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    [技术]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 @ 3b-  
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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。 o6X<FE#8  
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    模型 )IuwI#pm  
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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。 pS!N<;OWr  
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    Table 1. AZ眼睛模型的定义
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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. r+n hm"9  
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    光源 HmpV; <t3  
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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。 $t>ow~Xi  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 M-5zsN  
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 W0Q;1${  
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    图2. 字母F光源的设定方法光 gjy:o5{vA*  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 c6HH%|  
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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。 ,,(BW7(  
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    图4. 视网膜朗伯散射设定
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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。 bhT:MW!  
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    图5. 视网膜重点采样规格设定
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    脚本 FuO'%3;c  
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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: xwrleB  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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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。 2d-C}&}L\  
    余下的脚本计算与屈光度有关的所有参数。 T8J[B( )L  
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    分析 24/ ^_Td  
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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。 0t}&32lL&  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 J9/}ZD^  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. NpYzN|W:  
    . vQCX1V(  
    Dim entity As T_ENTITY _cH 7lO[  
    Dim op As T_OPERATION )3~):+  
    Dim mat As T_MODELMATERIAL W%cJ#R[o  
    Dim A As Double "# BI"  
    Dim pupilDiam As Double giz#(61j^  
    Dim eID As Long |0/~7l  
    Dim parID As Long khtSZ"8X  
    Dim count As Integer fP:g}Z  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double /0qLMlL$  
    Dim tlens As Double, nlens As Double )]5}d$83  
    Dim curv As Double, conic As Double O9]+Jd4W  
    Dim ok As Long '`Iuf\  
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    Sub Main }e*OprF  
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        '用户输入对话框 )R'~{;z }  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 B @8 ]!  
            TextBox 220,21,40,21,.TextBox1 'default: 0 lZ9rB^!  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 BSB;0OM  
            OKButton 40,91,90,21 J M,ndl  
            CancelButton 190,91,90,21 nB1[OB{  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 \P|PAU@,  
            TextBox 220,49,40,21,.TextBox2 'default: 4 B#K{Y$!v  
        End Dialog h|j $Jy  
        Dim dlg As UserDialog I ;Sm<P7*  
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        ok = Dialog (dlg) /&#Gh?z  
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        If ok=0 Then    'cancel button was pressed B#T4m]E/  
            Print "Execution cancelled." GF-\WD  
            End CQx#Xp>=s  
        End If zg2}R4h  
    = j,Hxq  
        'Assign accommodation and pupil diameter & use defaults if field left empty ``Wf%~  
        If dlg.TextBox1 = "" Then af<R.  
            A = 0           'Default accommodation MIJ^ n(-G  
        Else '-7rHx  
            A = CDbl(dlg.TextBox1) Gd8FXk,.!  
        End If >qBQfz:U>  
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        If dlg.TextBox2 = "" Then kgV_*0^  
            pupilDiam = 4   'Default pupil diameter :Ej#qYi  
        Else jr<`@  
            pupilDiam = CDbl(dlg.TextBox2) O IMsxXF\J  
        End If m ["`Op4  
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        Print " " =-e` OHA  
        Print "Accommodation = " & A & " Diopters" ,33[/j  
        Print "Pupil Diameter = " & pupilDiam & " mm" ^T#bla893  
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        ' Calculate new parameters with accommodation 1sqBBd"=PY  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness <B?@,S>  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens .BR2pf|R  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Qt@_C*,P  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens %)$^_4.g  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens .m&JRzzV  
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        tlens = 3.767 + 0.04*A                  'Lens thickness s^{hdCCl67  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Sd !!1a s  
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        'Adjust parameters to account for accommodation _bi]Bpxf  
    \<}4D\qz  
        '************************************************************************* =o@CCUKpj  
        'Aqueous thickness (Position of Lens) (|<e4HfZL  
        '************************************************************************* 3~I|KF7x  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) &o$z[ b  
        GetCustomElement eID, entity (}W+W\.  
