[技术]Arizona眼睛模型 [复制链接]

简介 eSW}H_3  
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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。 &4M,)Q (  
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模型 jCg4$),b  
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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。 G!Y7RjWD  
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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. q'Y)Y(d  
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光源 %T;VS-f  
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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。 jq|fIP  
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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。 '(3|hh)Tl  
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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。 OPv~1h<[  
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视网膜的散射 rC,ZRFF  
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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。 mP_c-qD |  
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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。 `mN5sq  
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脚本 v0pev;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： jF{\=&fU  
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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。 <VT|R~  
余下的脚本计算与屈光度有关的所有参数。 ~eekv5  
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分析 TM,Fab &  
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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。 nYnv.5  
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脚本代码 }>'1Qg  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. vUJQ<D  
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Dim entity As T_ENTITY ygqWy1C  
Dim op As T_OPERATION Mqmy*m[
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Dim mat As T_MODELMATERIAL 'L veCi_  
Dim A As Double 9XN/ wp  
Dim pupilDiam As Double \U HI%1^  
Dim eID As Long m Wh   
Dim parID As Long vu_ u\2d  
Dim count As Integer ]_:j+6i  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Q::_i"?c  
Dim tlens As Double, nlens As Double VCvFCyAz  
Dim curv As Double, conic As Double jd}-&DN  
Dim ok As Long 1u_< 1X3  
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Sub Main oP`Qyk  
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    '用户输入对话框 .J2tm2]"EZ  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 %O
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        TextBox 220,21,40,21,.TextBox1 'default: 0 <;zcz[~  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 >8w=Vlp  
        OKButton 40,91,90,21 [xl+/F7  
        CancelButton 190,91,90,21 %j;mDR95  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ko`KAU<T_  
        TextBox 220,49,40,21,.TextBox2 'default: 4 #Dl=K<I  
    End Dialog aHSl_[  
    Dim dlg As UserDialog N=TDywRI  
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    ok = Dialog (dlg) Y86mg7[U/  
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    If ok=0 Then    'cancel button was pressed ^wb$wtL('  
        Print "Execution cancelled." PsyXt5Dk  
        End ?0'db  
    End If aQL$?,  
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    'Assign accommodation and pupil diameter & use defaults if field left empty rLI);!^-  
    If dlg.TextBox1 = "" Then c7t.  
        A = 0           'Default accommodation ECLQqjB  
    Else Tu}?Q.pKo  
        A = CDbl(dlg.TextBox1) 3KN})
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    End If vQ1#Zgy  
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    If dlg.TextBox2 = "" Then rHD_sC*  
        pupilDiam = 4   'Default pupil diameter '\/|K  
    Else fzW!-  
        pupilDiam = CDbl(dlg.TextBox2) e c4vX  
    End If ?m:,hI  
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    Print " " U$=#yg2 :  
    Print "Accommodation = " & A & " Diopters" vALH!Kh  
    Print "Pupil Diameter = " & pupilDiam & " mm" Q
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    ' Calculate new parameters with accommodation oO&R3z
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 9{XV=a v  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens gEkH5|*Y  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 9<-7AN}Z  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens \jHIjFwQ  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 6~!l7HqO  
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    tlens = 3.767 + 0.04*A                  'Lens thickness _REAzxeS  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction t-VU&.Y  
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    'Adjust parameters to account for accommodation L_Lhmtm}m  
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    '************************************************************************* p\ _&  
    'Aqueous thickness (Position of Lens) <@J0 770  
    '************************************************************************* )6:1`&6  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) #Mrc!pT]xy  
    GetCustomElement eID, entity -5d^n\CDK  
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    parID = FindFullName( "Geometry.Arizona Eye" ) tDn:B$*}W,  
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    ' Delete any shift(s) in z F8d:7`lO@/  
    count = 0 Vl%UT@D|  
    While GetOperationCount(eID)>count Qk]^]I  
        GetOperation eID, count, op g&?{^4t]  
        If op.Type="ShiftZ" Then eR>|1s%^  
            DeleteOperation eID,count sz+%4T  
            count=count-1 w>TTu: 7  
        End If qcGsx2  
        count=count+1 G:i>MJbxT  
    Wend BY`vs+]XY  
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    'Set new shift in s&F& *5W  
    op.Type = "ShiftZ" ^!*nhs%  
    op.val1 = taq cN%@ nW0i  
    op.parent = parID I T?~`vi  
    AddOperation eID, op K7=>o*p  
    Print "Set aqueous humor thickness = " & taq-0.55 EClx+tz;`  
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    '************************************************************************* <KBS ;t="1  
    'Radius and conic constant of anterior lens )8*}-z  
    '************************************************************************* W=\4
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) kV@?Oj.&I,  
    GetConic eID, entity, curv, conic eNu]K,rT  
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    SetConic eID, entity, 1/Rant, CCant U%rq(`;  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Fuy"JmeR  
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    '************************************************************************* &.[I}KH|B  
    'Radius and conic constant of posterior lens =2e{T J/  
    '************************************************************************* <ZjT4><  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 9NeHN@D)  
    GetConic eID, entity, curv, conic '9@AhiNV  
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    SetConic eID, entity, 1/Rpost, CCpost xv~Sk2Z+d  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost =B0AG9Fz  
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    '************************************************************************* K@tELYb  
    'Lens thickness (Position of posterior lens surface) *=X61`0  
    '************************************************************************* sQBKzvFO3  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) @K\hgaQ  
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    ' Delete any z-shift(s) y 'Ah
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    count = 0 mjKu\7F  
    While GetOperationCount(eID)>count zx7A}rs3oX  
        GetOperation eID, count, op %>Mcme>(W  
        If op.Type="ShiftZ" Then oaG;i51!  
