[技术]Arizona眼睛模型 [复制链接]

简介 VhGs/5  
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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。 G2{O9  
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模型 hg@}@Wq\)  
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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。 [P4$Khu$  
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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. YV4#%I!<  
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光源 CWo1.pVw  
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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。 [k$*4u>  
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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。 p{)
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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。 |%a4`
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视网膜的散射 x3ERCqTR  
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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。 e(F42;$$  
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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。 ]&~]#vB#  
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脚本 Syp"L;H8Em  
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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： ^[-el=oKn0  
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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。 Z4$cyL'
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余下的脚本计算与屈光度有关的所有参数。 d1@%W;qX!  
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分析 Wjh/M&,  
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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。 PfS:AIy  
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脚本代码 U'UQ|%5f  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Sw`RBN[ yo  
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Dim entity As T_ENTITY I|-p3g8\  
Dim op As T_OPERATION aq+Y7IR_  
Dim mat As T_MODELMATERIAL AB Xl  
Dim A As Double !|q<E0@w\  
Dim pupilDiam As Double zOEY6lAwI  
Dim eID As Long SjjI
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Dim parID As Long 1pv}]&X  
Dim count As Integer %u^JpC{E  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double MC((M,3L  
Dim tlens As Double, nlens As Double GT hL/M  
Dim curv As Double, conic As Double uJR%0E7!  
Dim ok As Long Kz<@x`0   
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Sub Main !}\4utHY  
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    '用户输入对话框 +#b:d=v!  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 z|7z
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        TextBox 220,21,40,21,.TextBox1 'default: 0 (\"k&O{  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 be5,U\&z  
        OKButton 40,91,90,21 "xMD,}+5$$  
        CancelButton 190,91,90,21 &bqT/H18  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 )5JU:jNy  
        TextBox 220,49,40,21,.TextBox2 'default: 4 .,~(%#Wl$  
    End Dialog f"7M^1)h2%  
    Dim dlg As UserDialog w#JJXXQI  
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    ok = Dialog (dlg) }~h'FHCC+  
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    If ok=0 Then    'cancel button was pressed \ 6EKgC1  
        Print "Execution cancelled." 2,vB'CAI  
        End t:JI!DR  
    End If ]J9cVp  
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    'Assign accommodation and pupil diameter & use defaults if field left empty >U1R.B7f  
    If dlg.TextBox1 = "" Then =.|J!
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        A = 0           'Default accommodation 2M)]!lYy  
    Else #U=X NU}k  
        A = CDbl(dlg.TextBox1) 9p 4"r^  
    End If H4OhIxK  
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    If dlg.TextBox2 = "" Then ~9F,%  
        pupilDiam = 4   'Default pupil diameter 4>^K:/y  
    Else 'tN25$=V&W  
        pupilDiam = CDbl(dlg.TextBox2) M,j(=hRJ/E  
    End If =5D nR  
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    Print " " !$A37j6  
    Print "Accommodation = " & A & " Diopters" {Z;jhR,  
    Print "Pupil Diameter = " & pupilDiam & " mm" #jpoHvth  
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    ' Calculate new parameters with accommodation #tt?!\8C  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness H?}[r)|(3i  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens =k3!RW'  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens o01kYBD  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens J" j.'.  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens IYWjHE+)d  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ""O"  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction $d+DDm1o  
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    'Adjust parameters to account for accommodation 9[v1h,L  
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    '************************************************************************* k&#a\OJ7u  
    'Aqueous thickness (Position of Lens) bG&"9b_c  
    '************************************************************************* U,/6;}  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) rA0,`}8\  
    GetCustomElement eID, entity A>VI{  
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    parID = FindFullName( "Geometry.Arizona Eye" ) -71dN0hWh  
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    ' Delete any shift(s) in z d{et8N  
    count = 0 ^n#1<K[E  
    While GetOperationCount(eID)>count @RD+xYm  
        GetOperation eID, count, op 0,*%vG?Q  
        If op.Type="ShiftZ" Then ;TQf5|R
