Closed-Chain Inverse Dynamics for the Biomechanical Analysis of Manual Material Handling Tasks through a Deep Learning Assisted Wearable Sensor Network.

Despite the automatization of many industrial and logistics processes, human workers are still often involved in the manual handling of loads. These activities lead to many work-related disorders that reduce the quality of life and the productivity of aged workers. A biomechanical analysis of such activities is the basis for a detailed estimation of the biomechanical overload, thus enabling focused prevention actions. Thanks to wearable sensor networks, it is now possible to analyze human biomechanics by an inverse dynamics approach in ecological conditions. The purposes of this study are the conceptualization, formulation, and implementation of a deep learning-assisted fully wearable sensor system for an online evaluation of the biomechanical effort that an operator exerts during a manual material handling task. In this paper, we show a novel, computationally efficient algorithm, implemented in ROS, to analyze the biomechanics of the human musculoskeletal systems by an inverse dynamics approach. We also propose a method for estimating the load and its distribution, relying on an egocentric camera and deep learning-based object recognition. This method is suitable for objects of known weight, as is often the case in logistics. Kinematic data, along with foot contact information, are provided by a fully wearable sensor network composed of inertial measurement units. The results show good accuracy and robustness of the system for object detection and grasp recognition, thus providing reliable load estimation for a high-impact field such as logistics. The outcome of the biomechanical analysis is consistent with the literature. However, improvements in gait segmentation are necessary to reduce discontinuities in the estimated lower limb articular wrenches.

Inter-brain co-activations during mindfulness meditation. Implications for devotional and clinical settings.

Mindfulness meditation usually takes place as personal, introspective activity. It is not known if this practice activates the brain differently when done alone or with someone else. Sixteen couples of expert meditators performed mindfulness-oriented meditation (MOM) and instructed mind-wandering (IMW) tasks in two conditions: once sitting in the same room (SR) and once in two different rooms (DR). Spontaneous electroencephalographic (EEG) data was collected during 7-minute recording sessions in the four experimental settings (MOM/SR, MOM/DR, IMW/SR, IMW/DR). Power in band was computed in separate clusters of independent components of the EEG signals. In addition to significant task effects, found in frontolimbic (MOM > IMW in gamma) and frontoparietal locations (MOM < IMW in theta), significant condition effects were found in frontal (SR > DR in delta) and in temporo-occipital regions (SR > DR in theta and alpha). Moreover, a significant interaction between task and condition revealed higher gamma activity in limbic areas during MOM/SR vs. MOM/DR settings. This effect was not attributable to gender, age nor the meditation expertise of participants. We thus show that the brains of two people work differently when they are doing something together or alone; some of these differences are specific to mindfulness meditation. Implications for devotional and clinical settings are discussed.

Evaluation of the effects of the Arm Light Exoskeleton on movement execution and muscle activities: a pilot study on healthy subjects.

BACKGROUND: Exoskeletons for lower and upper extremities have been introduced in neurorehabilitation because they can guide the patient's limb following its anatomy, covering many degrees of freedom and most of its natural workspace, and allowing the control of the articular joints. The aims of this study were to evaluate the possible use of a novel exoskeleton, the Arm Light Exoskeleton (ALEx), for robot-aided neurorehabilitation and to investigate the effects of some rehabilitative strategies adopted in robot-assisted training. METHODS: We studied movement execution and muscle activities of 16 upper limb muscles in six healthy subjects, focusing on end-effector and joint kinematics, muscle synergies, and spinal maps. The subjects performed three dimensional point-to-point reaching movements, without and with the exoskeleton in different assistive modalities and control strategies. RESULTS: The results showed that ALEx supported the upper limb in all modalities and control strategies: it reduced the muscular activity of the shoulder's abductors and it increased the activity of the elbow flexors. The different assistive modalities favored kinematics and muscle coordination similar to natural movements, but the muscle activity during the movements assisted by the exoskeleton was reduced with respect to the movements actively performed by the subjects. Moreover, natural trajectories recorded from the movements actively performed by the subjects seemed to promote an activity of muscles and spinal circuitries more similar to the natural one. CONCLUSIONS: The preliminary analysis on healthy subjects supported the use of ALEx for post-stroke upper limb robotic assisted rehabilitation, and it provided clues on the effects of different rehabilitative strategies on movement and muscle coordination.

