Sensors and Actuators A: Physical

ContentslistsavailableatScienceDirect

Sensors

and

Actuators

A:

Physical

j our na l h o me p a g e :w w w . e l s e v i e r . c o m / l o c a t e / s n a

An

FPGA-based

versatile

development

system

for

endoscopic

capsule

design

optimization

C.

Cavallotti

a,∗

_,

_P.

_Merlino

b

_,

_M.

_Vatteroni

a

_,

_P.

_Valdastri

a

_,

_A.

_Abramo

c

_,

_A.

_Menciassi

a

_,

_P.

_Dario

a

a_{TheBioRoboticsInstitute,ScuolaSuperioreSantAnna,Pisa56100,Italy} b_{PTLab,AgemontS.p.A.,Amaro33020,Italy}

c_{DIEGM,Universita’diUdine,Udine33100,Italy}

a

r

t

i

c

l

e

i

n

f

o

Articlehistory:

Received30September2010

Receivedinrevisedform11January2011 Accepted12January2011

Available online 31 January 2011 Keywords:

FPGA

WirelessCapsuleEndoscopy Sensor

a

b

s

t

r

a

c

t

Thisworkpresentsadevelopmentsystem,basedonFieldProgrammableGateArray(FPGA),thatwas specificallydesignedfortestingtheentireelectronicstobeintegratedinanendoscopiccapsule,suchasa camera,animagecompressionengine,ahigh-speedtelemetricsystem,illuminationandinertialsensors. Thankstoitshighflexibility,severalfeaturesweretestedandevaluated,thusallowingtofindtheoptimal configuration,intermsofpowerconsumption,performancesandsize,tobefitinacapsule.Asfinalresult, anaverageframerateof19framepersecond(fps)overatransmissionchannelof1.5Mbit/swaschosen asthebestchoiceforthedevelopmentofaminiaturizedendoscopiccapsuleprototype.

© 2011 Elsevier B.V. All rights reserved.

1. Introduction

WirelessCapsuleEndoscopy(WCE)isanemergingtechnology

which is producing a bigimpact onthepracticeof endoscopy.

A typicalendoscopiccapsule isequipped withanimaging

sen-sor,anilluminationsystem,animageprocessor,aradio-frequency

transmitter and a power sourcewhich provides energy to the

wholesystem[1].WCEseemstobesuperiorinthediagnosisof

thesmallbowelpathologiestootherpainlessimagingmodalities,

suchasX-ray,computerizedtomographicenterographyand

mag-neticresonanceenteroclysis,becauseitprovidesadirectvisionof

somegastrointestinal(GI)tractsotherwisedifficulttoreach

with-outsurgery[2].Thistechnologyhashelpeddoctorstodiagnose

pathologies suchas obscure GIbleeding, small-bowel tumours,

Crohn’s disease,and celiac disease[3]. Moreover,WCE reduces

theinvasivenessandpainoftraditionalproceduresresultingmore

acceptableforpatients.

Sinceitscommercialdistributionin2002,differentcapsulesare

nowavailableonthemarket[4].Despiteofseveralenhancements

[5],mainlimitationsarestillrelatedtocorepartssuchasthevision

system.Thecommerciallyavailableendoscopiccapsuletransmits

theimagesattheresolutionof256-by-2568-bitpixelswitha

maxi-mumframerateof7fps.Thisframerateisnotenoughforarealtime

videostreaming,whichishighlydesirableforacorrectdiagnosis.

However,theselimitationsmustbeovercometakingintoaccount

∗Correspondingauthor.

E-mailaddress:c.cavallotti@sssup.it(C.Cavallotti).

thelimitedpowersupplyandthemaximumdimensions(11mm

in diameter(d)×31mminlength(l))suitable fora swallowable

device.

OuraimistodevelopaWCEdevicewithrealtimevision,thus

framerateatleastof15fpsmustbeguaranteedinordertoavoid

flashingimages[6].Moreover,ahighimagequalityintermsof

fea-tureperception,noiseandsufficientilluminationhastobeassured

toachieveacorrectdiagnosis.

