[技术]Arizona眼睛模型 [复制链接]

简介 P7 h^!a/  
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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。 >qy$W4  
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模型 r1&eA%eh  
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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。  ^:^  
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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. 5(>ux@[qI:  
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光源 %N#A1   
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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。 !ra,HkU
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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。 \IhHbcF`d  
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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。 B)x^S >  
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视网膜的散射 jA? 7>"|  
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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。 _oHxpeM  
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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。 58t_j
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脚本 z
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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： %KPQ|^WE  
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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。 OYfRtfE  
余下的脚本计算与屈光度有关的所有参数。 gSHN,8. `  
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分析 R_=fH\c;  
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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。 w5vzj%6i  
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脚本代码 !iL6/  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. :<H4hYt2  
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Dim entity As T_ENTITY U1D;O}z~  
Dim op As T_OPERATION $k+XH+1CW  
Dim mat As T_MODELMATERIAL VHLt,?G  
Dim A As Double ?jsgBol  
Dim pupilDiam As Double `NyO|9/4
 
Dim eID As Long ctPT=i60  
Dim parID As Long /A-VT  
Dim count As Integer ;3iWV"&_A  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double tlYB'8bJY  
Dim tlens As Double, nlens As Double RJ-J/NhWyI  
Dim curv As Double, conic As Double iGBHlw;A  
Dim ok As Long L=5Y^f'aU  
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Sub Main TCK#bJ  
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    '用户输入对话框 "$3~):o  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 #
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        TextBox 220,21,40,21,.TextBox1 'default: 0 9fYof  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 TpYdIt9#>  
        OKButton 40,91,90,21 ($!g= 7  
        CancelButton 190,91,90,21 dFZh1*1  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9R:?vk4  
        TextBox 220,49,40,21,.TextBox2 'default: 4 )>N=B2P  
    End Dialog Z ?ATWCa  
    Dim dlg As UserDialog (rQ)0g@  
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    ok = Dialog (dlg) Icx)+Mq  
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    If ok=0 Then    'cancel button was pressed 'X
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        Print "Execution cancelled." N_p^DP  
        End Gw#z:gX2  
    End If S-79
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    'Assign accommodation and pupil diameter & use defaults if field left empty FX+^S?x.  
    If dlg.TextBox1 = "" Then `a8&7J(  
        A = 0           'Default accommodation {D
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    Else ;I>77gi`]  
        A = CDbl(dlg.TextBox1) +$R%Vbd  
    End If b(A;mt#N  
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    If dlg.TextBox2 = "" Then p]6/1&t="  
        pupilDiam = 4   'Default pupil diameter F~3 &@TWi  
    Else kZQ$Iv+^(  
        pupilDiam = CDbl(dlg.TextBox2) rUmnv%qTS  
    End If ,%KMi-w]q,  
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    Print " " 9abn6S(XpJ  
    Print "Accommodation = " & A & " Diopters" _<jccQ  
    Print "Pupil Diameter = " & pupilDiam & " mm" V_9>Z?  
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    ' Calculate new parameters with accommodation Y|<1|wG
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness h=_h,?_  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens tp b(.`G  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ^ |>)
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ScC!?rTW~7  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 9-?kamA  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Of{'A  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction LESF*rh=  
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    'Adjust parameters to account for accommodation ]K%D$x{+\  
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    '************************************************************************* `pXC= []B2  
    'Aqueous thickness (Position of Lens) r<.*:]L
 
