[技术]Arizona眼睛模型 [复制链接]

简介 zWpJ\/k~  
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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。 ~K}iVX  
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模型 sS;6QkI"y  
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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。 j_*$Av
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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. B*7Y5_N  
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光源 >(mp$#+w  
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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。 &<6E*qM  
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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。 W1'F)5(?7  
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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。 %jz]s4u$5j  
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视网膜的散射 jGpSECs  
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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。 ITJ{]7N  
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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。 FJ0Ity4u6  
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脚本 p=%Vo@*]  
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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： :5Vk+s]8  
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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。 .nN=M>#/  
余下的脚本计算与屈光度有关的所有参数。 oV"d%ks  
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分析 {gh41G;n  
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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。 8K+(CS>xvO  
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脚本代码 a&:1W83  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. J{>9ctN  
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Dim entity As T_ENTITY
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Dim op As T_OPERATION 9R_2>BDn  
Dim mat As T_MODELMATERIAL (NfP2E|B  
Dim A As Double $!Z><&^/  
Dim pupilDiam As Double \H(r }D$u<  
Dim eID As Long vHR-mQUs  
Dim parID As Long ;:<z hO  
Dim count As Integer -7MR2)U  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double @z $,KUH  
Dim tlens As Double, nlens As Double TljN!nv]  
Dim curv As Double, conic As Double 5)h#NkA\J  
Dim ok As Long ,TeJx+z^  
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Sub Main 6cR}Mm9Hx3  
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    '用户输入对话框 PJd7t%m;  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 t][U`1>i  
        TextBox 220,21,40,21,.TextBox1 'default: 0 %8c <C  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 758`lfz=_  
        OKButton 40,91,90,21 6P,vGmR  
        CancelButton 190,91,90,21 j,<3[  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 .CJQ]ECl7p  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ^gw htnI  
    End Dialog ^RL#(O  
    Dim dlg As UserDialog '?| (QU:)F  
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    ok = Dialog (dlg) Mc8|4/<Z  
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    If ok=0 Then    'cancel button was pressed B$A`thQp  
        Print "Execution cancelled." eKRslMa  
        End &d,chb(  
    End If {u!Q=D$3  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 3[q&%Z.  
    If dlg.TextBox1 = "" Then Q?"o
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        A = 0           'Default accommodation )"(
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    Else '8%pEl^  
        A = CDbl(dlg.TextBox1) #+VH]7]  
    End If q%H`/~AYM  
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    If dlg.TextBox2 = "" Then \.0cA4)[$  
        pupilDiam = 4   'Default pupil diameter m(2(Caz{  
    Else }
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        pupilDiam = CDbl(dlg.TextBox2) Ufx^@%v  
    End If 2bJqZ,@  
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    Print " " N=2BrKb)o  
    Print "Accommodation = " & A & " Diopters" T >pz/7gb  
    Print "Pupil Diameter = " & pupilDiam & " mm" l'yX_`*Iq  
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    ' Calculate new parameters with accommodation )gX7qQ  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness CMQlxX?  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens A%Ov.~&\G  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens }Iyr u3M][  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens T/[8w  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens $x5,Oen  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Sf_q;Ws  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction #9R[%R7Nz  
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    'Adjust parameters to account for accommodation 5,Q3#f~!  
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    '************************************************************************* y#Cp Vm#!>  
    'Aqueous thickness (Position of Lens) KBUClx?  
    '************************************************************************* t>f61<27eB  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) S\\3?[!p  
    GetCustomElement eID, entity {"^LUw8fd  
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    parID = FindFullName( "Geometry.Arizona Eye" ) [Ej#NHs  
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    ' Delete any shift(s) in z $
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    count = 0 "-y2En  
    While GetOperationCount(eID)>count !b !C+ \v  
        GetOperation eID, count, op 4yZ'+\ +I  
        If op.Type="ShiftZ" Then For`
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            DeleteOperation eID,count sl5y1W/]]  
            count=count-1 |igr3p5Fw  
        End If PZT]H?  
