[技术]Arizona眼睛模型 [复制链接]

简介 4IZlUJ?j+c  
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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。 1]j^d  
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模型 8W;2oQN7  
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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。 NvQ%J+  
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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. G
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光源 e2c1pgs&+  
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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。 #|Oj]bd(=  
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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。 cx{T  '1  
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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。 ^;r+W-MQ  
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视网膜的散射 *_1[[~Aw  
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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。 \gItZ}+c4}  
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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。 h%TLD[[/jr  
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脚本 6):Xzx,  
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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： L\e>B>u  
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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。 {U"^UuU]  
余下的脚本计算与屈光度有关的所有参数。 !8R@@,_v  
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分析 HI`q1m.  
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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。 \4{2eU  
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脚本代码 !tXZ%BP.u  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. d-B7["z,  
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Dim entity As T_ENTITY xx)-d,S  
Dim op As T_OPERATION G[h(xp?,l  
Dim mat As T_MODELMATERIAL `uo,__y  
Dim A As Double h2w}wsb0l  
Dim pupilDiam As Double {v` 2sB  
Dim eID As Long hoQ7).>  
Dim parID As Long S1J<9xqSQ8  
Dim count As Integer B$vr'U   
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 4woO;
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Dim tlens As Double, nlens As Double lA^+Flh  
Dim curv As Double, conic As Double 1J}8sG2`  
Dim ok As Long `f9gC3Hk  
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Sub Main ~AZWds(,N  
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    '用户输入对话框 2c(aO[%h9  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 @Uo6>-WF  
        TextBox 220,21,40,21,.TextBox1 'default: 0 L]d-33.c!H  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 "D][e'  
        OKButton 40,91,90,21 &dR=?bz-A  
        CancelButton 190,91,90,21 r$(~j^<s  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Hkd^-=]]no  
        TextBox 220,49,40,21,.TextBox2 'default: 4 hhI)' $  
    End Dialog (Yb[)m>fQ}  
    Dim dlg As UserDialog wy,p&g)>  
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    ok = Dialog (dlg) ',I0ih#Ls  
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    If ok=0 Then    'cancel button was pressed ][;G=oCT  
        Print "Execution cancelled." RA O`i>
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        End 9z>z3,ftN  
    End If ]N{0:Va@D  
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    'Assign accommodation and pupil diameter & use defaults if field left empty mQ~:Y
  
    If dlg.TextBox1 = "" Then NbRn*nb/T  
        A = 0           'Default accommodation nBItO~l  
    Else $s5a G)?7  
        A = CDbl(dlg.TextBox1) E=]4ctK  
    End If *|#T8t,}n  
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    If dlg.TextBox2 = "" Then gI]GUD-  
        pupilDiam = 4   'Default pupil diameter >vbY<HGt  
    Else \ I`p|&vG  
        pupilDiam = CDbl(dlg.TextBox2) ^:=f^N=^  
    End If 9uk<&nqx  
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    Print " " ``U^COD  
    Print "Accommodation = " & A & " Diopters" 13hE}g;.  
    Print "Pupil Diameter = " & pupilDiam & " mm" XT>.`, sv  
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    ' Calculate new parameters with accommodation Zw1U@5}A  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness rN)V[5R#M  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [K/m  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens eLD|A=X?  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens *f%>YxF  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens N_pUv  
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    tlens = 3.767 + 0.04*A                  'Lens thickness nC1zzFFJ  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \!]hU%Un  
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    'Adjust parameters to account for accommodation Iq7}   
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    '************************************************************************* }~K`/kvs
 
    'Aqueous thickness (Position of Lens) \b=Pj!^gwb  
    '************************************************************************* WI> P-D  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) .iMN,+qP  
    GetCustomElement eID, entity Cqii}  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 2dp>Z",  
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    ' Delete any shift(s) in z B.r4$:+jb2  
    count = 0 uj>WgU  
    While GetOperationCount(eID)>count 1NQbl+w#I  
        GetOperation eID, count, op $$APgj"|<  
        If op.Type="ShiftZ" Then tVrY3)c  
            DeleteOperation eID,count 7\]E~/g  
            count=count-1 DGW+>\G  
        End If =@2FX&&E_  
        count=count+1 (+uj1z^  
    Wend xv{O^Ie+S  
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    'Set new shift in =@,Q Dm]L  
    op.Type = "ShiftZ" m7EcnQf  
    op.val1 = taq -HSs^d
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    op.parent = parID r(d':LV  
    AddOperation eID, op g~V+4+  
    Print "Set aqueous humor thickness = " & taq-0.55 Z6\+  
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    '************************************************************************* 7dsefNPb  
    'Radius and conic constant of anterior lens WE]e m >  
    '************************************************************************* KL$bqgc(p3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 2(5ebe[
 
