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    [分享]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: 2020-12-09
    简介 J ]ri|a  
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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。 fG" 4\A  
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    模型 KN< KZM  
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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。 f\u5=!kjN  
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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. M <K}H8?  
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    光源 Iy;bzHXs  
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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。 GhC%32F  
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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。 cnL@j_mb  
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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。 }>yQ!3/i  
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    图2. 字母F光源的设定方法光 91oAg[@4G  
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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 3e?a$~9  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 w)<h$ <tU  
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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。 evE$$# 6R  
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    图5. 视网膜重点采样规格设定
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    脚本 1z-Q~m@@  
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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: qwvch^?>FQ  
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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。 ;T|hNsSt  
    余下的脚本计算与屈光度有关的所有参数。 ~+anI  
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    分析 te b/  
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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。 .ZVo0  
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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 9UcSQ"D  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ^T_2 s  
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    Dim entity As T_ENTITY dL|*#e  
    Dim op As T_OPERATION }^Ky)**  
    Dim mat As T_MODELMATERIAL :eL ja*  
    Dim A As Double k(R&`  
    Dim pupilDiam As Double a {4RG(I_  
    Dim eID As Long jbs)]fqC;  
    Dim parID As Long }x+s5a;!3/  
    Dim count As Integer (nt=  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double \"=b8x  
    Dim tlens As Double, nlens As Double RrRE$g  
    Dim curv As Double, conic As Double iNEE2BPp  
    Dim ok As Long BLcsIyq  
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    Sub Main B$&&'i%  
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        '用户输入对话框 "Rq)%o$Z  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 _?~)B\@~0  
            TextBox 220,21,40,21,.TextBox1 'default: 0 O`2hTY\  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Fa9gr/.F,@  
            OKButton 40,91,90,21 N-<m/RS  
            CancelButton 190,91,90,21 Z >F5rkJ  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 {aYCrk1  
            TextBox 220,49,40,21,.TextBox2 'default: 4 YN($rAkL  
        End Dialog 6^v HFJ$  
        Dim dlg As UserDialog > @n?W"  
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        ok = Dialog (dlg) TptXH?  
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        If ok=0 Then    'cancel button was pressed QP1 bm]QYA  
            Print "Execution cancelled." V8IEfU  
            End U(u$5  
        End If r^$WX@ t&  
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        'Assign accommodation and pupil diameter & use defaults if field left empty @DK;i_i  
        If dlg.TextBox1 = "" Then 7 J+cs^2  
            A = 0           'Default accommodation 0\Ga&Q0-(O  
        Else riY[p,  
            A = CDbl(dlg.TextBox1) X)k+BJ  
        End If N[8y+2SZ  
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        If dlg.TextBox2 = "" Then Fc.1)yh.  
            pupilDiam = 4   'Default pupil diameter h;`]rK;g  
        Else z\r|5Z  
            pupilDiam = CDbl(dlg.TextBox2) .qG*$W2f  
        End If `6 `oLu\l  
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        Print " " = *~Q5F  
        Print "Accommodation = " & A & " Diopters" 7(1UXtT  
        Print "Pupil Diameter = " & pupilDiam & " mm" " H; i Av  
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        ' Calculate new parameters with accommodation HE>sZ;  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness !>gu#Q{\-  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens eE-c40Bae  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 4.}J'3 .  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens &0QtHcXpR  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens >Pw ZHY  
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        tlens = 3.767 + 0.04*A                  'Lens thickness ]eD5It\  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction >djTJ>dl_u  
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        'Adjust parameters to account for accommodation #(Ah>y  
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        '************************************************************************* d:1TSJff%/  
        'Aqueous thickness (Position of Lens) _;yi/)-2  
        '************************************************************************* dLIZ)16&  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 6pi^rpo  
        GetCustomElement eID, entity E]26a,^L  
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        parID = FindFullName( "Geometry.Arizona Eye" ) K%/:V  
