Mario Cortese

A light-weight active orthosis for hip movement assistance

In the last decades, wearable powered orthoses have been developed with the aim of augmenting or assisting motor activities. In particular, among many applications, wearable powered orthoses have been also introduced in the state of the art with the goal of providing lower-limb movement assistance in locomotion-related tasks (e.g.: walking, ascending/descending stairs) in scenarios of activities of daily living. In this paper we present a light-weight active orthosis endowed with two series elastic actuators for hip flexion-extension assistance. Along with the description of its mechatronic modules, we report the experimental characterization of the performance of the actuation and control system, as well as the usability test carried out with a healthy subject. Results showed a suitable dynamic behavior of the actuation unit: the closed-loop torque control bandwidth is about 15 Hz and the output impedance ranges from about 1 N m/rad to 35 N m/rad in the frequency spectrum between 0.2 and 3.2 Hz. Results from the tests with the healthy subject proved the overall system usability: the subject could walk with the device without being hindered and while he received a smooth assistive flexion-extension torque profile on both hip articulations. Development of a novel light-weight wearable powered bilateral pelvis orthosis.Design of a novel compact, light-weight series-elastic actuator (SEA).SEA closed-loop torque control bandwidth equal to 15 Hz.SEA output impedance ranges from 1 to 35 N m /rad in human gait frequency spectrum.The overall system usability was proved by tests with a healthy subject.

A Powered Finger–Thumb Wearable Hand Exoskeleton With Self-Aligning Joint Axes

In recent years, the robotic research area has become extremely prolific in terms of wearable active exoskeletons for human body motion assistance, with the presentation of many novel devices, for upper limbs, lower limbs, and the hand. The hand shows a complex morphology, a high intersubject variability, and offers limited space for physical interaction with a robot: as a result, hand exoskeletons usually are heavy, cumbersome, and poorly usable. This paper introduces a novel device designed on the basis of human kinematic compatibility, wearability, and portability criteria. This hand exoskeleton, briefly HX, embeds several features as underactuated joints, passive degrees of freedom ensuring adaptability and compliance toward the hand anthropometric variability, and an ad hoc design of self-alignment mechanisms to absorb human/robot joint axes misplacement, and proposes a novel mechanism for the thumb opposition. The HX kinematic design and actuation are discussed together with theoretical and experimental data validating its adaptability performances. Results suggest that HX matches the self-alignment design goal and is then suited for close human-robot interaction.

Kinematics and design of a portable and wearable exoskeleton for hand rehabilitation

We present the kinematic design and actuation mechanics of a wearable exoskeleton for hand rehabilitation of post-stroke. Our design method is focused on achieving maximum safety, comfort and reliability in the interaction, and allowing different users to wear the device with no manual regulations. In particular, we propose a kinematic and actuation solution for the index finger flexion/extension, which leaves full movement freedom on the abduction-adduction plane. This paper presents a detailed kineto-static analysis of the system and a first prototype of the device.

Enhancing brain-machine interface (BMI) control of a hand exoskeleton using electrooculography (EOG)

BackgroundBrain-machine interfaces (BMIs) allow direct translation of electric, magnetic or metabolic brain signals into control commands of external devices such as robots, prostheses or exoskeletons. However, non-stationarity of brain signals and susceptibility to biological or environmental artifacts impede reliable control and safety of BMIs, particularly in daily life environments. Here we introduce and tested a novel hybrid brain-neural computer interaction (BNCI) system fusing electroencephalography (EEG) and electrooculography (EOG) to enhance reliability and safety of continuous hand exoskeleton-driven grasping motions.Findings12 healthy volunteers (8 male, mean age 28.1 ± 3.63y) used EEG (condition #1) and hybrid EEG/EOG (condition #2) signals to control a hand exoskeleton. Motor imagery-related brain activity was translated into exoskeleton-driven hand closing motions. Unintended motions could be interrupted by eye movement-related EOG signals. In order to evaluate BNCI control and safety, participants were instructed to follow a visual cue indicating either to move or not to move the hand exoskeleton in a random order. Movements exceeding 25% of a full grasping motion when the device was not supposed to be moved were defined as safety violation. While participants reached comparable control under both conditions, safety was frequently violated under condition #1 (EEG), but not under condition #2 (EEG/EOG).ConclusionEEG/EOG biosignal fusion can substantially enhance safety of assistive BNCI systems improving their applicability in daily life environments.

Hybrid EEG/EOG-based brain/neural hand exoskeleton restores fully independent daily living activities after quadriplegia

A noninvasive, hybrid brain/neural hand exoskeleton restored intuitive control of grasping motion, restoring independent activities to quadriplegics. Direct brain control of advanced robotic systems promises substantial improvements in health care, for example, to restore intuitive control of hand movements required for activities of daily living in quadriplegics, like holding a cup and drinking, eating with cutlery, or manipulating different objects. However, such integrated, brain- or neural-controlled robotic systems have yet to enter broader clinical use or daily life environments. We demonstrate full restoration of independent daily living activities, such as eating and drinking, in an everyday life scenario across six paraplegic individuals (five males, 30 ± 14 years) who used a noninvasive, hybrid brain/neural hand exoskeleton (B/NHE) to open and close their paralyzed hand. The results broadly suggest that brain/neural-assistive technology can restore autonomy and independence in quadriplegic individuals’ everyday life.

