Effect of a Wireless Vital Sign Monitoring System on the Rapid Response System in the General Ward.

While wireless vital sign monitoring is expected to reduce the vital sign measurement time (thus reducing the nursing workload), its impact on the rapid response system is unclear. This study compared the time from vital sign measurement to recording and rapid response system activation between wireless and conventional vital sign monitoring in the general ward, to investigate the impact of wireless vital sign monitoring system on the rapid response system. The study divided 249 patients (age > 18 years; female: 47, male: 202) admitted to the general ward into non-wireless (n = 101) and wireless (n = 148) groups. Intervals from vital sign measurement to recording and from vital sign measurement to rapid response system activation were recorded. Effects of wireless system implementation for vital sign measurement on the nursing workload were surveyed in 30 nurses. The interval from vital sign measurement to recording was significantly shorter in the wireless group than in the non-wireless group (4.3 ± 2.9 vs. 44.7 ± 14.4 min, P < 0.001). The interval from vital sign measurement to rapid response system activation was also significantly lesser in the wireless group than in the non-wireless group (27.5 ± 12.9 vs. 41.8 ± 19.6 min, P = 0.029). The nursing workload related to vital sign measurement significantly decreased from 3 ± 0.87 to 2.4 ± 9.7 (P = 0.021) with wireless system implementation. Wireless vital sign monitoring significantly reduced the time to rapid response system activation by shortening the time required to measure the vital signs. It also significantly reduced the nursing workload.

Millimeter-wave Channel-Sounder Performance Verification using Vector Network Analyzer in a Controlled RF Channel.

A new comparison-to-reference performance verification technique compares an E-band channel-sounder and reference vector network analyzer measurements of the same controlled, static channel. This new technique reduces the number of inaccurate assumptions that exist in other methods providing a stronger verification of the channel-sounder hardware and processing performance. This technique compares the channel-sounder and VNA derived channel metrics from these measurements. Using mechanical switches, we established a controlled, static RF channel. The vector network analyzer has a comprehensive uncertainty analysis that propagates systematic and random uncertainties through to the power delay profiles. The method is suitable for millimeter-wave channel-sounder hardware with removable antennas.

Uncertainty in Reverberation-Chamber Antenna-Efficiency Measurements in the Presence of a Phantom.

The effect of a user's proximity on wireless device performance is critical to test the device under realistic conditions. In this work, we propose and demonstrate an improved uncertainty estimation method for antenna efficiency measurements in a reverberation chamber. The improved method separately computes uncertainties due to the effects of chamber loading by a phantom and the effects of antenna mismatch introduced by this phantom, illustrating the sensitivity of uncertainty to close-proximity user effects. We demonstrate that, while the impact of the phantom may be significant on antenna efficiency, and, it has some influence on the uncertainty in the measurement, its impact on overall uncertainty may be insignificant. This is demonstrated using the two-antenna method in the presence of a phantom close to the antenna under test. We illustrate the method by summarizing the antenna efficiencies with their uncertainties and the impact of the phantom for important communication bands. Due to the large effect of the user on antenna performance, this type of measurement and its uncertainty evaluation is a valuable way to characterize antenna efficiency including user effects.

A Sensor Platform for Athletes' Training Supervision: A Proof of Concept Study.

One of the basic needs of professional athletes is the real-time and non-invasive monitoring of their activities. The use of these kind of data is necessary to develop strategies for specific tailored training in order to improve performances. The sensor system presented in this work has the aim to adopt a novel approach for the monitoring of physiological parameters, and athletes' performances, during their training. The anaerobic threshold is herein identified with the monitoring of the lactate concentration and the respiratory parameters. The data collected by the sensor are used to build a model using a supervised method (based on the partial least squares method, PLS) to predict the values of the parameters of interest. The sensor is able to measure the lactate concentration from a sample of saliva and it can estimate a respiratory parameter, such as maximal oxygen consumption, maximal carbon dioxide production and respiratory rate from a sample of exhaled breath. The main advantages of the device are the low power; the wireless communication; and the non-invasive sampling method, which allow its use in a real context of sport practice.

A Significance Test for Reverberation-Chamber Measurement Uncertainty in Total Radiated Power of Wireless Devices.

We develop a significance test that determines whether the component of uncertainty due to the finite number of stepped mode-stirring samples or the component due to the lack of spatial uniformity dominates for a particular chamber set-up and stirring sequence, as well as expressions for uncertainty for both cases. The significance test is illustrated with a measurement example comparing unloaded and loaded chambers for the measurement of a large-form-factor machine-to-machine device transmitting the W-CDMA protocol. Based on this example, we illustrate a method that allows users to estimate the minimum number of stepped mode-stirring samples needed to ensure that the component of uncertainty due to spatial uniformity dominates for a given chamber set-up, allowing use of a simplified expression for uncertainty.

