[技术]Arizona眼睛模型 [复制链接]

简介 265df Y9Pu  
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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。 'TezUBRAz  
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模型 ;/ WtO2  
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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。 :/d#U:I  
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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. 9boNB"h]T  
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光源 53@*GXzE  
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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。 m03;'Nj'7#  
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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。 ->$Do$  
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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。 0
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视网膜的散射 $x
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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。 @e3O=_m-  
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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。 DF P0WXbOE  
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脚本 %N=-i]+Id  
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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： z~UqA1r  
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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。 w0q.cj@nd  
余下的脚本计算与屈光度有关的所有参数。 "+~La{POc  
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分析 N/4`afiV.  
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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。 ~jQ|X?tR  
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脚本代码 {D={>0  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. h2QoBGL5  
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Dim entity As T_ENTITY &O/;YGEAB  
Dim op As T_OPERATION Cd?aC  
Dim mat As T_MODELMATERIAL o $7:*jU  
Dim A As Double XJ^dX]4  
Dim pupilDiam As Double 2"cUBFc1I  
Dim eID As Long rF'_YYpr>  
Dim parID As Long ds}:t.3}6  
Dim count As Integer U(4>e!  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double kc Q~}uFB  
Dim tlens As Double, nlens As Double IlJ!jq  
Dim curv As Double, conic As Double {ZP0%MD  
Dim ok As Long _lcx?IV  
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Sub Main Zi<Y?Vm/,O  
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    '用户输入对话框 V+G.TI P  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 KzZ|{!C  
        TextBox 220,21,40,21,.TextBox1 'default: 0 G6]W'Kk  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 }TI"j{(QJ  
        OKButton 40,91,90,21 Lq: !?)I  
        CancelButton 190,91,90,21 l|TiUjs  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 8vpB(VxV+  
        TextBox 220,49,40,21,.TextBox2 'default: 4 !6{; z/Hy  
    End Dialog U.g7'`Z<  
    Dim dlg As UserDialog }#]2u|G  
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    ok = Dialog (dlg) 0&XdCoIe  
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    If ok=0 Then    'cancel button was pressed ]06orBV  
        Print "Execution cancelled." %xv }  
        End ^Y[.-MJt+  
    End If )nE=H,U?y  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 4}-{sS}MP  
    If dlg.TextBox1 = "" Then StZ GKY[Q  
        A = 0           'Default accommodation as%@dUK?  
    Else `#J0@ -  
        A = CDbl(dlg.TextBox1) {HoeK>rd  
    End If t*J*?Ma  
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    If dlg.TextBox2 = "" Then L{PH8Xl_  
        pupilDiam = 4   'Default pupil diameter gkkT<hEV=  
    Else uknX py))  
        pupilDiam = CDbl(dlg.TextBox2) Lh`B5  
    End If `_"F7Czn  
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    Print " " qrdA4S  
    Print "Accommodation = " & A & " Diopters" 8);G'7O  
    Print "Pupil Diameter = " & pupilDiam & " mm" GS_+KR\  
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    ' Calculate new parameters with accommodation jgpSFb<9F  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness <cig^B{nX  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Hst]}g' .  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens oJ4OVfknD  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens A?)nLp&Y  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens vU(uu:U9  
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    tlens = 3.767 + 0.04*A                  'Lens thickness m+m2<|%x  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ECW=865jL  
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    'Adjust parameters to account for accommodation 1 >}x9D  
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    '************************************************************************* cpLlkR O  
    'Aqueous thickness (Position of Lens) ."X}A t  
    '************************************************************************* E!Ljq3iT`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) vIzREu|5  
    GetCustomElement eID, entity E^K<b7  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ue8"_N  
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    ' Delete any shift(s) in z :o"9x,  
    count = 0 (i2R1HCa  
    While GetOperationCount(eID)>count c
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        GetOperation eID, count, op 8GN_3pT  
        If op.Type="ShiftZ" Then v^0*{7N'  
            DeleteOperation eID,count Q%T[&A}3B  
            count=count-1 NpPuh9e{  
        End If iY[+BI:  
        count=count+1 ahoXQ8c:\}  
