Assessing REALTER simulator: analysis of ocular movements in simulated low-vision conditions with extended reality technology.

Immersive technology, such as extended reality, holds promise as a tool for educating ophthalmologists about the effects of low vision and for enhancing visual rehabilitation protocols. However, immersive simulators have not been evaluated for their ability to induce changes in the oculomotor system, which is crucial for understanding the visual experiences of visually impaired individuals. This study aimed to assess the REALTER (Wearable Egocentric Altered Reality Simulator) system's capacity to induce specific alterations in healthy individuals' oculomotor systems under simulated low-vision conditions. We examined task performance, eye movements, and head movements in healthy participants across various simulated scenarios. Our findings suggest that REALTER can effectively elicit behaviors in healthy individuals resembling those observed in individuals with low vision. Participants with simulated binocular maculopathy demonstrated unstable fixations and a high frequency of wide saccades. Individuals with simulated homonymous hemianopsia showed a tendency to maintain a fixed head position while executing wide saccades to survey their surroundings. Simulation of tubular vision resulted in a significant reduction in saccade amplitudes. REALTER holds promise as both a training tool for ophthalmologists and a research instrument for studying low vision conditions. The simulator has the potential to enhance ophthalmologists' comprehension of the limitations imposed by visual disabilities, thereby facilitating the development of new rehabilitation protocols.

A Green Conformable Thermoformed Printed Circuit Board Sourced from Renewable Materials.

Printed circuit boards (PCBs) physically support and connect electronic components to the implementation of complex circuits. The most widespread insulating substrate that also acts as a mechanical support in PCBs is commercially known as FR4, and it is a glass-fiber-reinforced epoxy resin laminate. FR4 has exceptional dielectric, mechanical, and thermal properties. However, it was designed without considering sustainability and end-of-life aspects, heavily contributing to the accumulation of electronic waste in the environment. Thus, greener alternatives that can be reprocessed, reused, biodegraded, or composted at the end of their function are needed. This work presents the development and characterization of a PCB substrate based on poly(lactic acid) and cotton fabric, a compostable alternative to the conventional FR4. The substrate has been developed by compression molding, a process compatible with the polymer industry. We demonstrate that conductive silver ink can be additively printed on the substrate's surface, as its morphology and wettability are similar to those of FR4. For example, the compostable PCB's water contact angle is 72°, close to FR4's contact angle of 64°. The developed substrate can be thermoformed to curved surfaces at low temperatures while preserving the conductivity of the silver tracks. The green substrate has a dielectric constant comparable to that of the standard FR4, showing a value of 5.6 and 4.6 at 10 and 100 kHz, respectively, which is close to the constant value of 4.6 of FR4. The substrate is suitable for microdrilling, a fundamental process for integrating electronic components to the PCB. We implemented a proof-of-principle circuit to control the blinking of LEDs on top of the PCB, comprising resistors, capacitors, LEDs, and a dual in-line package circuit timer. The developed PCB substrate represents a sustainable alternative to standard FR4 and could contribute to the reduction of the overwhelming load of electronic waste in landfills.

Neural network-based Bluetooth synchronization of multiple wearable devices.

Bluetooth-enabled wearables can be linked to form synchronized networks to provide insightful and representative data that is exceptionally beneficial in healthcare applications. However, synchronization can be affected by inevitable variations in the component's performance from their ideal behavior. Here, we report an application-level solution that embeds a Neural network to analyze and overcome these variations. The neural network examines the timing at each wearable node, recognizes time shifts, and fine-tunes a virtual clock to make them operate in unison and thus achieve synchronization. We demonstrate the integration of multiple Kinematics Detectors to provide synchronized motion capture at a high frequency (200 Hz) that could be used for performing spatial and temporal interpolation in movement assessments. The technique presented in this work is general and independent from the physical layer used, and it can be potentially applied to any wireless communication protocol.

Proposing magnetoimpedance effect for neuromorphic computing.

Oscillation of physical parameters in materials can result in a peak signal in the frequency spectrum of the voltage measured from the materials. This spectrum and its amplitude/frequency tunability, through the application of bias voltage or current, can be used to perform neuron-like cognitive tasks. Magnetic materials, after achieving broad distribution for data storage applications in classical Von Neumann computer architectures, are under intense investigation for their neuromorphic computing capabilities. A recent successful demonstration regards magnetisation oscillation in magnetic thin films by spin transfer or spin orbit torques accompanied by magnetoresistance (MR) effect that can give a voltage peak in the frequency spectrum of voltage with bias current dependence of both peak frequency and amplitude. Here we use classical magnetoimpedance (MI) effect in a magnetic wire to produce such a peak and manipulate its frequency and amplitude by means of the bias voltage. We applied a noise signal to a magnetic wire with high magnetic permeability and owing to the frequency dependence of the magnetic permeability we got frequency dependent impedance with a peak at the maximum permeability. Frequency dependence of the MI effect results in different changes in the voltage amplitude at each frequency when a bias voltage is applied and therefore a shift in the peak position and amplitude can be obtained. The presented method and material provide optimal features in structural simplicity, low-frequency operation (tens of MHz-order) and high robustness at different environmental conditions. Our universal approach can be applied to any system with frequency dependent bias responses.

