[技术]Arizona眼睛模型 [复制链接]

简介 L9GLjRp-  
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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。 >O'\ jp}$l  
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模型 P/%7kD@5;  
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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。 OO:S2-]Y>e  
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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. g4K+AK  
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光源 $)lkiA&;  
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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。 ,Qj G|P  
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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。 !)s(Lv%]  
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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。 L.n@;*  
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视网膜的散射 _O`prX.:B0  
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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。 kmQ:wf:  
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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。 E=NjWO  
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脚本 UZdnsG7  
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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： \!ZA#7  
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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。 y?sz&*:  
余下的脚本计算与屈光度有关的所有参数。 H_xHoCLI  
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分析 }8'_M/u\  
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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。 #}A"yo  
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脚本代码 h#1:ypA6l  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. P~7(x7/7~  
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Dim entity As T_ENTITY fTxd8an{  
Dim op As T_OPERATION [Rj4=qq=  
Dim mat As T_MODELMATERIAL bTs2$81[  
Dim A As Double (Mc{nFqS  
Dim pupilDiam As Double tI^91I  
Dim eID As Long GRc)3 2,  
Dim parID As Long V_i&@<J  
Dim count As Integer \8(Je"S  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double EU(e5vO  
Dim tlens As Double, nlens As Double PYQ0&;z  
Dim curv As Double, conic As Double ?e%*q^~Cu  
Dim ok As Long 2Z; !N37U  
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Sub Main kEh9J>|M  
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    '用户输入对话框 yLRe'5#m  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ,Uh
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        TextBox 220,21,40,21,.TextBox1 'default: 0 <?41-p-;  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 1 |z4]R,<  
        OKButton 40,91,90,21 4KH'S'eR  
        CancelButton 190,91,90,21 7-3  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 S @[]znH  
        TextBox 220,49,40,21,.TextBox2 'default: 4 gj|5"'g%  
    End Dialog $YJ 1
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    Dim dlg As UserDialog ?0)K[Kd'Y  
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    ok = Dialog (dlg) KKwM\  
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    If ok=0 Then    'cancel button was pressed 8kKL=  
        Print "Execution cancelled." NG3?OAQTw  
        End 8{Wl  
    End If {?
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    'Assign accommodation and pupil diameter & use defaults if field left empty _J*l,]}S  
    If dlg.TextBox1 = "" Then A}"|_&E  
        A = 0           'Default accommodation nLL2/!'n  
    Else "%K'~"S#Q,  
        A = CDbl(dlg.TextBox1) #-%D(=&I  
    End If -.Wwo(4  
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    If dlg.TextBox2 = "" Then @de  ZZ  
        pupilDiam = 4   'Default pupil diameter @Ez>?#z  
    Else >QDyG8*  
        pupilDiam = CDbl(dlg.TextBox2) V 2Xv)  
    End If M.
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    Print " " S))B^).0-  
    Print "Accommodation = " & A & " Diopters" :TVo2Zm[@  
    Print "Pupil Diameter = " & pupilDiam & " mm" Qfp4}a=  
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    ' Calculate new parameters with accommodation a<*+rG
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness E2l"e?AN~  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Uhu?G0>O  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \[!{tbK`2  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Wrbv<8}%c  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens kM-8%a2i  
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    tlens = 3.767 + 0.04*A                  'Lens thickness */~|IbZ`o  

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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction '`tFZfT  
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    'Adjust parameters to account for accommodation "r`2V-E  
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    '************************************************************************* g3s5ra[
 