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        ' Delete any shift(s) in z [r"`r Bw  
        count = 0 h.D*Y3=<  
        While GetOperationCount(eID)>count X9xXL%Q  
            GetOperation eID, count, op L4C_qb k;:  
            If op.Type="ShiftZ" Then "8|a4Y+F  
                DeleteOperation eID,count U*7Yi-"/*  
                count=count-1 %.3] F2_Q  
            End If >:yU bo)  
            count=count+1 0zvA>4cq)  
        Wend "Ooc;xD3<  
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        'Set new shift in eX9Hwq4X44  
        op.Type = "ShiftZ" k yI-nE  
        op.val1 = taq XK7$Xbd  
        op.parent = parID 07:N)y,  
        AddOperation eID, op hB:}0@l6p=  
        Print "Set aqueous humor thickness = " & taq-0.55 ;[>g(W+  
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        '************************************************************************* pg;y\}  
        'Radius and conic constant of anterior lens I||4.YT  
        '************************************************************************* bRzw.(k0`r  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) PWw2;3`-6w  
        GetConic eID, entity, curv, conic @<W^/D1#L  
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        SetConic eID, entity, 1/Rant, CCant WFBVAD  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant *U69rbYI  
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        '************************************************************************* %m5&U6  
        'Radius and conic constant of posterior lens RN0=jo!58  
        '************************************************************************* h72#AN  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ' 3MCb  
        GetConic eID, entity, curv, conic ; OpN &q+  
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        SetConic eID, entity, 1/Rpost, CCpost 8w|-7$ v  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost %tRQK$]c  
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        '************************************************************************* M((]> *g  
        'Lens thickness (Position of posterior lens surface) n,E =eNc  
        '************************************************************************* }&{z-/;H  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) n)'5h &#  
    .h;PMY+  
        ' Delete any z-shift(s) !y{t}|U/d  
        count = 0 =oPc\VYW  
        While GetOperationCount(eID)>count AM ZWPU  
            GetOperation eID, count, op lwU$*?yv  
            If op.Type="ShiftZ" Then 1 ynjDin<  
                DeleteOperation eID,count zAxscD f'  
                count=count-1 GvCB3z  
            End If ]U8VU  
            count=count+1 M#PutrH  
        Wend -!kfwJg8N(  
    .<Lbv5m  
        'Set new z-shift 1JIo,7  
        op.Type = "ShiftZ" > (.V(]{3y  
        op.val1 = tlens !k= ~5)x  
        op.parent = parID aj71oki)  
        AddOperation eID, op Q0\tK=Z/  
        Print "Set lens thickness = " & tlens fuQb h  
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        '************************************************************************* \ tK{!v+  
        'Lens index of refraction >O:31Uk  
        '************************************************************************* 0xe!tA  
        eID = FindMaterial( "Lens" ) W_##8[r(?  
        GetModelMaterial eID, mat 4KkjBPV  
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        mat.Nd = nlens Y<vsMf_U  
        SetModelMaterial eID, mat aq|R?  
        Print "Set lens index of refraction = " & nlens EPZ^I)  
    qXH\e|  
        '************************************************************************* @4'bI)  
        'Pupil diameter !p4y@U{  
        '************************************************************************* jBTXs5q  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) u9:+^F+  
    Pa{)@xT  
        'Adjust pupil diameter (trimming volume inner hole) oBm^RHTZ  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" GomTec9.  
    aa'u5<<W  
        ' Adjust pupil location to just in front of the lens I4%p?'i,C  
        parID = FindFullName( "Geometry.Arizona Eye" ) 0 tZ>yR  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) h#o3qY  
        count = 0 yJheni  
        While GetOperationCount(eID)>count KVvzVQ1  
            GetOperation eID, count, op _msV3JBr  
            If op.Type="ShiftZ" Then QEavbh^S  
                DeleteOperation eID,count 7.r}98V  
                count=count-1 &!y7PWHJ  
            End If (&w'"-`  
            count=count+1 v[aFSXGj)  
        Wend 9'qU4I  
        op.Type = "ShiftZ" }|k_sx:  
        op.val1 = taq-0.01 0{8^)apII  
        op.parent = parID [BH^SvE  
        AddOperation eID, op y}fF<qih'>  
    j=%^CRum  
        Print "Set pupil diameter = " & pupilDiam #q06K2  
    c\n&Z'vK  
        'Update AZ Eye subassembly Description 6(Qr!<  
        eID = FindFullName( "Geometry.Arizona Eye" ) &?],uHB?d  
        GetEntity eID, entity Ag>E%N  
        entity.Description = "Accommodation = " & A & "D" Xm|Uz`A;  
        SetEntity eID, entity nTJ-1A7EP  
    n9;z=   
        Update >d`XR"_e  
        Print "DONE!" =1JS6~CTLN  
         {M7`z,,[  
    End Sub "funFvY  
    B]`!L/  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: /D]V3|@E  
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    Accommodation = 4 Diopters >t[beRcR6  
    Pupil Diameter = 4 mm wIrjWU2  
    Set aqueous humor thickness = 2.81 wH=L+bA>a  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 aKLA_-E  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 UN~dzA~V  
    Set lens thickness = 3.927 WcCJ;z:S?k  
    Set lens index of refraction = 1.42672 _^)Wrf+  
    Set pupil diameter = 4 o]&w"3vOP0  
    DONE! F/"Q0%(m  
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