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    [技术]Arizona眼睛模型 [复制链接]

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    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 ~\jP+[>M'  
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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。 =GPXuo  
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    模型 'z(Y9%+a  
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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。 O -1O@:}c  
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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. :ZV |8xI  
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    光源 o$sD9xx  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 6]?mjG6  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 E EDFyZ  
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 OlOOg  
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    图2. 字母F光源的设定方法光 )S g6B;CJ  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 QxYm3x5  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 V`^*Z}d9  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 {dpC;jsW1  
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    图5. 视网膜重点采样规格设定
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    脚本 >^s2$@J?p  
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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: fEHFlgN3Ap  
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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。 ; llPM`)  
    余下的脚本计算与屈光度有关的所有参数。 atTR6%!6  
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    分析 *7xcwj eP  
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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。 pU7;!u:c4%  
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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 5Z>a}s_i  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. |?T=4~b  
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    Dim entity As T_ENTITY g0B] ;Y>(  
    Dim op As T_OPERATION Hr?lRaV  
    Dim mat As T_MODELMATERIAL @+b$43 ^  
    Dim A As Double zZCl]cql  
    Dim pupilDiam As Double ET}Z>vU}+  
    Dim eID As Long 4z<c8 E8  
    Dim parID As Long 9O;Sn+  
    Dim count As Integer ?'> .>  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double !85bpQ.  
    Dim tlens As Double, nlens As Double @z1QoZ^w  
    Dim curv As Double, conic As Double A6z ,6v6  
    Dim ok As Long $${I[2 R)  
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    Sub Main !Cr3>tA  
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        '用户输入对话框 N~!, S;w  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 W.j^L;  
            TextBox 220,21,40,21,.TextBox1 'default: 0 h4` 8C]  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 #[ prG  
            OKButton 40,91,90,21 d A)T>  
            CancelButton 190,91,90,21 \?n6l7*t>  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ;M~,S^U  
            TextBox 220,49,40,21,.TextBox2 'default: 4 `+,?%W)  
        End Dialog <x}wy+SG  
        Dim dlg As UserDialog `etw[#~N  
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        ok = Dialog (dlg) 8_%GH}{  
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        If ok=0 Then    'cancel button was pressed ' [$KG  
            Print "Execution cancelled." Lf9hOMHx  
            End rI$NNk'A  
        End If y0xBNhev  
    #}^waYAk)  
        'Assign accommodation and pupil diameter & use defaults if field left empty wkp2A18n  
        If dlg.TextBox1 = "" Then U"Gx Xrl  
            A = 0           'Default accommodation h@ lz  
        Else %0Ur3  
            A = CDbl(dlg.TextBox1) $Tbsre\MJ  
        End If u> {aF{  
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        If dlg.TextBox2 = "" Then &wQ;J)13  
            pupilDiam = 4   'Default pupil diameter fu!T4{2  
        Else rUKg<]&@  
            pupilDiam = CDbl(dlg.TextBox2) |+Wn5iT  
        End If 9`f@"%h  
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        Print " " l#[Z$+!09  
        Print "Accommodation = " & A & " Diopters" Tt: (l/1  
        Print "Pupil Diameter = " & pupilDiam & " mm" &PC6C<<f  
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        ' Calculate new parameters with accommodation xNIrmqm5]  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness <+*0{8?0  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens Jr5S8 c|"  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens m1W) PUy  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens  /b=C  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens a"@f< wU~  
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        tlens = 3.767 + 0.04*A                  'Lens thickness gKb,Vrt  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Ek<Qz5)  
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        'Adjust parameters to account for accommodation *O[/KR%  
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        '************************************************************************* ^SpQtW118  
        'Aqueous thickness (Position of Lens) gXI-{R7Me  
        '************************************************************************* {Z c8,jm  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) y]Nk^ga:U6  
        GetCustomElement eID, entity JMB#KzvN[  
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        parID = FindFullName( "Geometry.Arizona Eye" )  bUcp8  
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        ' Delete any shift(s) in z .2%t3ul[  
        count = 0 ]$2 yV&V&  
        While GetOperationCount(eID)>count &5y  
            GetOperation eID, count, op 1J[$f>%n]  
            If op.Type="ShiftZ" Then 1%_RXQVG  
                DeleteOperation eID,count $.D )Llcq  
                count=count-1 cAN!5?D\  
            End If 4`8s]X  
            count=count+1 "mQp#d/'  
        Wend }-fHS;/  
    3VLwY!2:  
        'Set new shift in T+L=GnYl  
        op.Type = "ShiftZ" )h@PRDI_  
        op.val1 = taq ~HIj+kN  
        op.parent = parID aV$kxzEc  
        AddOperation eID, op }.o.*N  
        Print "Set aqueous humor thickness = " & taq-0.55 t"B3?<?]  
