234 research outputs found

    An integrated DC/DC converter with online monitoring of hot-carrier degradation

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    An integrated DC/DC converter with online monitoring of the degradation induced by hot-carrier stress (HCD) in new generation power LDMOS transistors is proposed. In particular, when a relatively high drain voltage is applied during on-state regime (switching phase), degradation mechanisms lead to an increase of the transistor on-resistance (RON). To this purpose, the converter is able to dynamically estimate the RON of the power LDMOS and to provide its value to the user during normal operation. The presented solution, developed in STMicroelectronics 90nm BCD technology, features a non-invasive current sensing and voltage sampling architecture, which is applied to a common DC/DC boost converter to evaluate the resistance of the power LDMOS. Without lack of generality, this specific sensing structure can be applied to any kind of converter, e.g. buck or buck-boost, as it does not require any change in the main conversion circuit

    An Automatic Offset Correction Platform for High-Throughput Ion-Channel Electrophysiology

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    High-throughput ion channel screening for drug discovery is at the base of the recent shift of resources in the pharmaceutical industry towards addressing drug safety issues earlier in the discovery process. Very few examples of parallel ion-channel recording platforms are currently present in literature, due to the complexity of the setup. However, single-junction Ag/AgCl electrodes suffer of intrinsic voltage offsets, due to the electrode-buffer interface variability. This is very critical, since ion- channel recording requires high accuracy (pA resolution) within the full-scale (nA range), limiting the operability of the measurement, especially on a multi-channel approach. This paper presents an automatic offset correction system fully implemented on a lipid bilayer membrane platform. The platform allows offset-free recording of ion-channel signals acquired and displayed by means of a graphical user interface

    Non-Invasive Estimation of Plasma Sodium Concentration During Hemodialysis via Capacitively-Coupled Electrical Impedance Spectroscopy

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    This paper presents a compact, low-cost, and noninvasive system for real-time estimation of plasma sodium concentration ([Na]Pl) during a hemodialysis (HD) session with state-of-the-art accuracy. It is based on electrical impedance spectroscopy (EIS) performed with a capacitively-coupled impedance sensing cell and a high-frequency measurement device, both custom-built. The EIS data are processed to infer the resistance of the liquid inside the cell, which is used together with an optical hemoglobin sensor to estimate the [Na]Pl. Validation of the EIS was performed by estimating the conductivity of bloodmimicking fluid (BMF). The complete method was validated using whole bovine blood, comparing the results to those obtained with standard instruments. The system was able to estimate the [Na]Pl with sufficient accuracy (RMS error of 3.0 mol/m3 with respect to reference data) to provide clinically useful information. The proof-of-concept hardware can be converted to a cheap and compact circuit board for integration into an HD machine

    THE IMPLANT TREATMENT OF TWO PATIENTS SUFFERING FROM SJÖGREN’S SYNDROME WITH MULTIFACTORIAL REGENERATIVE PROTOCOL

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    The purpose of the work is to show that it is possible to rehabilitate with Multifatorial Regenerative Protocol (MFRP) also the patients with diseases considered to be absolute contraindications to the implant rehabilitation. For the rehabilitation it has been used the PBR rehabilitation technique, that allows to insert prosthetic roots not excessively traumatizing the bone tissue and to avoid the use of high speed rotary burs. Despite the disease and the poor bone quality, it has been possible to obtain the osteo-connection only in 45 days. Using the MFRP implants, it is possible to rehabilitate with a high percentage of success also patients with poor bone quality and density

    Static Characterization of the X-Hall Current Sensor in BCD10 Technology

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    This work presents on-wafer characterization measurements of the X-Hall current sensor architecture implemented in 90-nm BCD10 silicon process by STMicroelectronics. With respect to a previous implementation, technological improvements in terms of active region, isolation layers, and metal stack configuration result in a substantially improved sensitivity. In addition, it is reported that the sensitivity can be further improved by applying a negative voltage to the depletion layer

    Training the Moral Self: An 8-Week Mindfulness Meditation Program Leads to Reduced Dishonest Behavior and Increased Regulation of Interoceptive Awareness

