Upload
others
View
3
Download
0
Embed Size (px)
Citation preview
VirtualrealityobjectsimprovelearningefficiencyandsustainedabilitiesinfetalultrasoundJ.Ebert1,B.Tutschek2
1MedicalSchool,ZürichUniversity,Zürich,Switzerland,2PrenatalZürich,Zürich,Switzerland,andMedicalFaculty,HeinrichHeineUniversity,Düsseldorf,Germany
ACCEPTEDFORPUBLICATION,JULY2018,UltrasoundinObstetricsandGynecology
Abstract
ObjectiveVirtualreality(VR)objectsoffetalultrasound(US)volumeshavebeenproposedforteachingandlearningdiagnosticultrasound.WehypothesizedthatVRobjectsimprovelearningefficiencyandretentionofdiagnosticabilities.
MethodsMedicalstudentsandjuniordoctorsweretaughtnormalandabnormalsonographicfetalbrainanatomyusingconventionalmeans(videolecturesandreviewarticles;controlgroup)oradditionallywithselectedVRobjectsfromanovelfetalbrainatlas(http://pb.fetal.ch;studygroup).Knowledge,speedofrecognitionandretentionofdiagnosticabilitiesweretestedoneandfourmonthslater.
ResultsThestudygroupansweredsignificantlymorequestionscorrectlyandsolvedthetestsquickerthancontrols,bothoneandfourmonthsaftertheteaching.
ConclusionTheuseofVRobjectssignificantlyimproveslearningefficiencyandknowledgeretentioninfetalultrasoundteaching.
TeachingultrasoundusingVR
2
IntroductionUltrasoundisthemaintoolforprenataldiagnosis.Specificprotocolshavebeendevelopedforscreeninganddiagnosticaspects1.However,theperformanceofdiagnosticultrasoundisveryoperator-dependent.Increasinglysophisticatedequipmentandextendedprotocolswidenthegapbetweenthetheoreticallypossiblediagnosesandtheskillsofexaminers2.Ultrasoundeducationinvolvesdirecttuitionbyateacher,supervisedimageacquisitionandapplicationofpracticalskills,andobservationofeducationalnormalandpathologicalcases.Someaspectscanbeachievedbyself-study,usingdigitalteachingmaterial2,3.
Ultrasoundimagingdataarewellsuitedfortransformationintodigitallearningobjects4.Virtualreality(VR)objectsoffersuchanewwayofsimulation-basedultrasoundtraining5,6.„PocketBrain“isawebbasedlearningtoolthatuseshighlyinstructiveimagingdatafromnormalandstructurallyabnormalfetuses,capturedusingvolumeultrasoundandpresentedasVRobjects,whichare“‘scroll-through’movies“,withafixedorientationtoenablesimpleandconvenientuse7.Westudiedtheeffectof“PocketBrain”onlearningofjuniordoctorswithregardtofetalcerebralmalformations.Themainobjectivewastostudyiftheuseofvirtualrealityobjectsimproveslearningefficiencyandknowledgeretention,usingmultiple-choicequestionsinstandardizedtestsaboutfetalbrainanomalies.Secondaryobjectivesweretoanalyzehowthiseffectdiffersovertime,testingtheparticipantstwice,threemonthsapart;toexamineapossibleinfluenceontestsolvingspeed;andifvirtualrealityobjectscanhelpwithdiagnosticallychallenginganomalies.
MethodsThestudywasperformedbetweenMayandDecember2016.Participantswerejuniordoctorsandmedicalmasterstudentswithoutspecificpriorultrasoundteaching,recruitedfrommedicalschoolsandvariousuniversityandnon-universityteachinghospitals(seeAppendixA)throughpersonalcontactortherespectivedepartmentaleducators.
Theentirestudywasconductedonline,usingaweb-basedlearningplatform(Moodle,MoodlePtyLtd,Perth,Australia)thatcontainedallteachingandtestmaterial(seeAppendixB).
Forrandomallocationofparticipantstothecontrolandstudygroups,firstly,raffleticketswiththeassignmentofparticipantstostudyorcontrolgroupwereprepared,pleatedtohidetheassignmentandshuffled.Then,theywerehandedouttoparticipantsaccordingtothereceiptoftheenrollment.