Asapreliminarywork,wedevelopedaversatiledevelopment

system,basedonanFPGAdevice,fortestingdifferent

configura-tionsofsomesub-moduleswhicharecorepartsinthecapsule,

suchasacamera,anilluminationsystem,butalsoahighdatarate

transmitterandacompressorenginewhicharecrucialtoreachthe

desiredframerate.Themainfeatureoftheproposedsystemisthe

highflexibility,whichallowstoinvestigatethewholevision

sys-temchainandtohighlightthecriticalissues.TheFPGAcoremakes

developmentsystemeasy-fittingtodifferentconfigurationswhich

canbetestedwithoutanyphysicalhardwarechange.Thissystem

canbeusedasacasestudyforassessingtheoptimumconfiguration

intermsofperformance,powerconsumptionandoverall

dimen-sions,andtosolvethecriticalaspectsbeforetostartthedesignof

theminiaturizedversionsuitableforWCEapplications.

2. Developmentsystemarchitecture

The system is composedby three units: a dedicated vision

board, a main control board and a third board for debug

pur-poses(Figs.1and2).Inthefollowingsectionstheseboardswill

bedescribedindetails.

0924-4247/$–seefrontmatter© 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.sna.2011.01.010

Fig.1. Developmentsystemwithopticsandilluminationsystem. 2.1. Visionboard

ThecoreofthevisionboardisacustomComplementary

Metal-Oxide Semiconductor(CMOS)imagesensor,calledVector2.The

chip was produced in the UMC 0.18!-CIS (CMOS Image

Sen-sor)technologyandincludesaQuarterofVGA(QVGA)320×240

pixel array witha Bayer Color Filter Array(CFA) up, the

com-pletereadoutchannel,a10-bitAnalog-to-Digitalconverter(ADC),

aseriesofDigital-to-Analogconverters(DAC)forinternal

refer-encesanddigitalblocksforthechipcontrol[7].AnI2C-likeinput

isusedforsettingand controlwhilea seriallow-voltage

differ-entialsignaling (LVDS) output interface allows totransmit the

data.Arollingshutterread-outisimplementedinorderto

max-imize sensitivity of the sensor. Its highsensitivity, low power

consumptionandasimplecontrolofthefullchipmakeitsuitable

for WCE applications. Taking into account thephysical

dimen-sion of the Vector2 sensing area (1.408mminhorizontal(d)×

1.056mminvertical(

v

))andthedepthoffocusfrom1mmto10

mmwhichisdrivenbythefinalapplication,acommercial

posi-tivefocallens(NT45-589,EdmundOptics,NewJersey,USA)was

chosen,withafocallengthof1mmandadiameterof1mm,thus

achievingafieldofviewof82◦_(h)×61◦₍

_v

_{).Aplastic,unreflective}

holderwasalsodesignedinordertofixandaligntheoptical

mod-uleinfrontofthechip.Thevisionboardallowstoconnectdifferent

types ofilluminationsystems. Fourwhite light-emittingdiodes

(LED)werearrangedontoaroundshapeprintedcircuitboard(PCB).

Thedesignofthisilluminationsystemwascarriedoutconsidering

atrade-offbetweenpowerconsumption,sizeandtheamountof

lightnecessaryfordiagnosticpurposes.Takingintoaccountthese

features high efficiency LEDs (Nesw007AT, Nichia, Nokushima,

Japan) were chosenwith a dimensionof 1.2mminheight(h)×

2mminwidth(w)×1.3mminthickness(t)andlightintensityof

1000mcdwithapowerconsumptionof15mA@3.3V[8].

ThewhiteLEDsboardcanbereplacedwithcolorLEDsboard

withnomajordesignchangesinthehardware,inordertoobtain

whitelightbycolorlightcombination[9]ortoenablespectroscopic

imaging,suchasautofluorescenceimaging[10].Inthesecases,the

colorLEDsarecontrolledbyindependentdrivingcircuits

imple-mentedontheFPGAenablingaprecisecontrolontheamountof

lightprovidedtothescene,aswillbeexplanedinmoredetailsin

Section3.1.

2.2. ControlboardandFPGAarchitecture

ThecontrolboardisbasedonaFPGAwhichimplementsthe

mainfunctionalitiesofthewholesystem.FPGAswereintroducedas

analternativetodigitalcustomIntegratedCircuits(ICs)for

imple-mentingtheentiresystemononechipandtoprovideflexibility

of re-programmabilitytotheuser[11]. Therefore,thanksto its

high-flexibilityandlowcost,FPGArepresentsthebestchoicefor

testingdifferentsolutionstoselecttheoptimalforourapplication.

