Collaborative robots are expected to physically interact with humans in daily living and the workplace, including industrial and healthcare settings. A key related enabling technology is tactile sensing, which currently requires addressing the outstanding scientific challenge to simultaneously detect contact location and intensity by means of soft conformable artificial skins adapting over large areas to the complex curved geometries of robot embodiments. In this work, the development of a large-area sensitive soft skin with a curved geometry is presented, allowing for robot total-body coverage through modular patches. The biomimetic skin consists of a soft polymeric matrix, resembling a human forearm, embedded with photonic fibre Bragg grating transducers, which partially mimics Ruffini mechanoreceptor functionality with diffuse, overlapping receptive fields. A convolutional neural network deep learning algorithm and a multigrid neuron integration process were implemented to decode the fibre Bragg grating sensor outputs for inference of contact force magnitude and localization through the skin surface. Results of 35 mN (interquartile range 56 mN) and 3.2 mm (interquartile range 2.3 mm) median errors were achieved for force and localization predictions, respectively. Demonstrations with an anthropomorphic arm pave the way towards artificial intelligence based integrated skins enabling safe human–robot cooperation via machine intelligence.

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Hydrothermal growth of ZnO nanorods has been widely used for the development of tactile sensors, with the aid of ZnO seed layers, favoring the growth of dense and vertically aligned nanorods. However, seed layers represent an additional fabrication step in the sensor design. In this study, a seedless hydrothermal growth of ZnO nanorods was carried out on Au-coated Si and polyimide substrates. The effects of both the Au morphology and the growth temperature on the characteristics of the nanorods were investigated, finding that smaller Au grains produced tilted rods, while larger grains provided vertical rods. Highly dense and high-aspect-ratio nanorods with hexagonal prismatic shape were obtained at 75 °C and 85 °C, while pyramid-like rods were grown when the temperature was set to 95 °C. Finite-element simulations demonstrated that prismatic rods produce higher voltage responses than the pyramid-shaped ones. A tactile sensor, with an active area of 1 cm2, was fabricated on flexible polyimide substrate and embedding the nanorods forest in a polydimethylsiloxane matrix as a separation layer between the bottom and the top Au electrodes. The prototype showed clear responses upon applied loads of 2–4 N and vibrations over frequencies in the range of 20–800 Hz.

Continuous and reliable cardiac function monitoring could improve medication adherence in patients at risk of heart failure. This work presents an innovative implantable Fiber Bragg Grating-based soft sensor designed to sense mechanical cardiac activity. The sensor was tested in an isolated beating ovine heart platform, with 3 different hearts operated in wide-ranging conditions. In order to investigate the sensor capability to track the ventricular beats in real-time, two causal algorithms were proposed for detecting the beats from sensor data and to discriminate artifacts. The first based on dynamic thresholds while the second is a hybrid convolutional and recurrent Neural Network. An error of 2.7 ± 0.7 beats per minute was achieved in tracking the heart rate. Finally, we have confirmed the sensor reliability in monitoring the heart activity of healthy adult minipig with an error systematically lower than 1 Bpm.

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Objective: Renal denervation (RDN) is increasingly used to reduce sympathetic outflow and improve blood pressure (BP) control in patients with resistant or difficult-to-treat arterial hypertension. However, the BP response to the procedure is variable, and factors influencing this variability remain largely unknown. Sympathetic outflow recorded before the procedure might predict the BP response to RDN, although results from different studies remain conflicting. These discrepancies might depend on the limited characterization of the sympathetic outflow before RDN, making its better definition an important goal to refine the patient selection. Design and method: We prospectively enrolled patients with difficult-to-treat arterial hypertension undergoing RDN. Patients underwent an extensive clinical evaluation, and the muscle sympathetic nerve activity (MSNA) in resting conditions and during respiratory maneuvers (controlled inspiratory apneas, evaluation of chemoreflex sensitivity to hypoxia and hypercapnia with the rebreathing technique) was recorded through microneurography. Sympathetic burst frequency, incidence, amplitude, duration and integral, as well as inter-burst interval, were calculated with a semi-automated in-house software. Results: Table 1 reports the clinical characteristics of the 10 patients that were enrolled and underwent MSNA recording before RDN. Only in 6 patients the MSNA signal was clearly interpretable and, of these, 5 subjects (Figure 1) completed the whole battery of the respiratory stimuli (2 patients couldn’t perform chemoreflex testing due to panic attack and loss of neural signal). Apnea increased the burst frequency and incidence in all patients, although the magnitude of the changes from the resting acquisition was variable. The MSNA responses to the other respiratory maneuvers were jeopardized. Burst duration remained stable, whereas an increased MSNA could be observed (subjects 1 and 3) in terms of risen burst integral and reduced inter-burst interval compared to baseline. The sympathetic response to inspiratory apneas seems mediated by chemoreflex responses in these patients. The other subjects did not show such variations. Conclusions: Respiratory maneuvers are feasible during MSNA acquisitions and unveil different patterns of sympathetic responses in patients with hypertension undergoing RDN. Such differences might be missed at rest but could represent novel predictors of the BP response to the procedure.