[技术]Arizona眼睛模型 [复制链接]

简介 1(@$bsgu2  
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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。 &%rM|  
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模型 fJlNxdVr  
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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。 di/QJrw  
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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. Tc(=J7*r&  
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光源 OK]
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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。 }@q/.Ct! x  
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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。 |OJWQU![by  
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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。 +vy fhw4  
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视网膜的散射 o#p%IGG`  
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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。 bVzi^R"  
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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。 bVUIeX'  
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脚本 !Q[v"6?  
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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： XY| y1L 3[  
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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。 jn5xYKv  
余下的脚本计算与屈光度有关的所有参数。 yIL=jzm`7  
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分析 dLp1l2h!0  
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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。 bqE'9GI  
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脚本代码 6|NH*#s  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. rk8pL[|  
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Dim entity As T_ENTITY #`u}#(  
Dim op As T_OPERATION ,Iyc0  
Dim mat As T_MODELMATERIAL 8vVE  
Dim A As Double &q>8D'  
Dim pupilDiam As Double ]B3](TH"  
Dim eID As Long  ?CAU
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Dim parID As Long hty'L61\z  
Dim count As Integer w!"L\QT  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double `0NU c)`  
Dim tlens As Double, nlens As Double (S!UnBb&  
Dim curv As Double, conic As Double Q~]oN  
Dim ok As Long -LiGO#U  
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Sub Main Hi09?AX  
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    '用户输入对话框 Q|)>9m!tt  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 !
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        TextBox 220,21,40,21,.TextBox1 'default: 0 ceG\Q2  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 `a&L  
        OKButton 40,91,90,21 m~&  
        CancelButton 190,91,90,21 {c*$i^T  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 2V@5:tf  
        TextBox 220,49,40,21,.TextBox2 'default: 4 \< .BN;t{  
    End Dialog .hW>#  
    Dim dlg As UserDialog %k#+nad  
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    ok = Dialog (dlg) P7-k!p"  
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    If ok=0 Then    'cancel button was pressed iW6O9~  
        Print "Execution cancelled." \na$Sb+  
        End ;$
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    End If CC=I|/mBM  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 7 {92_xRL  
    If dlg.TextBox1 = "" Then Tm`@5  
        A = 0           'Default accommodation TAUl{??,  
    Else +DRt2a#  
        A = CDbl(dlg.TextBox1) fJ/INL   
    End If t5E$u(&+'B  
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    If dlg.TextBox2 = "" Then 6vK`J"d{~D  
        pupilDiam = 4   'Default pupil diameter %d+Fq=<  
    Else DoczQc-U+  
        pupilDiam = CDbl(dlg.TextBox2) 'b.jKkW7  
    End If Xgx/ubca0  
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    Print " " C?|sQcCE  
    Print "Accommodation = " & A & " Diopters" C)U4Fr ?E:  
    Print "Pupil Diameter = " & pupilDiam & " mm" @S3L%lOH  
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    ' Calculate new parameters with accommodation 2-'_Nwkl*  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ~a_hOKU5  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 'yCVB&`b  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens .h <=C&Yg  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens d9JAt-6z2  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens |y7TYjg6  
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    tlens = 3.767 + 0.04*A                  'Lens thickness _t-6m2A  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 6H0kY/quL|  
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    'Adjust parameters to account for accommodation oL~1M=r  
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    '************************************************************************* M;XU"8  
    'Aqueous thickness (Position of Lens) N_ ODr]L  
    '************************************************************************* Vl$RMW@Ds  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) |\Gkhi>;  
    GetCustomElement eID, entity B4un6-<i  
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    parID = FindFullName( "Geometry.Arizona Eye" ) J <z ^C  
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    ' Delete any shift(s) in z 1CJ1-]S(3  
    count = 0 O_ r-(wE4  
    While GetOperationCount(eID)>count dUB;ZB7  
        GetOperation eID, count, op YN)qMI_`A  
        If op.Type="ShiftZ" Then oTvg%bX  
