Scuola Superiore Sant'Anna
Recent publications
This paper proposes a methodology to investigate soil penetration requirements to extract specifications for designing robotic soil excavators and explorers. To this purpose, a three-dimensional (3-D) numerical model based on the Discrete Element Method (DEM) is proposed to simulate an intruder penetration and its interaction with the environment. In this study, the penetration process was analyzed as a function of the intruder diameter to median particle size ratio (Droot/D50), highlighting important differences for small and big ratios conditions (i.e., Droot/D50<<1 and Droot/D50>>1). In particular, the soil resistance force that autonomous penetration systems must overcome when moving into cohesionless granular soil was estimated based on the intruder size (diameter) and the median granularity (D50). This study estimates how the penetration requirements vary according to different penetration strategies. Specifically, a plant root-inspired axial movement emulating the growth from the tip adopted by plants is compared with a penetration obtained by pushing a system from the top. Our findings provide important guidelines about the design requirements (system size, penetration strategy, and actuation power) for artificial penetrating systems, like autonomous explorative robots, to improve their performances during underground exploration.
Objective This study aims at evaluating the cost-of-illness (COI) of patients diagnosed with Behcet’s syndrome (BS) in Italy, trying to depict the impact of different costs’ components to the overall economic burden and analysing the variability of costs according to years since diagnosis and age at first symptoms. Methods With a cross-sectional evaluation, we surveyed a large sample of BS patients in Italy assessing several dimensions related to BS, also including fact related to the use of health resources utilization, formal and informal care, and productivity losses. Overall costs, direct health, direct non-health, and indirect costs were thus estimated per patient/year considering a Societal perspective and the impact of years since diagnosis, age at first symptoms on costs was evaluated using generalized linear model (GLM) and a two-part model, adjusting for age and distinguishing among employed and non-employed responders. Results A total of 207 patients were considered in the present study. From the perspective of the Society, mean overall costs for BS patient were estimated to be 21,624 € (0;193,617) per patient/year. Direct non-health expenses were the main costs component accounting for 58% of the overall costs, followed direct health costs, 36%, while indirect costs because of productivity losses represented 6% of the overall costs. Being employed resulted in significantly lower overall costs (p = 0.006). Results from the multivariate regression analyses suggested that the probability of incurring in overall costs equal to zero decreased as time from BS diagnosis is 1 year or more as compared to newly diagnosed patients (p < 0.001); while among those incurring in expenses, costs decreased for those experiencing first symptoms between 21 and 30 years (p = 0.027) or later (p = 0.032) as compared to those having symptoms earlier. Similar findings emerged among the subgroups of patients declaring themselves as workers, while no impact of years since diagnosis or age of first symptoms was found among non-workers. Conclusions The present study offers a comprehensive overview of the economic consequences imposed by BS in a societal perspective, providing insights into the distribution of the different costs component related to BS, thus helping the development of targeted policies.
Background and aims: The aims of this study were to assess prescription patterns, dosages, discontinuation rates and association with prognosis of conventional heart failure (HF) medications in patients with transthyretin cardiac amyloidosis (ATTR-CA). Methods: A retrospective analysis of all consecutive patients diagnosed with ATTR-CA at the National Amyloidosis Centre between 2000-2022 identified 2371 patients with ATTR-CA. Results: Prescription of HF medications was greater among patients with a more severe cardiac phenotype, comprising beta-blockers in 55.4%, angiotensin-converting enzyme inhibitors (ACEi)/angiotensin-II receptor blockers (ARB) in 57.4%, and mineralocorticoid receptor antagonists (MRAs) in 39.0% of cases. During a median follow-up of 27.8 months (IQR 10.6-51.3), 21.7% had beta-blockers discontinued, and 32.9% had ACEi/ARB discontinued. In contrast, only 7.5% had MRAs discontinued. Propensity score-matched analysis demonstrated that treatment with MRAs was independently associated with a reduced risk of mortality in the overall population (HR 0.77 [95% CI 0.66-0.89], P<0.001) and in a pre-specified subgroup of patients with a left ventricular ejection fraction (LVEF) >40% (HR 0.75 [95% CI 0.63-0.90], P=0.002); and treatment with low-dose beta-blockers was independently associated with a reduced risk of mortality in a pre-specified subgroup of patients with a LVEF ≤40% (HR 0.61 [95% CI 0.45-0.83], P=0.002). No convincing differences were found for treatment with ACEi/ARBs. Conclusions: Conventional HF medications are currently not widely prescribed in ATTR-CA, and those that received medication had more severe cardiac disease. Beta-blockers and ACEi/ARBs were often discontinued, but low-dose beta-blockers were associated with reduced risk of mortality in patients with a LVEF ≤40%. In contrast, MRAs were rarely discontinued and were associated with reduced risk of mortality in the overall population; but these findings require confirmation in prospective randomized controlled trials.
