[技术]Arizona眼睛模型 [复制链接]

简介 .])X.7@x  
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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。 VUz+_)  
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模型 G2+ gEg  
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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。 B7'yc`)H  
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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. Z+[W@5q  
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光源 |`V=hqe{  
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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。 S2W@;XvV  
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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。 j'hWhLax  
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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。 y7GgTC/H  

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视网膜的散射 jpoNTl'  
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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。 82?LZ?!PD  
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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。 ,q{~lf-  
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脚本 0[N1SY\lj  
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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： wrK@1F9!  
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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。 fE3%$M[V7  
余下的脚本计算与屈光度有关的所有参数。 &n0Ag]$P  
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分析 kf9]nIo  
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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。 ^),t=!;p  
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脚本代码 YNKvR  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. y-gXGvZ  
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Dim entity As T_ENTITY T,PN6d  
Dim op As T_OPERATION }Gx@1)??  
Dim mat As T_MODELMATERIAL E]r<t#  
Dim A As Double ,pQ[e$u1  
Dim pupilDiam As Double 2:e7'}\D.  
Dim eID As Long EV
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Dim parID As Long &yOl}?u  
Dim count As Integer lk /Ke  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double , E$f"  
Dim tlens As Double, nlens As Double \pSRG=`  
Dim curv As Double, conic As Double 2d  YU  
Dim ok As Long Z J1
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Sub Main U:[CcN/~3  
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    '用户输入对话框 @uG/2'
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 x;LO{S4Z  
        TextBox 220,21,40,21,.TextBox1 'default: 0 B7oUS}M  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 UDnCHGq  
        OKButton 40,91,90,21 =5YbK1Q^  
        CancelButton 190,91,90,21 sN5Mm8~  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 HsT6 #K  
        TextBox 220,49,40,21,.TextBox2 'default: 4 w"O;: `|n  
    End Dialog Be<bBKQb  
    Dim dlg As UserDialog :&2%x  
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    ok = Dialog (dlg) 9F~5Ht  
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    If ok=0 Then    'cancel button was pressed ,_=LV  
        Print "Execution cancelled." PGVP0H+RV  
        End 7_rDNK@e  
    End If ,Z7
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    'Assign accommodation and pupil diameter & use defaults if field left empty lTtc#  
    If dlg.TextBox1 = "" Then aQzmobleep  
        A = 0           'Default accommodation niYD[Ra\xP  
    Else bQI.Qk  
        A = CDbl(dlg.TextBox1) 4! F$nmG)  
    End If tq=M 9c  
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    If dlg.TextBox2 = "" Then {Hvkn{{'  
        pupilDiam = 4   'Default pupil diameter 0}T56aD=!  
    Else j)juvat  
        pupilDiam = CDbl(dlg.TextBox2) wWq-zGH|&  
    End If Q trU_c2k  
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    Print " " z(>:LX"xz  
    Print "Accommodation = " & A & " Diopters" -OKXfN]  
    Print "Pupil Diameter = " & pupilDiam & " mm" gI@nE:(m  
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    ' Calculate new parameters with accommodation s=z$;1C  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Q^?$2ck=  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [d>2F  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens g|4>S<uC  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens T/J1 b-  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens A v;NQt8ut  
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    tlens = 3.767 + 0.04*A                  'Lens thickness *0r!eD   
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 
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    'Adjust parameters to account for accommodation {`Mb),G  
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    '************************************************************************* z@jKzy
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    'Aqueous thickness (Position of Lens) QPvWdjf#mM  
    '************************************************************************* _LWMz=U=J/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) '}F9f?  
    GetCustomElement eID, entity M[_Ptqjb  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 8Kn}o@Yd  
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    ' Delete any shift(s) in z EvA8<o  
    count = 0 NxF
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    While GetOperationCount(eID)>count *;lb<uLv  
        GetOperation eID, count, op iA'p!l|P  
        If op.Type="ShiftZ" Then Ku3NE-)  
            DeleteOperation eID,count !8RJHMX&  
            count=count-1 !Uhcjfq`e  
        End If _~*ba+
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        count=count+1 vQDR;T"]  
    Wend ^6!8)7b  
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    'Set new shift in CKU)wJ5t  
    op.Type = "ShiftZ" GB6(WAmr  
    op.val1 = taq fRzJiM{  
    op.parent = parID s:tWEgZk?  