AdetailedbenchmarkanalysiswascarriedouttochooseanFPGA,

suitablenotonlyfortestingpurposebutalsotobeintegratedin

afutureminiaturizedversionofthesystem,whichwillbefitted

inanendoscopicpill.Asconsequence,parameterssuchaspower

consumption,physicalsizeandoverallgatecountweretakeninto

account.AcompactsystemfromSiliconBlue(iCE65L08)was

cho-senbeing4.79(h)×4.37(

v

)mmin sizewitha verylow power

consumption(12mA@32MHz).ThesefeaturesmaketheiCE65L08

suitabletobefitinanendoscopicpill.

Inordertohavearealtimevideo streaming,aframerateof

atleast15fpsisneeded.However,increasingtheamountofdata

causeshugeincreaseinpowerconsumptionintheRFtransmission

[12],thatisthemainconstraintinWCE.Hence,applyingimage

compressionisnecessaryforlimitingthetransmissionworkload

andsavingthepowerdissipation.

A compression engine which is well suited for WCE must

havelowpowerconsumption,logicresourcesandlimited

mem-orysizeneededforthecompression.CurrentJPEGcompression

chipsrequiretheavailabilityofaconsiderableamountofhardware

resourcesresultinginahighpowerconsumption(typicallymore

than 100mW),which is notacceptablein this application[13].

Amongsimplededicatedalgorithms,wechosethelow-complexity

compressionenginedevelopedby[14]becauseitsperformances

arecomparablewithJPEG2000,butloweringthecomplexity

allow-ingitsimplementationonthechosenFPGA.

TheFPGAisalsousedtodistributetheclocktothewhole

sys-tem. The imagesensor is then driven by a 8MHz@1.8V clock,

whiletheFPGAinternallogicbya16MHz@1.8Vwithanexternal

32MHz@3.3VoscillatorininputtotheFPGA.

AsinFig.2,severallogicblockswereimplementedontheFPGA

inordertocarryoutsomebasictaskssuchastheVector2

config-uration,theimageacquisitionandilluminationcontrol.Moreover,

asimplePC-basedsoftwareallowstheusertoconfiguretheFPGA

andthevisionchipandtoshowtheacquiredimagesonscreen

throughtheUSBconnection.TheVector2configurationtaskis

per-formedbytheUSBInterface,theInstruction(n.b.)ControlandI2C

Masterblocks.Theconfigurationdata,sentbytheuserthroughthe

developedsoftware,arereceivedbytheUSBInterfaceblockthat

interconnectstheFPGAwiththeexternalCypress FX2USB

con-troller.TheInstructionControlblockdecodestheinstructionsand

sendstheconfigurationdatatotheI2CMasterblock.Finally,theI2C

MasterconfigurestheVector2chipthroughtheI2Cbus.The Instruc-tionControlblocksendsconfigurationdataalsototheLEDDriverin

ordertocontroltheLEDsandtheamountoflightprovidedtothe

scene,asitwillbeexplainedinSection3.1.Aftertheconfiguration

phase,theVector2Receiverdecodesthedataacquiredbythevision

chip,convertingtheLVDSsignalstoa10-bitparallelformat.Then

theacquiredframesarestoredintheexternalSRAMchip,whichis

usedasaframebuffer.Thememorizedframescanbereadfromthe

SRAMbytheMemoryControllerblockandsenttothePCthrough theUSBInterfaceblockandexternalUSBcontroller.

Thelogicblocksimplementedinthisconfigurationarewritten

withVHSICHardwareDescriptionLanguage(VHDL),anduse31%1

ofthetotalFPGA(2400logiccells)andcanoperateatamaximum

frequencyofabout41MHz.Thepowerconsumptionofthe

devel-opedsystemislessthan360mWanditsplitsasfollows:40mW

fortheVector2chip,about10mWfortheFPGAand310mWfor

debugblockswhichwillbenotforeseeninthefinalminiaturized

prototype.

2.3. Debugboard

Thesystemisalsoequippedwithadebugboardtoincreasethe

flexibilityofthesystem.TheboardisequippedwiththeCypress

FX2USBcontrollerthatprovideshigh-speedconnectionandfully

configurabilitybytheintegrated8051microcontroller.Thedebug

boardisalsoequippedbytheCypressCY7C1339GSRAMchipthat

isusedasframebufferfortheacquisitionofimagesfromthe

sen-sorchipandtostoreadditionaldataforimageprocessing.Finally,

severalconnectorsareusedtomonitoreachpinoftheFPGA.The

1_{WeusethelogiccellsasameasureoftheFPGAresourcesoccupation.The}

pre-sentedareaoccupationreferstothebasicconfiguration,withoutthecompressor, brightnesscontrolblockorwirelesstransmitterblock.

