[技术]Arizona眼睛模型 [复制链接]

简介 )} I>"n  
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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。 D*Cn!v$  
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模型 Nq$Xe~,*  
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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。 :sf(=Y.qA  
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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. [VD)DO5  
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光源 x&ngCB@O  
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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。 _'W en  
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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。 8&g`Uy/b  
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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。 ([mC!d@a  
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视网膜的散射 h#Z5vH  
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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。 P?.j wI  
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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。 U2lDTRt  
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脚本 -naj.omG|  
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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： rJ@yOed["b  
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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{)|z-n  
余下的脚本计算与屈光度有关的所有参数。 /]_a\x5Ss  
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分析 `T-lBwH  
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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。 ^:(:P9h  
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脚本代码 bG'"l qn  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 8,5H^Bi  
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Dim entity As T_ENTITY .y)Y20=o!  
Dim op As T_OPERATION M)<4|x  
Dim mat As T_MODELMATERIAL >z,SN  
Dim A As Double A#WvN>  
Dim pupilDiam As Double S~Z`?qHWh  
Dim eID As Long &3o[^_Ti  
Dim parID As Long W@T_-pTCjK  
Dim count As Integer !,I530eh7  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Q9\6Pn ]T  
Dim tlens As Double, nlens As Double :epjJ1mW  
Dim curv As Double, conic As Double ftw@nQNU  
Dim ok As Long XW^Sw;[efZ  
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Sub Main ",pN.<F9O  
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    '用户输入对话框  .Lvg $d  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 )(aj  
        TextBox 220,21,40,21,.TextBox1 'default: 0 -t5DcEAb$  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Uc?4!{$X  
        OKButton 40,91,90,21 |, Lp1  
        CancelButton 190,91,90,21 MV~-']2u  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 PGj?`y4  
        TextBox 220,49,40,21,.TextBox2 'default: 4 *1>zE>
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    End Dialog C4
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    Dim dlg As UserDialog /.[;u1z"^  
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    ok = Dialog (dlg) xpzQ"'be  
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    If ok=0 Then    'cancel button was pressed c^$+=-G{fd  
        Print "Execution cancelled." Y(`# J[  
        End Z6`oGFq  
    End If =>_k;x  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 1l~(J:DT  
    If dlg.TextBox1 = "" Then c'678!r9 P  
        A = 0           'Default accommodation og! d  
    Else hZudVBn  
        A = CDbl(dlg.TextBox1) ? 7H'#l  
    End If y*AB=d^  
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    If dlg.TextBox2 = "" Then W$l%= /  
        pupilDiam = 4   'Default pupil diameter <gdKuoY  
    Else Gz>M`M`[
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        pupilDiam = CDbl(dlg.TextBox2) }`SXUM_sD`  
    End If @ZD/y%e  
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    Print " " v+3-o/G7  
    Print "Accommodation = " & A & " Diopters" L&i_  
    Print "Pupil Diameter = " & pupilDiam & " mm" bay7%[BLB  
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    ' Calculate new parameters with accommodation =36e&z-#  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness EK-Qa<[|  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens $?dAO}f3O)  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens v7L}I[f  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens #ilU(39e  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens T.=du$  
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    tlens = 3.767 + 0.04*A                  'Lens thickness icX$<lD  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction  h,D6MP  
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    'Adjust parameters to account for accommodation xyoh B#'W  
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    '************************************************************************* Fe4QWB6\U  
    'Aqueous thickness (Position of Lens) T}?vp~./   
    '************************************************************************* T%Vg0Y)P;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) &|:T+LVv$+  
    GetCustomElement eID, entity s 4Mi9h_  
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    parID = FindFullName( "Geometry.Arizona Eye" ) K-xmLEu  
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    ' Delete any shift(s) in z f>u{e~Q,  
    count = 0 =uYz4IDB  
    While GetOperationCount(eID)>count "/EE$eU  
        GetOperation eID, count, op a-`OE"  
        If op.Type="ShiftZ" Then 4HG@moYn@  
            DeleteOperation eID,count Ozygr?*X  
            count=count-1 4E Hb  
        End If .?TPoqs7Z  
        count=count+1 Kp|#04]  
    Wend I)
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    'Set new shift in Z
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    op.Type = "ShiftZ" ?|i6]y=D  
    op.val1 = taq n&. bs7N2  
    op.parent = parID =
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    AddOperation eID, op [n`SXBi+n  
    Print "Set aqueous humor thickness = " & taq-0.55 5 i1T?  
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    '************************************************************************* )8c`o  
    'Radius and conic constant of anterior lens 6zQ {Y"0  
    '************************************************************************* I6]|dA3G  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) }T?MWcG4  
    GetConic eID, entity, curv, conic m_%1IJ  
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    SetConic eID, entity, 1/Rant, CCant seFug  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant X^tVq..0  
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    '************************************************************************* %j].' ;  
    'Radius and conic constant of posterior lens |~! R5|Q  
    '************************************************************************* 8F$b/Z  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 5G~;g  
    GetConic eID, entity, curv, conic $jYwV0  
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    SetConic eID, entity, 1/Rpost, CCpost K8dlECy  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost !b O8apn  
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    '************************************************************************* 4>4*4!KR}  
    'Lens thickness (Position of posterior lens surface) Nxu10  
    '************************************************************************* E"Z9 NDgl#  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) B|IQ/g?  
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    ' Delete any z-shift(s) ?VMj;+'tr  
    count = 0 p}KZ#"Q  
    While GetOperationCount(eID)>count _tR%7%3*  
        GetOperation eID, count, op &jgpeFiiC  
        If op.Type="ShiftZ" Then YyX/:1 sg>  
            DeleteOperation eID,count '676\2.  
            count=count-1 l`2X'sw[/  
        End If eNlE]W,=  
        count=count+1 6 ^X$;  
    Wend 5/Ng!bW  
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    'Set new z-shift =*.Nt*;;  
    op.Type = "ShiftZ" %/dYSC  
    op.val1 = tlens }>JFO:v&  
    op.parent = parID D4yJ:ATO&  
    AddOperation eID, op [y y D-  
    Print "Set lens thickness = " & tlens ce{GpmW  
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    '************************************************************************* UA[2R1}d  
    'Lens index of refraction c=l 3Sz?  
    '************************************************************************* L!E/ )#{  
    eID = FindMaterial( "Lens" ) zCD?5*7  
    GetModelMaterial eID, mat a z 7Vy-  
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    mat.Nd = nlens 5y! 4ny_  
    SetModelMaterial eID, mat w>T1
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    Print "Set lens index of refraction = " & nlens rt%.IQdY  
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    '************************************************************************* 05:`(vl  
    'Pupil diameter FxSBxz<N-A  
    '************************************************************************* YzU(U_g
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) >Fm}s,  
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    'Adjust pupil diameter (trimming volume inner hole) E%\iNU!  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"
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    ' Adjust pupil location to just in front of the lens BVxg=7%St  
    parID = FindFullName( "Geometry.Arizona Eye" ) lIO.LF3  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) $}<+~JpGfP  
    count = 0 N<+ ><>9  
    While GetOperationCount(eID)>count 3%m2$\  
        GetOperation eID, count, op s+>""yi
 