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            DeleteOperation eID,count D+V7hpH-  
            count=count-1 @vgG1w  
        End If BhpOXqg  
        count=count+1 D0Z\Vvy  
    Wend s)voII&  
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    'Set new shift in r%wA&FQ8U  
    op.Type = "ShiftZ" AJt!!crs  
    op.val1 = taq CZ2`H[8  
    op.parent = parID B bhfG64  
    AddOperation eID, op HLQ"?OFlz  
    Print "Set aqueous humor thickness = " & taq-0.55 PYB+FcR6?n  
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    '************************************************************************* `Yc_5&"  
    'Radius and conic constant of anterior lens x+? 9C  
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ]!1OH |Ad  
    GetConic eID, entity, curv, conic y<W8Q<9  
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    SetConic eID, entity, 1/Rant, CCant F}Mhs17!|  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant hovGQHg  
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    '************************************************************************* \^+ILYO:$  
    'Radius and conic constant of posterior lens >YW\~T  
    '************************************************************************* y;" n9  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) XA0(f*  
    GetConic eID, entity, curv, conic JL}\*  
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    SetConic eID, entity, 1/Rpost, CCpost dYFzye  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost RKd  
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    '************************************************************************* (A k\Lm  
    'Lens thickness (Position of posterior lens surface) Qz<d~N  
    '************************************************************************* UIJx*  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) {TSY|D2  
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    ' Delete any z-shift(s) v=YK8fNi  
    count = 0 >Dm8m[76  
    While GetOperationCount(eID)>count {mYP<NBT  
        GetOperation eID, count, op @z6!a  
        If op.Type="ShiftZ" Then ;'T{
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            DeleteOperation eID,count g]mtFrP  
            count=count-1 FD7H@L5
 
        End If A)nW  
        count=count+1 n_[i0x7#  
    Wend Dkw%`(Oh/,  
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    'Set new z-shift @`u?bnx]e  
    op.Type = "ShiftZ" 3{raKM6F  
    op.val1 = tlens T*2C_oW  
    op.parent = parID %:6?Y%`*[  
    AddOperation eID, op ! U0z"  
    Print "Set lens thickness = " & tlens e]+OO g&  
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    '************************************************************************* )9"oL!2h  
    'Lens index of refraction U S
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    '************************************************************************* S[M4ukYK  
    eID = FindMaterial( "Lens" ) u.|~   
    GetModelMaterial eID, mat  ~m=EM;  
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    mat.Nd = nlens AG"l1wz  
    SetModelMaterial eID, mat W+>wu%[L  
    Print "Set lens index of refraction = " & nlens b=##A  
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    '************************************************************************* _v5t<_^N  
    'Pupil diameter Aw^yH+ae  
    '************************************************************************* Os),;W0w4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ;|ub!z9GG  
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    'Adjust pupil diameter (trimming volume inner hole) D=?{8'R'  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" @98;VWY\  
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    ' Adjust pupil location to just in front of the lens HB& &  
    parID = FindFullName( "Geometry.Arizona Eye" ) uK*|2U6t  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) /9ZcM]X B  
    count = 0 X
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    While GetOperationCount(eID)>count S0w> hr  
        GetOperation eID, count, op :Z`4j  
        If op.Type="ShiftZ" Then iv%w!3#  
            DeleteOperation eID,count  -/{af  
            count=count-1 )na&"b
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        End If y>o>WN<q  
        count=count+1 eMMx8E)B  
    Wend W^g'}}]T  
    op.Type = "ShiftZ" IhonnLLW  
    op.val1 = taq-0.01 h* .w"JO  
    op.parent = parID Q}vbm4)[  
    AddOperation eID, op n[k1np$7?6  
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    Print "Set pupil diameter = " & pupilDiam $3 8gs{+  
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    'Update AZ Eye subassembly Description @ RR\lZ  
    eID = FindFullName( "Geometry.Arizona Eye" ) >q( 5ir  
    GetEntity eID, entity q^Tis>*u6  
    entity.Description = "Accommodation = " & A & "D" us{nyil1  
    SetEntity eID, entity TQ9'76INb  
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    Update w+UV"\!G)Q  
    Print "DONE!" )s")y  
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End Sub E&2tBrAq  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： A3UQJ  
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Accommodation = 4 Diopters 'Ji+c  
Pupil Diameter = 4 mm cH"@d^"+q|  
Set aqueous humor thickness = 2.81 c~tAvDX  
Set anterior lens radius = 10.4 and conic constant = -2.375869 }B)jq`a?|\  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 }p'8w\C$  
Set lens thickness = 3.927 &4kM8Qh  
Set lens index of refraction = 1.42672 -J$g(sikt  
Set pupil diameter = 4 !Yh}H<w0  
DONE! (([I]q