Illusory movements induced by tendon vibration in right- and left-handed people.

Frequency-specific vibratory stimulation of peripheral tendons induces an illusion of limb movement that may be useful for restoring proprioceptive information in people with sensorimotor disability. This potential application may be limited by inter- and intra-subject variability in the susceptibility to such an illusion, which may depend on a variety of factors. To explore the influence of stimulation parameters and participants' handedness on the movement illusion, we vibrated the right and left tendon of the biceps brachii in a group of right- and left-handed people with five stimulation frequencies (from 40 to 120 Hz in step of 20 Hz). We found that all participants reported the expected illusion of elbow extension, especially after 40 and 60 Hz. Left-handers exhibited less variability in reporting the illusion compared to right-handers across the different stimulation frequencies. Moreover, the stimulation of the non-dominant arm elicited a more vivid illusion with faster onset relative to the stimulation of the dominant arm, an effect that was independent from participants' handedness. Overall, our data show that stimulation frequency, handedness and arm dominance influence the tendon vibration movement illusion. The results are discussed in reference to their relevance in linking motor awareness, improving current devices for motor ability recovery after brain or spinal damage and developing prosthetics and virtual embodiment systems.

Hypnotizability and the position sense: proprioceptive localization of the hand.

We  investigated whether healthy subjects with high (highs) and low (lows) hypnotizability scores differ in the ability to report the position of their right hand in the horizontal plane at the end of passive and active arm movements directed to lateral, intermediate and medial targets of the right hemispace under correct or incorrect visual feedback. Results showed that incorrect visual feedback increased the error in both groups. In lows, the error was similar after active and passive movements; in highs, it was lower for active than passive movements toward the medial position, but lower for passive than for active movements for the lateral one. The highs' error was significantly lower than the lows' one only for the active movements directed toward the medial hand position. Hypnotizability-related differences may be due to different role of efferent copies in highs and lows.

N400-like responses to three-chord harmonic sequences with unexpected out of key endings: scalp topography, cortical sources, and perspectives for a clinical use.

A series of ERP components, each provided with both a precise timing with respect to stimulation and a specific cortical localization, reflects the temporal succession of processing stages of music information. This makes the musical stimulus potentially usable to probe residual brain functions in non-communicating patients with disorders of consciousness. In an attempt to find a simple stimulation protocol that was suitable for use in a clinical setting, the purpose of this study was to verify whether a minimum-length musical stimulus, provided with a definite music-syntactic connotation, was still able to elicit musical ERPs in a group of eight healthy subjects. The stimulus was composed of the minimum number of chords necessary and sufficient to enable the subject to predict a plausible closure of the sequence (priming) and, at the same time, to provide him/her with the closing chord of the sequence (target), either congruous (probable closing) or not (improbable closing) to the tonal context. The subject's task was to discriminate and recognize the irregular targets. The components that were expected to be elicited, in this experimental situation, were ERAN, N5, P600/LPC. Conversely, in addition to these former components, we unexpectedly observed a N400-like component. To determine whether this component was a real N400, we submitted our data to a sLORETA analysis in order to identify its cortical generators. Irregular chords showed higher current densities with respect to regular ones on the right-sided medial and superior temporal gyri, superior and inferior parietal lobules, fusiform and parahippocampal gyri, and on the bilateral posterior cingulate cortex. In particular, the N400-like wave seems to share with the word-primed music-elicited N400 certain generators that are located in cortical areas BA 21/37 and BA 22. This suggests that even chord-primed chord targets can convey extra-musical meanings and that, consequently, they might be useful in assessing residual higher-order information-processing capabilities in non-communicating patients with disorders of consciousness.

A perspective-based analysis of attachment from prenatal period to second year postnatal life.

Attachment is one of the foundational themes in the history of the psychological development of human beings. For this reason, we assume that it must be approached by taking into account multiple scientific perspectives. The present review aims at analyzing the state of the art regarding the genetic, neurobiological and cognitive mechanisms underlying the development of attachment bonding, considering the child as the frame of reference. We hypothesize that attachment may be present in prototypical forms even in the prenatal period, thus our analysis has a temporal origin in the intrauterine period preceding birth. The intrauterine period is assumed to be a period of maximum sensitivity to stimuli and in particular to those coming from a potential primary caregiver: the biological mother. We conclude with a reframing of the state of the art and propose that future research work would benefit from a superordinate model of attachment, capable of containing and regulating all its components and variables.

