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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 N{&Hq4^c  
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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。 rI#,FZ  
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    模型 ePo :::  
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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。 3~EPX`#[W  
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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. 8 3Tv-X  
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    光源 kYZj^tR  
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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。 ~m3Tq.sYrY  
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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。 L2IY$+=M  
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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。 }u.I%{4  
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    图2. 字母F光源的设定方法光 FO:k >F  
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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 ~COd(,ul  
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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。 MDauHtF,  
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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。 \hD jZ  
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    图5. 视网膜重点采样规格设定
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    脚本 8Z>=sUMQ  
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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: ,HwOMoP7  
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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。 j>)yV@g/  
    余下的脚本计算与屈光度有关的所有参数。 _n+ 5{\z  
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    分析 jg3T1ROL  
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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。 Vi>`g{\  
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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 64l(ru<  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. F/:Jp3@  
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    Dim entity As T_ENTITY ]O0:0Z\  
    Dim op As T_OPERATION ?@H/;hB[|  
    Dim mat As T_MODELMATERIAL ~y>NJM>1  
    Dim A As Double /{!?e<N>  
    Dim pupilDiam As Double {Z1^/F v3  
    Dim eID As Long }TG=ZVi  
    Dim parID As Long 'a=' (,%  
    Dim count As Integer ]dL#k>$0q  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ]] 50c  
    Dim tlens As Double, nlens As Double kz^?!l)X0  
    Dim curv As Double, conic As Double - aQf( =  
    Dim ok As Long \s_`ZEB  
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    Sub Main 6$ ag<  
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        '用户输入对话框 jbTsrj"g  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ^ ^k]2oG  
            TextBox 220,21,40,21,.TextBox1 'default: 0 &5Huv?^a'  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ,rWej;CzN  
            OKButton 40,91,90,21 v|wO qS  
            CancelButton 190,91,90,21 frUO+  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 TSUT3'&~p  
            TextBox 220,49,40,21,.TextBox2 'default: 4 {xCqz0  
        End Dialog :NXM.@jJ="  
        Dim dlg As UserDialog f~{4hVA  
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        ok = Dialog (dlg) T*qSk!  
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        If ok=0 Then    'cancel button was pressed c. 06Sw*  
            Print "Execution cancelled." tQ Ia6c4|  
            End ,L$, d  
        End If CQ:38l\`gd  
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        'Assign accommodation and pupil diameter & use defaults if field left empty x?RYt4S  
        If dlg.TextBox1 = "" Then s'=w/os  
            A = 0           'Default accommodation ^'Qe.DW[  
        Else e<r}{=1w  
            A = CDbl(dlg.TextBox1) ;}4^WzmK^(  
        End If eY8rm  
    3pjK`"Nmz\  
        If dlg.TextBox2 = "" Then y28 e=i  
            pupilDiam = 4   'Default pupil diameter P:fcbfH+  
        Else yR[htD`  
            pupilDiam = CDbl(dlg.TextBox2) =k:yBswi  
        End If YOQ>A*@4  
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        Print " " WO{E T  
        Print "Accommodation = " & A & " Diopters" s}bv o  
        Print "Pupil Diameter = " & pupilDiam & " mm" )GR4U8<>g  
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        ' Calculate new parameters with accommodation LW*v/`@  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Ms14]M[\  
    C(}N*e1  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 3h`_Qv%g  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens G!.%Qqs  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ;P9cjfSn  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens BMYvxSsm  
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        tlens = 3.767 + 0.04*A                  'Lens thickness ~;yP{F8?  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^n9)rsb  
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        'Adjust parameters to account for accommodation  C^*3nd3  
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        '************************************************************************* Z!2%{HQ=q  
        'Aqueous thickness (Position of Lens) @ ('/NjTZ  
        '************************************************************************* ^~7ouA  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0YO/G1O&  
        GetCustomElement eID, entity %JPBD]&M  
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        parID = FindFullName( "Geometry.Arizona Eye" ) >8.o  
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        ' Delete any shift(s) in z ]i Yp  
        count = 0 THY=8&x)  
        While GetOperationCount(eID)>count tO+Lf2Ni+  
            GetOperation eID, count, op 36UUt!}p  
            If op.Type="ShiftZ" Then 4KB>O)YNg'  
                DeleteOperation eID,count raJv$P  
                count=count-1 9y?)Ga  
            End If bPVQ-  
            count=count+1 5F$~ZDu  
        Wend u#nM_UJe  
    &n~v;M  
        'Set new shift in ;}}k*< Z  
        op.Type = "ShiftZ" :N64FR#  
        op.val1 = taq 85qD~o?O  
        op.parent = parID C9^C4   
        AddOperation eID, op  i)= \-C  
        Print "Set aqueous humor thickness = " & taq-0.55 Q/`W[Et  
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        '************************************************************************* /@Ec[4^=!.  