Simultaneous Dopamine and Serotonin Monitoring in Freely Moving Crayfish Using a Wireless Electrochemical Sensing System.

Dopamine (DA) and serotonin (5-HT) are neurotransmitters that regulate a wide range of physiological and behavioral processes. Monitoring of both neurotransmitters with real-time analysis offers important insight into the mechanisms that shape animal behavior. However, bioelectronic tools to simultaneously monitor DA and 5-HT interactive dynamics in freely moving animals are underdeveloped. This is mainly due to the limited sensor sensitivity with miniaturized electronics. Here, we present a semi-implantable electrochemical device achieved by integrating a multi-surface-modified carbon fiber microelectrode with a miniaturized potentiostat module to detect DA and 5-HT in vivo with high sensitivity and selectivity. Specifically, carbon fiber microelectrodes were modified through electrochemical treatment and surface coatings to improve sensitivity, selectivity, and antifouling properties. A customized, lightweight potentiostat module was developed for untethered electrochemical measurements. Integrated with the microelectrode, the microsystem is compact (2.8 × 2.3 × 2.1 cm) to minimize its impacts on animal behavior and achieved simultaneous detection of DA and 5-HT with sensitivities of 48.4 and 133.0 nA/µM, respectively, within submicromolar ranges. The system was attached to the crayfish dorsal carapace, allowing electrode implantation into the heart of a crayfish to monitor DA and 5-HT dynamics, followed by drug injections. The semi-implantable biosensor system displayed a significant increase in oxidation peak currents after DA and 5-HT injections. The device successfully demonstrated the application for in vivo simultaneous monitoring of DA and 5-HT in the hemolymph (i.e., blood) of freely behaving crayfish underwater, yielding a valuable experimental tool to expand our understanding of the comodulation of DA and 5-HT.

Magnetic Manipulation of Locomotive Liquid Electrodes for Wireless Active Cardiac Monitoring.

For electrocardiogram (ECG) detection, the position of conventional patch-type electrodes based on solid-state metals are difficult to manipulate after attachment and also can lead to poor interface with stretchable, rough skin surfaces. Herein, we present a liquid form of ECG electrodes that can be magnetically reconfigured on human skin by providing its conformal interfacing. These electrodes consist of biocompatible liquid-metal droplets where magnetic particles are homogeneously dispersed, and their conformal contact with skin can yield significantly low impedance as well as high signal-to-noise ratio of ECG peaks. These electrodes are also capable of complex motions such as linear movements, splitting, and merging under external magnetic fields. Furthermore, magnetic manipulation of each electrode position on human skin enables precise monitoring of ECG signals with the change in ECG vectors. The integration of liquid-state electrodes with electronic circuitry demonstrates wireless and continuous ECG monitoring while magnetically moving this entire system on human skin.

Foot plantar pressure measurement system: a review.

Foot plantar pressure is the pressure field that acts between the foot and the support surface during everyday locomotor activities. Information derived from such pressure measures is important in gait and posture research for diagnosing lower limb problems, footwear design, sport biomechanics, injury prevention and other applications. This paper reviews foot plantar sensors characteristics as reported in the literature in addition to foot plantar pressure measurement systems applied to a variety of research problems. Strengths and limitations of current systems are discussed and a wireless foot plantar pressure system is proposed suitable for measuring high pressure distributions under the foot with high accuracy and reliability. The novel system is based on highly linear pressure sensors with no hysteresis.

Touching to Feel: Brain Activity During In-Store Consumer Experience.

To gain a deeper understanding of consumers' brain responses during a real-time in-store exploration could help retailers to get much closer to costumers' experience. To our knowledge, this is the first time the specific role of touch has been investigated by means of a neuroscientific approach during consumer in-store experience within the field of sensory marketing. This study explores the presence of distinct cortical brain oscillations in consumers' brain while navigating a store that provides a high level of sensory arousal and being allowed or not to touch products. A 16-channel wireless electroencephalogram (EEG) was applied to 23 healthy participants (mean age = 24.57 years, SD = 3.54), with interest in cosmetics but naive about the store explored. Subjects were assigned to two experimental conditions based on the chance of touching or not touching the products. Cortical oscillations were explored by means of power spectral analysis of the following frequency bands: delta, theta, alpha, and beta. Results highlighted the presence of delta, theta, and beta bands within the frontal brain regions during both sensory conditions. The absence of touch was experienced as a lack of perception that needs cognitive control, as reflected by Delta and Theta band left activation, whereas a right increase of Beta band for touch condition was associated with sustained awareness on the sensory experience. Overall, EEG cortical oscillations' functional meaning could help highlight the neurophysiological implicit responses to tactile conditions and the importance of touch integration in consumers' experience.

NB-IoT Devices in Reverberation Chambers: A Comprehensive Uncertainty Analysis.