The use of hands for gathering rich sensory information is essential for proper interaction with the environment; therefore, the restoration of sensation is critical for reestablishing the sense of embodiment in hand amputees. Here, we show that a noninvasive wearable device can be used to provide thermal sensations on amputees' phantom hands. The device delivers thermal stimuli to specific regions of skin on their residual limb. These sensations were phenomenologically similar to those on the intact limbs and were stable over time. Using the device, the subjects could successfully exploit the thermal phantom hand maps to detect and discriminate different thermal stimuli. The use of a wearable device that provides thermal sensation can increase the sense of embodiment and improve life quality in hand amputees.
Annulus cells of fern sporangia spontaneously deform driven by water transpiration and cavitation, resulting in the peculiar macroscale catapult‐like movement of the sporangium. Annulus cells' behavior, if artificially replicated, can inspire a novel class of fast actuators composed of annulus‐mimicking units. However, the transpiration and cavitation‐driven dynamics observed in annulus cells is never reproduced. Here, prismatic microcavities are assembled with a polydimethylsiloxane (PDMS) microfilm to realize artificial microchambers that mimic the annulus cells, replicating for the first time their evaporation‐driven collapse and their fast return triggered by the nucleation of bubbles. The microchambers, in turn, can be fabricated in adjacency, resulting in bending arrays driven by transpiration. Working with an artificial system allows this study to investigate the fluidic phenomena arising from the interplay of a soft, semi‐permeable membrane with a micro‐confined liquid bounded by rigid walls. First, the microchambers aspect ratio influences the membrane dynamics and the bubble shape (either spherical or non‐spherical). Second, the growth rate of the bubble interplay with the membrane in the expansion dynamics. This study's results demonstrate the artificial replication of annulus cells' behavior, offering a plant‐like solution to realize fast, microscale movements, and a novel tool to investigate complex fluidic mechanisms involving micro‐confined cavitation.
In the growing therapeutic armamentarium for heart failure (HF) management, vericiguat represents an innovative therapeutic option. The biological target of this drug is different from that of other drugs for HF. Indeed, vericiguat does not inhibit neuro-hormonal systems overactivated in HF or sodium–glucose co-transporter 2 but stimulates the biological pathway of nitric oxide and cyclic guanosine monophosphate, which is impaired in patients with HF. Vericiguat has recently been approved by international and national regulatory authorities for the treatment of patients with HF and reduced ejection fraction who are symptomatic despite optimal medical therapy and have worsening HF. This ANMCO position paper summarises key aspects of vericiguat mechanism of action and provides a review of available clinical evidence. Furthermore, this document reports use indications based on international guideline recommendations and local regulatory authority approval at the time of writing.
The performance of different probabilistic amplitude shaping (PAS)techniques in the nonlinear regime is investigated, highlighting its dependence on the PAS block length and the interaction with carrier phase recovery (CPR). Different PAS implementations are considered, based on different distribution matching (DM) techniques—namely, sphere shaping, shell mapping with different number of shells, and constant composition DM—and amplitude-to-symbol maps. When CPR is not included, PAS with optimal block length provides a nonlinear shaping gain with respect to a linearly optimized PAS (with infinite block length); among the considered DM techniques, the largest gain is obtained with sphere shaping. On the other hand, the nonlinear shaping gain becomes smaller, or completely vanishes, when CPR is included, meaning that in this case all the considered implementations achieve a similar performance for a sufficiently long block length. Similar results are obtained in different link configurations ( $1\times 180$ km, $15\times 80$ km, and $27\times 80$ km single-mode-fiber links), and also including laser phase noise, except when in-line dispersion compensation is used. Furthermore, we define a new metric, the nonlinear phase noise (NPN) metric, which is based on the frequency resolved logarithmic perturbation models and explains the interaction of CPR and PAS. We show that the NPN metric is highly correlated with the performance of the system. Our results suggest that, in general, the optimization of PAS in the nonlinear regime should always account for the presence of a CPR algorithm. In this case, the reduction of the rate loss (obtained by using sphere shaping and increasing the DM block length) turns out to be more important than the mitigation of the nonlinear phase noise (obtained by using constant-energy DMs and reducing the block length), the latter being already granted by the CPR algorithm.