            DeleteOperation eID,count /mJb$5=1  
            count=count-1 Gu{1%bb#kL  
        End If lFuW8G,-f@  
        count=count+1 yE N3/-S+  
    Wend Pjq9BK9p  
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    'Set new shift in <,O|fY%  
    op.Type = "ShiftZ" gGNo!'o  
    op.val1 = taq 0>m$e(Z  
    op.parent = parID BT(eU*m-  
    AddOperation eID, op 0<uL0FOT  
    Print "Set aqueous humor thickness = " & taq-0.55 lre(]oBXA  
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    '************************************************************************* 0Bgj.?l  
    'Radius and conic constant of anterior lens 6 [bQ'Ir^8  
    '************************************************************************* |9i[*]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) !gyW15z'  
    GetConic eID, entity, curv, conic -^_^ByJe  
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    SetConic eID, entity, 1/Rant, CCant Y, Lpv|  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant >G1]#'6;  
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    '************************************************************************* Foj|1zJS_  
    'Radius and conic constant of posterior lens ymrnu-p o  
    '************************************************************************* }x6)}sz7  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) xGOmvn^lQ  
    GetConic eID, entity, curv, conic DQ$m@_/4w  
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    SetConic eID, entity, 1/Rpost, CCpost ??Urm[Y
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost \Dr( /n  
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    '************************************************************************* Q-iBK*-w  
    'Lens thickness (Position of posterior lens surface) c;KMox/  
    '************************************************************************* Wt5
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9h+TO_T@F  
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    ' Delete any z-shift(s) Yx66Xy  
    count = 0 kg(}%Ih  
    While GetOperationCount(eID)>count ;fQIaE&H  
        GetOperation eID, count, op +i /4G.=*  
        If op.Type="ShiftZ" Then ,ZYPffu<*  
            DeleteOperation eID,count Lf.Ia*R:  
            count=count-1 1"t9x.  
        End If F1}d@^K 7d  
        count=count+1 .LM|@OeaD!  
    Wend ijcF[bmE  
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    'Set new z-shift Qo]qs+  
    op.Type = "ShiftZ" TrgKl2xfx  
    op.val1 = tlens b5~p:f-&4B  
    op.parent = parID 2.{zfr  
    AddOperation eID, op DgRn^gL{Q  
    Print "Set lens thickness = " & tlens u!HbS*jqq  
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    '************************************************************************* p")"t`k7  
    'Lens index of refraction FBrh!vQ<  
    '************************************************************************* =(R3-['QIb  
    eID = FindMaterial( "Lens" ) U0W2  
    GetModelMaterial eID, mat hZ|0<u  
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    mat.Nd = nlens @d8Nr:  
    SetModelMaterial eID, mat zDm3$P=  
    Print "Set lens index of refraction = " & nlens @I&k|\  
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    '************************************************************************* '19?  
    'Pupil diameter 8B "^}y\0  
    '************************************************************************* +~==qLsU  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) '"hSX=  
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    'Adjust pupil diameter (trimming volume inner hole) rNm_w>bq  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ww+,GnV  
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    ' Adjust pupil location to just in front of the lens oBnes*  
    parID = FindFullName( "Geometry.Arizona Eye" ) =|fB":vk  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 5+b73R3r  
    count = 0 0a!|*Z  
    While GetOperationCount(eID)>count FLG{1dS  
        GetOperation eID, count, op Vvv;m5.  
        If op.Type="ShiftZ" Then X_3hh}=  
            DeleteOperation eID,count |~v2~   
            count=count-1 WFmW[< g  
        End If 6@:<62!;  
        count=count+1 !F Zg' 9  
    Wend ^%\MOjSN  
    op.Type = "ShiftZ" J{5p4bkb  
    op.val1 = taq-0.01 p9MJa[}V  
    op.parent = parID 4,=;:#n,J  
    AddOperation eID, op +sq_fd ;'D  
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    Print "Set pupil diameter = " & pupilDiam #op0|:/

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    'Update AZ Eye subassembly Description ssH[\i  
    eID = FindFullName( "Geometry.Arizona Eye" ) v4X ` Ul*  
    GetEntity eID, entity T;,
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    entity.Description = "Accommodation = " & A & "D" m*lcIa  
    SetEntity eID, entity )g^O'e=m  
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    Update V1Gnr~GM  
    Print "DONE!" va"bw!zXo*  
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End Sub D mky!Cp
 
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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： CFoR!r:X  
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Accommodation = 4 Diopters \0e`sOS`L  
Pupil Diameter = 4 mm %z~kHL  
Set aqueous humor thickness = 2.81 :N_DJ51
 
Set anterior lens radius = 10.4 and conic constant = -2.375869 ^q|W@uG-(  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 \W\*'C8q\  
Set lens thickness = 3.927 3m&  
Set lens index of refraction = 1.42672 #\K"FE0PGz  
Set pupil diameter = 4 N&$ ,uhmO  
DONE! nuA 0%K