[技术]Arizona眼睛模型 [复制链接]

简介 @ 3b-  
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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。 o6X<FE#8  
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模型 )IuwI#pm  
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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。 pS!N<;OWr  
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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. r+nhm"9  
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光源 HmpV; <t3  
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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。 $t>ow~Xi  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 M-5zsN  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 W0Q;1${  
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视网膜的散射 c6HH%|  
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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。 ,,(BW7(  
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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。 bhT:MW!  
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脚本 FuO'%3;c  
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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： xwrleB  
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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。 2d-C}&}L\  
余下的脚本计算与屈光度有关的所有参数。 T8J[B( )L  
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分析 24/ ^_Td  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 0t}&32lL&  
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脚本代码 J9/}ZD^  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. NpYzN|W:  
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Dim entity As T_ENTITY _cH 7lO[  
Dim op As T_OPERATION )3~):+  
Dim mat As T_MODELMATERIAL W%cJ#R[o  
Dim A As Double "# BI"  
Dim pupilDiam As Double giz#(61j^  
Dim eID As Long |0/~7l  
Dim parID As Long khtSZ"8X  
Dim count As Integer fP:g}Z  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double /0qLMlL$  
Dim tlens As Double, nlens As Double )]5}d$83  
Dim curv As Double, conic As Double O9]+Jd4W  
Dim ok As Long 
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Sub Main }e*OprF  
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    '用户输入对话框 )R'~{;z }  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 B @8 ]!  
        TextBox 220,21,40,21,.TextBox1 'default: 0 lZ9rB^!  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 BSB;0OM  
        OKButton 40,91,90,21 J M,ndl  
        CancelButton 190,91,90,21 n
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 \P|PAU@,  
        TextBox 220,49,40,21,.TextBox2 'default: 4 B#K{Y$!v  
    End Dialog h|j
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    Dim dlg As UserDialog I ;Sm<P7*  

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    ok = Dialog (dlg) /&#Gh?
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    If ok=0 Then    'cancel button was pressed B#T4m]E/  
        Print "Execution cancelled." GF-\WD  
        End CQx#Xp>=s  
    End If zg2}R4h  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ``Wf%~  
    If dlg.TextBox1 = "" Then af<R.  
        A = 0           'Default accommodation MIJ^n(-G  
    Else '-7rHx  
        A = CDbl(dlg.TextBox1) Gd8FXk,.!  
    End If >qBQfz:U>  
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    If dlg.TextBox2 = "" Then kgV_*0^  
        pupilDiam = 4   'Default pupil diameter :Ej#qYi  
    Else jr<`@  
        pupilDiam = CDbl(dlg.TextBox2) OIMsxXF\J  
    End If m["`Op4  
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    Print " " =-e`OHA  
    Print "Accommodation = " & A & " Diopters" ,33[/j  
    Print "Pupil Diameter = " & pupilDiam & " mm" ^T#bla893  
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    ' Calculate new parameters with accommodation 1sqBBd"=PY  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness <B?@,S>  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens .BR2pf|R  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Qt@_C*,P  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens %)$^_4.g  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens .m&JRzzV  
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    tlens = 3.767 + 0.04*A                  'Lens thickness s^{hdCCl67  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Sd!!1as  
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    'Adjust parameters to account for accommodation _bi]Bpxf  
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    '************************************************************************* =o@CCUKpj  
    'Aqueous thickness (Position of Lens) (|<e4HfZL  
    '************************************************************************* 3~I|KF7x  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) &o$z[b  
    GetCustomElement eID, entity (}W+W\.  
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    parID = FindFullName( "Geometry.Arizona Eye" ) OO Hw-MW  
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    ' Delete any shift(s) in z TzC'xWO  
    count = 0 =q1=.VTn  
    While GetOperationCount(eID)>count ] rP^  
        GetOperation eID, count, op {{G`0i2KV  
        If op.Type="ShiftZ" Then #mI{D\UR  
            DeleteOperation eID,count ! z^%$;p  
            count=count-1 IMKyFp]h-  
        End If PJq;OM|  
        count=count+1 Fgf5OHX  
    Wend tai=2,'  
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    'Set new shift in _6b?3[Xz  
    op.Type = "ShiftZ" i'w8Li  
    op.val1 = taq hV(>}hb  
    op.parent = parID ?s=O6D&   
    AddOperation eID, op cBZKt  
    Print "Set aqueous humor thickness = " & taq-0.55 x)Y?kVw21"  
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    '************************************************************************* o$*aAgS+  
    'Radius and conic constant of anterior lens B-oQ 9[~  
    '************************************************************************* pO^PkX  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) |[/<[@\''  
    GetConic eID, entity, curv, conic %h}Qf&U_  
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    SetConic eID, entity, 1/Rant, CCant 3pxZk%  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant WrA!'I  
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    '************************************************************************* )\ `AD#  
    'Radius and conic constant of posterior lens tx,_0[hZi  
    '************************************************************************* <G9HVMiP  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +-DF3(  
    GetConic eID, entity, curv, conic V`c"q.8  
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    SetConic eID, entity, 1/Rpost, CCpost scf.>K2  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost N~""Lc&  
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    '************************************************************************* "!V-@F$@N  
    'Lens thickness (Position of posterior lens surface) QKW\z aG  
    '************************************************************************* Nl4,c[$C  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) y*F !k{P  
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    ' Delete any z-shift(s) _d|CO  
    count = 0 <r9L-4  
    While GetOperationCount(eID)>count |/qwR~  
        GetOperation eID, count, op 'YKzs;y$  
        If op.Type="ShiftZ" Then lOp7rW]$  
            DeleteOperation eID,count X#ZQpo'h  
            count=count-1 PBeBI:  
        End If j*.K|77WHj  
        count=count+1 YiO3.
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    Wend 2)~`.CD?L  
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    'Set new z-shift fH@P&SX  
    op.Type = "ShiftZ" Y3_C':r  
    op.val1 = tlens (#&-ld6  
    op.parent = parID {Jna' eS  
    AddOperation eID, op = 9Ow!(!@  
    Print "Set lens thickness = " & tlens 6
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    '************************************************************************* *:5S*E&}V  
    'Lens index of refraction NmuzAZr  
    '************************************************************************* H;h$k]T  
    eID = FindMaterial( "Lens" ) t)4><22of  
    GetModelMaterial eID, mat ?XlPKY  
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    mat.Nd = nlens fT2F$U  
    SetModelMaterial eID, mat o2 ;  
    Print "Set lens index of refraction = " & nlens *;&[q{hz  
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    '************************************************************************* qj7}]T_  
    'Pupil diameter >\7Mf@c  
    '************************************************************************* 22T\-g{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 0h=}BCb+i  

