title: Inhomogeneous Point-Processes to Instantaneously Assess Affective Haptic Perception through Heartbeat Dynamics Information.
abstract: This study proposes the application of a comprehensive signal processing framework, based on inhomogeneous point-process models of heartbeat dynamics, to instantaneously assess affective haptic perception using electrocardiogram-derived information exclusively. The framework relies on inverse-Gaussian point-processes with Laguerre expansion of the nonlinear Wiener-Volterra kernels, accounting for the long-term information given by the past heartbeat events. Up to cubic-order nonlinearities allow for an instantaneous estimation of the dynamic spectrum and bispectrum of the considered cardiovascular dynamics, as well as for instantaneous measures of complexity, through Lyapunov exponents and entropy. Short-term caress-like stimuli were administered for 4.3-25 seconds on the forearms of 32 healthy volunteers (16 females) through a wearable haptic device, by selectively superimposing two levels of force, 2 N and 6 N, and two levels of velocity, 9.4 mm/s and 65 mm/s. Results demonstrated that our instantaneous linear and nonlinear features were able to finely characterize the affective haptic perception, with a recognition accuracy of 69.79% along the force dimension, and 81.25% along the velocity dimension.
authors.affiliation: Neuroscience Statistics Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.|Department of Information Engineering and Research Centre E Piaggio, University of Pisa, Pisa, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Valenza
authors.affiliation: Department of Information Engineering and Research Centre E Piaggio, University of Pisa, Pisa, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Greco
authors.affiliation: School of Computer Science and Electronic Engineering, University of Essex, Colchester, CO43SQ, UK.
authors.forename: L
authors.initials: L
authors.lastname: Citi
authors.affiliation: Department of Information Engineering and Research Centre E Piaggio, University of Pisa, Pisa, Italy.|Department of Advanced Robotics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Bianchi
authors.affiliation: Neuroscience Statistics Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: R
authors.initials: R
authors.lastname: Barbieri
authors.affiliation: Department of Information Engineering and Research Centre E Piaggio, University of Pisa, Pisa, Italy.
authors.forename: E P
authors.initials: EP
authors.lastname: Scilingo