            DeleteOperation eID,count qyzH*#d=Cf  
            count=count-1 \1<8'at  
        End If TgA>(HcO  
        count=count+1 ){*9$486  
    Wend 'Lh nl3  
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    'Set new z-shift 4Q:r83#  
    op.Type = "ShiftZ" ~rlPS#]o  
    op.val1 = tlens #=N6[:,  
    op.parent = parID rlY n"3%  
    AddOperation eID, op QYc/f"9  
    Print "Set lens thickness = " & tlens @cc}[Uw4B  
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    '************************************************************************* [*1:?mD$  
    'Lens index of refraction ;:/C.%d  
    '************************************************************************* -?w3j9kk>  
    eID = FindMaterial( "Lens" ) y+h/jEbM</  
    GetModelMaterial eID, mat sKC(xO@L;`  
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    mat.Nd = nlens o_a'<7\#i  
    SetModelMaterial eID, mat kgd dq  
    Print "Set lens index of refraction = " & nlens 3hcWR'|  
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    '************************************************************************* #j'7\SV  
    'Pupil diameter Kx02 2rgDU  
    '************************************************************************* }Z)YK}_1  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) M[cAfu  
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    'Adjust pupil diameter (trimming volume inner hole) }=A+W2D  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" =R*IOJ  
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    ' Adjust pupil location to just in front of the lens ?}HZJ@:lB  
    parID = FindFullName( "Geometry.Arizona Eye" ) `
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 4lI&y<F  
    count = 0 NR"C@3kD]o  
    While GetOperationCount(eID)>count A@Cvx7X  
        GetOperation eID, count, op r`i.h ^2De  
        If op.Type="ShiftZ" Then KQ0f2?  
            DeleteOperation eID,count F~/~_9RJ  
            count=count-1 WW-}c;cnK  
        End If
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        count=count+1 BwAmNW&i  
    Wend 9'p*7o  
    op.Type = "ShiftZ" :s1.TQ;Y(  
    op.val1 = taq-0.01 h6?o)Q>N  
    op.parent = parID 3xgU=@!;  
    AddOperation eID, op \F
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    Print "Set pupil diameter = " & pupilDiam 1Se2@WR'  
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    'Update AZ Eye subassembly Description tMXNi
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    eID = FindFullName( "Geometry.Arizona Eye" ) O&sUPv  
    GetEntity eID, entity @2`nBtk  
    entity.Description = "Accommodation = " & A & "D" OS1f}<  
    SetEntity eID, entity &3SmTg %  
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    Update ExF6y#Y G<  
    Print "DONE!" }"[/BT5t  
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End Sub UG4I@@=  
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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： "LH3ZPD  
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Accommodation = 4 Diopters VxE;t
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Pupil Diameter = 4 mm kOC0d,  
Set aqueous humor thickness = 2.81 Pa"Kk9!o36  
Set anterior lens radius = 10.4 and conic constant = -2.375869 CZ>Ujw=&k  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 u95D0S  
Set lens thickness = 3.927 M"-.D;sa1  
Set lens index of refraction = 1.42672 ^1<i7
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Set pupil diameter = 4 -Rx;"J.H  
DONE! &8I*N6p:%/