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        parID = FindFullName( "Geometry.Arizona Eye" ) OO Hw-MW  
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        ' Delete any shift(s) in z TzC'x WO  
        count = 0 =q1=.VTn  
        While GetOperationCount(eID)>count ] rP^  
            GetOperation eID, count, op {{G`0i2KV  
            If op.Type="ShiftZ" Then #mI{D\UR  
                DeleteOperation eID,count ! z^%$;p  
                count=count-1 IMKyFp]h-  
            End If PJq;OM|  
            count=count+1 Fgf5OHX  
        Wend tai=2,'  
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        'Set new shift in _6b?3[Xz  
        op.Type = "ShiftZ" i'w8Li  
        op.val1 = taq hV(>}hb  
        op.parent = parID ?s=O6D&   
        AddOperation eID, op cBZK t  
        Print "Set aqueous humor thickness = " & taq-0.55 x)Y?kVw21"  
    #JmVq-)  
        '************************************************************************* o$*aAgS+  
        'Radius and conic constant of anterior lens B-oQ 9[~  
        '************************************************************************* pO^PkX  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) |[/<[@\''  
        GetConic eID, entity, curv, conic %h}Qf&U_  
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        SetConic eID, entity, 1/Rant, CCant 3pxZk%  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant WrA!'I  
    #GDnV/0)  
        '************************************************************************* )\ `AD#  
        'Radius and conic constant of posterior lens tx,_0[hZi  
        '************************************************************************* <G9HVMiP  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +-DF3(  
        GetConic eID, entity, curv, conic V`c"q.8  
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        SetConic eID, entity, 1/Rpost, CCpost scf.> K2  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost N~""Lc&  
    -6Y@_N  
        '************************************************************************* "!V-@F$@N  
        'Lens thickness (Position of posterior lens surface) QKW\z aG  
        '************************************************************************* Nl4,c[$C  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) y*F !k{P  
    ;6 ?a8t@  
        ' Delete any z-shift(s) _d|CO  
        count = 0 <r9L-4  
        While GetOperationCount(eID)>count |/qwR~  
            GetOperation eID, count, op 'YKzs;y$  
            If op.Type="ShiftZ" Then lOp7rW]$  
                DeleteOperation eID,count X#ZQpo'h  
                count=count-1 PBeBI:  
            End If j*.K|77WHj  
            count=count+1 YiO3.+H  
        Wend 2)~`.CD?L  
    [P'"|TM[ ~  
        'Set new z-shift fH@P&SX  
        op.Type = "ShiftZ" Y3_C':r  
        op.val1 = tlens (#&-ld6  
        op.parent = parID {Jna' eS  
        AddOperation eID, op = 9Ow!(!@  
        Print "Set lens thickness = " & tlens 6"h,0rR  
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        '************************************************************************* *:5S*E&}V  
        'Lens index of refraction NmuzAZr  
        '************************************************************************* H;h$k]T  
        eID = FindMaterial( "Lens" ) t)4><22of  
        GetModelMaterial eID, mat ?XlPK Y  
    tx*L8'jlN  
        mat.Nd = nlens fT2F$U  
        SetModelMaterial eID, mat o2 ;  
        Print "Set lens index of refraction = " & nlens *;&[q{hz  
    AMw#_8Y  
        '************************************************************************* qj7 }]T_  
        'Pupil diameter >\7M f@c  
        '************************************************************************* 22T\ -g{  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 0h=}BCb+i  
    r4isn^g  
        'Adjust pupil diameter (trimming volume inner hole) }@y(-7t  
    `SH14A*  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" O"GuVC}B  
    ^Q\Hy\  
        ' Adjust pupil location to just in front of the lens mo?*nO|-  
        parID = FindFullName( "Geometry.Arizona Eye" ) b9xvLR8  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) kR+7JUq]  
        count = 0 Ud_7>P$a  
        While GetOperationCount(eID)>count )n&6= Li  
            GetOperation eID, count, op r) u@,P  
            If op.Type="ShiftZ" Then '8yCwk  
                DeleteOperation eID,count k-N}tk/5  
                count=count-1 q^DQ9B  
            End If &7XsyDo6  
            count=count+1 Vb8Qh601  
        Wend uq2C|=M-x\  
        op.Type = "ShiftZ" #z1/VZ  
        op.val1 = taq-0.01 ;u-[%(00S  
        op.parent = parID Z[9t?ePL  
        AddOperation eID, op h"y~!NWn  
    A>ve|us$  
        Print "Set pupil diameter = " & pupilDiam GBl[s,g[|  
    SHYbQF2  
        'Update AZ Eye subassembly Description T)I\?hqTB  
        eID = FindFullName( "Geometry.Arizona Eye" ) xHD$0eq  
        GetEntity eID, entity ]6 HR  
        entity.Description = "Accommodation = " & A & "D" `Frr?.3&-  
        SetEntity eID, entity 9SBTeJ$RZ  
    Q!!u=}GYK  
        Update ? Rk[P cX<  
        Print "DONE!" jL7r1pu5  
         =fy\W=c  
    End Sub RW<10:  
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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: HUChg{[  
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    Accommodation = 4 Diopters o%,?v 9  
    Pupil Diameter = 4 mm :}R,a=N  
    Set aqueous humor thickness = 2.81 m5o$Dus+?'  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 kWacc&*|  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 @uz(h'~  
    Set lens thickness = 3.927 UcKVL zKs  
    Set lens index of refraction = 1.42672 lWn}afI  
    Set pupil diameter = 4 O#k eoC4  
    DONE! !' 0PM[  
     
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