Construction of injectable wireless microstimulators based on rectification of volume conducted high frequency currents

Functional neuromuscular stimulation (FNS) refers to the delivery of electrical stimuli to nerves or muscles to enhance, modify or restore motor functions. Despite their invasiveness, implantable systems for FNS offer key advantages over surface and percutaneous systems in terms of selectivity and s...

Descripción completa

Detalles Bibliográficos
Autor: García-Moreno, Aracelys
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/673986
Acceso en línea:http://hdl.handle.net/10803/673986
Access Level:acceso abierto
Palabra clave:Microstimulators
Microelectronics
Implantable neuroprostheses
Thread-like implants
Minimal invasiveness
Wireless power transfer (WPT)
Volume conduction
Hermetic encapsulation
Adressable stimulators
Microestimuladores
Microelectrónica
Neuroprótesis implantables
Implantes filiformes
Invasividad mínima
Transferencia de energía inalámbrica (WPT)
Conducción volumétrica
Encapsulado hermético
Estimuladores direccionables
616.7
Descripción
Sumario:Functional neuromuscular stimulation (FNS) refers to the delivery of electrical stimuli to nerves or muscles to enhance, modify or restore motor functions. Despite their invasiveness, implantable systems for FNS offer key advantages over surface and percutaneous systems in terms of selectivity and safety. Most implantable FNS systems consist of a relatively bulky subcutaneous pulse genera-tor connected through leads to electrodes at the target stimulation sites. In the case of FNS systems for restoring motor functions in patients with paralysis, the leads are long and the electrodes are distributed over large and mobile body parts, thus making them highly invasive and prone to failure. Miniaturized wireless implantable stimulators represent a safer and more reliable alternative. By integrating all the components in the same device, long leads are avoided and minimally invasive implantation procedures are enabled. In this thesis, architectures and construction methods were devised to implement thin (diameter < 1 mm), flexible and biocompatible wireless microstimulators whose operation principle is based in rectifying high frequency currents delivered to tissues by volume conduction. These threadlike devices, which were successfully in vivo assayed, are intended to be deployed by injection forming a dense network of intramuscular addressable stimulators for the development of motor neuroprostheses. They were implemented adapting techniques well accepted in industry to facilitate early clinical adoption. A noteworthy feature of their construction is the inclusion of a biterminal hermetic metallic capsule housing the sophisticated microelectronic circuitry required for their operation. The applicability of the same technology and operation methods to an alternative clinical field was also explored in the scope of this thesis through the development and in vivo assay proof-of-concept novel leadless microstimulators. Furthermore, this thesis has contributed to the development of refined computer models to characterize the stimulation method previously described.