Afterconfirmationofparticipation,registrationandlog-in,thetraineeshadtocompleteatwo-hourlearningsession,accordingtotheirgroupallocation,withoutorwithvirtualrealityobjects.Participantswererandomizedtothecontrolortheexperimentalgroup.Participantsofbothgroupseachreceivedatotaloftwohoursteaching.Testcompletionandtimetrackingwasregisteredperparticipant,usingthewebsite’stools.
Teachingconsistedeitherofanone-hourvideolectureonthefetalbrainanditsmalformationsaswellasindividualreadingoftwoteachingarticlesforoneadditionalhourinthecontrolgroup;or,intheexperimentalgroup,participantswereadditionallyexposedtoselectedVRobjectsfrom„PocketBrain“,anovelonlineatlasandteaching
TeachingultrasoundusingVR
3
systemthatusesVRobjectsofnormalandabnormalfetalbrainvolumes7(seefig.1).Thecompleteteachingandtestingenvironmentisnow,aftertheendofthestudy,freelyaccessible(seeAppendixB).Diagnosticabilitiesweretestedinbothgroupsusingadigitalmultiple-choicequestionnaire(MCQ)oneandfourmonthsaftertheteaching(fig.1).TheMCQconsistedof20questionsaboutthefetalbrainanditsanomalies.Eightquestionstestedfactualknowledgethathadbeenpresentedinthelecturesandarticlesprovided,and12questionsrequiredrecognitionoffetalbrainmalformationsonultrasoundimages.
Onespecificquestion(MCQno.17)concernedvisualrecognitionofagenesisofthecorpuscallosum),whichhasbeensuggestedasaparticularlydifficultand,therefore,discriminatingquestion8.TheresultsofthegroupsregardingMCQ17werecomparedseparatelyinadditiontotheentiretestresults.
Onlyparticipantscompletingbothtestswereevaluated.
ThestatisticalprogramR(R.Gentlemanetal.,StatisticsDepartmentoftheUniversityofAuckland,NewZealand),version3.4.1,wasusedforstatisticalanalyses.Todetectanassumedsignificantdifferenceof5%forcorrectlyansweredquestions,thepowercalculation,performedusingG*Power(version3.1,HeinrichHeineUniversityDüsseldorf),showedarequiredparticipantnumberofn=84(42pergroup).NormaldistributionwastestedaccordingtoShapiro-Wilk.Levene’stestwasusedtoassesshomogeneityofvariance.Forvariablewithhomogeneityofvarianceandnormaldistributionoftheresidualsone-wayANOVAwasused(indicating“mean”values)includingCohen’sdtestforeffectsize;notnormallydistributedvariablesweretestedusingtheMann-WhitneyUTest(indicating“median”values)includingZvaluesforeffectsizer9.TheFisher'sexacttestwasusedforevaluationofthespecificquestion17.
Fig.1Recruitment,randomization,teachingandtesting(oneandfourmonthsaftertheteaching)
TeachingultrasoundusingVR
4
ResultsOftheinitiallyrecruitedparticipantsfromtwocountries(Switzerland,Germany)and13differenthospitals,51completedbothtests:30inthecontrolgroup,and21inthestudygroup.
VRsignificantlyimproveslearningefficiency.Thestudygroupansweredmorequestionscorrectlythancontrols,bothoneandfourmonthsaftertheteaching;thisdifferencewasbiggerfourmonthsaftertheteaching(seetable1andfig.2).Cohen’sdbothtests(oneandfourmonthsaftertheteaching)showedstrongeffects:Cohen’sd(test1)=1.05;Cohen’sd(test2)=1.32.
A. B.
Fig.2:Testresultsofcontrols(group1)andstudygroup(group2)onemonth(test1;fig.2A)andfourmonthslater(test2;fig.2B).UseofVRobjectinteachingimprovesabilitiesoneandfourmothsafterteaching.Thestudygroupalsosolvedthetestsquicker,bothonemonth(medianVR-group=13.2minvs.mediannon-VR-group=15.9min,Z=6.2148,p-value<0.001,effectsizer=0.87,i.e.astrongeffect)andfourmonthsaftertheteaching(medianVR-group=10.3minvs.mediannon-VR-group13.5min,Z=6.2155,p-value<0.001,effectsizer=0.53,i.e.astrongeffect).Theabilitytorecognizeagenesisofthecorpuscallosum,MCQno.17inourtest,hasbeenproposedasadiscriminatingfactorforappliedspecificknowledge8.ThestudygroupdidbetteratMCQ17comparedtothecontrols,bothonemonthandfourmonthsaftertheteaching(71%and67%vs.55%and57%),butthesedifferenceswerenotstatisticallysignificant(p=0.25andp=0.57).