Background: Urinary incontinence (UI) is a common and frustrating condition that affects patients' quality of life as well as the Healthcare systems. Currently, the most severe cases of UI are treated using implanted, invasive artificial sphincters. We propose an innovative, minimally invasive magnetic endourethral sphincter for the treatment of stress UI (SUI) in patients for whom previous medical and surgical treatments have failed. Methods: Six patients with severe SUI were enrolled at a single center and underwent cystoscopic sphincter implantation. After 10 days, correct device position was confirmed by ultrasonography. The sphincter was explanted after 28 days. Results: In all patients, the sphincter was successfully implanted using an endoscopic approach. One patient reached the end of the pilot test (28 days) with the sphincter correctly placed. Patients' responses on the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form questionnaire improved from a score of 18 out of 21 at the screening visit (UI without reasons) to a score of 3 out of 21 (almost perfect continence). No major pain and discomfort were reported. Conclusions: This study showed the feasibility of sphincter implantation, explantation, and overall tolerability, although a redesign of the sphincter distal part is needed.
We present a novel soft exoskeleton providing active support for hand closing and opening. The main novelty is a different tendon routing, folded laterally on both sides of the hand, and adding clenching forces when the exoskeleton is activated. It improves the stability of the glove, diminishing slippage and detachment of tendons from the hand palm toward the grasping workspace. The clenching effect is released when the hand is relaxed, thus enhancing the user's comfort. The alternative routing allowed embedding a single actuator on the hand dorsum, resulting more compact with no remote cable transmission. Enhanced adaptation to the hand is introduced by the modular design of the soft polymer open rings. FEM simulations were performed to understand the interaction between soft modules and fingers. Different experiments assessed the desired effect of the proposed routing in terms of stability and deformation of the glove, evaluated the inter-finger compliance for non-cylindrical grasping, and characterized the output grasping force. Experiments with subjects explored the grasping performance of the soft exoskeleton with different hand sizes. A preliminary evaluation with Spinal Cord Injury patients was useful to highlight the strengths and limitations of the device when applied to the target scenario.
In this paper, we present a mechanical hand-tracking system with tactile feedback designed for fine manipulation in teleoperation scenarios. Alternative tracking methods based on artificial vision and data gloves have become an asset for virtual reality interaction. Yet, occlusions, lack of precision, and the absence of effective haptic feedback beyond vibrotactile still appear as a limit for teleoperation applications. In this work, we propose a methodology to design a linkage mechanism for hand pose tracking purposes, preserving complete finger mobility. Presentation of the method is followed by design and implementation of a working prototype, and by evaluation of the tracking accuracy using optical markers. Moreover, a teleoperation experiment involving a dexterous robotic arm and hand was proposed to ten participants. It investigated the effectiveness and repeatability of the hand tracking with combined haptic feedback during a proposed pick and place manipulation tasks.
Background The aging of the population and the progressive increase of life expectancy in developed countries is leading to a high incidence of age-related cerebrovascular diseases, which affect people’s motor and cognitive capabilities and might result in the loss of arm and hand functions. Such conditions have a detrimental impact on people’s quality of life. Assistive robots have been developed to help people with motor or cognitive disabilities to perform activities of daily living (ADLs) independently. Most of the robotic systems for assisting on ADLs proposed in the state of the art are mainly external manipulators and exoskeletal devices. The main objective of this study is to compare the performance of an hybrid EEG/EOG interface to perform ADLs when the user is controlling an exoskeleton rather than using an external manipulator. Methods Ten impaired participants (5 males and 5 females, mean age 52 ± 16 years) were instructed to use both systems to perform a drinking task and a pouring task comprising multiple subtasks. For each device, two modes of operation were studied: synchronous mode (the user received a visual cue indicating the sub-tasks to be performed at each time) and asynchronous mode (the user started and finished each of the sub-tasks independently). Fluent control was assumed when the time for successful initializations ranged below 3 s and a reliable control in case it remained below 5 s. NASA-TLX questionnaire was used to evaluate the task workload. For the trials involving the use of the exoskeleton, a custom Likert-Scale questionnaire was used to evaluate the user’s experience in terms of perceived comfort, safety, and reliability. Results All participants were able to control both systems fluently and reliably. However, results suggest better performances of the exoskeleton over the external manipulator (75% successful initializations remain below 3 s in case of the exoskeleton and bellow 5s in case of the external manipulator). Conclusions Although the results of our study in terms of fluency and reliability of EEG control suggest better performances of the exoskeleton over the external manipulator, such results cannot be considered conclusive, due to the heterogeneity of the population under test and the relatively limited number of participants.