A Mechatronic System for Robot-Mediated Hand Telerehabilitation

This paper presents a novel mechatronics master-slave setup for hand telerehabilitation. The system consists of a sensorized glove acting as a remote master and a powered hand exoskeleton acting as a slave. The proposed architecture presents three main innovative solutions. First, it provides the therapist with an intuitive interface (a sensorized wearable glove) for conducting the rehabilitation exercises. Second, the patient can benefit from a robot-aided physical rehabilitation in which the slave hand robotic exoskeleton can provide an effective treatment outside the clinical environment without the physical presence of the therapist. Third, the mechatronics setup is integrated with a sensorized object, which allows for the execution of manipulation exercises and the recording of patients improvements. In this paper, we also present the results of the experimental characterization carried out to verify the system usability of the proposed architecture with healthy volunteers.

NEUROExos: A powered elbow orthosis for post-stroke early neurorehabilitation

This paper presents the development of a portable version of the robotic elbow exoskeleton NEUROExos, designed for the treatment of stroke survivors in acute/sub-acute phases. The design was improved by a novel Series Elastic Actuation (SEA) system. The system implements two control modalities: a near-zero output impedance torque control and a passive-compliance position control.

The effects on biomechanics of walking and balance recovery in a novel pelvis exoskeleton during zero-torque control

Fall-related accidents are among the most serious concerns in elderly people, amputees and subjects with neurological disorders. The aim of this paper was to investigate the behaviour of healthy subjects wearing a novel light-weight pelvis exoskeleton controlled in zero-torque mode while carrying out unperturbed locomotion and managing unexpected perturbations. Results showed that the proposed exoskeleton was unobtrusive and had a minimum loading effect on the human biomechanics during unperturbed locomotion. Conversely, it affected the movement of the trailing leg while subjects managed unexpected slipping-like perturbations. These findings support further investigations on the potential use of powered exoskeletons to assist locomotion and, possibly prevent incipient falls.

Analysis of relative displacement between the HX wearable robotic exoskeleton and the user’s hand

BackgroundAdvances in technology are allowing for the production of several viable wearable robotic devices to assist with activities of daily living and with rehabilitation. One of the most pressing limitations to user satisfaction is the lack of consistency in motion between the user and the robotic device. The displacement between the robot and the body segment may not correspond because of differences in skin and tissue compliance, mechanical backlash, and/or incorrect fit.FindingsThis report presents the results of an analysis of relative displacement between the user’s hand and a wearable exoskeleton, the HX. HX has been designed to maximize comfort, wearability and user safety, exploiting chains with multiple degrees-of-freedom with a modular architecture. These appealing features may introduce several uncertainties in the kinematic performances, especially when considering the anthropometry, morphology and degree of mobility of the human hand. The small relative displacements between the hand and the exoskeleton were measured with a video-based motion capture system, while the user executed several different grips in different exoskeleton modes.ConclusionsThe analysis furnished quantitative results about the device performance, differentiated among device modules and test conditions. In general, the global relative displacement for the distal part of the device was in the range 0.5–1.5 mm, while within 3 mm (worse but still acceptable) for displacements nearest to the hand dorsum. Conclusions over the HX design principles have been drawn, as well as guidelines for future developments.

Usability test of a hand exoskeleton for activities of daily living: an example of user-centered design

Abstract Purpose: (1) To assess a robotic device (Handexos) during the design process with regard to usability, end user satisfaction and safety, (2) to determine whether Handexos can improve the activities of daily living (ADLs) of spinal cord injury (SCI) patients and stroke patients with upper-limb dysfunction. Methods: During a 2-year development stage of the device, a total of 37 participants (aged 22–68), 28 clinicians (experts) and nine patients with SCI or stroke (end users) were included in a user-centered design process featuring usability tests. They performed five grasps wearing the device. The assessments were obtained at the end of the session by filling out a questionnaire and making suggestions. Results: The experts’ opinion was that the modified device was an improvement over the preliminary version, although this was not reflected in the scores. Whereas end user scores for comfort, grasp, performance and safety were above the sufficiency threshold, the scores for year 2 were lower than those for year 1. Conclusions: The findings demonstrate that although Handexos meets the initial functional requirements and underlines the potential for assisting SCI and post-stroke subjects in ADLs, several aspects such as mechanical complexity and low adaptability to different hand sizes need to be further addressed. Implications for Rehabilitation Wearable robotics devices could improve the activities of daily living in patients with spinal cord injury or stroke. They could be a tool for rehabilitation of the upper limb. Further usability tests to improve this type of tools are recommended.