Threefourthsoftheparticipantsinbothgroupswerefemale.Bothgendersscoredthesameaveragenumbersofcorrectanswersinbothtests(test1:femalemean=13.1points,SD3.21vs.malemean=13.1points,SD3.12,p=0.96;test2:femalemean=12.3points,SD4.14vs.malemean=12.9points,SD4.01,p=0.62).Fig.S1showsthecorrelationbetweencorrectanswersandgenderoftheparticipants.
Notallregisteredparticipantscompletedtheteachingandbothtests.Aftertest2,therewere21medicalstudents(70%)and9juniordoctorsinthecontrolgroup,5studentsand16juniordoctors(76%)intheVRgroup.Toassessaneffectofthisuneven
TeachingultrasoundusingVR
5
distributionofstudentsbetweenthetwogroups,separateanalysesofonlythestudentsandonlythejuniorresidentsinbothgroupsweredone.Overall,juniordoctorsscoredbetter,butjuniordoctorsandmedicalstudentsinthestudygroupperformedbetterthanpeercontrols.ThecomparisonsbetweenstudentsandjuniordoctorsaswellasbetweencontrolsandVRgroupareshownintable1.Fig.S2showstestperformances(intest1and2)ofjuniordoctororstudentstatus.
Allparticipants
Medicalstudents
Juniordoctors
Test1
Test2Test1
Test2Test1
Test2
Controlgroup
(n=30)
§median=11.9
IQR=3.51
§median=10.6
IQR=5.0
§median=11.2
IQR=3.1
#median=9
IQR=5
#median=14
IQR=2
§median=12.6
IQR=6.21
VRgroup
(n=21)
§median=14.9
IQR=4.2
§median=15.1
IQR=4.05
§median=12.0
IQR=3.51
#median=14
IQR=5
#median=16.5
IQR=4.25
§median=15.8
IQR=2.43
p-values<0.001
<0.001
0.52
<0.001
<0.001
0.07
Tab.1Compariso
noflearningeffectb
ygroupassig
nmentandpriortra
ining(co
rrecta
nswerso
utof20questio
nsperte
st).Afterte
stingfor
normaldistrib
ution(datanotsh
own),m
eanvaluesandsta
ndarddeviations(S
D)w
erecalculatedfornormallydistrib
utedvariables
(indicatedby“§”),u
singone-wayANOVA;th
eywerethenconvertedintomedian10andIQR 11fo
runiformityofpresentation.Fornot
normallydistrib
utedvariables(in
dicatedby“#”)m
edianvaluesandinterquartile
ranges(IQ
R)w
erecalculated,usingtheMann-WhitneyU
test.
DiscussionTheuseofultrasoundishighlyoperator-dependent.Developmentofincreasinglysophisticatedequipmentmagnifiesthepotentialfordiagnosticerror.Duetoalackoftraining,thereisawideninggapbetweenthesophisticationofthemostadvancedmachinesandtechniquesandtheskillsofthoseexpectedtousethemandinterprettheimages2.Clinicalexperienceanddirectobservationandtraininginspecializedultrasoundunitspredicttrainees’confidenceinperformingdiagnosticobstetricultrasoundexamindependently,butconcernsexistabouttheadequacyofcurrentultrasoundtrainingprograms.Simulation-basedtrainingmayimprovelearningefficiencyandknowledgeretention12.
VirtualReality(VR)objectshavebeenproposedasteachingandself-studytools3,4,6,12.Inaclinicallyrelevantcontext,i.e.teachingjuniordoctorsandmedicalstudentstorecognizefetalbrainanomaliesonultrasoundimaging,westudiedifVRobjectsimproveteachingsuccess.OurresultsshowthattheuseofVRobjectsimproveslearningsignificantlyandinasustainedway.Theexperimentalgrouphadself-studyexposuretoVRobjectsforaslittleasonehour,yettheyansweredmorequestionscorrectlythanthecontrolgroup.KnowledgeretentionwasalsobetterafterVRteaching.Thesefindingsareconsistentwithotherresultsonlearningbehaviorthatshowbeneficialeffectsofvisuallearning13.
