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infotek 2022-02-25 09:52

Arizona眼睛模型

简介 DvA#zX[  
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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。 [u-=<hnoa  
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模型 XD[9wd5w8  
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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。 s GrI%3[e"  
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. p%OVl[^jp  
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光源 `"$9L[>  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 9YBlMf`KEf  
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图1. 光源和提示信息使用
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 T$V8 n_;  
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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。 t V7{j'If  
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图2. 字母F光源的设定方法光 W5&KmA  
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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 Zj nWbnW  
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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。 ^;Yjs.bI`F  
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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。 8JO(P0aT  
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图5. 视网膜重点采样规格设定
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脚本 CY)[{r  
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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: L-e6^%eU  
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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。 !,*Uvs@b  
余下的脚本计算与屈光度有关的所有参数。 B{1yMJA  
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分析 ay28%[Q b4  
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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。 -}Rh+n`  
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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 0fR?zT?  
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  1. Option Explicit     'Remove this to enable non-dimensioned variables to be used. ]Vf2Mn=]"  
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    Dim entity As T_ENTITY qp]s VY  
    Dim op As T_OPERATION P;e@<O  
    Dim mat As T_MODELMATERIAL j,N,WtE  
    Dim A As Double .O9Pn,:  
    Dim pupilDiam As Double c5{3  
    Dim eID As Long &|Vzo@D(!  
    Dim parID As Long kgRgHkAH~  
    Dim count As Integer v1E(K09h2  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double IPnx5#eB  
    Dim tlens As Double, nlens As Double .~4DlT  
    Dim curv As Double, conic As Double 'ExQG$t  
    Dim ok As Long R"QWap}  
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    Sub Main $H7T|`WI.,  
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        '用户输入对话框  ~&_BT`a  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 5%R$7>`Z  
            TextBox 220,21,40,21,.TextBox1 'default: 0 vslN([@JR  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ~"vRH  
            OKButton 40,91,90,21 e&=T`  
            CancelButton 190,91,90,21 kn6X I*  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ,j\UZ  
            TextBox 220,49,40,21,.TextBox2 'default: 4 Y!CGuLHL`[  
        End Dialog /I q6'oo  
        Dim dlg As UserDialog |B@\Nf7  
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        ok = Dialog (dlg) PvS\  
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        If ok=0 Then    'cancel button was pressed P.]O8r  
            Print "Execution cancelled." ww~gmz  
            End 1;[ZkRbzL  
        End If QdP)-Fx  
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        'Assign accommodation and pupil diameter & use defaults if field left empty  /w(t=Y  
        If dlg.TextBox1 = "" Then |'12Kv]#Xa  
            A = 0           'Default accommodation @jH8x!5u:  
        Else d##'0yg   
            A = CDbl(dlg.TextBox1) }9(:W</}  
        End If /%h<^YDBf  
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        If dlg.TextBox2 = "" Then FtxmCIVIV~  
            pupilDiam = 4   'Default pupil diameter 7_AcvsdW  
        Else 0p ZX_L'  
            pupilDiam = CDbl(dlg.TextBox2) ~,P."  
        End If uVV;"LVK~  
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        Print " " =Ev* Q[  
        Print "Accommodation = " & A & " Diopters" 8{J{)gF  
        Print "Pupil Diameter = " & pupilDiam & " mm" o_ SR  
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        ' Calculate new parameters with accommodation !l1ycQM  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness F /% 5 r{  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens -OV!56&  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 6/eh~ME=  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens )]C7+{ImC  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Ym "Nj  
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        tlens = 3.767 + 0.04*A                  'Lens thickness l*C(FPw4  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction !&OybjQ  
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        'Adjust parameters to account for accommodation `l8^n0-  
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        '************************************************************************* ?Wm.'S'to  
        'Aqueous thickness (Position of Lens) :3Hr: ~  
        '************************************************************************* 5n'C6q "  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) .I&]G  
        GetCustomElement eID, entity RtVG6'Y  
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        parID = FindFullName( "Geometry.Arizona Eye" ) rwUKg[ 1N  
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        ' Delete any shift(s) in z X}$uvB}+>  
        count = 0 Dk XB  
        While GetOperationCount(eID)>count ngoAFb  
            GetOperation eID, count, op {qHf%y&[  
            If op.Type="ShiftZ" Then kmXaLt2Z  
                DeleteOperation eID,count { f@k2^  
                count=count-1 ~L.)<{?  