The Fondazione Toscana Gabriele Monasterio app: a digital health system to improve wellbeing of inpatients with heart or lung disease.

BACKGROUND: An app providing material for education and entertaining is a possible way to support patients and healthcare providers in achieving person-centered care. METHODS: An app tailored on the Fondazione Toscana Gabriele Monasterio (FTGM), a research hospital treating cardiac and lung disorders, was created. A pilot evaluation project was conducted on consecutive patients hospitalized for heart or lung disorders. Patients were asked to complete an assessment questionnaire. RESULTS: The FTGM app provides information on diagnostic and therapeutic investigations, hospital and healthcare personnel, and includes content for entertainment and learning. It was tested on 215 consecutive patients (75% men, 66% aged >60 years, and 40% with a primary or middle school degree). Sixty-nine percentage of patients used the FTGM app, including 67% of patients aged >80 years and 65% of those with an elementary education (65%). Patients gave positive feedback on the app layout. Many (76%) looked for information on doctors and nurses in the 'People' section. Sixty-five percent of responders had used at least one of the sections called 'Music' and 'Museum visits'. The app helped many patients perceive the hospital as a more liveable place (68%), and to feel less anxious (76%), and more engaged in the diagnostic and therapeutic workup (65%). Overall, the majority of responders (87%) rated the app as 'excellent' or 'good', and almost all (95%) would have recommended other patients to use the app. CONCLUSIONS: The FTGM app is a possible tool to improve patient wellbeing during hospitalization.

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

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.

Novel magnetic sensing approach with improved linearity.

This paper introduces a novel contactless sensing principle conceived for measuring the rotation angle of a shaft. The sensor is based on a smart combination of low-cost components that can be effectively integrated in a mechanical assembly of a rotary joint. The working principle is based on the relative rotation of a small diametrically magnetized cylindrical or annular magnet and at least one Hall effect sensor. One of the main strengths of the new sensing principle is to be adaptable to any assigned dimensions and encumbrances without typical design limitations given by the use of standard components. A numerical model is developed for predicting the sensor output characteristic on the base of the concept of magnetic charge. Such a model is validated against results from laboratory experiments. The parameters that define the geometry and layout of the sensor are optimized in order to maximize linearity over an assigned angular range of measurement. Two examples of mechatronic systems that employ the new sensing principle are presented in order to show the possibility of obtaining with the new principle a compact/integrated sensor-design.

Virtual Reality Training for Post-Earthquake Rescue Operators.

Urban Search And Rescue (USAR) personnel need to be appropriately trained to effectively operate in post-disaster conditions, as they need to quickly identify locations where the presence of survivors is more likely. Currently, the training procedure for this kind of triage is based on showing static pictures presenting different types of building collapses accompanied by cards providing additional environmental information. This article presents VRescue, a simulator for training USAR operators using the paradigm of immersive virtual reality (VR). VRescue recreates a range of operation conditions (day/night, presence of people, dangerous locations, etc.) experienced by real rescuers, and enables learning the use of the equipment commonly used in such scenarios.

Positive effects of robotic exoskeleton training of upper limb reaching movements after stroke.

This study, conducted in a group of nine chronic patients with right-side hemiparesis after stroke, investigated the effects of a robotic-assisted rehabilitation training with an upper limb robotic exoskeleton for the restoration of motor function in spatial reaching movements. The robotic assisted rehabilitation training was administered for a period of 6 weeks including reaching and spatial antigravity movements. To assess the carry-over of the observed improvements in movement during training into improved function, a kinesiologic assessment of the effects of the training was performed by means of motion and dynamic electromyographic analysis of reaching movements performed before and after training. The same kinesiologic measurements were performed in a healthy control group of seven volunteers, to determine a benchmark for the experimental observations in the patients' group. Moreover degree of functional impairment at the enrolment and discharge was measured by clinical evaluation with upper limb Fugl-Meyer Assessment scale (FMA, 0-66 points), Modified Ashworth scale (MA, 0-60 pts) and active ranges of motion. The robot aided training induced, independently by time of stroke, statistical significant improvements of kinesiologic (movement time, smoothness of motion) and clinical (4.6 ± 4.2 increase in FMA, 3.2 ± 2.1 decrease in MA) parameters, as a result of the increased active ranges of motion and improved co-contraction index for shoulder extension/flexion. Kinesiologic parameters correlated significantly with clinical assessment values, and their changes after the training were affected by the direction of motion (inward vs. outward movement) and position of target to be reached (ipsilateral, central and contralateral peripersonal space). These changes can be explained as a result of the motor recovery induced by the robotic training, in terms of regained ability to execute single joint movements and of improved interjoint coordination of elbow and shoulder joints.