    '************************************************************************* @3>nVa  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) po+1  
    GetCustomElement eID, entity |)Sx"B)  
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    parID = FindFullName( "Geometry.Arizona Eye" ) )h(yh50 B  
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    ' Delete any shift(s) in z zyFbu=d|O:  
    count = 0 Uf-`g>  
    While GetOperationCount(eID)>count I\ y>I?X  
        GetOperation eID, count, op XcQ'(  
        If op.Type="ShiftZ" Then ,6a }l;lv  
            DeleteOperation eID,count q\87<=9J  
            count=count-1 FZtILlw  
        End If |y7#D9m  
        count=count+1 ;AgXl%Q  
    Wend [es-&X07<  
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    'Set new shift in zXg/.
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    op.Type = "ShiftZ" {~:F1J~=  
    op.val1 = taq Gnmxp%&}P|  
    op.parent = parID -%)8=  
    AddOperation eID, op
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    Print "Set aqueous humor thickness = " & taq-0.55 (#k2S-5  
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    '************************************************************************* y-CVyl  
    'Radius and conic constant of anterior lens @y`7csbp  
    '************************************************************************* s&*s9F  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) u<{uUui}$v  
    GetConic eID, entity, curv, conic g3uI1]QXLg  
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    SetConic eID, entity, 1/Rant, CCant gL;tyf1P  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ni x1_Wo;  
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    '************************************************************************* FzGla})  
    'Radius and conic constant of posterior lens 5%6r,?/7KM  
    '************************************************************************* !ZlNPPrq}  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) FqK2[]8  
    GetConic eID, entity, curv, conic c\pPwG  
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    SetConic eID, entity, 1/Rpost, CCpost S}cm.,/w  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost i&?do{YQ)  
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    '************************************************************************* h47l;`kD-#  
    'Lens thickness (Position of posterior lens surface) *n%J#[e(  
    '************************************************************************* \ >(;t#>  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) (PN!k0Y  
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    ' Delete any z-shift(s) #5x[Z[m  
    count = 0 S?_ ;$Cn  
    While GetOperationCount(eID)>count sx0:g?F3j  
        GetOperation eID, count, op Tfl4MDZb  
        If op.Type="ShiftZ" Then pB;p\9A*q  
            DeleteOperation eID,count (_ElM>  
            count=count-1 KwiTnP!Dca  
        End If >_$DKY>$`  
        count=count+1 RT)*H>|  
    Wend =NzA2td  
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    'Set new z-shift O5Xu(q5+  
    op.Type = "ShiftZ" }]H_|V*f  
    op.val1 = tlens <99Xg_e  
    op.parent = parID kEE8cW
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    AddOperation eID, op }GCt)i_  
    Print "Set lens thickness = " & tlens \5_7!.  
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    '************************************************************************* QpPJ99B|  
    'Lens index of refraction mu/O\'5  
    '************************************************************************* [EJ[Gg0m  
    eID = FindMaterial( "Lens" ) j9za)G-J  
    GetModelMaterial eID, mat ;?i(WV}ee  
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    mat.Nd = nlens rnVh ]xJ  
    SetModelMaterial eID, mat 5u\si4BL{  
    Print "Set lens index of refraction = " & nlens ~Cj55S+  
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    '*************************************************************************  (Ia}]q  
    'Pupil diameter u9FXZK7  
    '************************************************************************* o~F @1  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) xh\{ dUPA  
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    'Adjust pupil diameter (trimming volume inner hole) 2Ek6YNx  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" F}A@H<?  
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    ' Adjust pupil location to just in front of the lens H85HL-{  
    parID = FindFullName( "Geometry.Arizona Eye" ) _{o=I?+]  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 31y=Ar""  
    count = 0 *Ri?mEv hF  
    While GetOperationCount(eID)>count /)xG%J7H  
        GetOperation eID, count, op p IXBJk  
        If op.Type="ShiftZ" Then JI}(R4uV  
            DeleteOperation eID,count
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            count=count-1 OedL?4  
        End If DA@YjebP'  
        count=count+1 85l 1
 
    Wend 4?X#d)L(  
    op.Type = "ShiftZ" AyKaazm]9  
    op.val1 = taq-0.01 B3'qmi<  
    op.parent = parID @M?N[LG  
    AddOperation eID, op =/"Of  
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    Print "Set pupil diameter = " & pupilDiam #:Di1I9<O7  
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    'Update AZ Eye subassembly Description H>e?FDs0*R  
    eID = FindFullName( "Geometry.Arizona Eye" ) 'N],d&fu^^  
    GetEntity eID, entity zqqpBwk#  
    entity.Description = "Accommodation = " & A & "D" 4em7PmT  
    SetEntity eID, entity =8j;!7p  
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    Update S'HM|&  
    Print "DONE!" G.O0*E2V  
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End Sub ;"&^ckP  
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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： cU5x8[2  
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Accommodation = 4 Diopters 9tXLC|yl?  
Pupil Diameter = 4 mm MwL' H<  
Set aqueous humor thickness = 2.81 tn;e PcU  
Set anterior lens radius = 10.4 and conic constant = -2.375869 '!Vn  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 xUPM-eF=  
Set lens thickness = 3.927 3~BL!e,  
Set lens index of refraction = 1.42672 %$I\\qq>{  
Set pupil diameter = 4 J}TS-j0  
DONE!  "=H7p3