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Ultra-wide-band (UWB) communication based on the impulse radio paradigm is becoming increasingly popular. According to the IEEE 802.15 WPAN Low Rate Alternative PHY Task Group 4a, UWB will play a major role in localization applications, due to the high time resolution of UWB signals which allow accurate indirect measurements of distance between transceivers. Key for the successful implementation of UWB transceivers is the level of integration that will be reached, for which a simulation environment that helps take appropriate design decisions is crucial. Owing to this motivation, in this paper we propose a multiresolution UWB simulation environment based on the VHDL-AMS hardware description language, along with a proper methodology which helps tackle the complexity of designing a mixed-signal UWB system-on-chip. We applied the methodology and used the simulation environment for the specification and design of an UWB transceiver based on the energy detection principle. As a by-product, simulation results show the effectiveness of UWB in the so-called ranging application, that is the accurate evaluation of the distance between a couple of transceivers using the two-way-ranging method. Index Terms--Mixed-signal integrated circuits, ultra-wide-band (UWB) communications, VHDL-AMS.

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. [ABSTRACT FROM AUTHOR]

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 $10~\mu \text{W}$ 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This paper presents a robust, capacitive digital read-out circuit (ROC) for sensitive skin applications in humanoid robots. The ROC can be calibrated to null the parasitic effects of transducer variation due to physical assembly. A prototype is fabricated in a 130 nm RFCMOS process, with an active area of 221\times 79~\mu \textm^2 and 1.84 \mu W power consumption at V_{\mathrm {DD}}=1.2\text{V} and 1ms read-out rate. The ROC output is robust to V_{\mathrm {DD}} and temperature variations in a range |\Delta V\mathrm {DD|}\leq 20\% and (25–53) °C. Furthermore, it can provide up to 200m V\mathrm {pp} power supply sine wave rejection in the range 50Hz–5MHz at V\mathrm {DD}=1.1\text{V} , for an output standard deviation lower than one LSB. Owing to its features and its digital modularity, the ROC was co-designed with a scalable and modular Multi-Walled Carbon NanoTube (MW-CNT) Nano composite transducer, to achieve tunable output sensitivity by adjusting the sensor nominal capacitance and the reference capacitance. The maximum sensitivity of 5.23 fF per LSB was reached when both match. The ROC was then validated with the MW-CNT nanocomposite sensor which exhibits a piecewise behaviour. 5.3 and 7.1 ENOB were extrapolated in the low-load and medium-load regions, respectively. Besides the major advantage of tunable sensitivity, the presented ROC features the lowest acquisition time and one of the most compact sizes among the state-of-the-art ROCs. Moreover, process voltage and temperature (PVT) robust output and ultra-low power consumption make this solution very attractive to replicate human physiology at robotic-level. [ABSTRACT FROM PUBLISHER]

In the last two decades, wearable robots have emerged as human-oriented devices to complement, substitute or enhance human capabilities and, more specifically, empower or replace a human limb [1], [2]. Among the most complex and interesting limbs to assist, the hand represents perhaps the biggest challenge, because of its primary role in environment exploration, stimuli sensing and object manipulation [3]. Hence, the development of wearable and rehabilitative exoskeletons is increasingly attracting attention to help finger movements in free motion and assist the user with grasping. This paper shows that a simple underpowered digital oscillator electronic interface takes advantage of the capacitive variations in commercial piezoresistive transducers to sense applied pressure. Furthermore, thanks to the analysis of the static performance, practical considerations are drawn about the use of commercial sensors and a read out circuit (ROC) to be exploited in a control system for hand exoskeletons (Fig. 1). [ABSTRACT FROM PUBLISHER]

At the end of their studies, master's degree students can get very close to solving research problems, but sometimes they can be very easily discouraged, dropping the option to earn a Ph.D. degree. Their listlessness and disorientation might be due to their lack of knowledge of what is research, science, and engineering (and innovation). The lack of understanding combined with 1) the impact of deal ing with heavy research subjects (the analysis of the state of the art, the understanding of the problem, and the project development) and 2) the memory of their just-finished, often-boring laboratory sessions, reporting activities can be disappointing and cause students to lose interest, especially if some basic ideas are not clear. [ABSTRACT FROM PUBLISHER]

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\, \times \,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. [ABSTRACT FROM PUBLISHER]

This paper presents a flexible and low-power Read-Out Circuit (ROC) with tunable sensitivity, designed to interface a wide range of commercial resistive pressure sensors for robotic applications. The ROC provides contact detection, monitoring small capacitance variations at low pressure (<100 mbar), and encodes pressure measurement on 8 bit, evaluating resistive variations. Two all-digital circuits implement the conversion of the input resistance and capacitance-to-frequency, exploiting an on-chip ring oscillator as timing reference. A 130 nm RFCMOS prototype (with an active area of 428\times 159~\mu \textm^2 ) has a power consumption of 27.2 \mu \textW , for V\mathrm {DD}~1 V. Using digital control inputs, the ROC allows a wide range tuning of measurement sensitivity (6.7–46.4 mbar/LSB) and adjustable acquisition time (226.6–461.7 \mu \texts and 648–890 \mu \texts , for contact detection and pressure evaluation, respectively). The read-out time of $\sim 1$ ms is compatible with human response after touch. [ABSTRACT FROM PUBLISHER]

This paper presents a low-power system conceived for the integration and measurement of a nanowire (NW)-based sensor array onto a 130-nm CMOS technology process. Each array element includes a dielectrophoresis (DEP) signal generator for NWs alignment and a quasi-digital read-out circuit (ROC) for impedance conversion. The two subsystems can be digitally controlled by an external microcontroller which reads the ROC output and calculates the resistance and capacitance of the NW. Measurements show that the integrated two-quadrants quasi-digital ROC covers the range 1 \textM\Omega –1 \textG\Omega and 100 fF–1 \mu \textF with a signal-to-noise ratio ≥44.89 dB. The CMOS system can be considered a building block for the implementation of a complete NW-based sensing array and each element, including both DEP and ROC subsystems, occupies an active area of 0.008 mm ^2 and only consumes 14.76 \mu \textW during read-out phase. The ROC has been also validated using an off-chip nanogap-based nanodevice integrating a single ZnO-NW which has been used as ultraviolet (UV) sensor during experiments. The device has been stimulated by an external UV source providing an irradiance \geq93\mu \textW /cm ^2 to the nanodevice surface. We have proved that the ROC is able to measure the ZnO-NW electrical characteristics and their variations due to the photogenerated charge carriers. [ABSTRACT FROM PUBLISHER]

Electronic systems are increasingly fusing multiple technology solutions exchanging information both at electrical and at non-electrical levels, and in general both analog and digital operation coexists in multiple physical domains. [ABSTRACT FROM PUBLISHER]