Antonio Frisoli

Publications

• 6.26

  Impact points

  Cortical source of blink-related delta oscillations and their correlation with levels of consciousness.

  Luca Bonfiglio, Umberto Olcese, Bruno Rossi, Antonio Frisoli, Pieranna Arrighi, Giovanni Greco, Simone Carozzo, Paolo Andre, Massimo Bergamasco, Maria Chiara Carboncini

  Human brain mapping. 03/2012;

  Recently, blink-related delta oscillations (delta BROs) have been observed in healthy subjects during spontaneous blinking at rest. Delta BROs have been linked with continuous gathering of information from the surrounding environment, which is classically attributed to the precuneus. Furthermore, fM... [more] Recently, blink-related delta oscillations (delta BROs) have been observed in healthy subjects during spontaneous blinking at rest. Delta BROs have been linked with continuous gathering of information from the surrounding environment, which is classically attributed to the precuneus. Furthermore, fMRI studies have shown that precuneal activity is reduced or missing when consciousness is low or absent. We therefore hypothesized that the source of delta BROs in healthy subjects could be located in the precuneus and that delta BROs could be absent or reduced in patients with disorders of consciousness (DOC). To test these hypotheses, electroencephalographic (EEG) activity at rest was recorded in 12 healthy controls and nine patients with DOC (four vegetative states, and five minimally conscious states). Three-second-lasting EEG epochs centred on each blink instance were analyzed in both time- (BROs) and frequency domains (event-related spectral perturbation or ERSP and intertrial coherence or ITC). Cortical sources of the maximum blink-related delta power, corresponding to the positive peak of the delta BROs, were estimated by standardized Low Resolution Electromagnetic Tomography. In control subjects, as expected, the source of delta BROs was located in the precuneus, whereas in DOC patients, delta BROs were not recognizable and no precuneal localization was possible. Furthermore, we observed a direct relationship between spectral indexes and levels of cognitive functioning in all subjects participating in the study. This reinforces the hypothesis that delta BROs reflect neural processes linked with awareness of the self and of the environment. Hum Brain Mapp, 2012. © 2012 Wiley Periodicals, Inc.
• 2.71

  Impact points

  Motion detection technology as a tool for cardiopulmonary resuscitation (CPR) quality improvement.

  Federico Semeraro, Luca Marchetti, Antonio Frisoli, Erga L Cerchiari, Gavin D Perkins

  Resuscitation. 09/2011; 83(1):e11-2.

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• Design and implementation of a training strategy in chronic stroke with an arm robotic exoskeleton.

  A Frisoli, E Sotgiu, C Procopio, M Bergamasco, B Rossi, C Chisari

  IEEE ... International Conference on Rehabilitation Robotics : [proceedings]. 06/2011; 2011:1-8.

  The distinguishing features of active exoskeletons are the capability of guiding arm movement at the level of the full kinematic chain of the human arm, and training full 3D spatial movements. We have specifically developed a PD sliding mode control for upper limb rehabilitation with gain scheduling... [more] The distinguishing features of active exoskeletons are the capability of guiding arm movement at the level of the full kinematic chain of the human arm, and training full 3D spatial movements. We have specifically developed a PD sliding mode control for upper limb rehabilitation with gain scheduling for providing "assistance as needed", according to the force capability of the patient, and an automatic measurement of the impaired arm joint torques, to evaluate the hypertonia associated to the movement during the execution of the training exercise. Two different training tasks in Virtual Reality were devised, that make use of the above control, and allow to make a performance based evaluation of patient's motor status. The PERCRO L-Exos (Light-Exoskeleton) was used to evaluate the proposed algorithms and training exercises in two clinical case studies of patients with chronic stroke, that performed 6 weeks of robotic assisted training. Clinical evaluation (Fugl-Meyer Scale, Modified Ashworth Scale, Bimanual Activity Test) was conducted before and after treatment and compared to the scores and the quantitative indices, such as task time, position/joint error and resistance torques, associated to the training exercises.
• 1.41

  Impact points

  A new screw theory method for the estimation of position accuracy in spatial parallel manipulators with joint clearances

  Antonio Frisoli, Massimiliano Solazzi, Dario Pellegrinetti, Massimo Bergamasco

  Mechanism and Machine Theory. 01/2011; 46(46):1929-1949.

