Electronic Tongue Based on ZnO/ITO@glass for Electrochemical Monitoring of Spiciness Levels.

Capsaicin, a chemical compound present in chili peppers, is widely acknowledged as the main contributor to the spicy and hot sensations encountered during consumption. Elevated levels of capsaicin can result in meals being excessively spicy, potentially leading to health issues, such as skin burning, irritation, increased heart rate and circulation, and discomfort in the gastrointestinal system and even inducing nausea or diarrhea. The level of spiciness that individuals can tolerate may vary, so what may be considered incredibly hot for one person could be mild for another. To ensure food safety, human healthcare, regulatory compliance, and quality control in spicy food products, capsaicin levels must be measured. For these purposes, a reliable and stable sensor is required to quantify the capsaicin level. To leverage the effect of zinc oxide (ZnO), herein, we demonstrated the one-step fabrication process of an electronic tongue (E-Tongue) based on an electrochemical biosensor for the determination of capsaicin. ZnO was electrodeposited on the indium tin oxide (ITO) surface. The biosensor demonstrated the two notable linear ranges from 0.01 to 50 µM and from 50 to 500 µM with a limit of detection (LOD) of 2.1 nM. The present study also included the analysis of real samples, such as green chilis, red chili powder, and dried red chilis, to evaluate their spiciness levels. Furthermore, the E-Tongue exhibited notable degrees of sensitivity, selectivity, and long-term stability for a duration of more than a month. The development of an E-Tongue for capsaicin real-time monitoring as a point-of-care (POC) device has the potential to impact various industries and improve safety, product quality, and healthcare outcomes.

Adaptive Body Area Networks Using Kinematics and Biosignals.

The increasing penetration of wearable and implantable devices necessitates energy-efficient and robust ways of connecting them to each other and to the cloud. However, the wireless channel around the human body poses unique challenges such as a high and variable path-loss caused by frequent changes in the relative node positions as well as the surrounding environment. An adaptive wireless body area network (WBAN) scheme is presented that reconfigures the network by learning from body kinematics and biosignals. It has very low overhead since these signals are already captured by the WBAN sensor nodes to support their basic functionality. Periodic channel fluctuations in activities like walking can be exploited by reusing accelerometer data and scheduling packet transmissions at optimal times. Network states can be predicted based on changes in observed biosignals to reconfigure the network parameters in real time. A realistic body channel emulator that evaluates the path-loss for everyday human activities was developed to assess the efficacy of the proposed techniques. Simulation results show up to 41% improvement in packet delivery ratio (PDR) and up to 27% reduction in power consumption by intelligent scheduling at lower transmission power levels. Moreover, experimental results on a custom test-bed demonstrate an average PDR increase of 20% and 18% when using our adaptive EMG- and heart-rate-based transmission power control methods, respectively. The channel emulator and simulation code is made publicly available at https://github.com/a-moin/wban-pathloss.

A wireless and artefact-free 128-channel neuromodulation device for closed-loop stimulation and recording in non-human primates.

Closed-loop neuromodulation systems aim to treat a variety of neurological conditions by delivering and adjusting therapeutic electrical stimulation in response to a patient's neural state, recorded in real time. Existing systems are limited by low channel counts, lack of algorithmic flexibility, and the distortion of recorded signals by large and persistent stimulation artefacts. Here, we describe an artefact-free wireless neuromodulation device that enables research applications requiring high-throughput data streaming, low-latency biosignal processing, and simultaneous sensing and stimulation. The device is a miniaturized neural interface capable of closed-loop recording and stimulation on 128 channels, with on-board processing to fully cancel stimulation artefacts. In addition, it can detect neural biomarkers and automatically adjust stimulation parameters in closed-loop mode. In a behaving non-human primate, the device enabled long-term recordings of local field potentials and the real-time cancellation of stimulation artefacts, as well as closed-loop stimulation to disrupt movement preparatory activity during a delayed-reach task. The neuromodulation device may help advance neuroscientific discovery and preclinical investigations of stimulation-based therapeutic interventions.

A Comparative Study of On-Body Radio-Frequency Links in the 420 MHz⁻2.4 GHz Range.

While there exists a wide variety of radio frequency (RF) technologies amenable for usage in Wireless Body Area Networks (WBANs), which have been studied separately before, it is currently still unclear how their performance compares in true on-body scenarios. In this paper, a single reference on-body scenario-that is, propagation along the arm-is used to experimentally compare six distinct RF technologies (between 420 MHz and 2.4 GHz) in terms of path loss. To further quantify on-body path loss, measurements for five different on-body scenarios are presented as well. To compensate for the effect of often large path losses, two mitigation strategies to (dynamically) improve on-body links are introduced and experimentally verified: beam steering using a phased array, and usage of on-body RF repeaters. The results of this study can serve as a tool for WBAN designers to aid in the selection of the right RF frequency and technology for their application.

Powering and communication for OMNI: A distributed and modular closed-loop neuromodulation device.

A distributed, modular, intelligent, and efficient neuromodulation device, called OMNI, is presented. It supports closed-loop recording and stimulation on 256 channels from up to 4 physically distinct neuromodulation modules placed in any configuration around the brain, hence offering the capability of addressing neural disorders that are presented at the network level. The specific focus of this paper is the communication and power distribution network that enables the modular and distributed nature of the device.

Skin picking and sleep disturbances: relationship to anxiety and need for research.

Pathological excoriation (PE) or skin picking is seen in nearly 2% of patients attending dermatology clinics and is often associated with anxiety, stress and frequent help-seeking behaviors. While anxiety and stress are thought to cause poor sleep in the general population, not all anxious people, even those with disabling anxiety disorders, necessarily suffer from insomnia or other sleep problems. The relationship between anxiety symptoms and poor sleep, therefore, remains unclear and sleep quality in PE is unknown. We examined the sleep quality and levels of anxiety in dermatological patients with PE. Dermatological patients with (n = 10) and without (n = 10) PE and healthy controls (n = 10) were assessed on standardized and validated measures of subjective sleep quality [Pittsburgh Sleep Quality Index (PSQI)], anxiety (Spielberger State and Trait Anxiety Inventory; modified Zung Anxiety Scale), stress (Perceived Stress Scale) and work and social disability [Sheehan Disability Inventory subscale (SDI-4)]. Patients with dermatological complaints as a group reported poorer sleep quality, higher scores on Spielberger State and Zung anxiety, perceived stress, and SDI-4. Among both groups of dermatological patients, only the PE group had significantly poor sleep, high anxiety, and perceived stress compared to healthy controls. In the dermatological patients with PE, PSQI-global scores were significantly positively correlated to Spielberger State and Zung Anxiety scores. Dermatological patients with PE are more anxious and have poorer subjective sleep compared to dermatological patients without PE and healthy. Future research is needed to elucidate these relationship factors and to develop new behavioral and drug treatments for the management of PE.