title: Radio-frequency energy harvesting for wearable sensors.
abstract: The use of wearable biomedical sensors for the continuous monitoring of physiological signals will facilitate the involvement of the patients in the prevention and management of chronic diseases. The fabrication of small biomedical sensors transmitting physiological data wirelessly is possible as a result of the tremendous advances in ultra-low power electronics and radio communications. However, the widespread adoption of these devices depends very much on their ability to operate for long periods of time without the need to frequently change, recharge or even use batteries. In this context, energy harvesting (EH) is the disruptive technology that can pave the road towards the massive utilisation of wireless wearable sensors for patient self-monitoring and daily healthcare. Radio-frequency (RF) transmissions from commercial telecommunication networks represent reliable ambient energy that can be harvested as they are ubiquitous in urban and suburban areas. The state-of-the-art in RF EH for wearable biomedical sensors specifically targeting the global system of mobile 900/1800 cellular and 700 MHz digital terrestrial television networks as ambient RF energy sources are showcased. Furthermore, guidelines for the choice of the number of stages for the RF energy harvester are presented, depending on the requirements from the embedded system to power supply, which is useful for other researchers that work in the same area. The present authors' recent advances towards the development of an efficient RF energy harvester and storing system are presented and thoroughly discussed too.
authors.affiliation: Instituto de Telecomunicações/DEM , Universidade da Beira Interior , Covilhã , Portugal.
authors.forename: Luís M
authors.initials: LM
authors.lastname: Borges
authors.affiliation: The Intervention Centre , Oslo University Hospital , Oslo NO-0027 , Norway ; Norwegian University of Science and Technology (NTNU) , Oslo NO-0027 , Norway.
authors.forename: Raul
authors.initials: R
authors.lastname: Chávez-Santiago
authors.affiliation: Instituto de Telecomunicações/DEM , Universidade da Beira Interior , Covilhã , Portugal.
authors.forename: Norberto
authors.initials: N
authors.lastname: Barroca
authors.affiliation: Instituto de Telecomunicações/DEM , Universidade da Beira Interior , Covilhã , Portugal.
authors.forename: Fernando José
authors.initials: FJ
authors.lastname: Velez
authors.affiliation: The Intervention Centre , Oslo University Hospital , Oslo NO-0027 , Norway ; Norwegian University of Science and Technology (NTNU) , Oslo NO-0027 , Norway.
authors.forename: Ilangko
authors.initials: I
authors.lastname: Balasingham
keywords: RF energy harvester; ambient RF energy sources; biomedical equipment; biomedical telemetry; body sensor networks; chronic disease management; chronic disease prevention; commercial telecommunication networks; continuous monitoring; daily healthcare; digital television; digital terrestrial television networks; diseases; disruptive technology; embedded system; embedded systems; energy harvesting; frequency 700 MHz; health care; medical signal processing; mobile 900/1800 cellular; patient monitoring; patient self-monitoring; physiological signals; power supply; radiofrequency energy harvesting; reliable ambient energy; suburban areas; wearable biomedical sensors; wireless wearable sensors; wirelessly physiological data transmission