Floating EMG sensors and stimulators wirelessly powered and operated by volume conduction for networked neuroprosthetics
Metadatos
Mostrar el registro completo del ítemEditorial
BMC
Materia
Wireless power transfer Volume conduction AIMDs Bidirectional communications Electromyography Sensor Electrical stimulation
Fecha
2022-06-07Referencia bibliográfica
Becerra-Fajardo, L... [et al.]. Floating EMG sensors and stimulators wirelessly powered and operated by volume conduction for networked neuroprosthetics. J NeuroEngineering Rehabil 19, 57 (2022). [https://doi.org/10.1186/s12984-022-01033-3]
Patrocinador
European Commission 779982; European Research Council (ERC) 724244; CSIC Interdisciplinary Thematic Platform (PTI+) NEURO-AGINGl+ (PTI-NEURO-AGING+); ICREAResumen
Background: Implantable neuroprostheses consisting of a central electronic unit wired to electrodes benefit thousands
of patients worldwide. However, they present limitations that restrict their use. Those limitations, which are
more adverse in motor neuroprostheses, mostly arise from their bulkiness and the need to perform complex surgical
implantation procedures. Alternatively, it has been proposed the development of distributed networks of intramuscular
wireless microsensors and microstimulators that communicate with external systems for analyzing neuromuscular
activity and performing stimulation or controlling external devices. This paradigm requires the development
of miniaturized implants that can be wirelessly powered and operated by an external system. To accomplish this, we
propose a wireless power transfer (WPT) and communications approach based on volume conduction of innocuous
high frequency (HF) current bursts. The currents are applied through external textile electrodes and are collected by
the wireless devices through two electrodes for powering and bidirectional digital communications. As these devices
do not require bulky components for obtaining power, they may have a flexible threadlike conformation, facilitating
deep implantation by injection.
Methods: We report the design and evaluation of advanced prototypes based on the above approach. The system
consists of an external unit, floating semi-implantable devices for sensing and stimulation, and a bidirectional communications
protocol. The devices are intended for their future use in acute human trials to demonstrate the distributed
paradigm. The technology is assayed in vitro using an agar phantom, and in vivo in hindlimbs of anesthetized
rabbits.
Results: The semi-implantable devices were able to power and bidirectionally communicate with the external unit.
Using 13 commands modulated in innocuous 3 MHz HF current bursts, the external unit configured the sensing and
stimulation parameters, and controlled their execution. Raw EMG was successfully acquired by the wireless devices at
1 ksps.
Conclusions: The demonstrated approach overcomes key limitations of existing neuroprostheses, paving the way
to the development of distributed flexible threadlike sensors and stimulators. To the best of our knowledge, these
devices are the first based on WPT by volume conduction that can work as EMG sensors and as electrical stimulators
in a network of wireless devices.