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infotek 2021-10-22 09:55

Arizona眼睛模型

简介 .:_'l)-  
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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。 Sv=YI  
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模型 kUBE+a6#  
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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。 oXo>pl  
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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. "&L8d(ZuA  
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光源 HwU9 y   
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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。 #.8v[TkKq  
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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。 ^^q&VL  
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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。 txEN7!  
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图2. 字母F光源的设定方法光 a\sK{`|X*  
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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 XtCIUC{r,  
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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。 UfW=/T  
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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。 %/dOV[/  
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图5. 视网膜重点采样规格设定
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脚本 `%YMUBaI  
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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'EEmjJ  
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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。 9]Jv >_W*  
余下的脚本计算与屈光度有关的所有参数。 e5mu-  
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分析 si&du  
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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。 I`{3I-E  
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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 aOvqk ^  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. -1Tr!I:1  
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Dim entity As T_ENTITY vom3 C9o  
Dim op As T_OPERATION k"#gSCW$  
Dim mat As T_MODELMATERIAL (IV\s Y  
Dim A As Double 6uD<E  
Dim pupilDiam As Double !<TkX/O  
Dim eID As Long ]QlW{J  
Dim parID As Long !h1:AW_iz  
Dim count As Integer "U^m~N9k{  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double OROvy  
Dim tlens As Double, nlens As Double ZtZ3I?%U3  
Dim curv As Double, conic As Double .I_atv  
Dim ok As Long ezw*Lo!  
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Sub Main E5i5gE"\  
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    '用户输入对话框 ZK;/~9KU  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 WVD48}HF-  
        TextBox 220,21,40,21,.TextBox1 'default: 0 TG;[,oa  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 '$Z)2fn7  
        OKButton 40,91,90,21 XaCvBQ  
        CancelButton 190,91,90,21 U!uPf:p2  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 gcnX^[`S  
        TextBox 220,49,40,21,.TextBox2 'default: 4 .@): Uh  
    End Dialog %GTFub0 F  
    Dim dlg As UserDialog ;8oe-xS\+  
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    ok = Dialog (dlg) 'IY?=#xr'`  
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    If ok=0 Then    'cancel button was pressed MWme3u)D  
        Print "Execution cancelled." WowT!0$  
        End "gy&eR>  
    End If D\G.p |9=  
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    'Assign accommodation and pupil diameter & use defaults if field left empty @%fTdneH  
    If dlg.TextBox1 = "" Then ^?RH<z  
        A = 0           'Default accommodation 1UK= t  
    Else ^mn!;nu  
        A = CDbl(dlg.TextBox1) YyYZD{^  
    End If FD[*Q2fU  
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    If dlg.TextBox2 = "" Then Nl[&rZ-&  
        pupilDiam = 4   'Default pupil diameter Lfn$Q3}O`$  
    Else pl%!AY'oE>  
        pupilDiam = CDbl(dlg.TextBox2) l<XYDb~op  
    End If 0)SRLHTY%  
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    Print " " 6!>p<p"Ns  
    Print "Accommodation = " & A & " Diopters" rO>'QZ%  
    Print "Pupil Diameter = " & pupilDiam & " mm" 5IUdA?  
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    ' Calculate new parameters with accommodation ef^GJTv&k  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness |l8=z*v<  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens el`?:dY H  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 0 aH&M4  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens _%R^8FjH*  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens mDz44XO   
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    tlens = 3.767 + 0.04*A                  'Lens thickness W6T4Zsg  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction VOD-< "|  
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    'Adjust parameters to account for accommodation iXy1{=BDv  
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    '************************************************************************* OW#0$%f  
    'Aqueous thickness (Position of Lens) S>I` y]qlR  
    '************************************************************************* !O%!A<3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) keLeD1  
    GetCustomElement eID, entity {Vj&i.2,  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Wz.iDRFl  
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    ' Delete any shift(s) in z ;>mM9^Jaf  
    count = 0 l#enbQ`-~  
    While GetOperationCount(eID)>count ya1 aWs~  
        GetOperation eID, count, op 1s(T#jh  
        If op.Type="ShiftZ" Then YA,~qT|  
            DeleteOperation eID,count LUD .  
            count=count-1 SI~jM:S}  
        End If  .x%w#  
        count=count+1 i*/i"W<  
    Wend 1v|-+p42  
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    'Set new shift in 2|^@=.4\  
    op.Type = "ShiftZ" JWd[zJ[  
    op.val1 = taq u ,3B[  
    op.parent = parID OM0r*<D"!  