    'Aqueous thickness (Position of Lens) Q?hf2iw  
    '************************************************************************* f2tCB1[D+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) TlO=dLR7d  
    GetCustomElement eID, entity ZYY`f/qi  
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    parID = FindFullName( "Geometry.Arizona Eye" ) nUs=PD3)  
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    ' Delete any shift(s) in z t.&JPTK-H  
    count = 0 C
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    While GetOperationCount(eID)>count Ww~C[8q  
        GetOperation eID, count, op LD{~6RP  
        If op.Type="ShiftZ" Then r:rPzq1  
            DeleteOperation eID,count ?gu!P:lZS  
            count=count-1 fx:vhEX  
        End If -~sW@u)O  
        count=count+1 >q')%j  
    Wend 2./z6jXW_  
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    'Set new shift in ']Czn._  
    op.Type = "ShiftZ" O*2{V]Y @  
    op.val1 = taq .R)Ho4CE  
    op.parent = parID ; p+C0!B2  
    AddOperation eID, op FYNUap,A  
    Print "Set aqueous humor thickness = " & taq-0.55 &]f8Xd  
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    '************************************************************************* "tbKbFn9  
    'Radius and conic constant of anterior lens Hl}m*9<9us  
    '************************************************************************* H[R6 ?H@$F  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) aA%x9\Y  
    GetConic eID, entity, curv, conic U_9|ED:  
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    SetConic eID, entity, 1/Rant, CCant E-X02A  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant F)l1%FCm  
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    '************************************************************************* -R$Q`Xw  
    'Radius and conic constant of posterior lens yqJ>Z%)hf  
    '************************************************************************* e*<pO@Uy  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Ug[0l)  
    GetConic eID, entity, curv, conic #BEXj<m+J  
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    SetConic eID, entity, 1/Rpost, CCpost cri-u E?  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost
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    '************************************************************************* !~mPxGY  
    'Lens thickness (Position of posterior lens surface) FIJ]`  
    '************************************************************************* RR`\q>|  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) GB*^?Ii  
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    ' Delete any z-shift(s) bHDZ=Ik  
    count = 0 Kk\
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    While GetOperationCount(eID)>count %@I= $8j  
        GetOperation eID, count, op Pr/q?qZY  
        If op.Type="ShiftZ" Then vN6)Szim  
            DeleteOperation eID,count r"7 !J[u  
            count=count-1 +nYF9z2  
        End If \  6Y%z  
        count=count+1 1LmbXH]%  
    Wend P$__c{1\  
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    'Set new z-shift "NV~lJS%  
    op.Type = "ShiftZ" "v'%M({  
    op.val1 = tlens JWQd6JQ_~V  
    op.parent = parID =EHKu|rX~  
    AddOperation eID, op ypvz&SzIh  
    Print "Set lens thickness = " & tlens )C#>@W
  
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    '************************************************************************* >b*}Td~J  
    'Lens index of refraction L3S29-T  
    '************************************************************************* UE/iq\a>  
    eID = FindMaterial( "Lens" ) Q-e(>=Gv_  
    GetModelMaterial eID, mat
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    mat.Nd = nlens cS",Bw\  
    SetModelMaterial eID, mat . N5$s2t  
    Print "Set lens index of refraction = " & nlens 1mv8[^pF  
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    '************************************************************************* "6WE6zq  
    'Pupil diameter F@xKL;'N74  
    '************************************************************************* 1?y QjW,  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) #!jwn^yq  
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    'Adjust pupil diameter (trimming volume inner hole) 8$ _8Yva"e  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" .|LY /q\A  
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    ' Adjust pupil location to just in front of the lens c*V/2" 5  
    parID = FindFullName( "Geometry.Arizona Eye" ) ?[8s`caK.  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 3Q#3S  
    count = 0 \lpvRZ\L&g  
    While GetOperationCount(eID)>count \2[  
        GetOperation eID, count, op JIMi~mEiN  
        If op.Type="ShiftZ" Then Mgux(5`;  
            DeleteOperation eID,count iB*1Yy0DC  
            count=count-1 p=dM2>  
        End If E>1%7" i<  
        count=count+1 jGn2QL  
    Wend -aM7>YR  
    op.Type = "ShiftZ" $*+`;PG-  
    op.val1 = taq-0.01 vn.j>;E'  
    op.parent = parID f!}e*oX  
    AddOperation eID, op Uclta  
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    Print "Set pupil diameter = " & pupilDiam ej]>*n  
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    'Update AZ Eye subassembly Description Z7=k$e  
    eID = FindFullName( "Geometry.Arizona Eye" ) aB~=WWLR\  
    GetEntity eID, entity 7eyx cr;z  
    entity.Description = "Accommodation = " & A & "D" 7HQ|3rt  
    SetEntity eID, entity *qw//W  
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    Update k mX:~KMb  
    Print "DONE!" CQET  
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End Sub ,M9Hdm
 
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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： I~>Ye<g#  
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Accommodation = 4 Diopters e`t-:~'  
Pupil Diameter = 4 mm i/q1>  
Set aqueous humor thickness = 2.81 FrQRHbp3  
Set anterior lens radius = 10.4 and conic constant = -2.375869 2~!+EH  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 $McbVn)~f  
Set lens thickness = 3.927 LVNJlRK  
Set lens index of refraction = 1.42672 pa6-3c  
Set pupil diameter = 4 Qr]`flQ8  
DONE! _iZ9Ch\