            End If ^q0Ox&X  
            count=count+1 A12#v,  
        Wend GCTf/V\#  
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        'Set new shift in Ph*tZrd*#  
        op.Type = "ShiftZ" )q48cQ  
        op.val1 = taq 7#BpGQJQ  
        op.parent = parID "`AIU}[_I  
        AddOperation eID, op vUXas*s4  
        Print "Set aqueous humor thickness = " & taq-0.55 GX+oA]  
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        '************************************************************************* P]4C/UDS-~  
        'Radius and conic constant of anterior lens P+Ta|-  
        '************************************************************************* nRmZu\(Ow|  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) gUoTOA,  
        GetConic eID, entity, curv, conic K XP^F6@l  
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        SetConic eID, entity, 1/Rant, CCant ` qqUuFMM  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 8N|y   
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        '************************************************************************* p9[J 9D3~  
        'Radius and conic constant of posterior lens hi I`ot  
        '************************************************************************* 9oL/oL-J/  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) d&x1uso%L  
        GetConic eID, entity, curv, conic 6+9inWTT(  
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        SetConic eID, entity, 1/Rpost, CCpost rQ^$)%uP  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ^y,% Tv>  
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        '************************************************************************* JR1/\F<}  
        'Lens thickness (Position of posterior lens surface) Wv]NFHe#  
        '************************************************************************* {%K(O$H#  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) :6 ?&L  
    +IiL(\ew  
        ' Delete any z-shift(s) OYEL`!Q  
        count = 0 p xrd D7  
        While GetOperationCount(eID)>count > !thxG/_  
            GetOperation eID, count, op zice0({iJ  
            If op.Type="ShiftZ" Then fT-yY`  
                DeleteOperation eID,count LB|FVNW/S  
                count=count-1 5sD\4g)HK  
            End If c[4  H  
            count=count+1 $:R"IqDG  
        Wend #TLqo(/  
    ^@'LF T)  
        'Set new z-shift OQ>r;)/  
        op.Type = "ShiftZ" }];8v+M  
        op.val1 = tlens -,t2D/xK  
        op.parent = parID ]urrAIK  
        AddOperation eID, op t'bzhPQO)f  
        Print "Set lens thickness = " & tlens * _puW x  
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        '************************************************************************* !A(*?0`  
        'Lens index of refraction @tvAI2W  
        '************************************************************************* v*+.;60_  
        eID = FindMaterial( "Lens" ) lS.*/u*5  
        GetModelMaterial eID, mat ,4hQ#x  
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        mat.Nd = nlens MXWCYi  
        SetModelMaterial eID, mat rULrGoM  
        Print "Set lens index of refraction = " & nlens io_4d2uBh  
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        '************************************************************************* ALqP;/  
        'Pupil diameter je6H}eWTC6  
        '*************************************************************************  SrPZ^NF  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 4@D 8{?$~Q  
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        'Adjust pupil diameter (trimming volume inner hole) >}` q4U6$  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" H@$\SUc{  
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        ' Adjust pupil location to just in front of the lens O mkl|l9  
        parID = FindFullName( "Geometry.Arizona Eye" ) `}/&}Sp  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Hf( d x\5  
        count = 0 PT7L65  
        While GetOperationCount(eID)>count 9K*yds  
            GetOperation eID, count, op J>(I"K%  
            If op.Type="ShiftZ" Then R=jIVw'  
                DeleteOperation eID,count >r] bfN,  
                count=count-1 6$TE-l  
            End If yk1syN_  
            count=count+1 u|l]8T9L  
        Wend >'4Bq*5>  
        op.Type = "ShiftZ" qk pnXQ  
        op.val1 = taq-0.01 }~Z1C0 t  
        op.parent = parID +@),Fk_  
        AddOperation eID, op *Z"9QX  
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        Print "Set pupil diameter = " & pupilDiam qF m=(J%  
    &DC o;Ij;  
        'Update AZ Eye subassembly Description f)x^s$H  
        eID = FindFullName( "Geometry.Arizona Eye" ) *rPUVhD_  
        GetEntity eID, entity 'ojI_%9<  
        entity.Description = "Accommodation = " & A & "D" 4R5+"h:  
        SetEntity eID, entity 1?\ #hemL  
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        Update ZSj^\JU  
        Print "DONE!" n5i#GvO^  
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    End Sub 5#+G7 'k  
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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: /P bN!r<1  
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    Accommodation = 4 Diopters "' g*_  
    Pupil Diameter = 4 mm ydOJ^Yty  
    Set aqueous humor thickness = 2.81 ]YcM45xg  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 1*aw~nY0  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 Rckqr7q  
    Set lens thickness = 3.927 d4h1#MK  
    Set lens index of refraction = 1.42672 k 9 Xi|Yj  
    Set pupil diameter = 4 V=}AFGC85  
    DONE!
silence唯爱 2022-02-25 13:53
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