[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 $q$\GOQ 9  
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。 hJ*E"{xs  
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模型 W!B4<'Fjc  
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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。 HPdwx V  
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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. wP1VQUL  
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光源 ;f^jB;\<  
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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。 "K!BJQ  
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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。 _rJSkZO  
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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。 ujqktrhuLb  
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视网膜的散射 <sB45sNbU`  
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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。 #7T={mh  
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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。 [te7uZv-  
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脚本 G.e\#_RR?  
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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： $*-L8An?  
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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。 kxwm08/|f  
余下的脚本计算与屈光度有关的所有参数。 i~L7h=__  
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分析 s7} )4.vO  
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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。 n7uD(cL  
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脚本代码 Z+4Oaf!  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. |c/rHEZ  
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Dim entity As T_ENTITY i=QhXCM  
Dim op As T_OPERATION ".<p R} qp  
Dim mat As T_MODELMATERIAL IpmREl$j  
Dim A As Double o2jB~}VMl  
Dim pupilDiam As Double BZshTP[`  
Dim eID As Long 9Wrclai  
Dim parID As Long -h`0v  
Dim count As Integer )^sfEYoA  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double x=N;>  
Dim tlens As Double, nlens As Double 9V\`{(R  
Dim curv As Double, conic As Double yqI|BF`  
Dim ok As Long ':$a6f &T  
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Sub Main B ;$8<  
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    '用户输入对话框 $7YLU{0  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ^umAfk5r?H  
        TextBox 220,21,40,21,.TextBox1 'default: 0 M-|2W~YU  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 rzLlM  
        OKButton 40,91,90,21 nQ~L.V  
        CancelButton 190,91,90,21 U$bM:d  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :tG5~sK  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Y,~]ecI  
    End Dialog N2J!7uoQ  
    Dim dlg As UserDialog `,[c??h  
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    ok = Dialog (dlg) /]&1XT?  
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    If ok=0 Then    'cancel button was pressed +Wc[$,vk  
        Print "Execution cancelled." 5{TF6  
        End W0kq>s4  
    End If xW~@V)OH  
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    'Assign accommodation and pupil diameter & use defaults if field left empty e: tp7w 4  
    If dlg.TextBox1 = "" Then S(l^TF  
        A = 0           'Default accommodation BW 7[JD  
    Else a\E]ueVD2j  
        A = CDbl(dlg.TextBox1) yI<'J^1C[  
    End If %BKTN@;7  
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    If dlg.TextBox2 = "" Then [~wcHE  
        pupilDiam = 4   'Default pupil diameter &YNhKm@"  
    Else f *vziC<m  
        pupilDiam = CDbl(dlg.TextBox2) VuW19-G  
    End If :9Pqy pd+  
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    Print " " U"]i.J1  
    Print "Accommodation = " & A & " Diopters" m>_'f{&u  
    Print "Pupil Diameter = " & pupilDiam & " mm" u 36;;z  
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    ' Calculate new parameters with accommodation +qec>ALAg  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness x;Q2/YZ#  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens I<U 1V<g  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens /'&LM\  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 76/%Py|  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens [geY:v_B  
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    tlens = 3.767 + 0.04*A                  'Lens thickness d?n~9_9e  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction x&d<IU)5  
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    'Adjust parameters to account for accommodation MNzq}(p  
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    '************************************************************************* bOdD:=f  
    'Aqueous thickness (Position of Lens) .B*)A.   
    '************************************************************************* B|&<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) g d-fJ._1  
    GetCustomElement eID, entity ITV}f#  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Fwr,e;Z  
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    ' Delete any shift(s) in z W=*\4B]  
    count = 0 X)~-MY*p  
    While GetOperationCount(eID)>count ?kSs7e>  
        GetOperation eID, count, op ]{hfM  
        If op.Type="ShiftZ" Then xjYFTb}!  
            DeleteOperation eID,count 'zaB5d~l  
            count=count-1 e+mD$(h  
        End If 7o<RvM  
        count=count+1 C1J'. !  
    Wend sIpK@BQ'  
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    'Set new shift in sXWMXQ3  
    op.Type = "ShiftZ" C6`8dn   
    op.val1 = taq -vyC,A  
    op.parent = parID jcj)9;n=!  