Werecruitedstudentsandjuniordoctorsforourstudy,becauseconventionalsimulation-basedultrasoundtrainingworksbetteronnovicetraineesthanonexperiencedvolunteers14.WeexplicitlylimitedtheaccesstotheVRobjectstoarelativelyshortperiodoftimeforthestudygrouptoavoiduncontrolledadditionalself-study.Now,aftertheendofthestudy,thisweb-basedtooliscontinuallyavailable,cantheoreticallybeupdatedandenhancedtorepeatandaugmentthelearningprocessandtofurtherconsolidateindividualknowledgeandabilities.
Anotheradvantageofhavingweb-basedvirtualrealityobjectsfortheparticipantswastheresource’savailabilityatanytime,dayornight.Whilethisallowedtheparticipantstoselecttheirbestindividualconditionsforthelearningsessionandthetests,itmighthavebeenaconfoundersincedaytimeandlocationoftestperformancewerenotstandardized.Theoretically,externalauxiliarytoolsmighthavebeenused,buttheconditionswereidenticalforbothgroups.
Limitationsofourstudyare(i)themoderatenumberofparticipantswhocompletedbothtestsand(ii)theunevendistributionofthejuniordoctorsandthestudentssecondarytodropoutsofparticipants.Tryingtoavoidaneventualunevendistributionofjuniordoctorsandstudentstostudyandcontrolgroups,infurtherstudies,onecouldfirstbreakupparticipantsintojuniordoctorsandstudentsandthenallocaterandomly.
Theeffectsizeeventuallyfoundwasbiggerthanexpected,yieldingsignificancesforfewerparticipantsthaninitiallycalculated.OverestimatingtheutilityofVRobjectsisunlikelytohaveoccurred:Weacceptedonlymotivatedparticipants(finalyearsmedicalstudentandjuniordoctors)whoapproachedusvoluntarily,havingbeenalertedtothepossibilityofparticipation.Then,randomizationtookplace.Focusingonaveryspecifictopic(fetalbrainabnormalities)andspecifictestquestions(onlytestinginformationpreviouslypresentedtobothgroups)andequalallottedtimeduringteachingandexecutionofthetestsreducedpotentialerrorinthejudgmentoftestefficacy.
TeachingultrasoundusingVR
8
Inconclusion,weforthefirsttimedemonstratetheutilityofVRobjectsforacquisitionofdiagnosticabilitiesandknowledgeretentioninprenataldiagnosis.Basedonourresultsandoncurrentresearchonthetheoryoflearningandthevariouspossibilitiesofthedigitalage,weproposetomakeultrasoundtrainingasvisualaspossible.VRobjectsprovideanidealtoolforthis;theycanbeeasilycombinedwithadditionallearningresourcessuchasonlinelecturesandconventionalscriptsortextbooks.TheVRobjectsusedforthisstudyaswellastheteachingandtestingenvironmentarefreelyavailable,canbeusedbyothersandcouldbeadaptedtocoverotheraspectsofdiagnosticimaging.
VRobjectsincreasetheefficiencyoftrainingandtheretentionoftheacquireddiagnosticabilities.Furtherstudieswithmoreparticipantsandforotherorganregionsthanthefetalbrainshouldbeperformed.
AcknowledgementsWearegratefultoDr.OlivierMerlo,statistician,ZHAW,Wädenswil,Switzerland,andtheInstituteforStatisticsinMedicine,HeinrichHeineUniversity,Düsseldorf,Germany,fortheirvaluablestatisticalhelpandadvice.
TeachingultrasoundusingVR
9
Appendices
AppendixAWeareverygratefultotheparticipantswhowererecruitedfromthefollowinginstitutions:Dept.ofObstetrics,CharitéBerlin;Dept.ofObstetrics,UniversityHospitalDüsseldorf;ZürichUniversityMedicalSchool;UniversityHospitals,Basel,BernandZürich;CantonalhospitalsofSt.Gallen,Lucerne,Frauenfeld,andMünsterlingenandhospitalsZollikerberg,Grabs,Herisau,Wil.
AppendixBTeachingmaterial:anone-hourlectureonthenormalandabnormalfetalbrain(B.Tutschek,Zürich,andG.Pilu,Bologna);onehourreadingoftwoaccompanyingreviewarticles/guidelines1,13;and“PocketBrain”,anovelonlineatlasandlearningtool7thatisfreelyavailableathttp://pb.fetal.ch.Foraccesstotheteachingmaterialandenvironmentpleaseemailthecorrespondingauthor.