        count=count+1 *\-R
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    Wend ZsgJ6 Y  
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    'Set new shift in \(4"kY_=  
    op.Type = "ShiftZ" .Lwp`{F/  
    op.val1 = taq Qkk3>{I  
    op.parent = parID SxX2+|0g`g  
    AddOperation eID, op j{U
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    Print "Set aqueous humor thickness = " & taq-0.55 |8QXjzH  

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    '************************************************************************* z%4E~u10  
    'Radius and conic constant of anterior lens J|O=w(  
    '************************************************************************* &-S;.}  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) =up!lg^M  
    GetConic eID, entity, curv, conic b]-~{' +  
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    SetConic eID, entity, 1/Rant, CCant }\iH~T6  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant \n&l  
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    '************************************************************************* ;s^br17z~  
    'Radius and conic constant of posterior lens 4R c_C0O  
    '************************************************************************* Czl4^STiC  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) WxLmzSz{xD  
    GetConic eID, entity, curv, conic vb&1 S  
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    SetConic eID, entity, 1/Rpost, CCpost Z(|@C(IL0\  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost N7wKaezE  
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    '************************************************************************* 0h3-;%  
    'Lens thickness (Position of posterior lens surface) tny^sG/'  
    '************************************************************************* hc2AGeZr  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) u{asKUce\  
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    ' Delete any z-shift(s) {vp|f~}zTw  
    count = 0 %Voq"}}N  
    While GetOperationCount(eID)>count f;PPB@ :`$  
        GetOperation eID, count, op wt@Qjbqd8  
        If op.Type="ShiftZ" Then `<?{%ja  
            DeleteOperation eID,count *X_-8 ^~  
            count=count-1 4s:S_Dw  
        End If h/LlH9S:!  
        count=count+1 \68x]q[  
    Wend i[+cNJ|$B0  
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    'Set new z-shift 2!w5eWl,  
    op.Type = "ShiftZ" ORc20NFy7  
    op.val1 = tlens GKk>;X-  
    op.parent = parID w!5@PJ)~U  
    AddOperation eID, op 8E/wUN,Lxj  
    Print "Set lens thickness = " & tlens hja;d1yH  
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    '************************************************************************* \{GBaMwG~  
    'Lens index of refraction x;w^&<hQ\  
    '************************************************************************* tM% f#O  
    eID = FindMaterial( "Lens" ) lDWg%pI+  
    GetModelMaterial eID, mat =V[e
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    mat.Nd = nlens *EB`~s  
    SetModelMaterial eID, mat yF _@^V  
    Print "Set lens index of refraction = " & nlens fr19C%{  
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    '************************************************************************* z_ 01*O  
    'Pupil diameter x!i(M>P  
    '************************************************************************* l>kREfHq!{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) %XQ!>BeE  
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    'Adjust pupil diameter (trimming volume inner hole) D)_67w|u|  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Q4[^JQsR2  
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    ' Adjust pupil location to just in front of the lens lQq&tz,  
    parID = FindFullName( "Geometry.Arizona Eye" ) 
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) fqY;>Z  
    count = 0 J^Mq4&  
    While GetOperationCount(eID)>count !D \u2h  
        GetOperation eID, count, op 8M~^/
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        If op.Type="ShiftZ" Then c*@
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            DeleteOperation eID,count r](%9Y  
            count=count-1 P@xb  
        End If e -yL  
        count=count+1 $*k9e^{S  
    Wend HT% =o}y  
    op.Type = "ShiftZ" rD?G7l<~>_  
    op.val1 = taq-0.01 lG>,&(  
    op.parent = parID T`7HQf ;  
    AddOperation eID, op jMAZ4M  
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    Print "Set pupil diameter = " & pupilDiam ~CRd0T[^  
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    'Update AZ Eye subassembly Description <aPbKDF~V  
    eID = FindFullName( "Geometry.Arizona Eye" ) P\nz;}nv  
    GetEntity eID, entity V9 J`LQ\0  
    entity.Description = "Accommodation = " & A & "D" kgl7l?|O  
    SetEntity eID, entity jI;iTKjB(  
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    Update Pc:5*H  
    Print "DONE!" ;dR4a@  
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End Sub -"9&YkN  
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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： zF([{5r[!)  
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Accommodation = 4 Diopters 2|re4  
Pupil Diameter = 4 mm V:Lq>rs#  
Set aqueous humor thickness = 2.81 |({ M8!BS  
Set anterior lens radius = 10.4 and conic constant = -2.375869 s{:l yp  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 F^/b!)
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Set lens thickness = 3.927 ~TvKMW6/#  
Set lens index of refraction = 1.42672 "rJJ~[Y  
Set pupil diameter = 4 A7c*qBt  
DONE! |Vj@;+/j