************************* Up-^km
 
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) D7R;IA-w  
    GetConic eID, entity, curv, conic 1$))@K-I  
bPV}T`  
    SetConic eID, entity, 1/Rpost, CCpost s4 ,`  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost =WF@S1  
xz:  
    '************************************************************************* aIT0t0.  
    'Lens thickness (Position of posterior lens surface) s'/_0  
    '************************************************************************* -= c&K&  
NWwKp?  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) uj}%S_9  
vzAY+EEx
 
    ' Delete any z-shift(s) %N\45nYU:  
    count = 0 K\}qYdPF  
    While GetOperationCount(eID)>count 0I)eYksh  
        GetOperation eID, count, op =sAOWI,8!  
        If op.Type="ShiftZ" Then 1Xcj=I-4  
            DeleteOperation eID,count c~M'O26bW  
            count=count-1 P2>_qyX  
        End If 1.2qh"#  
        count=count+1 s Wj:m)  
    Wend 1h]nE/T.O  
9u^za!pE  
    'Set new z-shift O~Jf"Ht  
    op.Type = "ShiftZ" fuf'r>1n  
    op.val1 = tlens uf)!SxT  
    op.parent = parID ^~B#r#  
    AddOperation eID, op A;xH{vo{  
    Print "Set lens thickness = " & tlens c8l\1ce?7  
gBgaVG  
    '************************************************************************* 9nd,8Nji  
    'Lens index of refraction 7Or?$  
    '************************************************************************* 'uqY%&U  
    eID = FindMaterial( "Lens" ) ckdCd J  
    GetModelMaterial eID, mat RXO}mu]Iu  
m2
%
 
    mat.Nd = nlens tTq2AR|  
    SetModelMaterial eID, mat 9$sx+=(  
    Print "Set lens index of refraction = " & nlens &)Vuh=  
,=u!hg  
    '************************************************************************* F{&0(6^p!  
    'Pupil diameter ~!fOl)F  
    '************************************************************************* c~Y g(  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) _P_R`A)"  
Urm(A9|N  
    'Adjust pupil diameter (trimming volume inner hole) /u'V>=D;f  
utdus:B#0  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" :Mu]*N  
!&G& ~*.x  
    ' Adjust pupil location to just in front of the lens #9(iu S+BU  
    parID = FindFullName( "Geometry.Arizona Eye" ) jjoyMg95  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) *]S&V'Di  
    count = 0 2G/CN"  
    While GetOperationCount(eID)>count xCU pMB7  
        GetOperation eID, count, op s9b+uUt%  
        If op.Type="ShiftZ" Then `g'9)Xf4KT  
            DeleteOperation eID,count 2reQd
47  
            count=count-1 p ^I#9(PT  
        End If R5cpmCs@R  
        count=count+1 Vg`32nRN  
    Wend I!p[:.t7  
    op.Type = "ShiftZ" I(Q3YDdb  
    op.val1 = taq-0.01 }(UU~V  
    op.parent = parID CVgVyy^  
    AddOperation eID, op |HTTTz9R.  
sc# q03  
    Print "Set pupil diameter = " & pupilDiam Kb#
Z(C9  
{@67'jL  
    'Update AZ Eye subassembly Description DUs0L\  
    eID = FindFullName( "Geometry.Arizona Eye" ) Tm
l>>O  
    GetEntity eID, entity JW=P}h  
    entity.Description = "Accommodation = " & A & "D" tb'O:/  
    SetEntity eID, entity &(X-b"2  
y}>bJ:  
    Update lDtl6r/  
    Print "DONE!" &Ht5!zuW,  
     ET=-r  
End Sub ^s3SzB@  
fJOA5(  
如果屈光度是4，光瞳直径是4，则会输出如下数据：
}FAO.  
Z'\{hL S  
Accommodation = 4 Diopters .5YW>PV  
Pupil Diameter = 4 mm 8CGjI?j  
Set aqueous humor thickness = 2.81 ~&8bVA= .  
Set anterior lens radius = 10.4 and conic constant = -2.375869 a.G;s2>  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 5tu 4uYp;  
Set lens thickness = 3.927 /U,;]^  
Set lens index of refraction = 1.42672 4wx_@8  
Set pupil diameter = 4 %1PNP<3r0  
DONE! `BKV/Xl