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    [分享]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: 2020-12-09
    简介 ; h85=l<8u  
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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。 \sITwPA[z  
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    模型 lov%V*tL  
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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。 z0 \N{rP&  
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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. W~yLl%  
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    光源 !b63ik15O~  
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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。 '60//"9>k/  
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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。 G,|KL" H6  
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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。 nmg{%P  
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    图2. 字母F光源的设定方法光 x[x(y{&~  
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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 5gshKmt_  
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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。 En\Z#0,V  
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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。 ZLrHZhP-+  
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    图5. 视网膜重点采样规格设定
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    脚本 V{ |[oIp  
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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: x*q35K^PE  
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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。 (NaK3_  
    余下的脚本计算与屈光度有关的所有参数。 p[qg&VKB  
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    分析 #&BS ?@  
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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。 12OlrU  
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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 vaB!R 0  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ;s_"{f`Y6  
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    Dim entity As T_ENTITY x7$ax79ly  
    Dim op As T_OPERATION &S-er{]]  
    Dim mat As T_MODELMATERIAL  =:~(m  
    Dim A As Double $^h?:L:1n  
    Dim pupilDiam As Double y-a|Lu*  
    Dim eID As Long onnugj3  
    Dim parID As Long >lLo4M 3  
    Dim count As Integer B^q<2S;  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double U=m=1FYaG  
    Dim tlens As Double, nlens As Double Ep ">v>"  
    Dim curv As Double, conic As Double X-/Ban  
    Dim ok As Long _ECB^s_  
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    Sub Main "DpKrVuG  
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        '用户输入对话框 C6^j#rl  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 .8H}Lf\  
            TextBox 220,21,40,21,.TextBox1 'default: 0 u"FjwF?  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 9rcI+q=E  
            OKButton 40,91,90,21 V^rW?Do  
            CancelButton 190,91,90,21 : Ss3ck*=  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 dG0VBE  
            TextBox 220,49,40,21,.TextBox2 'default: 4 1exfCm  
        End Dialog CDCC1BG"  
        Dim dlg As UserDialog 8Q(8b@ZO,  
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        ok = Dialog (dlg) ,8##OB(  
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        If ok=0 Then    'cancel button was pressed [:B*6FXMN~  
            Print "Execution cancelled." hQ';{5IKvC  
            End } 0{B  
        End If E {>`MNj  
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        'Assign accommodation and pupil diameter & use defaults if field left empty Ekjf^Uo  
        If dlg.TextBox1 = "" Then F1c&0*_A  
            A = 0           'Default accommodation !G+u j(  
        Else 0p3vE,pF  
            A = CDbl(dlg.TextBox1) uvv.WbZ  
        End If 1VLLo~L%  
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        If dlg.TextBox2 = "" Then o , LK[Q  
            pupilDiam = 4   'Default pupil diameter >FF1)~  
        Else t.U{Bu P  
            pupilDiam = CDbl(dlg.TextBox2) %h/! Y<%  
        End If 7#pZa.B)k  
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        Print " " ?D=8{!R3  
        Print "Accommodation = " & A & " Diopters" 7cw]v"iv  
        Print "Pupil Diameter = " & pupilDiam & " mm" 5\S&)ZA@  
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        ' Calculate new parameters with accommodation `%y5\!X  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness QJSr:dP4dG  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens !<r8~A3!(  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens -3vh!JMN  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens V(..8}LlD  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens %6i=lyH-  
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        tlens = 3.767 + 0.04*A                  'Lens thickness 7\%$>< K  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction #LWg"i  
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        'Adjust parameters to account for accommodation  ?Ib}  
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        '************************************************************************* #r}uin*jD  
        'Aqueous thickness (Position of Lens) Vp7b4n<  
        '************************************************************************* f3n~{a,[  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) or.\)(m#(  
        GetCustomElement eID, entity ,8VXA +'_  
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        parID = FindFullName( "Geometry.Arizona Eye" ) e5OVq ,  
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        ' Delete any shift(s) in z P` ]ps?l  
        count = 0 =|V" #3$f  
        While GetOperationCount(eID)>count OjATSmZ@@  
            GetOperation eID, count, op +WL  D  
            If op.Type="ShiftZ" Then  XhA4:t  
                DeleteOperation eID,count  MYx88y  
                count=count-1 $W,zO|-  
            End If ~U%j{8uH  
            count=count+1 #90c$ dc  
        Wend 6[+j'pW?  