Experimental Demonstration of In-Memory Computing in a Ferrofluid System.

Magnetic fluids are excellent candidates for several important research fields including energy harvesting, biomedical applications, soft robotics, and exploration. However, notwithstanding relevant advancements such as shape reconfigurability, that have been demonstrated, there is no evidence for their computing capability, including the emulation of synaptic functions, which requires complex non-linear dynamics. Here, it is experimentally demonstrated that a Fe3 O4 water-based ferrofluid (FF) can perform electrical analogue computing and be programmed using quasi direct current (DC) signals and read at radio frequency (RF) mode. Features have been observed in all respects attributable to a memristive behavior, featuring both short and long-term information storage capacity and plasticity. The colloid is capable of classifying digits of a 8 × 8 pixel dataset using a custom in-memory signal processing scheme, and through physical reservoir computing by training a readout layer. These findings demonstrate the feasibility of in-memory computing using an amorphous FF system in a liquid aggregation state. This work poses the basis for the exploitation of a FF colloid as both an in-memory computing device and as a full-electric liquid computer thanks to its fluidity and the reported complex dynamics, via probing read-out and programming ports.

The BrightEyes-TTM as an open-source time-tagging module for democratising single-photon microscopy.

Fluorescence laser-scanning microscopy (LSM) is experiencing a revolution thanks to new single-photon (SP) array detectors, which give access to an entirely new set of single-photon information. Together with the blooming of new SP LSM techniques and the development of tailored SP array detectors, there is a growing need for (i) DAQ systems capable of handling the high-throughput and high-resolution photon information generated by these detectors, and (ii) incorporating these DAQ protocols in existing fluorescence LSMs. We developed an open-source, low-cost, multi-channel time-tagging module (TTM) based on a field-programmable gate array that can tag in parallel multiple single-photon events, with 30 ps precision, and multiple synchronisation events, with 4 ns precision. We use the TTM to demonstrate live-cell super-resolved fluorescence lifetime image scanning microscopy and fluorescence lifetime fluctuation spectroscopy. We expect that our BrightEyes-TTM will support the microscopy community in spreading SP-LSM in many life science laboratories.

Electrostatic polarization fields trigger glioblastoma stem cell differentiation.

Over the last few years it has been understood that the interface between living cells and the underlying materials can be a powerful tool to manipulate cell functions. In this study, we explore the hypothesis that the electrical cell/material interface can regulate the differentiation of cancer stem-like cells (CSCs). Electrospun polymer fibres, either polyamide 66 or poly(lactic acid), with embedded graphene nanoplatelets (GnPs), have been fabricated as CSC scaffolds, providing both the 3D microenvironment and a suitable electrical environment favorable for CSCs adhesion, growth and differentiation. We have investigated the impact of these scaffolds on the morphological, immunostaining and electrophysiological properties of CSCs extracted from human glioblastoma multiform (GBM) tumor cell line. Our data provide evidence in favor of the ability of GnP-incorporating scaffolds to promote CSC differentiation to the glial phenotype. Numerical simulations support the hypothesis that the electrical interface promotes the hyperpolarization of the cell membrane potential, thus triggering the CSC differentiation. We propose that the electrical cell/material interface can regulate endogenous bioelectrical cues, through the membrane potential manipulation, resulting in the differentiation of CSCs. Material-induced differentiation of stem cells and particularly of CSCs, can open new horizons in tissue engineering and new approaches to cancer treatment, especially GBM.

Integrated Micro-Devices for a Lab-in-Organoid Technology Platform: Current Status and Future Perspectives.

Advancements in stem cell technology together with an improved understanding of in vitro organogenesis have enabled new routes that exploit cell-autonomous self-organization responses of adult stem cells (ASCs) and homogenous pluripotent stem cells (PSCs) to grow complex, three-dimensional (3D), mini-organ like structures on demand, the so-called organoids. Conventional optical and electrical neurophysiological techniques to acquire functional data from brain organoids, however, are not adequate for chronic recordings of neural activity from these model systems, and are not ideal approaches for throughput screenings applied to drug discovery. To overcome these issues, new emerging approaches aim at fusing sensing mechanisms and/or actuating artificial devices within organoids. Here we introduce and develop the concept of the Lab-in-Organoid (LIO) technology for in-tissue sensing and actuation within 3D cell aggregates. This challenging technology grounds on the self-aggregation of brain cells and on integrated bioelectronic micro-scale devices to provide an advanced tool for generating 3D biological brain models with in-tissue artificial functionalities adapted for routine, label-free functional measurements and for assay's development. We complete previously reported results on the implementation of the integrated self-standing wireless silicon micro-devices with experiments aiming at investigating the impact on neuronal spheroids of sinusoidal electro-magnetic fields as those required for wireless power and data transmission. Finally, we discuss the technology headway and future perspectives.