Background: Nowadays, wearable sensors are widely used to quantify physical and motor activity during daily life, and they also represent innovative solutions for healthcare. In the clinical framework, the assessment of motor behaviour is entrusted to clinical scales, but they are dependent on operator experience. Thanks to their intrinsic objectivity, sensor data are extremely useful to provide support to clinicians. Moreover, wearable sensors are user-friendly and compliant to be used in an ecological environment (i.e., at home). This paper aims to propose an innovative approach useful to predict clinical assessment scores of infants' motor activity. Materials and methods: Starting from data acquired by accelerometers placed on infants' wrists and trunk during playtime, we exploit the method of functional data analysis to implement new models combining quantitative data and clinical scales. In particular, acceleration data, transformed into activity indexes and combined with baseline clinical data, represent the input dataset for functional linear models. Conclusions: Despite the small number of data samples available, results show correlation between clinical outcome and quantitative predictors, indicating that functional linear models could be able to predict the clinical evaluation. Future works will focus on a more refined and robust application of the proposed method, based on the acquisition of more data for validating the presented models. Trial registration number: ClincalTrials.gov; NCT03211533. Registered: July, 7th 2017. ClincalTrials.gov; NCT03234959. Registered: August, 1st 2017.
Objective: We recently proposed a new concept of human-machine interface to control hand prostheses which we dubbed the myokinetic control interface. Such interface detects muscle displacement during contraction by localizing permanent magnets implanted in the residual muscles. So far, we evaluated the feasibility of implanting one magnet per muscle and monitoring its displacement relative to its initial position. However, multiple magnets could actually be implanted in each muscle, as using their relative distance as a measure of muscle contraction could improve the system robustness against environmental disturbances. Methods: Here, we simulated the implant of pairs of magnets in each muscle and we compared the localization accuracy of such system with the one magnet per muscle approach, considering first a planar and then an anatomically appropriate configuration. Such comparison was also performed when simulating different grades of mechanical disturbances applied to the system (i.e. shift of the sensor grid). Results: We found that implanting one magnet per muscle always led to lower localization errors under ideal conditions (i.e. no external disturbances). Differently, when mechanical disturbances were applied, magnet pairs outperformed the single magnet approach, confirming that differential measurements are able to reject common mode disturbances. Conclusion: We identified important factors affecting the choice of the number of magnets to implant in a muscle. Significance: Our results provide important guidelines for the design of disturbance rejection strategies and for the development of the myokinetic control interface, as well as for a whole range of biomedical applications involving magnetic tracking.
Starting from its classical domain of long distance links, optical communication is conquering new application areas down to chip-to-chip interconnections in response to the ever-increasing demand for higher bandwidth. The use of coherent modulation formats, typically employed in long-haul systems, is now debated to be extended to short links to increase the bandwidth density. Next-generation transceivers are targeting high bandwidth, high energy efficiency, compact footprint, and low cost. Integrated photonics is the only technology to reach this goal, and silicon photonics is expected to play the leading actor. However, silicon modulators have some limits, in terms of bandwidth and footprint. Graphene is an ideal material to be integrated with silicon photonics to meet the requirements of next generation transceivers. This material provides optimal properties: high mobility, fast carrier dynamics and ultrabroadband optical properties. Graphene photonics for direct detection systems based on binary modulation formats have been demonstrated so far, including electro-absorption modulators, phase modulators, and photodetectors. However, coherent modulation for increased data-rates has not yet been reported for graphene photonics yet. In this work, we present the first graphene photonics I/Q modulator based on four graphene on silicon electro-absorption modulators for advanced modulation formats and demonstrate quadrature phase shift keying (QPSK) modulation up to 40 Gb/s.