New protocols related to internet-of-things applications may introduce previously unnoticed measurement effects in reverberation chambers due to the narrowband nature of these protocols. Such technologies also require less loading to meet the coherence-bandwidth conditions, which may lead to higher variations, hence uncertainties, across the channel. In this work, we extend a previous study of uncertainty in NB-IoT and CAT-M1 device measurements in reverberation chambers by providing, for the first time, a comprehensive uncertainty analysis of the components related to the reference and DUT measurements. By use of a significance test, we show that certain components of uncertainty become more dominant for such narrowband protocols, and cannot be considered as negligible, as in current standardized test methods. We show that the uncertainty, if not accounted for by using the extended formulation, will be greatly overestimated and could lead to non-compliance to standards.

Timing Offset and Timing Stability for a Dual-Clock Channel Sounder.

We describe a mathematical framework for evaluating timing offset and timing noise in channel sounders based on a second-order deterministic model and a stochastic metric based on the Allan Deviation. Using this framework, we analyze the timing offset and noise for a 1-6 GHz correlation-based channel sounder that uses rubidium clocks to provide a common timebase between the transmitter and receiver. We study timing behavior in three clock-distribution configurations. In the "untethered" configuration, the transmitter and receiver each have a rubidium clock, and no physical timing cable is connected between the clocks. In the "tethered" configuration, a coaxial cable synchronizes timing between the two separate clocks. Finally, a benchmark "single-clock" configuration is used where a single rubidium clock drives the transmitter and receiver.

Highly Transparent and Sensitive Graphene Sensors for Continuous and Non-invasive Intraocular Pressure Monitoring.

Intraocular pressure (IOP) is the prime indicator for the diagnosis and treatment of glaucoma. IOP has circadian rhythm changes and is dependent on body gestures; therefore, a single measurement in the clinic can be misleading for diagnosis. Herein, few-layer graphene is utilized to develop non-invasive sensors with high transparency, sensitivity, linearity, and biocompatibility for 24 h continuous IOP monitoring. The graphene Wheatstone bridge consisting of two strain gauges and two compensating resistors is designed to improve the sensitivity and accuracy of IOP measurement. Testing results on a silicone eyeball indicate that the output voltage of the sensor is proportional to the IOP fluctuation. Under the various ranges and speeds of IOP fluctuation, the sensor exhibits excellent performance of dynamic cycles and step responses with an average sensitivity of 150 µV/mmHg. With the linear relationship, the average relative error between the calibrated IOP and the standard pressure is maintained at about 5%. More than 100 cycles and interval time measurements illustrate that the sensor possesses significant stability, durability, and reliability. Furthermore, a wireless system is designed for the sensor to realize IOP monitoring using a mobile phone. This sensor, with the average transparency of 85% and its ease of fabrication, as well as its portability for continuous IOP monitoring, brings new promise to the diagnosis and treatment of glaucoma.

Stretchable wireless system for sweat pH monitoring.

Sensor-laden wearable systems that are capable of providing continuous measurement of key physiological parameters coupled with data storage, drug delivery and feedback therapy have attracted huge interest. Here we report a stretchable wireless system for sweat pH monitoring, which is able to withstand up to 53% uniaxial strain and more than 500 cycles to 30% strain. The stretchability of the pH sensor patch is provided by a pair of serpentine-shaped stretchable interconnects. The pH sensing electrode is made of graphite-polyurethane composite, which is suitable for biosensor application. The sensing patch validated through in-depth electrochemical studies, exhibits a pH sensitivity of 11.13 ±â€¯5.8 mV/pH with a maximum response time of 8 s. Interference study of ions and analyte (Na+, K+ and glucose) in test solutions shows negligible influence on the pH sensor performance. The pH data can be wirelessly and continuously transmitted to smartphone through a stretchable radio-frequency-identification antenna, of which the radiating performance is stable under 20% strain, as proved by vector network analyzer measurement. To evaluate the full system, the pH value of a human sweat equivalent solution has been measured and wirelessly transmitted to a custom-developed smart phone App.

Advantages of Frequency Specific Tri-microphone Binaural Wireless Hearing Aid Technology / 听力学及言语疾病杂志

Objective To examine adult speech recognition for words presented in different background noise when the adults used 4-band tri-microphone and traditional tri-microphone hearing aid technology,and to examine the ability of sound location when using wireless remote control.Methods A total 40(female 29,male 11) subjects with moderate to severe bilateral sensorineural hearing loss were encountered in this test,and were divided into two groups(group A and group B).With binaural fitting ACURIS P(frequency specific tri-microphone adaptive mode) and Triano 3 P(Tri-microphone adaptive mode),the patients were tested with speech recognition in two sound field through PB test and the accurateness of sound localization were investigated through questionnaire.Results Significant differences were found between the mean L50(the S/N at which 50% of running speech is correctly understood) obtained from group A versus group B in Tri-microphone adaptive directional condition in multiple sound fields(P