RoMAT: Robot for Multisensory Analysis and Testing of visual-tactile perceptual functions.

The present work aims to introduce a novel robotic platform suitable for investigating perception in multi-sensory motion tasks for individuals with and without sensory and motor disabilities. The system, called RoMAT, allows the study of how multisensory signals are integrated, taking into account the speed and direction of the stimuli. It is a robotic platform composed of a visual and tactile wheel mounted on two routable plates to be moved under the finger and the visual observation of the participants. We validated the system by implementing a rotation discrimination task considering two different sensory modalities: vision, touch and multisensory visual-tactile integration. Four healthy subjects were asked to report the length of motion rotation after perceiving a moving stimulus generated by the visual, tactile, or both stimuli. Results suggest that multisensory precision improves when multiple sensory stimulations are presented. The new system can therefore provide fundamental inputs in determining the perceptual principles of motion processing. Therefore, this device can be a potential system to design screening and rehabilitation protocols based on neuroscientific findings to be used in individuals with visual and motor impairments.Clinical relevance- This research presents a novel robotic motion simulator to deliver combined or independent stimulation of the visual and tactile sensory signals.

FITFES: A Wearable Myoelectrically Controlled Functional Electrical Stimulator Designed Using a User-Centered Approach.

Myoelectrically Controlled Functional Electrical Stimulation (MeCFES) has proven to be a useful tool in the rehabilitation of the hemiplegic arm. This paper reports the steps involved in the development of a wearable MeCFES device (FITFES) through a user-centered design. We defined the minimal viable features and functionalities requirements for the device design from a questionnaire-based survey among physiotherapists with experience in functional electrical stimulation. The result was a necklace layout that poses minimal hindrance to task-oriented movement therapy, the context in which it is aimed to be used. FITFES is battery-powered and embeds a standard low power Bluetooth module, enabling wireless control by using PC/Mobile devices vendor specific built-in libraries. It is designed to deliver a biphasic, charge-balanced stimulation current pulses of up to 113 mA with a maximum differential voltage of 300 V. The power consumption for typical clinical usage is 320 mW at 20mA stimulation current and of less than [Formula: see text] in sleep mode, thus ensuring an estimated full day of FITFES therapy on a battery charge. We conclude that a multidisciplinary user-centered approach can be successfully applied to the design of a clinically and ergonomically viable prototype of a wearable myoelectrically controlled functional electrical stimulator to be used in rehabilitation.

A low-cost stand-alone platform for measuring motor behavior across developmental applications.

Motion tracking provides unique insights into motor, cognitive, and social development by capturing subtle variations into how movements are planned and controlled. Here, we present a low-cost, wearable movement measurement platform, KiD, specifically designed for tracking the movements of infants and children in a variety of natural settings. KiD consists of a small, lightweight sensor containing a nine-axis inertial measurement unit plus an integrated processor for computing rotations. Measurements of three-dimensional acceleration using KiD compare well with those of current state-of-the-art optical motion capture systems. As a proof of concept, we demonstrate successful classification of different types of sinusoidal right arm movements using KiD.

The RT-Chair: a Novel Motion Simulator to Measure Vestibular Perception.

Vestibular perception is useful to maintain heading direction and successful spatial navigation. In this study, we present a novel equipment capable of delivering both rotational and translational movements, namely the RT-Chair. The system comprises two motors and it is controlled by the user via MATLAB. To validate the measurability of vestibular perception with the RT-chair, we ran a threshold measurement experiment with healthy participants. Our results show thresholds comparable to previous literature, thus confirming the validity of the system to measure vestibular perception.

Audio-Visual Thumble (AVT): A low-vision rehabilitation device using multisensory feedbacks.

