Point-process analysis of neural spiking activity of muscle spindles recorded from thin-film longitudinal intrafascicular electrodes
by Luca Citi
Co-authored with M. Djilas, C. Azevedo-Coste, K. Yoshida, E. N. Brown, and R. Barbieri
Recordings from thin-film Longitudinal Intra-Fascicular Electrodes (tfLIFE) together with a wavelet-based denoising... more Recordings from thin-film Longitudinal Intra-Fascicular Electrodes (tfLIFE) together with a wavelet-based denoising and a correlation-based spike sorting algorithm, give access to firing patterns of muscle spindle afferents. In this study we use a point process probability structure to assess mechanical stimulus-response characteristics of muscle spindle spike trains. We assume that the stimulus intensity is primarily a linear combination of the spontaneous firing rate, the muscle extension, and the stretch velocity. By using the ability of the point process framework to provide an objective goodness of fit analysis, we were able to distinguish two classes of spike clusters with different statistical structure. We found that spike clusters with higher SNR have a temporal structure that can be fitted by an inverse Gaussian distribution while lower SNR clusters follow a Poisson-like distribution. The point process algorithm is further able to provide the instantaneous intensity function associated with the stimulus-response model with the best goodness of fit. This important result is a first step towards a point process decoding algorithm to estimate the muscle length and possibly provide closed loop Functional Electrical Stimulation (FES) systems with natural sensory feedback information.
Download (.pdf) On the Use of Wavelet Denoising and Spike Sorting Techniques to Process Electroneurographic Signals Recorded Using Intraneural Electrodes
by Luca Citi
Among the possible interfaces with the peripheral nervous system (PNS), intraneural electrodes represent an... more Among the possible interfaces with the peripheral nervous system (PNS), intraneural electrodes represent an interesting solution for their potential advantages such as the possibility of extracting spikes from electroneurographic (ENG) signals. Their use could increase the precision and the amount of information which can be detected with respect to other processing methods. In this study, in order to verify this assumption, thin-film longitudinal intrafascicular electrodes (tfLIFE) were implanted in the sciatic nerve of rabbits. Various sensory stimuli were applied to the hind limb of the animal and the elicited ENG signals were recorded using the tfLIFEs. These signals were processed to determine whether the different types of information can be decoded. Signals were wavelet denoised and spike sorted. Support vector machines were trained to use the spike waveforms found to infer the stimulus applied to the rabbit. This approach was also compared with previously used ENG-processing methods. The results indicate that the combination of wavelet denoising and spike sorting techniques can increase the amount of information extractable from ENG signals recorded with intraneural electrodes. This strategy could allow the development of more effective closed-loop neuroprostheses and hybrid bionic systems connecting the human nervous system with artificial devices.
Decoding Information From Neural Signals Recorded Using Intraneural Electrodes: Toward the Development of a Neurocontrolled Hand Prosthesis
by Luca Citi
The possibility of controlling dexterous hand prostheses by using a direct connection with the nervous system is... more The possibility of controlling dexterous hand prostheses by using a direct connection with the nervous system is particularly interesting for the significant improvement of the quality of life of patients, which can derive from this achievement. Among the various approaches, peripheral nerve based intrafascicular electrodes are excellent neural interface candidates, representing an excellent compromise between high selectivity and relatively low invasiveness. Moreover, this approach has undergone preliminary testing in human volunteers and has shown promise. In this paper, we investigate whether the use of intrafascicular electrodes can be used to decode multiple sensory and motor information channels with the aim to develop a finite state algorithm that may be employed to control neuroprostheses and neurocontrolled hand prostheses. The results achieved both in animal and human experiments show that the combination of multiple sites recordings and advanced signal processing techniques (such as wavelet denoising and spike sorting algorithms) can be used to identify both sensory stimuli (in animal models) and motor commands (in a human volunteer). These findings have interesting implications, which should be investigated in future experiments.
Cipo_09 Music Box: Hybrid Robotic <organism> - [laterna]
Ambient Intelligence and Smart Environments
Volume 2, 2009
Intelligent Environments 2009 - Proceedings of the 5th International Conference on Intelligent Environments – Barcelona 2009
Edited by Vic Callaghan, Achilles Kameas, Angélica Reyes, Dolors Royo, Michael Weber
ISBN 978-1-60750-034-6
DOI: 10.3233/978-1-60750-034-6-493
Cipo_09 music box - hybrid robotic <organism> - [laterna], pp.493-496
Daflos E. Kostas
The CIPO artwork program are interactive action-based installations, that investigate through robot agents, the... more The CIPO artwork program are interactive action-based installations, that investigate through robot agents, the relationship between subjects, body and space. The interminglement of spectators within the digital framework transforms the space to an experimental place. The CIPO program involves the physical viewer participation and the live energy of the human presence; it agitates the spectators to perform into an active relation with subjects and objects in place. Cipo_09 art objects are (3) three similar interactive handmade music boxes bring sound events. Cipo_09 music boxes have been drawn such as unhistoric impromptu instruments, which appropriate the concept and sounds of old music boxes from the 19th century. Different sound events created by human presences, are transcribed through cipo_09 hybrid objects to open sound scenarios.
The "MUSIC BOX" C(2)IPO_06: interactive hybrid robotic sculpture
3rd IET International Conference on Intelligent Environments (IE 07)
(CP531)
Ulm, Germany, 24-25 Sept. 2007, ISBN: 978 0 86341 853 2
The "MUSIC BOX" C(2)IPO_06: interactive hybrid robotic sculpture, p.572–576
Kostas E. Daflos
The "ipo", "cipo" (K. Daflos, 2006) & "cibo" are active agents that agitate &... more The "ipo", "cipo" (K. Daflos, 2006) & "cibo" are active agents that agitate & bring the passive spectator into an active & interactive relationship with the subject. The interminglement of both, spectator (body) & subject (technology) transforms the given space into an experimental hybrid space where body & technology meet. The new medium of artworks is action-based. It involves the physical viewer participation & life's energy of human presence of the spectators or the performers. The body actions support the improvisation of self-discovery through this medium, and in turn the artwork itself becomes an improvisation. The successive transcriptions -transpositions of human presence & action in schemes, traces, signs, represent the distributed body, which is transcribed through various multiple mediums. Machine-organism inspired from: a) Gordon Pask's theory of discourse between man, machines and learning machines (P. Pangaro, 2002). b) Norbert Wiener's theory of control and communication of machines (N. Weiner, 1948).