Fig.3.Acquiredimagesfromdifferentgastrointestinaltracts,duringexvivotests.

purposeofthisboardistoprovidearealtimedebugplatformforthe

wholedemosystem.APC-basedsoftwareisusedtosetupthe

reg-istersoftheFPGAandoftheVector2chipandtomonitorthestatus

ofthesystemthroughtheUSBconnection.Theacquiredimagesare

storedintheSRAM,senttothePCandshownonthescreen.Finally,

theUSBconnectionisusedalsoforthecontroloftheillumination

andtheLEDdrivers.

3. Testsandsub-modulesintegration

Some experiments were done totest separately and finally

togethereachsub-modulewhichwillbeintegratedinthefinalpill.

3.1. Imagesacquisitionandbrightnesscontrol

Atfirst,imagesfromexvivoanimaltissuewereacquiredusing

thevisionboard,withtheopticsandwhiteillumination,inorder

todefinetheimagerandilluminationcontrolsettingsnecessaryto

achieveasuitableimagequalityfordiagnosticpurposes(Fig.3(a)

and(b)).AsimpleLEDdriverwasimplementedintheFPGAable

tosettheamountoflightdrivingtheLEDsbyaPulseWidth

Fig.4.Imageblocksusedtobrightnesslevelestimationandbrightnesscontrolarchitecture.

illuminationduringtheintegrationtimeoftheopticalsensor,thus

modulatingtheaveragecurrentprovidedtotheLEDs.Thelength

ofthecurrentpulsesprovidedtotheilluminationsystemandtheir

numberaresetbyafewinternalregisters,whichcanbemodifided

inrealtimewiththeUSBconnection.However,theillumination

isswitchedononlywhentheopticalsensorisinitsintegration

phaseinordertoavoidflickeringeffects.InthecaseofRGBLEDs,

threedriverscontrolledbythreedifferentgroupsofregistersare

implementedontheFPGAinordertodriveeach groupof LEDs

independentely.SinceinarealapplicationsuchasWCE,itisnot

desirabletomanuallysettheproperamountoflight,wealso

imple-mentedanautomaticbrightnesscontrolsystem.

Inmodernvisionsystems,thebrightnessoftheacquiredimages

dependsonseveralfactors.Amongothers,themostimportantones

arethelens,thesensitivityandintegrationtimeofthevisionsensor

andtheillumination.Inourprototypethelensischosenbasedon

thefieldofviewandsizerequirements,whiletheintegrationtime

ofthesensorisfixedinordertoachievethedesiredframerate.Asa

consequence,wecansetthebrightnessoftheimagesbycontrolling

theamountoflightprovidedtothescene.Thisisequivalentto

con-troltheexposuretimeinstandarddigitalcameras.Exposurecontrol

algorithmstypicallydividetheacquiredimageinseveralblocksand

computetheaverageluminancesignalineachblock.Thentheblock

luminancevaluesarecombinedwithdifferentweightsinorderto

estimatebacklitorfrontlitscene[15].Sinceinourapplicationthe

onlypossiblecaseisthefrontlitbecausetheonlysourceoflightare

theLEDs,wedecidedtocomputetheaverageluminancesignalof

asingle128×128pixelsblockinthecentreoftheimage(Fig.4).

Moreover,wecannotcomputetheluminancevaluesofthepixels

becauseoftheBayerCFAmountedontheVector2chipandthe

lackofthedemosaicingblock.Consequently,wedecidedto

esti-matethebrightnessbasedonlyonthegreenpixelvaluesbecause

thegreencomponentmostlycontributestotheluminanceofan

image[16]andinaBayerfiltertheirnumberaredoublethanthe

redand blueones.Thebrightness controlblockreadsthepixel

valuesrecoveredbythereceiveranddrivestheLEDdriverblock

accordinglywiththeestimatedbrightnesslevel.Hence,theLEDs

intensityiscontrolledtomaintainthebrightnesswithinadefined

interval.TheLEDsaredrivenbythedefinedsequenceofcurrent

pulsesonlyduringthesensorintegrationtimeinorder to

min-imizethepowerconsumption. Thisstrategy allowsnot only to

accuratelycontroltheamountoflightprovidedtothescenebut

alsotosimulateaglobalshutter.Theentiresensorstartsgathering

lightwhentheLEDsareturnedon,whilethecontentsofthe

sen-sorarereadoutwhentheyareturnedoff,thusminimizingimage

artefacts[17].