    AddOperation eID, op Lq5xp<  
    Print "Set aqueous humor thickness = " & taq-0.55 (a#gCG\  
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    '************************************************************************* : wS&3:h  
    'Radius and conic constant of anterior lens sR1_L/.  
    '************************************************************************* ]uox ^HC  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) `{:Nt#7  
    GetConic eID, entity, curv, conic KxK,en4)+  
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    SetConic eID, entity, 1/Rant, CCant (*$F7oO<  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant YA$YT8iMe  
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    '************************************************************************* Ur#jJR@%3  
    'Radius and conic constant of posterior lens  j5/pVXO  
    '************************************************************************* |&8XmexLb  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ns>$  
    GetConic eID, entity, curv, conic q~ a FV<Q  
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    SetConic eID, entity, 1/Rpost, CCpost r\Y,*e  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 0\XWdTj{  
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    '************************************************************************* (0.oE%B",1  
    'Lens thickness (Position of posterior lens surface) ^}Vc||S  
    '************************************************************************* +"-l~`+<es  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) iSO xQ  
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    ' Delete any z-shift(s) )iw-l~y;  
    count = 0 ?@4Mt2Z\  
    While GetOperationCount(eID)>count fX`u"`o5  
        GetOperation eID, count, op t$nJmfzm  
        If op.Type="ShiftZ" Then fE~KWLm  
            DeleteOperation eID,count `{!A1xKZ  
            count=count-1 SX"|~Pi(  
        End If ij0I!ilG4  
        count=count+1 Pv5S k8  
    Wend `f}s<At  
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    'Set new z-shift dP_Q kO  
    op.Type = "ShiftZ" ,WWd%DF)  
    op.val1 = tlens 9< ?w9D.1  
    op.parent = parID tcj "rV{G  
    AddOperation eID, op Zzjx; SF  
    Print "Set lens thickness = " & tlens LSc^3=X  
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    '************************************************************************* E7/UsUV.  
    'Lens index of refraction :ir#7/  
    '************************************************************************* +:@^nPfHy  
    eID = FindMaterial( "Lens" ) C`[2B0  
    GetModelMaterial eID, mat Ld*Ds!*'/  
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    mat.Nd = nlens #6\m TL4vg  
    SetModelMaterial eID, mat f?. VVlD  
    Print "Set lens index of refraction = " & nlens mbbhz,  
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    '************************************************************************* ra*|HcLD  
    'Pupil diameter 1R8tR#l  
    '************************************************************************* dY}5Kmt  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) A x8>  
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    'Adjust pupil diameter (trimming volume inner hole) ?<t?G  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" &'12,'8  
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    ' Adjust pupil location to just in front of the lens 9ad)=3A&L  
    parID = FindFullName( "Geometry.Arizona Eye" ) 3y.+03 W  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) _UTN4z2aTG  
    count = 0 [,Rc&7p~R  
    While GetOperationCount(eID)>count NE#`ZUr3  
        GetOperation eID, count, op #9(+)~irz`  
        If op.Type="ShiftZ" Then 17'd~-lE  
            DeleteOperation eID,count < !m.+  
            count=count-1 v+x<X5u  
        End If T^^7@\vDI  
        count=count+1 Rp2h[_>  
    Wend -%J9!(  
    op.Type = "ShiftZ" ef*Z;HI0  
    op.val1 = taq-0.01 |e#W;q$v  
    op.parent = parID | t:UpP  
    AddOperation eID, op FFZ?-sE  
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    Print "Set pupil diameter = " & pupilDiam ;V~x[J|x  
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    'Update AZ Eye subassembly Description A\S=>[ar-  
    eID = FindFullName( "Geometry.Arizona Eye" ) K@n-#  
    GetEntity eID, entity R(0[bMr3Q  
    entity.Description = "Accommodation = " & A & "D" \1<aBgK i  
    SetEntity eID, entity =A,T:!}'  
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    Update 0B 1nk!F  
    Print "DONE!" `%[m%Y9h  
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End Sub Y!]a*==  
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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: L %acsb}  
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Accommodation = 4 Diopters q<.k:v&  
Pupil Diameter = 4 mm yqx!{8=V  
Set aqueous humor thickness = 2.81 E2}X[EoBF  
Set anterior lens radius = 10.4 and conic constant = -2.375869 /NB|N*}O)  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 J0k!&d8  
Set lens thickness = 3.927 Y/UvNb<lK  
Set lens index of refraction = 1.42672 x Y$x= )  
Set pupil diameter = 4 93Gj#Mk  
DONE! Z/ml ,4e  
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