A three-axis force sensor for dual finger haptic interfaces.

In this work we present the design process, the characterization and testing of a novel three-axis mechanical force sensor. This sensor is optimized for use in closed-loop force control of haptic devices with three degrees of freedom. In particular the sensor has been conceived for integration with a dual finger haptic interface that aims at simulating forces that occur during grasping and surface exploration. The sensing spring structure has been purposely designed in order to match force and layout specifications for the application. In this paper the design of the sensor is presented, starting from an analytic model that describes the characteristic matrix of the sensor. A procedure for designing an optimal overload protection mechanism is proposed. In the last part of the paper the authors describe the experimental characterization and the integrated test on a haptic hand exoskeleton showing the improvements in the controller performances provided by the inclusion of the force sensor.

A robotic & virtual reality orthopedic rehabilitation system for the forearm.

We describe a robotic and virtual reality system for the rehabilitation of the forearm. It consists of a robotic arm and VR scenarios with a dynamic model of the human upper limb. The system allows to assign specific tasks to perform within the virtual environments. The system simulates the actions of the patient limb and allows exhaustive exercising and motor control, giving visuomotor and haptic feedback and trajectory positioning guidance. The system aids to evaluate the mobility condition of the patient, to personalize the difficult level of the therapy and provides kinematic measures of the patient evolution. The patients recruitment phase has already started for clinical pilot studies.

Using co-creation to develop a cardiology online open course: an effective approach for implementing digital learning.

AIMS: we developed a massive online open course (MOOC) through co-creation between medical students and academic staff on heart semeiotics and evaluated its teaching efficiency and user satisfaction. METHODS: "The Heart, Its Signs and Symptoms" was a MOOC aimed to teach medical students to collect clinical history and perform physical examination of patients presenting with chest pain, dyspnea, palpitations, or syncope. It consisted of 4 interactive cases with preliminary, interim and final evaluation tests. A group of medical students, with the supervision of a multidisciplinary team of University professors residents, health management and informatics researchers developed the MOOC. RESULTS: Users (n = 701) registered to the online platform over 1 month. Students from 34 of the 40 Italian medical faculties participated. 96% of those who started the online course completed at least one of the 4 modules. Among users completing both the preliminary test and the final exam (n = 239, 34% of those registered to the online platform), the percentage of subjects passing the evaluation test raised s from 74% to 95% after the course. Younger age, attendance of Universities in Southern Italy, and a lower number of correct answers during the pre-test predicted a greater increase in the number of correct answers; Almost all participants who provided a feedback (n = 238) felt satisfied by the course. CONCLUSIONS: Partnership of medical students and academic staff was a key asset for the success of the initiative. The high rate of involvement and positive feedback from learners suggest a still unmet need for online learning resources.

Do Virtual Humans Dream of Digital Sheep?

As human beings, we are so used to interacting with each other that any world without humans would feel alien to us, including digital ones. In this article, we present a survey on the role of digital human-like characters in virtual worlds, both as counterparts of real human users and as embodied agents driven by artificial intelligence. The main issues related to 3-D graphics, physics, animation, and behavioral modeling are introduced, suggesting wherever available different alternatives and related development pipelines. A sizeable list of examples illustrating the use of virtual humans in different application sectors is then presented, focusing in particular on four domains: environmental design, training, cultural heritage, and healthcare.

Virtual reality enhanced mannequin (VREM) that is well received by resuscitation experts.