TeachingultrasoundusingVR
10
Supplementalmaterial
• Recognizingcorpuscallosumundcavumseptipellucidi,bananasignundlemonsign,Dandy-Walkermalformation,megacisternamagna,holoprosenzephaly,myelocele,myelomeningozele,Blake’spouchcyste,vermishypoplasy,agenesisofcorpuscallosum
• Namingthetwoaxialsectionsasthediagnosticstandardsectionsofthefetalbrainscreeningexamination
• Theatriaoftheposteriorhornastheregionwheretheventricularwidthshouldbemeasured
• Definitionofmildtomoderateventriculomegalyaslateralventricularwidthof10-15mm
• Determiningthecoronalplaneinanultrasoundimageofanormalfetalbrain• Diagnosisofpartialagenesisofthecorpuscallosuminthesagittalsection• The"hourglassconfiguration"andBlake’spouchcyst.• Agenesisofcorpuscallosumnotbeingpartofthedifferentialdiagnosisincystic
spacesintheposteriorfossa.• Knowingthemaincausesofcysticenlargementsoftheposteriorfossa• Associationofthelemonsignwithspinabifida;incidenceoftheclosedform
spinabifidaTab.S1Specificteachingandtestingobjectives(containedinlectures,teachingarticlesandinPocketBrain)
A. B.
Fig.S1Correlationofcorrectsanswersintests1(onemonthafterteaching;fig.S1A)aswellas2(fourmonthsafterteaching;fig.S1B)bygenderoftheparticipants(1:XX,2:XY).
TeachingultrasoundusingVR
11
A. B.
Fig.S2Correlationbetweenaccuracyofanswersintests1(onemonthafterteaching;fig.S2A)aswellas2(fourmonthsafterteaching;fig.S2B)byprioreducation.Overall,juniordoctorsscoredbetterthanmedicalstudents,butjuniordoctorsandmedicalstudentsinthestudygroupperformedbetterthanpeercontrols.(3:medicalstudents,4:juniordoctors).
TeachingultrasoundusingVR
12
References
1. InternationalSocietyofUltrasoundinO,GynecologyEducationC.Sonographicexaminationofthefetalcentralnervoussystem:guidelinesforperformingthe'basicexamination'andthe'fetalneurosonogram'.UltrasoundObstetGynecol2007;29:109-116.2. SalvesenKA,LeesC,TutschekB.BasicEuropeanultrasoundtraininginobstetricsandgynecology:whereareweandwheredowegofromhere?UltrasoundObstetGynecol2010;36:525-529.3. TreleaseRB,NiederGL,DorupJ,HansenMS.GoingvirtualwithquicktimeVR:newmethodsandstandardizedtoolsforinteractivedynamicvisualizationofanatomicalstructures.AnatRec2000;261:64-77.4. TutschekB.Simplevirtualrealitydisplayoffetalvolumeultrasound.UltrasoundObstetGynecol2008;32:906-909.5. TutschekB,PiluG.Virtualrealityultrasoundimagingofthenormalandabnormalfetalcentralnervoussystem.UltrasoundObstetGynecol2009;34:259-267.6. TreleaseRB,NiederGL.Transformingclinicalimagingand3Ddataforvirtualrealitylearningobjects:HTML5andmobiledevicesimplementation.AnatSciEduc2013;6:263-270.7. TutschekB,PiluG.PocketBrain,aninteractive,web-basedultrasoundatlasofnormalandabnormalfetalbraindevelopment.UltrasoundObstetGynecol2017;49:431-432.8. WiechecM,NocunA,KnafelA,BeithonJ,StettnerD.FourStepsinDiagnosingCompleteAgenesisoftheCorpusCallosuminPrenatalLife.UltraschallMed2016;37:92-99.9. PallantJ.SPSSSurvivalManual.OpenUniversityPress:Buckingham,Philadelphia,2007.10. GausW,MucheR.MedizinischeStatistik:AngewandteBiometriefürÄrzteundGesundheitsberufe.Schattauer,2013,220.11. PeckR,DevoreJL.Statisticstheexplorationandanalysisofdata.CengageLearning,2011,118.12. TutschekB,TercanliS,ChantraineF.Teachingandlearningnormalgynecologicalultrasonographyusingsimplevirtualrealityobjects:aproposalforastandardizedapproach.UltrasoundObstetGynecol2012;39:595-596.13. DeCatteL,DeKeersmaekerB,ClausF.Prenatalneurologicanomalies:sonographicdiagnosisandtreatment.PaediatrDrugs2012;14:143-155.