    GetConic eID, entity, curv, conic HbP!KVHyk1  
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    SetConic eID, entity, 1/Rant, CCant m]
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !EUan  
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    '************************************************************************* .ERO|$fv  
    'Radius and conic constant of posterior lens oh#\]c\f  
    '************************************************************************* bR@p<;G|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ctE\ q  
    GetConic eID, entity, curv, conic ()&
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    SetConic eID, entity, 1/Rpost, CCpost iq( )8nxi  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost r.7$&BCng  
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    '************************************************************************* jw-0M1B  
    'Lens thickness (Position of posterior lens surface) lHgs;>U$  
    '************************************************************************* quY:pqG38q  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) {G?N E  
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    ' Delete any z-shift(s) w$JvB
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    count = 0 l;o1 d-n]  
    While GetOperationCount(eID)>count >EY3/Go>  
        GetOperation eID, count, op D!7`CH+  
        If op.Type="ShiftZ" Then A}eOFu`  
            DeleteOperation eID,count 95el'K[R  
            count=count-1 I? ,>DHUX  
        End If lNSLs"x^  
        count=count+1 M4as  
    Wend |sJSN.8  
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    'Set new z-shift bhniB@<  
    op.Type = "ShiftZ" '],J$ge  
    op.val1 = tlens >2~=)L  
    op.parent = parID ]+X@ 7  
    AddOperation eID, op a+n0|CvF  
    Print "Set lens thickness = " & tlens Gz.|]:1  
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    '************************************************************************* AK@9?_D  
    'Lens index of refraction SL5Ai/X0N  
    '************************************************************************* | Bi!  
    eID = FindMaterial( "Lens" ) &jmRA';sK  
    GetModelMaterial eID, mat .V,@k7U,V  
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    mat.Nd = nlens d3xmtG {i  
    SetModelMaterial eID, mat J{Q|mD=  
    Print "Set lens index of refraction = " & nlens 0Vx.nUQ
  
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    '************************************************************************* rW$[DdFA5{  
    'Pupil diameter 4<BjC[@~Z{  
    '************************************************************************* .SWlp2!M5  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) <7~'; K  
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    'Adjust pupil diameter (trimming volume inner hole) 7Op>i,HZk\  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 5 sX+~Q  
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    ' Adjust pupil location to just in front of the lens uA<
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    parID = FindFullName( "Geometry.Arizona Eye" ) Hl,W=2N  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) m;,N)<~  
    count = 0 1jcouD5?H  
    While GetOperationCount(eID)>count E 7{U|\  
        GetOperation eID, count, op V-BiF>+  
        If op.Type="ShiftZ" Then ;=MU';o  
            DeleteOperation eID,count y+NN< EY@  
            count=count-1 *}*FX+px)  
        End If A*\.NTM  
        count=count+1 ln6d<; M5  
    Wend F1yqxWHeo  
    op.Type = "ShiftZ" ,>%}B3O:Y=  
    op.val1 = taq-0.01 Vh4X%b$TV  
    op.parent = parID lgk.CC  
    AddOperation eID, op lNYt`xp  
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    Print "Set pupil diameter = " & pupilDiam $|@ (  
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    'Update AZ Eye subassembly Description "]} bFO7C  
    eID = FindFullName( "Geometry.Arizona Eye" ) ?Wlb3;  
    GetEntity eID, entity T{-CkHf9Q  
    entity.Description = "Accommodation = " & A & "D" bE !GJZ  
    SetEntity eID, entity ?82xdpg  
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    Update |IzPgC  
    Print "DONE!" rD3v$B
 
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End Sub 8.O8No:'&  
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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： 3`DQo%<  
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Accommodation = 4 Diopters s;ls qQk  
Pupil Diameter = 4 mm H&-zZc4\  
Set aqueous humor thickness = 2.81 P/W XaE4  
Set anterior lens radius = 10.4 and conic constant = -2.375869 T4Pgbop  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 yb\_zE\  
Set lens thickness = 3.927 GjvOM y  
Set lens index of refraction = 1.42672 ?^al9D[:lz  
Set pupil diameter = 4 UM"- nZ>[  
DONE! 0AL=S$B)