UNLABELLED: The objective of this study was to test acceptance of, and interest in, a newly developed prototype of virtual reality enhanced mannequin (VREM) on a sample of congress attendees who volunteered to participate in the evaluation session and to respond to a specifically designed questionnaire. METHODS: A commercial Laerdal HeartSim 4000 mannequin was developed to integrate virtual reality (VR) technologies with specially developed virtual reality software to increase the immersive perception of emergency scenarios. To evaluate the acceptance of a virtual reality enhanced mannequin (VREM), we presented it to a sample of 39 possible users. Each evaluation session involved one trainee and two instructors with a standardized procedure and scenario: the operator was invited by the instructor to wear the data-gloves and the head mounted display and was briefly introduced to the scope of the simulation. The instructor helped the operator familiarize himself with the environment. After the patient's collapse, the operator was asked to check the patient's clinical conditions and start CPR. Finally, the patient started to recover signs of circulation and the evaluation session was concluded. Each participant was then asked to respond to a questionnaire designed to explore the trainee's perception in the areas of user-friendliness, realism, and interaction/immersion. RESULTS: Overall, the evaluation of the system was very positive, as was the feeling of immersion and realism of the environment and simulation. Overall, 84.6% of the participants judged the virtual reality experience as interesting and believed that its development could be very useful for healthcare training. CONCLUSIONS: The prototype of the virtual reality enhanced mannequin was well-liked, without interfence by interaction devices, and deserves full technological development and validation in emergency medical training.

Robotic assisted rehabilitation in Virtual Reality with the L-EXOS.

This study presents the evaluation results of a clinical trial of robotic-assisted rehabilitation in Virtual Reality performed with the PERCRO L-Exos (Light-Exoskeleton) system, which is a 5-DoF force-feedback exoskeleton for the right arm. The device has demonstrated itself suitable for robotic arm rehabilitation therapy when integrated with a Virtual Reality (VR) system. Three different schemes of therapy in VR were tested in the clinical evaluation trial, which was conducted on a group of nine chronic stroke patients at the Santa Chiara Hospital in Pisa-Italy. The results of this clinical trial, both in terms of patients performance improvements in the proposed exercises and in terms of improvements in the standard clinical scales which were used to monitor patients receovery are reported and discussed. The evaluation both pre and post-therapy was carried out with both clinical and quantitative kinesiologic measurements. Statistically significant improvements were found in terms of Fugl-Meyer scores, Ashworth scale, increments of active and passive ranges of motion of the impaired limb, and quantitative indexes, such as task time and error.

Spontaneous eye movements during focused-attention mindfulness meditation.

Oculometric measures have been proven to be useful markers of mind-wandering during visual tasks such as reading. However, little is known about ocular activity during mindfulness meditation, a mental practice naturally involving mind-wandering episodes. In order to explore this issue, we extracted closed-eyes ocular movement measurements via a covert technique (EEG recordings) from expert meditators during two repetitions of a 7-minute mindfulness meditation session, focusing on the breath, and two repetitions of a 7-minute instructed mind-wandering task. Power spectral density was estimated on both the vertical and horizontal components of eye movements. The results show a significantly smaller average amplitude of eye movements in the delta band (1-4 Hz) during mindfulness meditation than instructed mind-wandering. Moreover, participants' meditation expertise correlated significantly with this average amplitude during both tasks, with more experienced meditators generally moving their eyes less than less experienced meditators. These findings suggest the potential use of this measure to detect mind-wandering episodes during mindfulness meditation and to assess meditation performance.

Effects of Continuous Kinaesthetic Feedback Based on Tendon Vibration on Motor Imagery BCI Performance.

BACKGROUND AND OBJECTIVES: Feedback plays a crucial role for using brain computer interface systems. This paper proposes the use of vibration-evoked kinaesthetic illusions as part of a novel multisensory feedback for a motor imagery (MI)-based BCI and investigates its contributions in terms of BCI performance and electroencephalographic (EEG) correlates. METHODS: sixteen subjects performed two different right arm MI-BCI sessions: with the visual feedback only and with both visual and vibration-evoked kinaesthetic feedback, conveyed by the stimulation of the biceps brachi tendon. In both conditions, the sensory feedback was driven by the MI-BCI. The rich and more natural multisensory feedback was expected to facilitate the execution of MI, and thus to improve the performance of the BCI. The EEG correlates of the proposed feedback were also investigated with and without the performing of MI. RESULTS AND CONCLUSIONS: the contribution of vibration-evoked kinaesthetic feedback led to statistically higher BCI performance (Anova, F(1,14) = 18.1, p < .01) and more stable EEG event-related-desynchronization. Obtained results suggest promising application of the proposed method in neuro-rehabilitation scenarios: the advantage of an improved usability could make the MI-BCIs more applicable for those patients having difficulties in performing kinaesthetic imagery.