Morphological characterization of particles by the intensity and polarization of the scattered radiation

(1)

Contents lists available atScienceDirect

Optik

j o u r n a l h o m e p a g e :w w w . e l s e v i e r . d e / i j l e o

Original

research

article

Morphological

characterization

of

particles

by

the

intensity

and

polarization

of

the

scattered

radiation

H. Chorﬁ

a,∗

_,

_K.

_Ayadi

a

_,

_R.

_Gader

a

_,

_L.

_Boufendi

b

a_Applied_Optics_Laboratory,_Institute_of_Optics_and_Precision_Mechanics_Setif-1-_University,₁₉₀₀₀_Setif,_Algeria b_GREMI,_Orléans_University,₁₄_Rue_d’Issoudun_BP6744,₄₅₀₆₇_Orléans_cedex_2,_France

a

r

t

i

c

l

e

i

n

f

o

Articlehistory: Received13July2017 Accepted10October2017 Keywords: Biosensors Lightscattering Mietheory

Light-biologicaltissuesinteraction Complexindexofbiologicaltissues

a

b

s

t

r

a

c

t

Opticaltechniquesarebeingusedmoreandmore,becausetheyhavetheadvantageofbeing non-destructive,thelightscatteringbythematerialprovidesaframeworkofprospecting pointedandfast.Theelasticandinelasticinteractionportionofthelightwiththematter allowsfollowingtheassessmentofparticulatematterincludingcellnucleiwhicharethe focusoftissuepathologies.Ourworkfocusedontheuseofthisphenomenontofollowthe evaluationinsizeandshapeofthenuclei,inordertopreventtumoractivity.

1. Introduction

Lightscatteredbythebiologicaltissueisratherrelatedtoitsstructure,includingtothedensity[1],size[2]andmorphology ofcellsnuclei[3],etc,theseimportantparametersareindicationsforthepathologisttomakedifferentiatebetweennormal cells(whichoftenhaveastructuredorganization),andtumorcells(whichpresentadisorderlystructure).

Inthepresentwork,thelightscatteringisusedasatooltocharacterizethiskindoftissue.Theadvantageofthistechnique isthatitismadewithoutcontactwiththeobjectstudied,non-destructiveandnon-ionizing.Thismeansthattheuseof electromagneticwaveinformationis nowthesubjectofincreasinginterest inthebiomedical ﬁeld,andthephysicsof materials[4,5].Theprecisiononthediagnosisisrelatedtotheprecisiononthemeasurementsofthescatteredradiation,the parametersofwhichextractsmaybeexploitedtostudytheevolutionofthemicroparticlessizeandmorphology.Various measurementsofthescatteringintensities,andinparticularofitsangular,spectral,orpolarizationdependence,canserve asadiagnosticmeans.

Our objective istomake help pathologicalanatomy services.Thistechnique offersvaluableassistance byits non-destructiveeffectanditsspeedandprecision,byvaryingsameopticalparameterssuchaswavelength,polarizationstate andscatteringangle,theinformationontheevolutionofparticlessizesandmorphologymakesitpossibletopredictdirectly theexistenceofpathology.

∗ Correspondingauthor.

E-mail addresses: chorfi[email protected], chorfi[email protected] (H. Chorfi), [email protected] (K. Ayadi),

[email protected](R.Gader),[email protected](L.Boufendi).

https://doi.org/10.1016/j.ijleo.2017.10.056

(2)

Theamplitudeofscatteredlightatdifferentanglesdependsnotonlyoncomplexrefractionindexofthemediuminwhich theparticleexistsandtheparticlesize[9],butalsoontheparticlemorphology[10,11].

Usingtheabovemethodforcalculationthescatteringphasefunctions,wecanexaminetheeffectsofparticlesize,shape, refractiveindexandparticlemorphology.Weﬁrstexaminetheeffectsofparticlesizeonthescatteringproperties.Weuse theMietheorytoplottheangularscatteringdistributionsforaseriesofradiusfrom0.1␮mto14.0␮mwhichhavebeen illuminatedwithseveralwavelengthsofpolarizedvisiblelight.

Takingintoaccountthepolarizationweusedthecomplexformulasofscattering[12,13].Theyinvolvetwocomplex functionsofscatteredamplitude:S1()andS2().

Theelectricﬁeldisdecomposedintotwopolarizations: ErPolarizedperpendicularelectricﬁeldtothescatteringplane.

EtPolarizedparallelelectricﬁeldtothescatteringplane.

Theexpressionofthediffusionis: Er=S1() e−ikr+ikz ikr Er0 (01) Et=S2() e−ikr+ikz ikr Et0 (02)

Er0andEt0areIncidentﬁelds.