    AddOperation eID, op !v-(O"a  
    Print "Set aqueous humor thickness = " & taq-0.55 ]:;gk&P  
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    '************************************************************************* - M]C-$  
    'Radius and conic constant of anterior lens ;3!TOY"j;e  
    '************************************************************************* -[=`bHo  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) PJLA^eC7>  
    GetConic eID, entity, curv, conic 1gC=xMAT  
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    SetConic eID, entity, 1/Rant, CCant MAXdgL[]  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 4{Iz\:G:{/  
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    '************************************************************************* z)26Ahm TV  
    'Radius and conic constant of posterior lens L4!$bB~L-  
    '************************************************************************* =k'dbcfO$9  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) (.c?)_G,  
    GetConic eID, entity, curv, conic pr2d}~q4{  
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    SetConic eID, entity, 1/Rpost, CCpost iG;6e
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost C8?/$1|RL  
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    '************************************************************************* Pw")|85  
    'Lens thickness (Position of posterior lens surface) <AVpFy  
    '************************************************************************* @*oi1
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) JwO+Dd  
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    ' Delete any z-shift(s) ?$ 3=m)s  
    count = 0 a
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    While GetOperationCount(eID)>count [L8gG.wy  
        GetOperation eID, count, op f /jN$p  
        If op.Type="ShiftZ" Then c[5>kQ-nq  
            DeleteOperation eID,count 8S0)_L#S  
            count=count-1 K= 69z  
        End If n8?gZ` W  
        count=count+1  np~oF  
    Wend {M=tw  
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    'Set new z-shift Rzb] mM  
    op.Type = "ShiftZ" o5)U3U1|  
    op.val1 = tlens $o
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    op.parent = parID ^}WeBU  
    AddOperation eID, op W>"i0p  
    Print "Set lens thickness = " & tlens =$HzEzrw  
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    '************************************************************************* xTe?*  
    'Lens index of refraction p5*i d5
 
    '************************************************************************* P6X 4m(t  
    eID = FindMaterial( "Lens" ) '\9A78NV{;  
    GetModelMaterial eID, mat a9"Gg}h\  
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    mat.Nd = nlens c!I> _PD`&  
    SetModelMaterial eID, mat W4Eo1 E  
    Print "Set lens index of refraction = " & nlens
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    '************************************************************************* 40Du*5M  
    'Pupil diameter ~2pct
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    '************************************************************************* %1#5 7-  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) {
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    'Adjust pupil diameter (trimming volume inner hole) TfJB;  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 'j}%ec1  
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    ' Adjust pupil location to just in front of the lens #fa~^]EM]  
    parID = FindFullName( "Geometry.Arizona Eye" ) wZ*m  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 8zr)oQ:  
    count = 0 ?4xTA  
    While GetOperationCount(eID)>count #j@Su )+  
        GetOperation eID, count, op dLv\H&  
        If op.Type="ShiftZ" Then &359tG0@P  
            DeleteOperation eID,count C[~b6UP  
            count=count-1 W$,c]/u|  
        End If Ij#?r2Z%  
        count=count+1 5^tL#  
    Wend )'nGuL-w!i  
    op.Type = "ShiftZ" S9mj/GpL3  
    op.val1 = taq-0.01 Wvcj\2'yd  
    op.parent = parID wJ+"JQY.J+  
    AddOperation eID, op Zr`:A$  
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    Print "Set pupil diameter = " & pupilDiam D7 .R NXo  
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    'Update AZ Eye subassembly Description 3EAu#c@q"  
    eID = FindFullName( "Geometry.Arizona Eye" ) #SQFI;zj  
    GetEntity eID, entity !k&<  
    entity.Description = "Accommodation = " & A & "D" RM,r0Kv17Y  
    SetEntity eID, entity V7 c7(G  
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    Update H+-9R  
    Print "DONE!" 7Sr7a{  
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End Sub 2E;*kKw[  
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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： 7j{SCE;  
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Accommodation = 4 Diopters DaaLRMQ=  
Pupil Diameter = 4 mm ^c
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Set aqueous humor thickness = 2.81 m ?LOd9  
Set anterior lens radius = 10.4 and conic constant = -2.375869 )j!22tlL  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 _aq3G9C_  
Set lens thickness = 3.927 KUZ'$oKg  
Set lens index of refraction = 1.42672 ]{Iy<  
Set pupil diameter = 4 )mJl-u[0+  
DONE! r=<,`_@Y  

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