• An online trajectory planning method for visually guided assisted reaching through a rehabilitation robot.

  Claudio Loconsole, Riccardo Bartalucci, Antonio Frisoli, Massimo Bergamasco

  IEEE International Conference on Robotics and Automation, ICRA 2011, Shanghai, China, 9-13 May 2011; 01/2011
• 2.18

  Impact points

  The contribution of cutaneous and kinesthetic sensory modalities in haptic perception of orientation.

  Antonio Frisoli, Massimiliano Solazzi, Miriam Reiner, Massimo Bergamasco

  Brain research bulletin. 12/2010; 85(5):260-6.

  The aim of this study was to understand the integration of cutaneous and kinesthetic sensory modalities in haptic perception of shape orientation. A specific robotic apparatus was employed to simulate the exploration of virtual surfaces by active touch with two fingers, with kinesthetic only, cutane... [more] The aim of this study was to understand the integration of cutaneous and kinesthetic sensory modalities in haptic perception of shape orientation. A specific robotic apparatus was employed to simulate the exploration of virtual surfaces by active touch with two fingers, with kinesthetic only, cutaneous only and combined sensory feedback. The cutaneous feedback was capable of displaying the local surface orientation at the contact point, through a small plate indenting the fingerpad at contact. A psychophysics test was conducted with SDT methodology on 6 subjects to assess the discrimination threshold of angle perception between two parallel surfaces, with three sensory modalities and two shape sizes. Results show that the cutaneous sensor modality is not affected by size of shape, but kinesthetic performance is decreasing with smaller size. Cutaneous and kinesthetic sensory cues are integrated according to a Bayesian model, so that the combined sensory stimulation always performs better than single modalities alone.

• Design of a cutaneous fingertip display for improving haptic exploration of virtual objects

  M. Solazzi, A. Frisoli, M. Bergamasco

  RO-MAN, 2010 IEEE; 10/2010

  A new prototype of portable device for haptic interaction with virtual environments is presented. It is a lightweight interface for the fingertips, designed for providing cutaneous feedback and displaying the contact ¿ non contact transition in highly immersive virtual environments. The second vers... [more] A new prototype of portable device for haptic interaction with virtual environments is presented. It is a lightweight interface for the fingertips, designed for providing cutaneous feedback and displaying the contact ¿ non contact transition in highly immersive virtual environments. The second version of the interface features a force sensor for controlling the force on the fingertip during contact, assuring a better haptic feedback. In this paper the kinematics, the mechanical design and the improved control system are described. The device has been mounted on a kinesthetic haptic interface which tracks its position: in this configuration, the overall system can provide both cutaneous and kinesthetic feedback and improve the fidelity of the haptic interaction. Finally the performance of the cutaneous device in a task of contour following has been evaluated.

• Mechanical design and optimization of a novel fMRI compatible haptic manipulator

  S. Li, A. Frisoli, M. Solazzi, M. Bergamasco

  RO-MAN, 2010 IEEE; 10/2010

  In this paper, we present the mechanical design of a new fMRI compatible haptic interface with 3DOFs, based on electrical DC actuation, for the study of brain mechanisms of human motor control. The 1DOF manipulator, which was evaluated successfully on the compatibility with fRMI environment in the p... [more] In this paper, we present the mechanical design of a new fMRI compatible haptic interface with 3DOFs, based on electrical DC actuation, for the study of brain mechanisms of human motor control. The 1DOF manipulator, which was evaluated successfully on the compatibility with fRMI environment in the preliminary experiments, was extended to the implementation of a 3DOFs parallel manipulator with 3- UPU kinematics. Kinematic properties were studied in different configurations to select the stroke of the prismatic joint and the radius difference between the moving platform and the base. Due to the dimensional constraints imposed by the fMRI environment, the choice of the dimensions and the adopted mechanical solution was a result of an optimization process presented in this work. A further optimization of the mechanical design was then conducted in order to reduce the torque requested to the actuators for gravity compensation and improve the mechanical stiffness with elastic compliance of the manipulator. The final design resulted in a system capable of satisfying all the environment and user requirements.