TheFPGA implementationoftheproposedbrightness control

blockuses320logiccells,whiletheimpactonthemaximumclock

frequencyisminimal.

3.2. Columnpatternnoisecorrection

TheCMOSimagersoftensufferfromFixedPatternNoise(FPN)

[18].FPNisanon-temporalspatialnoise,anditiscausedbythe

non-uniformityofthetransistor’scharacteristicswithinthepixels

andthecolumnamplifier,thisresultingfromfabricationprocess

tolerances.ThepixelFPNnoiseisusuallyremovedatthepixellevel

byhardwaresubtraction,whileawaytoeliminatethecolumnFPN

isasubtractionbetweentheacquiredimageandareferencedark

image.Thissimplemethodrequiresthatthedarkimageisacquired

and stored intotheFPGA or intheexternal SRAM. Sincea full

framecannotbememorizedinsidetheFPGAbecauseofthelack

ofmemoryandintherealapplicationitisnotdesirabletousean

externalSRAM,wedevelopedandtestedanalternativeversionof

thealgorithmthatreducesthememoryrequirements.Ourideais

tocomputethemeanvaluesoftheevenandoddrowsofadark

imageandtorecursivelysubtractthesefromtheacquiredimages.

Inthisway,thememoryrequirementsofthearchitecturecanbe

reducedtotworowsonly(2×320×10bits).Wecomputetwo

dif-ferentmeanvaluesforevenandoddrowsbecausetheCFAmounted

ontheimagerusesapatternof2×2pixels.

Atfirst,theilluminationisswitchedoffandtheFPGAstartsto

acquireadarkimage.Eachcoupleofrowsisaccumulatedina

two-rowsmemoryinsidetheFPGA.Attheendoftheacquisition,the

averagevaluesarecomputed.ThentheLEDsareswitchedonand

whenthenextimageisreceivedbytheFPGA,thereferencedark

rowsaresubstractedfromeachcoupleofrowacquired.Fig.5(a)

showstheimagewiththeFPN,whileFig.5(b)showstheresult

ofthecorrectionstrategy.Theresultingimageisbetterinterms

ofperceivedresolution.Inordertoevaluatetheeffectivenessof

ouralgorithmwecalculatedthestandarddeviationofthe

origi-nalimageandtheelaboratedone.Since thefixedpatternnoise

isashort-rangenoise,weacquiredawhiteimagewithanuniform

illuminationinordertoexcludethecontributionofimagecontrasts

anddarkfixedpatternnoise.Weobservedthatthestandard

devi-ationoftheimageafterelaborationis20%lessthantheoriginal

one.

3.3. Compressorimplementation

In ordertofulfiltheframeraterequirements, a image

Fig.5. Originalimageanddenoisedimagewithreconstructeddarkimage.

tested[13,19]takingintoaccountthepowerlimitationandsmall

sizeconditionswhicharethemainfeaturesofWCE.Forthese

rea-sons,alow-power,low-complexitylossycompressorspecifically

developed for capsule endoscopy was chosen [14]. The

imple-mentedcompressorisbasedonintegerversionofdiscretecosine

transform(DCT)andperformssequentiallyfouroperations:color

transformation, image transformation, coefficients quantization

andentropycoding.Thisconfigurationconsumesabout77%ofthe

resourcesoftheFPGAand25blockRAMsandcanworkata

fre-quencyofupto39MHz.

Finally,theresultsoftheimplementationofthechosen

com-pressorcanbeseeninFig.6(a)and(b).Thefirstpictureshows

animage acquiredwithan integrationtimeof 50ms and LEDs

switchedonfor25ms,whilethesecondoneshowsthesameimage

afterthecompressionstagewitharatioofabout8.Ascanbeseen,

thecompressorintroducessomeartifactsduetothelossynatureof

thecompressionalgorithm,butthequalityoftheimageissufficient

fordiagnosticpurposes.Asafinalremark,itcanbenotedthatthe

compressionratiocanbesetthroughaproperchoiceofthe

com-pressorparameters,thusallowingthereductionoftheamountof

databetween8and20[14].