    :rmauKR  
        'Set new shift in QgZJ`G--  
        op.Type = "ShiftZ" uO"8aD`W  
        op.val1 = taq GNZ#q)qT  
        op.parent = parID Wr#~GFg  
        AddOperation eID, op G?ZC 9w]rA  
        Print "Set aqueous humor thickness = " & taq-0.55 '!@A}&]  
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        '************************************************************************* b9#m m  
        'Radius and conic constant of anterior lens . s-5N\  
        '************************************************************************* xVTo4-[p  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Hz?,#>{  
        GetConic eID, entity, curv, conic 2@ *<9-9  
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        SetConic eID, entity, 1/Rant, CCant Xi+n`T'i  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant nl9kYE [  
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        '************************************************************************* Ays L-sqR  
        'Radius and conic constant of posterior lens dk:xnX%  
        '************************************************************************* Om6Mmoqh  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 2-7Z(7G{ F  
        GetConic eID, entity, curv, conic 5"uNj<.V  
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        SetConic eID, entity, 1/Rpost, CCpost -R8/`M8GbD  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost s9 &)Fv-#V  
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        '************************************************************************* Yx 3|G  
        'Lens thickness (Position of posterior lens surface) xD^wTtT  
        '************************************************************************* q|Fjm]AF  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) {83C,C-  
    B'#4;R!8P=  
        ' Delete any z-shift(s) 1 yJ75/  
        count = 0 Bs@:rhDi  
        While GetOperationCount(eID)>count +K&?)?/=  
            GetOperation eID, count, op I}_;A<U  
            If op.Type="ShiftZ" Then ,3k@L\$.x  
                DeleteOperation eID,count 6"%@ L{UQ  
                count=count-1 ?61L|vr  
            End If L9$&-A9ix  
            count=count+1 i)[kubM  
        Wend e`;t<7*i  
    {dBB{.hX  
        'Set new z-shift HM 90Sb  
        op.Type = "ShiftZ"  }Zt.*%  
        op.val1 = tlens jQ)L pjS1  
        op.parent = parID #)FDl70S8  
        AddOperation eID, op |SxMN %M!  
        Print "Set lens thickness = " & tlens F:S"gRKz  
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        '************************************************************************* TqXg e{r  
        'Lens index of refraction PY2[ S[  
        '************************************************************************* }\DAg'e)  
        eID = FindMaterial( "Lens" ) m[W/j/$A+x  
        GetModelMaterial eID, mat <5M_EJp  
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        mat.Nd = nlens .(JE-upJ"  
        SetModelMaterial eID, mat ygMd$0:MN  
        Print "Set lens index of refraction = " & nlens CX]RtV!  
    ~};]k}  
        '************************************************************************* K[e`t%2_  
        'Pupil diameter $.``OxJk%  
        '************************************************************************* b'&LBT7  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) iQu^|,tHEM  
    fjcr<&{:  
        'Adjust pupil diameter (trimming volume inner hole) g%ZdIKj!  
    b$dBV}0 L  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" xUQdVrFU  
    uL bp.N8  
        ' Adjust pupil location to just in front of the lens zf`5>h|  
        parID = FindFullName( "Geometry.Arizona Eye" ) j{)fC]8H  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) re]%f"v:5  
        count = 0 1k$2LQ  
        While GetOperationCount(eID)>count lK "' nLL  
            GetOperation eID, count, op W8< @sq~I  
            If op.Type="ShiftZ" Then u IAZo;  
                DeleteOperation eID,count =[s8q2V  
                count=count-1 *3 !(*F@M,  
            End If N`f!D>b:dn  
            count=count+1 KuIkul9^%  
        Wend E=}6 X9X  
        op.Type = "ShiftZ" $|rCrak;  
        op.val1 = taq-0.01 =n)JJS94  
        op.parent = parID L^6"' #  
        AddOperation eID, op NS h%t+XU]  
    P`7ojXy  
        Print "Set pupil diameter = " & pupilDiam uFz/PDOZ@  
    0K&_D)  
        'Update AZ Eye subassembly Description :sU!PF[<  
        eID = FindFullName( "Geometry.Arizona Eye" ) cLn;,u4  
        GetEntity eID, entity ;& RUE  
        entity.Description = "Accommodation = " & A & "D" [|y`y%  
        SetEntity eID, entity _c[|@D  
    p 7 , f6kG  
        Update x6"/z  
        Print "DONE!" qi( &8in  
         {F<)z% ^  
    End Sub -)p@BtMS  
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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: f;e_04K  
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    Accommodation = 4 Diopters JtSuD>H`"  
    Pupil Diameter = 4 mm -K:yU4V  
    Set aqueous humor thickness = 2.81 Qk?jGXB>^  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ,?C|.5  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 | -JI`!7  
    Set lens thickness = 3.927 c'"#q)  
    Set lens index of refraction = 1.42672 Xq+!eOT  
    Set pupil diameter = 4 -b].SG5S  
    DONE! R 4DM_ u  
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    QQ:2987619807 TFAYVK~  
     
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