[技术]Arizona眼睛模型 [复制链接]

简介 y44FejH(v  
Y5&Jgn.l  
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。 :~3sW< PR  
"aHY]E{  
模型 \:mx Ri  
5V!L~#  
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。 3Bee6N>  
}jBr[S5  
JryDbGc8  
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. 7Te`
#"  
M8
X*fYn  
光源 VQ5
T$,&  
WCA`34(  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 !f-mC,d  
}`&#{>]2  
s Z(LT'}  
{>tgNW>)  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 rVowH
P  
9a9<I  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 BoYWx^VHx^  
V|zz
j[c  
}@=m[Zx#  
X&nkc/erx  
视网膜的散射 <&\HXAOd  
-U)6o"O_CV  
在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 zB/$*Hd  
m663%b(5>  
I~y[8  
u4bPj2N8I  
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。 7GY[l3arxv  
vN
lYk  
o)
F^0t  
!yU!ta Q  
脚本 RKFj6u  
~j}di^<{  
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： c) Zid1  
oNY;z-QK  
vT"T*FKh:  
&MsnQP  
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。 *i|O!h1St  
余下的脚本计算与屈光度有关的所有参数。 N(q%|h<Z/=  
:$."x '  
分析 Ug*:o d  
u:tLO3VfJ  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 vS%o>"P  
S~0 mY} m  
ba& \~_4  
脚本代码 =Y#)c]`  
o
7<pI8\  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. qFp }+
s  
gfG Mu0FjB  
Dim entity As T_ENTITY 8X!^ 2B}J  
Dim op As T_OPERATION KZUB{
Y^)  
Dim mat As T_MODELMATERIAL hd1(q33  
Dim A As Double <
iVn!P  
Dim pupilDiam As Double [}q6bXM*  
Dim eID As Long 4CVtXi_Y  
Dim parID As Long :pj#t$:!  
Dim count As Integer ~K]5`(KV  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double JYA$_T
  
Dim tlens As Double, nlens As Double -:b0fKn  
Dim curv As Double, conic As Double | YmQO#''  
Dim ok As Long Jj4!O3\I  
' _Ij9{M  
Sub Main f{MXH&d 1\  
pe$" nUy|  
    '用户输入对话框 ]+\;pb}bq  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 %
Ez=  
        TextBox 220,21,40,21,.TextBox1 'default: 0 jPU:&1(_ n  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 PrqN5ND  
        OKButton 40,91,90,21 2Sbo7e  
        CancelButton 190,91,90,21 bzD <6Z  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 oG~a`9N%C  
        TextBox 220,49,40,21,.TextBox2 'default: 4 swV/Mi>  
    End Dialog 2iC7c6hc  
    Dim dlg As UserDialog /\P3UrQ&]  
rKg~H=4x2  
    ok = Dialog (dlg) ^[6eo8Ck>  
U86bn(9K  
    If ok=0 Then    'cancel button was pressed sc dU  
        Print "Execution cancelled." },G6IuH%  
        End h}r64<Y2{  
    End If `7$0
H]*6  
F,}wQN  
    'Assign accommodation and pupil diameter & use defaults if field left empty ]FV,}EZ  
    If dlg.TextBox1 = "" Then  Xr'Y[E[  
        A = 0           'Default accommodation .vHSKd{  
    Else V("@z<b|  
        A = CDbl(dlg.TextBox1) :MPWf4K2s  
    End If [)UL}vAO\q  
A3D"b9<D  
    If dlg.TextBox2 = "" Then :4RD.l  
        pupilDiam = 4   'Default pupil diameter j"o8]UT/  
    Else 5%M '
ewu  
        pupilDiam = CDbl(dlg.TextBox2) d Bn/_  
    End If gI<e=|J6w  
~5LlIpf36|  
    Print " " 6\"g,f  
    Print "Accommodation = " & A & " Diopters" K. [2uhB)  
    Print "Pupil Diameter = " & pupilDiam & " mm" nP`#z&C  
yneIY-g(p  
    ' Calculate new parameters with accommodation +Y;/10p  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness l]tda(  
b.HfxYt(  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens NvCq5B$
C  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens *b#00)d  
1N8gH&oF
 
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens NKyaR_q`  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens lS<T|:gz@  
$M%<i~VXe&  
    tlens = 3.767 + 0.04*A                  'Lens thickness esE5#Yq4.k  
T^FeahA7;  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction +pDZ,c,  
<X]'":  
    'Adjust parameters to account for accommodation  %T9'dcM  
IJX75hE0g  
    '************************************************************************* [!Uzw2  
    'Aqueous thickness (Position of Lens) o2p;$W4`  
    '************************************************************************* tx0`#x  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) +<qmVW^X  
    GetCustomElement eID, entity D}
4*Il?  
{|dU
|h  
    parID = FindFullName( "Geometry.Arizona Eye" ) 7bcl^~lY  
4r
Xjso|  
    ' Delete any shift(s) in z qu>5 rg-  
    count = 0 ;&="aD  
    While GetOperationCount(eID)>count fd Vye|%  
        GetOperation eID, count, op %K@s0uQ  
        If op.Type="ShiftZ" Then 79}voDFd  
            DeleteOperation eID,count Z?@1X`@  
            count=count-1 }?PvNK]",  
        End If ::'DWD1  
        count=count+1
&U<t*"  
    Wend O [Q;[@  
t4HDt\}&k~  
    'Set new shift in IC5[:UZ5]
 