Fig.6.Acquiredimagesbeforeandaftercompression.

Fig.7. Miniaturizedprototype. 4. Conclusionsandfutureworks

AnFPGA-baseddevelopmentsystemwasdesignedinorderto

test a complete wireless imaging acquisition chain suitable for

WCE.Thefinalgoalistoachieveasmoothrealtimevideostream

Themainchallengefacedintegratingthesystem,inorder to

enablearealtimediagnosis,wasrelatedtoimagecompressionand

wirelessvideostreamtransmissionvs.theoriginaldatapayload.

After the analysis of several wireless technologies [20], we

decidedtoimplementthetransmitterpresentedinRef.[21].The

chosensolutionisbasedonnear-fieldtechnologyandpresentsthe

bestperformanceintermsofdatarateandthebestefficiencyin

termsofpowerconsumptionvs.datarate[20],enablinga

trans-missionof1.5Mbit/swithapowerconsumptionof2mW@1.8V.

SincetheVector2imagerresolutionisaQVGAandeachpixelis

decodedby10bits,theoriginalamountofdataforeachframeis

768kbit.Consideringanaveragecompressionratioof10,the

min-imumframerateis19.53fpswithanoverallpowerconsumption

of90mA@3.3Vand26mA@1.8V.

Consideringtheresultsobtainedwiththedevelopmentsystem,

aminiaturizedversionwasdesignedandnowundertest(Fig.7).

Theprototypeconsistsoftwoboardsconnectedbyapermanent

flexible interconnectionwitha diameterof9.9 mmin order to

fitinapillcasewithaninnerdiameterof10mm.Moreover,the

additionalthreeflexiblecircuitpartsallowtheconnectionofother

boardswithcomponentsrequiredbythesystem,suchasbattery

orwirelesspowersupply[22]andinertialsensors[23].

Acknowledgements

TheworkdescribedinthispaperwasfundedbytheEuropean

CommissionintheframeworkofVECTOR FP6Europeanproject

EU/IST-2006-033970.

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Biographies

CarmelaCavallottireceivedadegreeinbiomedicalengineering(withhonours) fromtheCampusBio-MedicoUniversityinRomeinDecember2007.Sheiscurrently aPhDstudentinbioroboticsattheCRIMLaboftheScuolaSuperioreSant’Annain Pisa.Hermainresearchinterestsareinthefieldsofvisionsystemsforbiomedical applications.

PierantonioMerlinowasborninUdine,Italy,in1980.Hereceivedthelaureadegree inelectricalengineering(summacumlaude)fromtheUniversityofUdine,Italy, in2005andthePhDdegreeinelectricalengineeringfromthesameInstitutionin 2009.Hisresearchinterestsincludesthestudyandrealizationofelectronic sys-temsforpervasivecomputingapplications,communicationandpowertechnologies forwireless/contactlessapplications.Currentlyheisworkingonvisionsystemsfor endoscopicapplications.

MonicaVatteroniwasborninLaSpezia,Italy,in1975.ShereceivedanM.S.degreein electricalengineeringfromtheUniversityofPisa(Italy)in2001andaPhDdegreein physicsfromtheUniversityofTrento(Italy),in2008.From2002to2008,sheworked forNeuriCam,Trento(Italy),aspixelengineerandanaloguedesigner,andin2005 shebecameresponsibleforthedevelopmentofCMOSImageSensors.Presently, sheworksfortheScuolaSuperioreSant’AnnainPisa(Italy)aspostdoctoralfellow, wheresheisresponsiblefortheresearchanddevelopmentofimagesensorsand visionsystemsforbiomedicalapplications.Sheistheauthorandco-authorof sev-eralconferenceandjournalpublicationsandofthreepatents.Herinterestsinclude CMOSimagesensors,lownoiseanalogueelectronics,highdynamicrangepixelsand endoscopicvisionsystems.

PietroValdastrireceivedadegreeinelectronicengineering(withhonours)from theUniversityofPisainFebruary2002.InthesameyearhejoinedtheCRIMLab oftheScuolaSuperioreSant’AnnainPisaasaPhDstudent.In2006heobtained aPhDinbioengineeringfromtheScuolaSuperioreSant’Annadiscussinga the-sistitled“Multi-AxialForceSensinginMinimallyInvasiveRoboticSurgery”.Heis nowassistantprofessoratCRIMLab,withmainresearchinterestsinthefieldof implantableroboticsystemsandactivecapsularendoscopy.Heiscurrently work-ingonseveralEuropeanprojectsforthedevelopmentofminimallyinvasiveand wirelessbiomedicaldevices.