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    Objectives: Recent meta-analyses suggest that mindfulness meditation may enhance prosocial behavior, while evidence regarding moral behavior is still scarce. We combined a randomized controlled mindfulness training design with an ecologically valid moral decision-making task (Temptation to Lie Card Game; TLCG), in which participants were tempted to deceive an opponent to increase their monetary payoff. Method: TLCG and self-report measures (in the domains of attention regulation, body awareness, emotion regulation, and change in the perspective of the self) were administered to participants who underwent the mindfulness meditation training (experimental group, n = 44) or were waitlisted (control group, n = 25) twice: before and after the 8-week training. Results: Concerning moral decision-making, we observed a significant effect involving condition, time, and group. Trained participants deceived significantly less in the post-training as compared with the pre-training phase (p = 0.03), while untrained ones showed no significant change (p = 0.58). In the self-reports, significant effects involving time and group were found for the Multidimensional Assessment of Interoceptive Awareness (MAIA-2) in Self-Regulation, Attention Regulation, Body Listening, and for the Five Facet Mindfulness Questionnaire (FFMQ) in Non-Reactivity to inner experience. Trained participants showed a time-related increase in all subscales scores, while untrained ones did not. Finally, a moderation analysis revealed a significant interaction between weekly mindfulness meditation training minutes and MAIA-2 Attention Regulation (post-training) on moral behavior change. Conclusions: Our preliminary results suggest that mindfulness meditation practice decreases self-serving dishonest behavior and increases awareness of one’s bodily and emotional state. In particular, the amount of mindfulness meditation practice predicted moral behavior change in practitioners who reported the highest regulation of attention towards internal bodily signals. Preregistration: This study is not preregistered

    Development of an electrical impedance tomography set-up for the quantification of mineralization in biopolymer scaffolds

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    Objective. 3D cell cultures are becoming a fundamental resource for in-vitro studies, as they mimic more closely in-vivo behavior. The analysis of these constructs, however, generally rely on destructive techniques, that prevent the monitoring over time of the same construct, thus increasing the results variability and the resources needed for each experiment. Approach. In this work, we focus on mineralization, a crucial process during maturation of artificial bone models, and propose electrical impedance tomography (EIT) as an alternative non-destructive approach. In particular, we discuss the development of an integrated hardware/software system capable of acquiring experimental data from 3D scaffolds and reconstructing the corresponding conductivity maps. We also show how the same software can test how the measurement is affected by biological features such as scaffold shrinking during the culture. Main results. An initial validation, comprising the acquisition of both a non-conductive phantom and alginate/gelatin scaffolds with known calcium content will be presented, together with the in-silico study of a cell-induced mineralization process. This analysis will allow for an initial verification of the systems functionality while limiting the effects of biological variability due to cell number and activity. Significance. Our results show the potential of EIT for the non-destructive quantification of matrix mineralization in 3D scaffolds, and open to the possible long term monitoring of this fundamental hallmark of osteogenic differentiation in hybrid tissue engineered constructs

    A broadband current sensor based on the X-Hall architecture

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    A broadband current sensor, which is fully integrated and galvanically-isolated, is presented in this paper. The current sensor relies only on a Hall-effect probe to realize the magnetic sensing core so as to minimize the cost and the occupied space. Bandwidth limitations of state-of-the-art Hall-effect probes are overcame by combining the novel X-Hall architecture with a wide bandwidth differential-difference current-feedback amplifier. A prototype implemented in 0.16 \u3bcm BCD technology demonstrates a bandwidth wider than 20 MHz. Offset, sensitivity and power consumption are comparable to the state of the art. This is the first Hall-only current sensor achieving a bandwidth higher than 3 MHz

    Binary Sequences for Online Electrochemical Impedance Spectroscopy of Battery Cells

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    Online diagnostic of lithium-ion battery (LIB) cells may have significant impact on chemical energy storage systems. Electrochemical impedance spectroscopy (EIS) is widely used for the characterization of LIBs and could be the most appropriate technique for online diagnostic, but its response time should be shortened. This work investigates the usage of multisine excitation to shorten the measurement time and simplify the hardware implementation for EIS of battery cells. Two types of multisine binary sequences are considered: sigma-delta modulated multisine sequences (SDMSs) and maximum length binary sequences (MLBSs). Their applicability to online and in situ EIS monitoring is evaluated by designing a measurement architecture also suitable to be implemented in a system-on-chip. The calibrated measurement system is compared with a benchtop reference instrument, reporting an RMSE deviation smaller than 5% in the frequency range of interest 1-200 Hz. The realized system is then used for online monitoring of the discharge process of a commercial 18650 LIB cell. The two proposed sequences are compared in terms of accuracy using a digital battery emulator circuit. Both the sequences demonstrated to be suitable for fast measurement and simple hardware integration, enabling online in situ EIS monitoring at cell level
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