[技术]Arizona眼睛模型 [复制链接]

简介 y*}AX%8`e~  
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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。 *4-r`k|@>/  
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模型 4Y`! bT`  
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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。 +xn&K"]:3  
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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. 3?.6K0L  
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光源 =ZCH1J5"  
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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。 ?nB helW^  
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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。 WA<H  
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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。 0\V\qAk  
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视网膜的散射 4aj[5fhb-  
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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。 r$b:1C~  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 tfi2y]{A  
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脚本 V_Njk
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： h-z%C6  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 (1j(*
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余下的脚本计算与屈光度有关的所有参数。 ;s}-X_O<  
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分析 pKOT Qf  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 FiV^n6-F`  
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脚本代码 Ig40#pA  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Up]VU9z  
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Dim entity As T_ENTITY "uV0Oj9:  
Dim op As T_OPERATION :vn0|7W4  
Dim mat As T_MODELMATERIAL |YG)NO  
Dim A As Double w3>Y7vxiz`  
Dim pupilDiam As Double asm[-IB2u  
Dim eID As Long UiGUaBmF*  
Dim parID As Long htdn$kqG   
Dim count As Integer -~rr<D\  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double sqq/b9 uL/  
Dim tlens As Double, nlens As Double kMwIu
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Dim curv As Double, conic As Double :kf3_?9rc  
Dim ok As Long &lXx0"-$  
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Sub Main 4YU1Kr4  
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    '用户输入对话框 C%x(`S^/  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 dpc=yXg>"c  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ^>P@5gcoE(  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ByB0>G''.  
        OKButton 40,91,90,21 ;X9MA=b  
        CancelButton 190,91,90,21 oKMg7 3*  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 S`'uUvAA  
        TextBox 220,49,40,21,.TextBox2 'default: 4 % @^VrhS  
    End Dialog 6`$,-(J=  
    Dim dlg As UserDialog Z3u""oM/  
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    ok = Dialog (dlg) I'6ed`|  
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    If ok=0 Then    'cancel button was pressed nvUkbmZG#  
        Print "Execution cancelled." 8WLh]MD`  
        End 34O+#0<y~  
    End If Qh1Kl_a?Lv  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 7W>}7  
    If dlg.TextBox1 = "" Then ' /@!"IXz  
        A = 0           'Default accommodation G`3vH,  
    Else =t>`<T|(  
        A = CDbl(dlg.TextBox1) )}zA,FOA*  
    End If $F /p8AraK  
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    If dlg.TextBox2 = "" Then ,XF6
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        pupilDiam = 4   'Default pupil diameter :67d>wb  
    Else v#AO\zYKd  
        pupilDiam = CDbl(dlg.TextBox2) #L1yL<'  
    End If 5]2!Bb6>  
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    Print " " !&`7  
    Print "Accommodation = " & A & " Diopters" ogh2kh
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    Print "Pupil Diameter = " & pupilDiam & " mm" \gPNHL*  
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    ' Calculate new parameters with accommodation ,y{fqa4  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness @v:ILby4-  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens S)AE  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens N?u2,h-  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens <?`e9o  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens S+\Mt+o  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ^!s}2GcS`  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction a1Y_0  
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    'Adjust parameters to account for accommodation U:\oGa84A  
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    '************************************************************************* I^C
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    'Aqueous thickness (Position of Lens) \2VZkVO9  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) t)kr/Z*p\  
    GetCustomElement eID, entity EPUJa~4  
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    parID = FindFullName( "Geometry.Arizona Eye" ) MrygEC 5  
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    ' Delete any shift(s) in z fqp7a1qQl  
    count = 0 vXWESy  
    While GetOperationCount(eID)>count U=*q;$L#  
        GetOperation eID, count, op (Gb{ckzs  
        If op.Type="ShiftZ" Then
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            DeleteOperation eID,count l9Cy30O6  
            count=count-1 0i1?S6]d-  
        End If W SeRV?+T  
        count=count+1 b|pNc'u:Cn  
    Wend &cv/q$W4  
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    'Set new shift in 7}HA_@[  
    op.Type = "ShiftZ" @RG3*3(  
    op.val1 = taq jC }u>AB  
    op.parent = parID WlJRKM2  
    AddOperation eID, op %li{VDb  
    Print "Set aqueous humor thickness = " & taq-0.55 4xC6#:8  
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    '************************************************************************* (TK cSVR  
    'Radius and conic constant of anterior lens ^rZ+H@p:6  
    '************************************************************************* P_}_D{G  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) \$++.%0  
    GetConic eID, entity, curv, conic \>CBam8d  
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    SetConic eID, entity, 1/Rant, CCant :zTj"P>"I  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ,DsT:8  
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    '************************************************************************* m*WEge*$t  
    'Radius and conic constant of posterior lens <L[)P{jn?p  
    '************************************************************************* 2FtEt+A+'  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) { l~T~3/i  
    GetConic eID, entity, curv, conic '3,JL!  