Background Measuring employees’ satisfaction with their jobs and working environment have become increasingly common worldwide. Healthcare organizations are not extraneous to the irreversible trend of measuring employee perceptions to boost performance and improve service provision. Considering the multiplicity of aspects associated with job satisfaction, it is important to provide managers with a method for assessing which elements may carry key relevance. Our study identifies the mix of factors that are associated with an improvement of public healthcare professionals’ job satisfaction related to unit, organization, and regional government. Investigating employees’ satisfaction and perception about organizational climate with different governance level seems essential in light of extant evidence showing the interconnection as well as the uniqueness of each governance layer in enhancing or threatening motivation and satisfaction. Methods This study investigates the correlates of job satisfaction among 73,441 employees in healthcare regional governments in Italy. Across four cross sectional surveys in different healthcare systems, we use an optimization model to identify the most efficient combination of factors that is associated with an increase in employees’ satisfaction at three levels, namely one’s unit, organization, and regional healthcare system. Results Findings show that environmental characteristics, organizational management practices, and team coordination mechanisms correlates with professionals’ satisfaction. Optimization analyses reveal that improving the planning of activities and tasks in the unit, a sense of being part of a team, and supervisor’s managerial competences correlate with a higher satisfaction to work for one’s unit. Improving how managers do their job tend to be associated with more satisfaction to work for the organization. Conclusions The study unveils commonalities and differences of personnel administration and management across public healthcare systems and provides insights on the role that several layers of governance have in depicting human resource management strategies.
Objective: Syntax involves complex neurobiological mechanisms, which are difficult to disentangle for multiple reasons. Approach: Using a protocol able to separate syntactic information from sound information we investigated the neural causal connections evoked by the processing of homophonous phrases, i.e. with the same acoustic information but with different syntactic content. These could be either verb phrases (VP) or noun phrases (NP). We used event-related causality (ERC) from stereo-electroencephalographic (SEEG) recordings in 10 epileptic patients in multiple cortical and subcortical areas, including language areas and their homologous in the non-dominant hemisphere. The recordings were made while the subjects were listening to the homophonous phrases. Main results: We identified the different networks involved in the processing of these syntactic operations (faster in the dominant hemisphere) showing that VPs engage a wider cortical and subcortical network. We also present a proof-of-concept for the decoding of the syntactic category of a perceived phrase based on causality measures. Significance: Our findings help unravel the neural correlates of syntactic elaboration and show how a decoding based on multiple cortical and subcortical areas could contribute to the development of speech prostheses for speech impairment mitigation.&#xD.
Lately, soft fluidic actuation has gained widespread interest in all fields where compliance and adaptability are the main keywords. Despite their well-known advantages, soft fluidic actuators frequently present problems related to the elastomeric chambers' durability, affecting the overall system robustness and safety. Indeed, if a robot relies on the parallel pressurisation of multiple actuators, the burst of a single chamber leads to the failure of the entire fluidic circuit, with consequent potentially hazardous leaks. Here, we present the development of a Soft Mini-Fuse (SMIF) valve able to secure and maintain the system functionality even in case of burst failure of single components without affecting their overall bulkiness. By modelling the valve through both analytical and finite element tools, we defined the correlation between main geometrical features, material properties and a selected range of blocking pressures (0.1-1.0 bar). Finally, after validating the modelling tools, we characterised the device behaviour in a range of commonly employed actuation flows (0-15 l/min). The compact dimensions, the ease of integration and the demonstrated performances underline that the SMIF valve represents a novel valuable ally that guarantees stable actuation, limits human intervention and paves the way towards more resilient and autonomous soft fluidic robotic systems.
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1,332 members
Philippe Velha
  • Institute of Communication, lnformation and Perception Technologies TECIP
Tommaso Cucinotta
  • Real-Time Systems Laboratory (RETIS Lab)
Koteswararao Kondepu
  • Institute of Communication, lnformation and Perception Technologies TECIP
Antonio Minnocci
  • Institute of Life Sciences
Anna Maria Murante
  • Institute of Management - EMBEDS
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