    op.Type = "ShiftZ" @log=^  
    op.val1 = taq #fT1\1[]  
    op.parent = parID 8&d
s  
    AddOperation eID, op B^8]quOH  
    Print "Set aqueous humor thickness = " & taq-0.55 Y<1]{4Wt  
rID_^g_tP8  
    '************************************************************************* V* :Q~ ^  
    'Radius and conic constant of anterior lens W
sHC%+\'  
    '************************************************************************* ur*a!U  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) wO\,?SI4  
    GetConic eID, entity, curv, conic G3 h&nH,>  
G'>?/l#  
    SetConic eID, entity, 1/Rant, CCant Ed&;d+NM  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant kd0~@rPL  
Z]Zs"$q@  
    '************************************************************************* "l8
3O8 L  
    'Radius and conic constant of posterior lens ,Oqd4NS  
    '************************************************************************* gW0{s[}T  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Y@&1[Z  
    GetConic eID, entity, curv, conic Ky6.6Y<.|  
l;u_4`1H  
    SetConic eID, entity, 1/Rpost, CCpost ,gdf7&r  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost G5;N#^myJ  
`EFPY$9`D  
    '************************************************************************* H2EKr#(
 
    'Lens thickness (Position of posterior lens surface) [X9s\H  
    '************************************************************************* 'a&(
r;  
oh>X/uj  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4KO2oIR  
)Fa

6'M  
    ' Delete any z-shift(s) %Fb4   
    count = 0 G"_ 8`l  
    While GetOperationCount(eID)>count K/^70;/!.  
        GetOperation eID, count, op D7'P^*4_B  
        If op.Type="ShiftZ" Then |Wo_5|
E  
            DeleteOperation eID,count PP+-D~r`}  
            count=count-1  vbol70  
        End If  ~\0uy3%  
        count=count+1 Er 4P  
    Wend {9 PeBc  
/CXrxeo  
    'Set new z-shift S7/0B4[  
    op.Type = "ShiftZ" Py}`k1t*f  
    op.val1 = tlens ,{KjVv<  
    op.parent = parID vocXk_  
    AddOperation eID, op >icL,n"]  
    Print "Set lens thickness = " & tlens a.oZ}R7'Y  
QH?}uX'x)G  
    '************************************************************************* OJ2O?Te8  
    'Lens index of refraction Glt%%TJb  
    '************************************************************************* z3 zN^ZT  
    eID = FindMaterial( "Lens" ) R^nkcLFb/q  
    GetModelMaterial eID, mat 8ec6J*b  
oH[4<K>  
    mat.Nd = nlens ^5"2s:vP  
    SetModelMaterial eID, mat Y<A593  
    Print "Set lens index of refraction = " & nlens <%@S-+D`]  
)ifEgBT  
    '************************************************************************* /^BaQeH?R  
    'Pupil diameter kX\\t.nH  
    '************************************************************************* ]["=K!la:  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) !!WSGZUR  
i]qVT)j  
    'Adjust pupil diameter (trimming volume inner hole) gEejLyOag  
Q%x |  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" }w,^]fC:  
Z(' iZ'55F  
    ' Adjust pupil location to just in front of the lens ?<Tt1fpG  
    parID = FindFullName( "Geometry.Arizona Eye" ) im}=  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) AbWnDqv  
    count = 0 ka3(sctZ5  
    While GetOperationCount(eID)>count W~TT`%[  
        GetOperation eID, count, op 2g)W-M  
        If op.Type="ShiftZ" Then (l|:$%[0  
            DeleteOperation eID,count ("UzMr,  
            count=count-1 T'n~QfU  
        End If R4?OFhN9  
        count=count+1 G!y~Y]e  
    Wend JZCRu_M>|  
    op.Type = "ShiftZ" sQBl9E'!be  
    op.val1 = taq-0.01 f*+eu@  
    op.parent = parID &=seIc>x@  
    AddOperation eID, op "`sr#  
z[7j`J|Kk  
    Print "Set pupil diameter = " & pupilDiam F]#rH  
**zh>Y}6  
    'Update AZ Eye subassembly Description ?5%0zMC  
    eID = FindFullName( "Geometry.Arizona Eye" ) Jgf73IX[  
    GetEntity eID, entity ~AD%aHR  
    entity.Description = "Accommodation = " & A & "D" |{KZ<  
    SetEntity eID, entity Sdc yL%6!  
Nb))_+/  
    Update sj)$o94=  
    Print "DONE!" $;9zD11  
     /Dn,;@ZwAi  
End Sub M]S&vE{D  
t+R8{9L-  
如果屈光度是4，光瞳直径是4，则会输出如下数据： Ol}^'7H  
i.0}d5Y  
Accommodation = 4 Diopters N8<Wm>GLX~  
Pupil Diameter = 4 mm sC8C><y  
Set aqueous humor thickness = 2.81 I?).D?o  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Z#-:zD7_  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 l?+67cQLA  
Set lens thickness = 3.927 MjO.s+I  
Set lens index of refraction = 1.42672 C?UV3  
Set pupil diameter = 4 mN_KAln  
DONE! !'4HUB>+