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        '************************************************************************* _. 9 5>`  
        'Radius and conic constant of anterior lens +q pW"0[  
        '************************************************************************* '9!_:3[d\]  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 4~Qnhv7  
        GetConic eID, entity, curv, conic yP7b))AW9  
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        SetConic eID, entity, 1/Rant, CCant z%E(o%l8  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 'd2 :a2C]  
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        '************************************************************************* sUlf4<_zW  
        'Radius and conic constant of posterior lens 6CFnE7TQf  
        '************************************************************************* ^mL X}E]  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 7G+!9^  
        GetConic eID, entity, curv, conic Gy \ ]j  
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        SetConic eID, entity, 1/Rpost, CCpost ZP~H!  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost `<g]p-=":  
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        '************************************************************************* )(,O~w  
        'Lens thickness (Position of posterior lens surface) bit|L7*14  
        '************************************************************************* 9}QIqH\p  
    +IS6l*_y>6  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) cD]H~D}M  
    (nO2+@ !  
        ' Delete any z-shift(s) {F wvuk  
        count = 0 se.HA  
        While GetOperationCount(eID)>count oh-EEo4,  
            GetOperation eID, count, op }vh <x6  
            If op.Type="ShiftZ" Then Y-bTKSn  
                DeleteOperation eID,count Dh4 Lffy  
                count=count-1 bVz<8b6h'-  
            End If ~qZ6I)?  
            count=count+1 @&G}'6vF!  
        Wend 8 SU0q9X.  
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        'Set new z-shift kxKb}> =  
        op.Type = "ShiftZ" *` mxv0w~(  
        op.val1 = tlens NxF:s,a6  
        op.parent = parID >TglX t+  
        AddOperation eID, op !D F~]&  
        Print "Set lens thickness = " & tlens d;<'28A  
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        '************************************************************************* +@]k[9  
        'Lens index of refraction [;Ih I  
        '************************************************************************* 5/Qu5/  
        eID = FindMaterial( "Lens" ) AS]8rH  
        GetModelMaterial eID, mat "8%$,rG1&  
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        mat.Nd = nlens sSfP.R  
        SetModelMaterial eID, mat 7vXP|8j  
        Print "Set lens index of refraction = " & nlens J-/w{T8:  
    C$0u-Nx8  
        '************************************************************************* H ~3.F  
        'Pupil diameter cWo>DuW&  
        '************************************************************************* qqo#H O  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) mxZ+r#|di  
     omg#[  
        'Adjust pupil diameter (trimming volume inner hole) lusUmFm'*  
    Q3%]  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" E[#VWM I  
    V'#R1x"3  
        ' Adjust pupil location to just in front of the lens mS[``$Z\!  
        parID = FindFullName( "Geometry.Arizona Eye" ) Wu* 4r0  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) fZpi+I  
        count = 0 g%Tokl  
        While GetOperationCount(eID)>count Mi#i 3y(  
            GetOperation eID, count, op tl /i  
            If op.Type="ShiftZ" Then OvQzMXU^I  
                DeleteOperation eID,count lx4p Tw1  
                count=count-1 0?oL zw&  
            End If @;Jv/N6@  
            count=count+1 _cJ)v/]  
        Wend !&Q?ASJH  
        op.Type = "ShiftZ" =PY{Elf  
        op.val1 = taq-0.01 E9mu:T  
        op.parent = parID kh# QT_y  
        AddOperation eID, op PX/Y?DP  
    *Sdx:G~gp  
        Print "Set pupil diameter = " & pupilDiam N$e mS  
    '*L6@e#U  
        'Update AZ Eye subassembly Description w>cqsTq  
        eID = FindFullName( "Geometry.Arizona Eye" ) #8M?y*<I  
        GetEntity eID, entity hDTC~~J/  
        entity.Description = "Accommodation = " & A & "D" x#3*C|A  
        SetEntity eID, entity z/"*-+j  
    -5  
        Update UFT JobU  
        Print "DONE!" RtR@wZ2\s  
         bwhH2^ !  
    End Sub +kd1q  
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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: Q<u?BA/  
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    Accommodation = 4 Diopters $adZ|Q\  
    Pupil Diameter = 4 mm czIAx1R9  
    Set aqueous humor thickness = 2.81 E"VF BKB  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 wH!$TAZ:Yw  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 *GoTN  
    Set lens thickness = 3.927 w>9d^kU'  
    Set lens index of refraction = 1.42672 5b/ ~]v  
    Set pupil diameter = 4 =K0%bI  
    DONE! iii|;v ]+  
     
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