Wireless distributed functional electrical stimulation system

Abstract

BackgroundThe control of movement in humans is hierarchical and distributed and uses feedback. An assistive system could be best integrated into the therapy of a human with a central nervous system lesion if the system is controlled in a similar manner. Here, we present a novel wireless architecture and routing protocol for a distributed functional electrical stimulation system that enables control of movement.MethodsThe new system comprises a set of miniature battery-powered devices with stimulating and sensing functionality mounted on the body of the subject. The devices communicate wirelessly with one coordinator device, which is connected to a host computer. The control algorithm runs on the computer in open- or closed-loop form. A prototype of the system was designed using commercial, off-the-shelf components. The propagation characteristics of electromagnetic waves and the distributed nature of the system were considered during the development of a two-hop routing protocol, which was implemented in the prototype’s software.ResultsThe outcomes of this research include a novel system architecture and routing protocol and a functional prototype based on commercial, off-the-shelf components. A proof-of-concept study was performed on a hemiplegic subject with paresis of the right arm. The subject was tasked with generating a fully functional palmar grasp (closing of the fingers). One node was used to provide this movement, while a second node controlled the activation of extensor muscles to eliminate undesired wrist flexion. The system was tested with the open- and closed-loop control algorithms.ConclusionsThe system fulfilled technical and application requirements. The novel communication protocol enabled reliable real-time use of the system in both closed- and open-loop forms. The testing on a patient showed that the multi-node system could operate effectively to generate functional movement.

Stimulation map for control of functional grasp based on multi-channel EMG recordings

“…Two wearable electronic stimulators (7 × 3 × 2.5 cm 3 ) with a total of eight output channels generated compensated currentcontrolled biphasic pulses [21] . The stimulator allows the user to control the pulse frequency, duration, amplitude and delay on each of the channels.…”

A Wireless Functional Electrical Stimulation System

“…The scope was defined by the requirement to evaluate feasibility. The literature shows one provisional paper regarding a wireless FES solution [1]. Most commercially available products for FES in sport and rehabilitation are not currently wireless (an exception is the COMPEX Wireless system from Compex) but the technology is promising for a range of products and applications.…”

Inertial sensors signal processing methods for gait analysis of patients with impaired gait patterns

“…The acquisition system used for data collection is a distributed wireless sensor network (Djuric-Jovicic et al, 2011, Jovicic et al, 2012. SU were placed as shown in …”

“…The criterion for choosing redirection node is based on the equalization of delays from all nodes -redirection node should be the one that has the shortest delay of its data, as explained in (Jovicic et al, 2012). Central node is connected with computer using USB connection.…”

“…In this way, sensor data can be used for motor control and, in the same time it can perform the assessment of the movement made with it. This system is already developed and its architecture and preliminary testing are described in journal publication (Jovicic et al, 2012).…”