        If op.Type="ShiftZ" Then ]#N2:ych  
            DeleteOperation eID,count zpr`  
            count=count-1 k oo`JHC  
        End If U9IP`)z_5t  
        count=count+1 qUSImgg  
    Wend In|:6YDL&  
    op.Type = "ShiftZ" $rDeI-)S  
    op.val1 = taq-0.01 _3h(R`VdWO  
    op.parent = parID o)'T#uK  
    AddOperation eID, op K1Nhz'^=D  
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    Print "Set pupil diameter = " & pupilDiam JxI}#iA  
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    'Update AZ Eye subassembly Description DF'-dh</*  
    eID = FindFullName( "Geometry.Arizona Eye" ) Eom|*2vWIC  
    GetEntity eID, entity $78fR8|r-  
    entity.Description = "Accommodation = " & A & "D" F"j0;}+N  
    SetEntity eID, entity ;rpjXP
 
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    Update bC?uyo"  
    Print "DONE!" #EAP<h  
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End Sub 7*y_~H  

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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： st(l85  
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Accommodation = 4 Diopters CQ2{5  
Pupil Diameter = 4 mm 4)+MvKxjS  
Set aqueous humor thickness = 2.81 :kqJ~  
Set anterior lens radius = 10.4 and conic constant = -2.375869 (E59)z -  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 < i*v  
Set lens thickness = 3.927 r#*kx#"  
Set lens index of refraction = 1.42672 j[gX"PdQ  
Set pupil diameter = 4 "T@9]>6.f  
DONE! q5?g/-_0[