Since the 70s sensory substitution devices have been used for blind individuals to compensate for the lack of vision and enable them to perceive environment through intact sensory modalities. In this study, we present a rehabilitation device called Audio Visual Thumble (AVT), which is a small ring-like device with LED and buzzer, that can be worn on pharynx. We focus on a unique group of low-vision individuals with a black spot or scotoma in their visual field due to a disease called Macular Degeneration. The visual localization abilities of these individuals are highly impaired due to developing scotoma. We recently showed that also their audio localization skills are impaired [9]. Rehabilitation techniques developed so far for Macular Degeneration focus on visual modality only. Since audition can also be used to improve their spatial skills, we developed the AVT device. It permits to associate the multisensory information (audio and visual feedbacks) coming from the device with the own movement (proprioceptive feedback). We propose that the AVT has the potential to help people with visual dysfunctions to improve in the identification of audio and visual targets outside or at the edge of the residual visual field. AVT could be used for a wide range of applications combined with classical rehabilitation techniques in Macular Degeneration patients.Clinical relevance- This device can be an effective addition for low-vision rehabilitation experts and can be used combined with classical rehabilitation methods.

A Synchronous Neural Recording Platform for Multiple High-Resolution CMOS Probes and Passive Electrode Arrays.

Electrophysiological signals in the brain are distributed over broad spatial and temporal scales. Monitoring these signals at multiple scales is fundamental in order to decipher how brain circuits operate and might dysfunction in disease. A possible strategy to enlarge the experimentally accessible spatial and temporal scales consists in combining the use of multiple probes with different resolutions and sensing areas. Here, we propose a neural recording system capable of simultaneous and synchronous acquisitions from a new generation of high-resolution CMOS probes (512 microelectrodes, 25 kHz/electrode whole-array sampling frequency) as well as from a custom-designed CMOS-based headstage. While CMOS probes can provide recordings from a large number of closely spaced electrodes on single-shaft devices, the CMOS-based headstage can be used to interface the wide range of available intra- or epi-cortical passive electrode array devices. The current platform was designed to simultaneously manage high-resolution recordings from up to four differently located CMOS probes and from a single 36-channels low-resolution passive electrode array device. The design, implementation, and performances for both ICs and for the FPGA-based interface are presented. Experiments on retina and neuronal culture preparations demonstrate the recording of neural spiking activity for both CMOS devices and the functionality of the system.

On Integration and Validation of a Very Low Complexity ATC UWB System for Muscle Force Transmission.

The thresholding of Surface ElectroMyoGraphic (sEMG) signals, i.e., Average Threshold Crossing (ATC) technique, reduces the amount of data to be processed enabling circuit complexity reduction and low power consumption. This paper investigates the lowest level of complexity reachable by an ATC system through measurements and in-vivo experiments with an embedded prototype for wireless force transmission, based on asynchronous Impulse-Radio Ultra Wide Band (IR-UWB). The prototype is composed by the acquisition unit, a wearable PCB 23 × 34 mm, which includes a full custom IC integrating a UWB transmitter (chip active silicon area 0.016 mm(2), 1 mW power consumption), and the receiver. The system is completely asynchronous, it acquires a differential sEMG signal, generates the ATC events and triggers a 3.3 GHz IR-UWB transmission. ATC robustness relaxes filters constraints: two passive first order filters have been implemented, bandwidth from 10 Hz up to 1 kHz. Energy needed for the single pulse generation is 30 pJ while the whole PCB consumes 5.65 mW. The pulses radiated by the acquisition unit TX are received by a short-range and low complexity threshold-based 130 nm CMOS IR-UWB receiver with an Ultra Low Power (ULP) baseband unit capable of robustly receiving generic quasi-digital pulse sequences. The acquisition unit have been tested with 10 series of in vivo isometric and isotonic contractions, while the transmission channel with over-the-air and cable measurements obtained with a couple of planar monopole antennas and an integrated 0.004 mm(2) transmitter, the same used for the acquisition unit, with realistic channel conditions. The entire system, acquisition unit and receiver, consumes 15.49 mW.

Electrophoretic deposition of mesoporous bioactive glass on glass-ceramic foam scaffolds for bone tissue engineering.

In this work, the coating of 3-D foam-like glass-ceramic scaffolds with a bioactive mesoporous glass (MBG) was investigated. The starting scaffolds, based on a non-commercial silicate glass, were fabricated by the polymer sponge replica technique followed by sintering; then, electrophoretic deposition (EPD) was applied to deposit a MBG layer on the scaffold struts. EPD was also compared with other techniques (dipping and direct in situ gelation) and it was shown to lead to the most promising results. The scaffold pore structure was maintained after the MBG coating by EPD, as assessed by SEM and micro-CT. In vitro bioactivity of the scaffolds was assessed by immersion in simulated body fluid and subsequent evaluation of hydroxyapatite (HA) formation. The deposition of a MBG coating can be a smart strategy to impart bioactive properties to the scaffold, allowing the formation of nano-structured HA agglomerates within 48 h from immersion, which does not occur on uncoated scaffold surfaces. The mechanical properties of the scaffold do not vary after the EPD (compressive strength ~19 MPa, fracture energy ~1.2 × 10(6) J m(-3)) and suggest the suitability of the prepared highly bioactive constructs as bone tissue engineering implants for load-bearing applications.