• Linear-quadratic-Gaussian torque control: Application to a flexible joint of a rehabilitation exoskeleton

  R. Vertechy, A. Frisoli, M. Solazzi, A. Dettori, M. Bergamasco

  Robotics and Automation (ICRA), 2010 IEEE International Conference on; 06/2010

  A linear-quadratic-Gaussian regulator is proposed for the torque control of flexible robotic joints with built-in torque sensor. The regulator requires the joint-torque sensor information only and features: (1) a Kalman filter that, beside reducing the noise and evaluating the derivative of the torq... [more] A linear-quadratic-Gaussian regulator is proposed for the torque control of flexible robotic joints with built-in torque sensor. The regulator requires the joint-torque sensor information only and features: (1) a Kalman filter that, beside reducing the noise and evaluating the derivative of the torque sensor measure, is able to estimate all the external and internal torques acting on the joint; 2) a controller that optimizes system stability, responsiveness, accuracy and effort. The regulator is implemented on a flexible joint of a rehabilitation exoskeleton. Simulation and experimental results are provided which demonstrate regulator performance and efficacy.

• Design of a novel finger haptic interface for contact and orientation display

  M. Solazzi, A. Frisoli, M. Bergamasco

  Haptics Symposium, 2010 IEEE; 04/2010

  A new portable device for haptic interaction with virtual environments is presented. It is a lightweight interface for the fingertips, designed for providing cutaneous feedback and displaying the contact - non contact transition in highly immersive virtual environments. In this paper the kinematics,... [more] A new portable device for haptic interaction with virtual environments is presented. It is a lightweight interface for the fingertips, designed for providing cutaneous feedback and displaying the contact - non contact transition in highly immersive virtual environments. In this paper the kinematics, the mechanical design and the control system are described. The device has been mounted on a kinesthetic haptic interface which tracks its position: the overall system can provide both cutaneous and kinesthetic feedback. Finally the performance of the portable device in a simple task of shape exploration has been evaluated and compared to a kinesthetic haptic interface.

• Bimanual Haptic-desktop platform for upper-limb post-stroke rehabilitation: Practical trials

  Siqiao Li, A. Frisoli, C.A. Avizzano, E. Ruffaldi, L.I. Lugo-Villeda, M. Bergamasco

  Robotics and Biomimetics (ROBIO), 2009 IEEE International Conference on; 01/2010

  This paper presents three haptic-based virtual applications for the undergoing rehabilitation of upper-limb post stroke patients. The three exercises are developed for their use on the multi-modal interface so-called Bimanual Haptic Desktop System (BHDS), which integrates the haptic functionalities ... [more] This paper presents three haptic-based virtual applications for the undergoing rehabilitation of upper-limb post stroke patients. The three exercises are developed for their use on the multi-modal interface so-called Bimanual Haptic Desktop System (BHDS), which integrates the haptic functionalities and Video Display Terminal (VDT) within the work-plane of a desk. Firstly, two basic exercises, tracking task and lifting task, are carried out for the recovery of basic arm motion-coordination skills and steadiness of patients' upper-limb. Secondly, a video-game-like exercise, catching task, is developed to compare online the performance of healthy upper-limb with impaired ones wherein hand-eye coordination exercise of the patient is included. To this end, the proposed exercises provide to patients the potential methods to train their post-stroke upper-limbs malfunctions while reporting the quantitative parameters obtained to evaluate the improvement of patients recovery. Experimental results of a preliminary evaluation on healthy subjects are then reported and discussed to visualize in near future a pilot medical trials of the system on impaired people.

• Energy recovery in time-varying delay teleoperated system using wave-variables

  M. Satler, C.A. Avizzano, A. Frisoli, P. Tripicchio, M. Bergamasco

  RO-MAN, 2010 IEEE, Viareggio, Italy; 01/2010

  While control theory for bilateral teleoperation systems under constant time communication delay is well developed, the research on time-varying communication delay systems is still ongoing. Most wave-based approaches proposed in literature to deal with time-varying delay appear too conservative res... [more] While control theory for bilateral teleoperation systems under constant time communication delay is well developed, the research on time-varying communication delay systems is still ongoing. Most wave-based approaches proposed in literature to deal with time-varying delay appear too conservative resulting in high degradation from the constant time delay case. We have already proposed a bilateral control scheme with energy balance monitoring over packet switched communication networks. In the previous work, we dealt with a simplify situation where the time-varying was in the communication channel from master to the slave. However, we did not implement and test the system with a more complex scenario in which the delay was in both communication paths. The paper presents a complete bilateral teleoperation control scheme to compensate nonlinearity introduced by an Internet like communication channel. The system implements intelligent strategies to maintain the system passivity while it deals with position drift compensation, packets loss and blackouts management. Experimental results using the proposed control scheme are shown.

