Table Of ContentACSP · Analog Circuits And Signal Processing
Francesco Mazzilli
Catherine Dehollain
Ultrasound
Energy and
Data Transfer
for Medical
Implants
Analog Circuits and Signal Processing
SeriesEditors:
MohammedIsmail,Dublin,USA
MohamadSawan,Montreal,Canada
The Analog Circuits and Signal Processing book series, formerly known as the
Kluwer International Series inEngineering andComputer Science, isahigh level
academicandprofessionalseriespublishingresearchonthedesignandapplications
of analog integrated circuits and signal processing circuits and systems. Typically
per year we publish between 5–15 research monographs, professional books,
handbooks,editedvolumesandtextbookswithworldwidedistributiontoengineers,
researchers,educators,andlibraries.
Thebookseriespromotesandexpeditesthedisseminationofnewresearchresults
and tutorial views in the analog field. There is an exciting and large volume of
research activity inthe field worldwide. Researchers are strivingtobridge the gap
between classical analog work and recent advances in very large scale integration
(VLSI) technologies with improved analog capabilities. Analog VLSI has been
recognized as a major technology for future information processing. Analog work
is showing signs of dramatic changes with emphasis on interdisciplinary research
effortscombiningdevice/circuit/technologyissues.Consequently,newdesigncon-
cepts,strategiesanddesigntoolsarebeingunveiled.
Topicsofinterestinclude:
AnalogInterfaceCircuitsandSystems;
Dataconverters;
Active-RC,switched-capacitorandcontinuous-timeintegratedfilters;
Mixedanalog/digitalVLSI;
Simulationandmodeling,mixed-modesimulation;
Analognonlinearandcomputationalcircuitsandsignalprocessing;
AnalogArtificialNeuralNetworks/ArtificialIntelligence;
Current-modeSignalProcessing;
Computer-AidedDesign(CAD)tools;
AnalogDesigninemergingtechnologies(ScalableCMOS,BiCMOS,GaAs,
heterojunctionandfloatinggatetechnologies,etc.);
AnalogDesignforTest;
Integratedsensorsandactuators;
AnalogDesignAutomation/Knowledge-basedSystems;
AnalogVLSIcelllibraries;
Analogproductdevelopment;
RFFrontends,WirelesscommunicationsandMicrowaveCircuits;
Analogbehavioralmodeling,AnalogHDL.
Moreinformationaboutthisseriesathttp://www.springer.com/series/7381
Francesco Mazzilli (cid:129) Catherine Dehollain
Ultrasound Energy and Data
Transfer for Medical
Implants
FrancescoMazzilli CatherineDehollain
MelexisTechnologiesSA ELB231BatimentELB
Bevaix,Switzerland EPFLSCISTICD
Lausanne,Vaud,Switzerland
ISSN1872-082X ISSN2197-1854 (electronic)
AnalogCircuitsandSignalProcessing
ISBN978-3-030-49003-4 ISBN978-3-030-49004-1 (eBook)
https://doi.org/10.1007/978-3-030-49004-1
©SpringerNatureSwitzerlandAG2020
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Ifweknewwhatitwaswewersedoing,it
wouldnotbecalledresearch,wouldit?
—AlbertEinstein
Idedicatethisbooktomyparents,sisterand
mygirlfriendChloéwithloveandgratitude.
Preface
Thetechnologyevolutioninthelastdecadehaspromotedthedevelopmentofnew
sensing and monitoring devices for healthcare. The upcoming great challenge for
diagnosis devices lies in their ability to continuously monitor a patient’s physical
and biochemical parameters, under the natural physiological status of the patient,
and in any environment. Human body monitoring using a network of wireless
sensors may be achieved either by attaching these sensors to the body surface
(wearablemedicaldevices)orbyimplantingthemintotissues(implantablemedical
devices),dependingontheirfunctionality.
This book proposes systems and methods, not using RF or magnetic telemetry
withtheircripplinglimitations,butacousticwaves(ultrasonic),forcommunicating
with and energizing efficiently a network of transponders that are placed deep
within a human body. Therefore, the primary key objective is to develop a novel
telemetry technology that will enable any kind of device implanted deep inside
the body to communicate wirelessly with an external system, providing patients
andphysicianswithvaluabletools,respectively,tocontinuouslymonitorandtreat
severalpotentiallylife-threateningconditionsinaminimallyinvasivemanner.
The implantable transponder contains an energy exchanger which converts
acoustic energy into electrical energy, a small local energy storage (rechargeable
microbattery), a control and processing chip (low-power microcontroller), and a
simpletransceiver.Thisbookalsoincorporatesadedicatedsectionontheexternal
control unit, capable of powering and receiving information directly from the
implanteddeviceviaultrasound.
A discrete version of the implanted device is realized to test energy power
transmission and characterize the uplink communication while changing the dis-
tance between the control unit and the implant. The microcontroller ATMEGA
48Ahandlesthedifferentoperationsasthebatteryreachesenoughcharge.Forthe
uplink,thebackscatteringcommunicationprincipleisappliedtoultrasoundwaves
to remove the use of a local oscillator in the implanted device, thus minimizing
powerconsumption.
ix
x Preface
A second version of the implanted device is realized using a standard CMOS
process.Hence,anovelactiverectifierisdesignedin0.18μmHVCMOSprocess
which presents 80% power conversion efficiency and a chip area of 0.114 mm2.
Tosuppressvoltagenoiseonthesupplyrail,atwo-stagelow-drop-outregulatoris
designed with the same CMOS process aimed to recharge a Lithium Phosphorus
Oxynitride (LiPON) microbattery. The downlink communication is studied and
a non-coherent demodulation scheme is adopted, thus a variable gain amplifier
is designed in 0.18 μm low-power CMOS process, which shows a maximum of
58.8dBdifferentialgainat1MHzandabandwidthof2.5MHz.
The research leading to these results has received funding from the European
Community’sSeventhFrameworkProgramme(FP7/2007-2013)undergrantagree-
mentn.224009.
Bevaix,Switzerland FrancescoMazzilli
Lausanne,Switzerland CatherineDehollain
Acknowledgements
IthankDr.CatherineDehollainforthesupport,confidence,andacademicfreedom
shehasprovidedtocarryoutthiswork.
I thank all my friends and former colleagues who contributed to make pleasant
the several years I spent at EPFL while I was working on ultrasound. For many
years after my graduation as PhD student from EPFL, we stayed in touch. I greet
myvaluablefriends:Charly,ourdiscussionswereendlesslookingforthemeaning
of life, who is now living in Israel with his wife and son. Enver and Oguz, for
introducingmetotheTurkishculture;theyleftSwitzerlandtopursuetheircareerin
Canada and in the USA. Arnab, an explosive source of energy, who is working in
GermanyandLuca,thebreakoffouro’clock,whobecameamanager.Anenormous
thanksgoestomyflatmates,MassimoandAndrea,ourweeklyhomemadepizzaand
parties will be unforgettable. A special thanks goes to Vincent Praplan, a brilliant
engineerwhohelpedmeinthedesignofthehardwarefortheexternalbasestation.
Iwishtothankmyparents,mysister,mybrother-in-law,andmygirlfriendChloé
fortheirsupportandlove.
Lausanne,Switzerland FrancescoMazzilli
February2020
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