        'Radius and conic constant of anterior lens Cq[<CPAS  
        '************************************************************************* %/w%A:y#&  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 8c%_R23  
        GetConic eID, entity, curv, conic 5+[ 3@  
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        SetConic eID, entity, 1/Rant, CCant dU&hM<.|  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant B3&C=*y  
    7mA:~-.u  
        '************************************************************************* Kp>fOe'KW  
        'Radius and conic constant of posterior lens C_;A~iI7  
        '************************************************************************* 47!k!cHa  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) L\xR<m<,  
        GetConic eID, entity, curv, conic "Z)zKg  
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        SetConic eID, entity, 1/Rpost, CCpost 0DX)%s,KO  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost YnlZyw!  
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        '************************************************************************* cYz|Ux  
        'Lens thickness (Position of posterior lens surface) t6Nkv;)>@  
        '************************************************************************* N#GMvU#R  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) [r^WS;9n  
    ={\9-JJhE  
        ' Delete any z-shift(s) }#2I/dn  
        count = 0 Q!{,^Qb  
        While GetOperationCount(eID)>count 5M\bH'1  
            GetOperation eID, count, op `]F#j ]"  
            If op.Type="ShiftZ" Then EbnV"]1  
                DeleteOperation eID,count Y_/w}HB  
                count=count-1 v)JS4KS  
            End If '?1g_C QsS  
            count=count+1 ;]>a7o  
        Wend B^Hh rz!  
    r*UE>_3J  
        'Set new z-shift rPK1#  
        op.Type = "ShiftZ" %xdyG Al:  
        op.val1 = tlens <3laNk  
        op.parent = parID |?t}7V#[  
        AddOperation eID, op bMGXx>x  
        Print "Set lens thickness = " & tlens 2}rYH;Mx  
    qVE <voB8  
        '************************************************************************* m8Rt>DY  
        'Lens index of refraction {R?VB!dR  
        '************************************************************************* S5[}kfe  
        eID = FindMaterial( "Lens" ) MB+a?u0\  
        GetModelMaterial eID, mat :@~mN7O*  
    7*>,BhF#  
        mat.Nd = nlens \: R Akf<  
        SetModelMaterial eID, mat Sb^o`~ Eh  
        Print "Set lens index of refraction = " & nlens (Q"~bP{F  
    O@a7MzJ  
        '************************************************************************* f1|&umJ$  
        'Pupil diameter 7n7UL0Oc1  
        '************************************************************************* i93^E~q]  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) EZ[e  a<  
    ''}2JJU{  
        'Adjust pupil diameter (trimming volume inner hole) ,8o Y(h  
    "] ]aF1  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" o,'Fz?[T%  
    d$y?py  
        ' Adjust pupil location to just in front of the lens ;)z+dd#3  
        parID = FindFullName( "Geometry.Arizona Eye" ) lT_dzO  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) B1TWOl?d{  
        count = 0 t@jke  
        While GetOperationCount(eID)>count 5ljEh -  
            GetOperation eID, count, op ')ZZ)&U>z  
            If op.Type="ShiftZ" Then bycnh  
                DeleteOperation eID,count c]NZG n*  
                count=count-1 %II o  
            End If D&1(qi=x&  
            count=count+1 ;&XC*R+  
        Wend T3PwM2em_`  
        op.Type = "ShiftZ" zGa V^X  
        op.val1 = taq-0.01 k0,]2R  
        op.parent = parID ZUS06# t}  
        AddOperation eID, op 04:QEC"9mj  
    8zQN[[#n  
        Print "Set pupil diameter = " & pupilDiam Li9>RY+3  
    T }Wse{  
        'Update AZ Eye subassembly Description (?ZS 9&y}  
        eID = FindFullName( "Geometry.Arizona Eye" ) j+Q+.39s-~  
        GetEntity eID, entity ,%U\@*6=  
        entity.Description = "Accommodation = " & A & "D" _7 ^:1i~:.  
        SetEntity eID, entity fDAT#nlyp  
    |k]fY*z(  
        Update dte-2?%~j  
        Print "DONE!" <GSp%r  
         eE@7AM  
    End Sub r ?z}TtDp  
    &}d5'IRT  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: szp.\CMz  
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    Accommodation = 4 Diopters oG c9 6B%  
    Pupil Diameter = 4 mm eQ<G Nvm  
    Set aqueous humor thickness = 2.81 luJNdA:t&  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 G-'CjiMu  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 l0eh}d  
    Set lens thickness = 3.927 rLA^ &P:  
    Set lens index of refraction = 1.42672 PoD/i@  
    Set pupil diameter = 4 K;]Dh?  
    DONE! xW58B  
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    QQ:2987619807 `t+;[G>ZE  
     
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