• Linear-quadratic-Gaussian torque control: Application to a flexible joint of a rehabilitation exoskeleton.

  Rocco Vertechy, Antonio Frisoli, Massimiliano Solazzi, Andrea Dettori, Massimo Bergamasco

  IEEE International Conference on Robotics and Automation, ICRA 2010, Anchorage, Alaska, USA, 3-7 May 2010; 01/2010

• Right-Arm Robotic-Aided-Therapy with the Light-Exoskeleton: A General Overview.

  Luis Ivan Lugo-Villeda, Antonio Frisoli, Edoardo Sotgiu, Giovanni Greco, Massimo Bergamasco

  Emerging Trends in Technological Innovation, First IFIP WG 5.5/SOCOLNET Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2010, Costa de Caparica, Portugal, February 22-24, 2010. Proceedings; 01/2010

• Hand and Arm Ownership Illusion through Virtual Reality Physical Interaction and Vibrotactile Stimulations.

  Miguel A. Padilla, Silvia Pabon, Antonio Frisoli, Edoardo Sotgiu, Claudio Loconsole, Massimo Bergamasco

  Haptics: Generating and Perceiving Tangible Sensations, International Conference, EuroHaptics 2010, Amsterdam, The Netherlands, July 8-10, 2010. Proceedings, Part II; 01/2010
• 4.41

  Impact points

  Virtual hand illusion induced by visuomotor correlations.

  Maria V Sanchez-Vives, Bernhard Spanlang, Antonio Frisoli, Massimo Bergamasco, Mel Slater

  PloS one. 01/2010; 5(4):e10381.

  Our body schema gives the subjective impression of being highly stable. However, a number of easily-evoked illusions illustrate its remarkable malleability. In the rubber-hand illusion, illusory ownership of a rubber-hand is evoked by synchronous visual and tactile stimulation on a visible rubber ar... [more] Our body schema gives the subjective impression of being highly stable. However, a number of easily-evoked illusions illustrate its remarkable malleability. In the rubber-hand illusion, illusory ownership of a rubber-hand is evoked by synchronous visual and tactile stimulation on a visible rubber arm and on the hidden real arm. Ownership is concurrent with a proprioceptive illusion of displacement of the arm position towards the fake arm. We have previously shown that this illusion of ownership plus the proprioceptive displacement also occurs towards a virtual 3D projection of an arm when the appropriate synchronous visuotactile stimulation is provided. Our objective here was to explore whether these illusions (ownership and proprioceptive displacement) can be induced by only synchronous visuomotor stimulation, in the absence of tactile stimulation. To achieve this we used a data-glove that uses sensors transmitting the positions of fingers to a virtually projected hand in the synchronous but not in the asynchronous condition. The illusion of ownership was measured by means of questionnaires. Questions related to ownership gave significantly larger values for the synchronous than for the asynchronous condition. Proprioceptive displacement provided an objective measure of the illusion and had a median value of 3.5 cm difference between the synchronous and asynchronous conditions. In addition, the correlation between the feeling of ownership of the virtual arm and the size of the drift was significant. We conclude that synchrony between visual and proprioceptive information along with motor activity is able to induce an illusion of ownership over a virtual arm. This has implications regarding the brain mechanisms underlying body ownership as well as the use of virtual bodies in therapies and rehabilitation.

• Bilateral teleoperation under time-varying delay using wave variables

  M. Satler, C.A. Avizzano, A. Frisoli, P. Tripicchio, M. Bergamasco

  Intelligent Robots and Systems, 2009. IROS 2009. IEEE/RSJ International Conference on; 11/2009

  Any teleoperation system involving two distant devices is affected by communication delay due to the physical gap between the devices. Several approaches based on wave variables have already been proposed to deal with time-varying delay. However, these approaches are too conservative resulting in hi... [more] Any teleoperation system involving two distant devices is affected by communication delay due to the physical gap between the devices. Several approaches based on wave variables have already been proposed to deal with time-varying delay. However, these approaches are too conservative resulting in high degradation from the constant time delay case. In this paper, we propose a new control scheme for bilateral teleoperation under time-varying communication delay entirely developed in the wave variables domain. The proposed method minimizes the performance degradation from the constant time delay case. Experimental results show the validity of the proposed scheme.