Foranunpolarizedincidentwave,theintensityisthen: I=I0

1

2r2_k2(i1+i2) (03)

IfthewaveislinearlypolarizedalongOx: I₌I0 1 r2_k2(i1sin 2_(ϕ) +i2cos2(ϕ)) (04) When:i1=|S1()|2andi2=|S2()|2

TheamplitudefunctionsS1(perpendiculartothescatteringplane)andS2 (paralleltothescatteringplane)havethe

followingform: S1()=

∞ 1 2n₊1 n(n+1)[ann(cos()+bnn(cos())] (05) S2()=

∞ 1 2n(n+1) n(n+1)[bnn(cos()+ann(cos())] (06)

Theangularfactorsnandnhavethefollowingforms:

n(cos())= 1 sin()P 1 n(cos()) (07) n= d dP 1 n(cos()) (08)

(3)

Fig.1.Geometryusedtodescribetheincidentandscatteredfields.Weletthezaxisbethedirectionofpropagationoftheincidentlight,anddefinethe scatteringplaneasthatcontainingthezaxisandradiusvector.Wewritethescatteredfieldsintermsofadifferentbasisthanthatusedtodescribethe incidentfields.Eachofthesebasissetshasaunitvectorthatisparalleltoandaunitvectorthatisperpendiculartothescatteringplane[6].

Fig.2. Schemeoftheusedset-up.

4. Experimentalachievement

Tomeasurethescatteredintensityasafunctionoftheangleofobservation,weusedtheexperimentalsetupshownin theﬁgurebelow:

Theoutgoingbeamfromaxenonlightsourceiscollimatedbyusingtwolenses(lens1andlens2)forgettingaKöhler illumination.Forenhancingthebeam,afielddiaphragmandaspatialfilterareadded.Theobtainedbeamilluminatesthe samplesurfaceandahemisphericaldetectorisfinallyusedtodetectthescatteredintensitiesaccordingtotheangleof observation.Inthecaseofspectralandpolarizedlightapplications,apolarizerandachromaticfilterareinsertedbeforethe sampleposition(Figs.1and2).

Thepolarizedsignalscapturedareintegratedtoobtainthescatteredintensitywhichrelatesthesampleresponseusing anappropriateprogramunderMatlab-Clanguagesoftwarethatwehavedeveloped.

5. Cartesianrepresentationofintensities

Theobservationofthedifferentcurvesofthescatteredintensitiesasafunctionoftheangleofobservationandthe wavelengthgivesthesameappearanceforthedifferentcases.Nevertheless,weobservedifferentspecularintensitiesasa functionof␭,thisisexplainedbytheinﬂuenceoftheabsorptionparameterbythetissue.Infact,wenoticealessimportant lossforlongwavelengths.Fromthere,wewillusethelongestwavelengthtominimizetheeffectofabsorption(Tables1–4). Theresultsshowﬂuctuationsasafunctionofthepolarizationstateofthescatteredwave;thismayhelpustoevaluate anaveragemorphologyofthescatteringparticlesbycalculatingthediametersasafunctionofthepolarizationangle.

Forthecalculations,wehavedevelopedprogramstoplotthecurvesandtodeterminetheareas(theglobalintensities) ofthedifferentmeasurements,andthenonthebasisofthemathematicalmodelofMie,wehaveimprovedouralgorithm inordertoextractthemorphologiesfromthecalculatedparticlessizes.

Thefollowingtableshowssomeresultsobtained:

Byobservingtheresultsrepresentedinthetableabove,itisnotedthattheareasunderthecurvesofthescattered intensitiesinthecaseofthetumortissuearelargercomparedtothenormaltissue.Thepolarizationshowsasigniﬁcant differenceinthelevelofintensitysensedaccordingtothedifferentstates,thiscanbeexploitedtodeterminethespatial geometryofthediffuser(morphology).Wehaveconﬁrmedexperimentallythattheintensityofthescatteredlightisvery

(4)

30◦

60◦

(5)

Table1(Continued)

Polarizationangle(␤) NormalColon TumoralColon

120◦

150◦

180◦

Table2

RepresentationoftheareasofthecurvesfortheColonasafunctionoftheWavelengthandthepolarizationstate:(A)NormalColon,(B)TumorColon.

␤(◦) ␭=470nm ␭=510nm ␭=630nm Areas A B A B A B 0◦ _0.6845 _2.3383 _1.0342 _1.1509 _0.9671 _1.7345 30◦ _0.4135 _1.7938 _0.6184 _1.2360 _0.9556 _1.7598 60◦ 0.3149 2.1616 0.5836 1.2406 0.9641 2.1732 90◦ 0.2578 2.1927 0.6312 1.2556 0.9140 1.7686 120◦ _0.3832 _2.0513 _0.8275 _1.1094 _0.9431 _1.3235 150◦ _0.4185 _0.9144 _0.3088 _1.1353 _1.0072 _1.9776 180◦ _0.5383 _0.8161 _0.2339 _1.4989 _0.9498 _1.6517

stronglydependentonseveralexperimentalparameterssuchasthewavelength,thepolarizationstateandtheparticlesize ofthescatteringmedium.