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    'Adjust pupil diameter (trimming volume inner hole) }@y(-7t  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" O"GuVC}B  
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    ' Adjust pupil location to just in front of the lens mo?*nO|-  
    parID = FindFullName( "Geometry.Arizona Eye" ) b9xvLR8  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) kR+7JUq]  
    count = 0 Ud_7>P$a  
    While GetOperationCount(eID)>count )n&6= Li  
        GetOperation eID, count, op r) u@,P  
        If op.Type="ShiftZ" Then '8yCwk  
            DeleteOperation eID,count k-N}tk/5  
            count=count-1 q^DQ9B  
        End If &7XsyDo6  
        count=count+1 Vb8Q
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    Wend uq2C|=M-x\  
    op.Type = "ShiftZ" #z1/VZ  
    op.val1 = taq-0.01 ;u-[%(00S  
    op.parent = parID
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    AddOperation eID, op h"y~!NWn  
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    Print "Set pupil diameter = " & pupilDiam GBl[s,g[|  
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    'Update AZ Eye subassembly Description T)I\?hqTB  
    eID = FindFullName( "Geometry.Arizona Eye" ) xHD$0eq  
    GetEntity eID, entity ]6 HR  
    entity.Description = "Accommodation = " & A & "D" `Frr?.3&-  
    SetEntity eID, entity 9SBTeJ$RZ  
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    Update ?Rk[P cX<  
    Print "DONE!" jL7r1pu5  
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End Sub RW<10:  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： HUChg{[  
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Accommodation = 4 Diopters o%,?v 9  
Pupil Diameter = 4 mm :}R,a=N  
Set aqueous humor thickness = 2.81 m5o$Dus+?'  
Set anterior lens radius = 10.4 and conic constant = -2.375869 kWacc&*|  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 @uz(h'~  
Set lens thickness = 3.927 UcKVLzKs  
Set lens index of refraction = 1.42672 lWn}afI  
Set pupil diameter = 4 O#k eoC4  
DONE! !' 0PM[