    Wend 'r0kX||  
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    'Set new shift in  WPu-P  
    op.Type = "ShiftZ" ovXU +8  
    op.val1 = taq d}:eLC  
    op.parent = parID Ea,L04K  
    AddOperation eID, op [C-4*qOaa2  
    Print "Set aqueous humor thickness = " & taq-0.55 ,%=SO 82W  
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    '************************************************************************* N e<D'-  
    'Radius and conic constant of anterior lens 14DHU  
    '************************************************************************* m8ApiGG  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) (&osR|/Tq  
    GetConic eID, entity, curv, conic *DUP$@}k  
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    SetConic eID, entity, 1/Rant, CCant w\}@+w3b~  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant d8C44q+ds  
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    '************************************************************************* qG)M8xk  
    'Radius and conic constant of posterior lens ABaK60.O[O  
    '************************************************************************* "h`oT4j5q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) :3N&&
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    GetConic eID, entity, curv, conic a\l?7Jr  
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    SetConic eID, entity, 1/Rpost, CCpost eYQPK?jo  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost I6e[K(7NY  
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    '************************************************************************* oniVC',  
    'Lens thickness (Position of posterior lens surface) tv 7"4$T  
    '************************************************************************* eHl)/='  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) $a#-d;  
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    ' Delete any z-shift(s) t9eEcqMg  
    count = 0 /$'|`jKsB  
    While GetOperationCount(eID)>count 259R5X<V  
        GetOperation eID, count, op 2 r';)8:  
        If op.Type="ShiftZ" Then oAprM Z7Y  
            DeleteOperation eID,count Y a/+|mv  
            count=count-1 0&$,?CL?  
        End If vrq5 +K&||  
        count=count+1 IQ\5!e  
    Wend i9+qU  
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    'Set new z-shift K6EG"Vv!  
    op.Type = "ShiftZ" S&J>15oWM`  
    op.val1 = tlens 5q,ZH6\ {  
    op.parent = parID $)#?4v<  
    AddOperation eID, op 7!g"q\s  
    Print "Set lens thickness = " & tlens -T=sY/O  
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    '************************************************************************* wx*03(|j;  
    'Lens index of refraction Zg&o][T  
    '************************************************************************* =&t]R? F  
    eID = FindMaterial( "Lens" ) ^xX1G_{  
    GetModelMaterial eID, mat 8pXqgIbmb  
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    mat.Nd = nlens gp<XTLJ@>  
    SetModelMaterial eID, mat J{U 171  
    Print "Set lens index of refraction = " & nlens ;DgQ8"f  
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    '************************************************************************* 
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    'Pupil diameter hw({>cH\  
    '************************************************************************* 3}2;*:p4Y  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Y[0mTL4IO  
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    'Adjust pupil diameter (trimming volume inner hole) lO
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" |,Kk#`lW<f  
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    ' Adjust pupil location to just in front of the lens : "^/?Sd  
    parID = FindFullName( "Geometry.Arizona Eye" ) 7g>|e  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 8ByNaXMO6  
    count = 0 l:+$Ks  
    While GetOperationCount(eID)>count BG8`B'i  
        GetOperation eID, count, op /:@)De(S  
        If op.Type="ShiftZ" Then wx8Qz,Z  
            DeleteOperation eID,count 8ly6CP+^B  
            count=count-1 W3gHzT?{  
        End If &Jd_@F#J  
        count=count+1 9qkJ<  
    Wend `ES+$O>  
    op.Type = "ShiftZ" y!c<P,Lt3f  
    op.val1 = taq-0.01 WP{U9YF2  
    op.parent = parID }g& KT!r  
    AddOperation eID, op 0Ibe~!EiQJ  
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    Print "Set pupil diameter = " & pupilDiam Q`!^EyRA:^  
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    'Update AZ Eye subassembly Description ${e5Ka  
    eID = FindFullName( "Geometry.Arizona Eye" ) BvS
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    GetEntity eID, entity E9\u^"GVO  
    entity.Description = "Accommodation = " & A & "D" :JU$6  
    SetEntity eID, entity PqMu2 e  
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    Update J1w,;T\55  
    Print "DONE!" Dy*K;e-+  
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End Sub d;nk>6<|  
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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： CfT(a!;Eox  
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Accommodation = 4 Diopters 9iV9q]($0  
Pupil Diameter = 4 mm DzIV5FG  
Set aqueous humor thickness = 2.81 |]~],  
Set anterior lens radius = 10.4 and conic constant = -2.375869 nErr&{C  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 .kTOG'K\e  
Set lens thickness = 3.927 Qxfds`4V9i  
Set lens index of refraction = 1.42672 1vYa&!  
Set pupil diameter = 4 ,$Cr9R&/  
DONE! H<tU[U=G