    AddOperation eID, op vgr5j  
    Print "Set aqueous humor thickness = " & taq-0.55 !__^M3S,k  
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    '************************************************************************* b}hQU~,E  
    'Radius and conic constant of anterior lens fECmELd  
    '************************************************************************* |CBJ8],mT  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) z qd1G(tO  
    GetConic eID, entity, curv, conic QxBH{TG  
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    SetConic eID, entity, 1/Rant, CCant aZta%3`)  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant =Q!V6+}nY^  
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    '************************************************************************* `0R>r7f)H  
    'Radius and conic constant of posterior lens ,JJ1sf2A  
    '************************************************************************* AJP-7PPD  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 1flBA,6L  
    GetConic eID, entity, curv, conic uU+?:C  
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    SetConic eID, entity, 1/Rpost, CCpost }</"~Kw!  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Vz y )jf  
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    '************************************************************************* SQJ4}w>i  
    'Lens thickness (Position of posterior lens surface) U(<~("ocN  
    '************************************************************************* \6/!{D,  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ip*UujmNyR  
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    ' Delete any z-shift(s) }&EdA;/o_  
    count = 0 5N|hsfkx  
    While GetOperationCount(eID)>count lhF)$M  
        GetOperation eID, count, op #5^S@}e  
        If op.Type="ShiftZ" Then qqu]r  
            DeleteOperation eID,count -TyBb]  
            count=count-1 F Zk[w>{  
        End If m khp@^5  
        count=count+1 /8lmNA  
    Wend F[0w*i&u5  
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    'Set new z-shift F=;nWQ&  
    op.Type = "ShiftZ" v=YI%{tx)  
    op.val1 = tlens BM02k\%  
    op.parent = parID H*&!$s.  
    AddOperation eID, op W!a'KI'  
    Print "Set lens thickness = " & tlens iUf?MDE  
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    '************************************************************************* sTi3x)#xB  
    'Lens index of refraction +?0r%R%\  
    '************************************************************************* H$xUOqL  
    eID = FindMaterial( "Lens" ) c+UZ UgP  
    GetModelMaterial eID, mat <T$rvS  
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    mat.Nd = nlens ov'C0e+o  
    SetModelMaterial eID, mat snny! 0E\m  
    Print "Set lens index of refraction = " & nlens EB5^eNdL  
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    '************************************************************************* G}'\  
    'Pupil diameter 5g phza  
    '************************************************************************* *Di ;Gf@  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) F2$?[1^f  
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    'Adjust pupil diameter (trimming volume inner hole) ztV%W6  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ZJ|&t  
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    ' Adjust pupil location to just in front of the lens u%nhQ%  
    parID = FindFullName( "Geometry.Arizona Eye" ) C.hRL4+;Zm  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) b|g=&T:pp  
    count = 0 ?qczMck_  
    While GetOperationCount(eID)>count jp#/]>(9Z  
        GetOperation eID, count, op >F;
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        If op.Type="ShiftZ" Then v`~egE17  
            DeleteOperation eID,count ;)!);q+  
            count=count-1 DbH'Qs?z  
        End If Hr=?_Un"  
        count=count+1 -KiI&Q  
    Wend !]!J"!xg*  
    op.Type = "ShiftZ" UAtdRVi]M  
    op.val1 = taq-0.01 G8OnNI  
    op.parent = parID 8"J6(KS  
    AddOperation eID, op Uy{ZK*c8i  
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    Print "Set pupil diameter = " & pupilDiam W^1)7
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    'Update AZ Eye subassembly Description 3aEO9v,n  
    eID = FindFullName( "Geometry.Arizona Eye" ) a O(&<  
    GetEntity eID, entity h2ou]  
    entity.Description = "Accommodation = " & A & "D" O|0}m  
    SetEntity eID, entity Rj/y.g  
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    Update !R1OSVFp  
    Print "DONE!" ZNY),3?  
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End Sub hbTJXP~~?  
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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： hE}y/A[  
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Accommodation = 4 Diopters oJVpJA0IA  
Pupil Diameter = 4 mm 8POLp9>X  
Set aqueous humor thickness = 2.81 !v]~ut !p  
Set anterior lens radius = 10.4 and conic constant = -2.375869 @z7$1pl}  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 hg}R(.1K=  
Set lens thickness = 3.927 {$)pkhJ  
Set lens index of refraction = 1.42672 ,M$J yda  
Set pupil diameter = 4 -n`2>L1  
DONE! #i[V{J8.p