AntonioAbramowasborninBologna,Italy,in1962.Hereceivedthelaureadegree inelectricalengineering(magnacumlaude)fromtheUniversityofBologna,Italy, in1987,andthePhDdegreeinelectricalengineeringfromthesameInstitutionin 1995.HisexperienceincludesresearchperiodswiththeIntelCorporation,Santa Clara(CA),USA(1992),attheCenterforIntegratedSystems,StanfordUniversity, Stanford(CA),USA(2000).BetweenOctober1993andDecember1994hewas resi-dentscientistattheAT&TBellLaboratories,MurrayHill(NJ),USA,whilefrom1995 to1997hewaspost-docattheDepartmentofPhysics,UniversityofModena,Italy. AntonioAbramoisco-authorofabout70scientificpublicationsonInternational JournalsandConferences.Inyears2001–2002hehasbeenappointedmemberof the“ModelingandSimulation”technicalsub-committeeoftheIEEEInternational ElectronDeviceMeeting(IEDM)Conference,andinyear2003Chairofthesame sub-committee.Presently,heisassociateprofessorofelectronicsattheUniversity ofUdine,Italy.Afterabout10yearsofscientificactivityinthefieldofmodelingand simulationofcarriertransportinelectrondevices,startingfromyear2001his scien-tificinteresthasmovedtothedesignofcircuitandsystemforwirelessapplications, tothestudyofneuralnetworkscircuitsforreconfigurableplatforms,tothedesign ofwearablesystems,andtowardsthemethodologiesfordistributedcomputingin wirelesssensornetworks.

AriannaMenciassireceivedherlaureadegreeinphysics(withhonours)from the University of Pisa in 1995. In the same year, shejoined the CRIM Lab oftheScuolaSuperioreSant’AnnainPisaasaPhDstudentinbioengineering witharesearchprogramonthemicromanipulationofmechanicaland biologi-calmicroobjects.In1999,shereceivedherPhDdegreebydiscussingathesis

titled“MicrofabricatedGrippersforMicromanipulationofBiologicalandMechanical Objects”.CurrentlysheisaprofessorofbiomedicalroboticsattheScuola Supe-rioreSant’Anna,Pisa.Hermainresearchinterestsareinthefieldsofbiomedical microandnano-robotics,microfabricationtechnologies,micromechatronicsand microsystemtechnologies.SheisworkingonseveralEuropeanprojectsand interna-tionalprojectsforthedevelopmentofmicroandnano-roboticsystemsformedical applications.

PaoloDarioreceivedhislaureadegreeinmechanicalengineeringfromthe Univer-sityofPisain1977.Currently,heisaprofessorofbiomedicalroboticsattheScuola SuperioreSant’Anna,Pisa.Healsoestablishedandteachesthecourseon mechatron-icsattheSchoolofEngineering,UniversityofPisa.Hehasbeenavisitingprofessorat theEcolePolytechniqueFederaledeLausanne(EPFL),Lausanne,Switzerland,andat

WasedaUniversity,Tokyo,Japan.HeisthedirectoroftheCRIMLabofScuola Superi-oreSant’Anna,wherehesupervisesateamofabout70researchersandPhDstudents. Hismainresearchinterestsareinthefieldsofmedicalrobotics,mechatronicsand microengineering,andspecificallyinsensorsandactuatorsfortheabove applica-tions.HeisthecoordinatorofmanynationalandEuropeanprojects,theeditoroftwo booksonthesubjectofroboticsandtheauthorofmorethan200journalpapers.He isamemberoftheBoardoftheInternationalFoundationofRoboticsResearch.Heis anassociateeditoroftheIEEETransactionsonRoboticsandAutomation,amember oftheSteeringCommitteeoftheJournalofMicroelectromechanicalSystemsand aguesteditoroftheSpecialIssueonMedicalRoboticsoftheIEEETransactionson RoboticsandAutomation.HeservesaspresidentoftheIEEERoboticsand Automa-tionSocietyandastheco-chairmanoftheTechnicalCommitteeonMedicalRobotics ofthesamesociety.