6. Measurementofnucleussizesusinglightscattering

Theefﬁciencyoflightscatteringpushedustodevelopacalculationprogramtodeterminetheparticlesizesfromthe collectedpolarizedintensities.ThisprogrambasedonMie’stheoryallowedustoobtainthesizesgatheredinthetable.The resultsobtainedwerecomparedwiththemicroscopicvalueswhichseemtobeingoodagreement.

(6)

150◦ 2.02 3.76

160◦ _2.42 _3.76

170◦ _2.18 _3.72

180◦ _2.20 _3.88

Table4

Polarrepresentationofthemorphologyofthestudiednuclei.

Coreofanormalcell Coreofatumorcell

Colon

Bysimplifyingthesemeasurements,wecandeterminethesizeofthesupposedsphericalparticle: Theaveragecoresizeofanormalcell(Colon)is:3.02_␮m

Theaveragesizeofthetumorcell(colon)is:3.81␮m

Thedifferentdiametervaluescanbecollectedinapolarcoordinatesystemtoevaluatetheparticlemorphology.

7. Studyofmorphology

Amorphologicalstudybasedonthecorrelationofthesizesobtainedbyourprogramwascarriedout,theresultsmade itpossibletoevaluatethegeneralmorphologyofthenucleibyplottingthespatialdistributionofsizes.

Thestudyofthemorphologyofcellnucleishowsthedifferencebetweenthenormalandtumoralnucleus,thisdifference isveryclearbyobservingthetableabove.FortheColon,wecansaythatthemorphologyhasbeenmodiﬁedinvalueand form,infavorofabiologicalevolution,theevolutionofthesizeandmorphologyofnuclei(diffusingparticles)Canleadto theemergenceofapathologyoftissue.

8. Conclusion

Thespatialdistributionofthescatteredlightintensitydependsoncell’smorphologyandthepolarizationstatesofincident light;wecanextractcellularmorphologicalinformationfromthescatteredlightinspeciﬁcangularrangesortheoverall patterntodiscriminatedifferentcelltypes.

Theangularandspectralvariationsallowedustoevaluatethesizesofthenucleibetweenthenormalandpathological organ.Thepolarizationstateparametermadeitpossibletoevaluatethemorphologyofthetwocases.Theresultsobtained havebeenconfrontedwithmeasurementsbymicroscopyofthesesameparticles,andthecomparisonwasgivenasatisfaction withtheopticaltoolsetup.

(7)

Acknowledgments

“ThisworkwassupportedbytheMinistryofHigherEducationandScientiﬁcResearch(Ministèredel’Enseignement SupérieuretdelaRechercheScientiﬁque,MESRS).Wewouldliketothanktheteamofthepathologicalanatomyservice− theuniversityhospitalofSetif,fortheirhelp."

References

[1]W.F.CHEONG,S.A.PRAHL,A.J.WELCH,AreviewoftheopticalpropertiesofBiologicalTissues,IEEEJ.Quant.Electr.26(1990)2166–2185. [2]C.F.BOHREN,D.R.Huffman,AbsorptionandScatteringofLightbySmallParticles,Wiley-VCh,2004.

[3]Y.Wang,G.Chen,Simulationoflightscatteringpropertiesofmaterialsurfaceconsideringthespeciﬁcmorphologyinformation,Optik-Int.J.Light ElectronOpt.(2016).

[4]A.Wax,V.Backman,BiomedicalApplicationsofLightScattering,McGraw-Hill,2010.

[5]J.Holoubek,Someapplicationsoflightscatteringinmaterialsscience,J.Quant.Spectrosc.Radiat.Transf.106(2007)104–121.

[6]J.D.Wilson,MeasurementsandInterpretationsofLightScatteringfromIntactBiologicalCells,Rochesteruniversity,2007(Philosophydoctorat). [7]Y.Pu,J.Chen,W.Wang,InvestigationofscatteringcoefﬁcientsandanisotropyfactorsofhumancancerousandnormalprostatetissuesusingMie

theory,Proc.SPIE8941(2014).

[8]W.Meng,etal.,GeneralizedmultiparticleMiemodelingoflightscatteringbycells,Chin.Sci.Bull.58(2013).

[9]H.Ding,J.L.Lu,W.A.Wooden,P.J.Kragel,X.H.Hu,Refractiveindexofhumanskintissuesateightwavelengthsandestimateddispersionrelations between300and1600nm,Phys.Med.Biol.51(2006)1479–1489.

[10]V.Devarakonda,S.Manickavasagam,Polarizedlightscatteringtechniqueformorphologicalcharacterizationofwaterbornepathogens,J.Biomed. Opt.7306(2016)73061.

[11]E.Zubko,Y.Shkuratov,G.Videen,Effectofmorphologyonlightscatteringbyagglomerates,J.Quant.Spectrosc.Radiat.Transf.150(2015)42–54. [12]D.W.Hahn,LightScatteringTheory,Floridauniversity,2009.