• Regressor-free force/position control of fixed-base exoskeletons for rehabilitation tasks

  L.I. Lugo-Villeda, A. Frisoli, V. Parra-Vega, M. Bergamasco

  Intelligent Robots and Systems, 2009. IROS 2009. IEEE/RSJ International Conference on; 11/2009

  The required tasks in fixed-base exoskeletons demand a fast position/force controller; yet robust against unknown disturbances due to the application itself is tightly coupled with a human in a wide range of operational conditions, which give rise to human-exoskeleton interaction dynamics, high nonl... [more] The required tasks in fixed-base exoskeletons demand a fast position/force controller; yet robust against unknown disturbances due to the application itself is tightly coupled with a human in a wide range of operational conditions, which give rise to human-exoskeleton interaction dynamics, high nonlinear uncertain exoskeleton dynamics, noisy sensors and other parametric uncertainties, such as environmental contacts. These factors do not allow to account on a precise dynamical model, thus model-based (regressor-based) controllers are difficult to implement. This paper deals with a regressor-free smooth PID-like fast force/position controller which guarantees finite-time convergence within second order sliding modes, thus ensuring inherent robustness. Experimental platform allows assessing its performance for rehabilitation tasks, which validates its functionality in practical implementation.

• Haptic guidance of Light-Exoskeleton for arm-rehabilitation tasks

  L.I. Lugo-Villeda, A. Frisoli, O. Sandoval-Gonzalez, M.A. Padilla, V. Parra-Vega, C.A. Avizzano, E. Ruffaldi, M. Bergamasco

  Robot and Human Interactive Communication, 2009. RO-MAN 2009. The 18th IEEE International Symposium on; 11/2009

  Fixed-Base Exoskeleton applications have increased rapidly in the last few years, evidently as part of promising rehabilitation robotic programs of the robotics worldwide community, where in particular Human-Robot-Interaction (HRI) plays an important role in its design and control because they are t... [more] Fixed-Base Exoskeleton applications have increased rapidly in the last few years, evidently as part of promising rehabilitation robotic programs of the robotics worldwide community, where in particular Human-Robot-Interaction (HRI) plays an important role in its design and control because they are tightly coupled to human-limbs. Exoskeletons embrace HRI as well as technological and theoretical challenges towards real and effective rehabilitation. In this realm, some questions arise, to name a few, what is the relationship between the exchanged energy between human and exoskeleton? How can we assess rehabilitation factors under HRI philosophy? This paper attempts to establish answers to these questions, which can be embodied into rehabilitation HRI using a Light-Exoskeleton. A compliant haptic guidance scheme for human arm subject to minimum-jerk-trajectories criterion is proposed. Preliminary experimental results provide further insight of a haptic guidance scheme taking into account decisive factors into the HRI such as human pose, haptic guidance control, reaching and tracking tasks, the complexity of the virtual environment, and muscles activity.

• Light-Exoskeleton and Data-Glove integration for enhancing virtual reality applications

  L.I. Lugo-Villeda, A. Frisoli, S. Pabon, M.A. Padilla, E. Sotgiu, M. Bergamasco

  Advanced Robotics, 2009. ICAR 2009. International Conference on; 07/2009

  This contribution discusses the advanced technologies integration: the PERCRO light-exoskeleton and the PERCRO data-glove wherein the main pursuit is the enhancement of the human grasping skills inside virtual environments. The mastering of motor human skills for taking up, lifting or manipulating o... [more] This contribution discusses the advanced technologies integration: the PERCRO light-exoskeleton and the PERCRO data-glove wherein the main pursuit is the enhancement of the human grasping skills inside virtual environments. The mastering of motor human skills for taking up, lifting or manipulating objects during grasping tasks, could be effectively enhanced thanks to the inclusion of an arm exoskeleton which provides arm haptic-guidance-positioning (HGPo) into spatial coordinates and the data-glove for hand dexterity practicing. This paper takes into account a synergetic fusion of theoretical concepts and practical developments, pointing out the feasibility of having robust and accurate hand/arm haptic-robotic guidance positioning within virtual reality environments. Notice that those applications demand high precision, robustness, repeatability and hand/arm dexterity; such a mentioned properties are covered by the proposed system.