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    SetConic eID, entity, 1/Rpost, CCpost (>% Vj  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost p5 PON0dS  
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    '************************************************************************* uX!y,a/"  
    'Lens thickness (Position of posterior lens surface) IQ`aDo-V  
    '************************************************************************* aQ3vG08L>  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) W;*vcbP  
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    ' Delete any z-shift(s) j7%%/%$o[  
    count = 0 IBHG1<
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    While GetOperationCount(eID)>count tz>X'L  
        GetOperation eID, count, op 'Z%aBCM  
        If op.Type="ShiftZ" Then r/w@Dh]{_  
            DeleteOperation eID,count X%qR6mMfT7  
            count=count-1 %Y[/Ucdm  
        End If lY8Qy2k|  
        count=count+1 Hw3ES  
    Wend jWjK-q@Y  
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    'Set new z-shift  o=
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    op.Type = "ShiftZ" 2{q
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    op.val1 = tlens ]nGA1S{  
    op.parent = parID Q^;\!$:M  
    AddOperation eID, op f\_Q+!^  
    Print "Set lens thickness = " & tlens
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    '************************************************************************* eJdQ7g[>  
    'Lens index of refraction ^OsUWhkV  
    '************************************************************************* l"g%vS,;`  
    eID = FindMaterial( "Lens" )
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    GetModelMaterial eID, mat 9%veU
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    mat.Nd = nlens y
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    SetModelMaterial eID, mat p5w g+K  
    Print "Set lens index of refraction = " & nlens @Kb~!y@G  
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    '************************************************************************* FX%E7H  
    'Pupil diameter 3 +9|7=d  
    '************************************************************************* a];i4lt(c  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) *38\&"s4_  
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    'Adjust pupil diameter (trimming volume inner hole) uU"s50m  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" W u{nC  
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    ' Adjust pupil location to just in front of the lens ?Cl"jcQ*  
    parID = FindFullName( "Geometry.Arizona Eye" ) msJn;(Pn  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) BE;iC.rW  
    count = 0 wN.Jyb  
    While GetOperationCount(eID)>count SpQ6A]M gm  
        GetOperation eID, count, op J?DyTs3Z  
        If op.Type="ShiftZ" Then )^3655mb  
            DeleteOperation eID,count W{2y*yqY  
            count=count-1 ZmF32Ir  
        End If cE?
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        count=count+1 Z0^do  
    Wend 3_:k12%p  
    op.Type = "ShiftZ" 81C?U5  
    op.val1 = taq-0.01 +[qy HTcG  
    op.parent = parID QJ'C?hn  
    AddOperation eID, op Cl=ExpX/O  
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    Print "Set pupil diameter = " & pupilDiam bBL"F!.  
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    'Update AZ Eye subassembly Description B 8,{jwB  
    eID = FindFullName( "Geometry.Arizona Eye" ) )Qp?LECrt  
    GetEntity eID, entity w=
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    entity.Description = "Accommodation = " & A & "D" wVX0!y6  
    SetEntity eID, entity h<q``hn>  
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    Update 1Zzw|@#>o  
    Print "DONE!" s6IuM )x  
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End Sub dDn:^)  
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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： sIe(;%[`  
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Accommodation = 4 Diopters h[?28q$  
Pupil Diameter = 4 mm XFYl[?`G  
Set aqueous humor thickness = 2.81 $cedO']  
Set anterior lens radius = 10.4 and conic constant = -2.375869 S{06bLXU"  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 1:8: yFV  
Set lens thickness = 3.927 HF:PF"|3  
Set lens index of refraction = 1.42672 it@s(1EO#  
Set pupil diameter = 4 FB`HwE<  
DONE! f #14%?/