Social neuroscience: Primate research goes wireless.

A new study leads the way to a more ethical and ethologically meaningful way of investigating brain functions of complex behaviors in social animals.

Injectable ultrasonic sensor for wireless monitoring of intracranial signals.

Direct and precise monitoring of intracranial physiology holds immense importance in delineating injuries, prognostication and averting disease1. Wired clinical instruments that use percutaneous leads are accurate but are susceptible to infection, patient mobility constraints and potential surgical complications during removal2. Wireless implantable devices provide greater operational freedom but include issues such as limited detection range, poor degradation and difficulty in size reduction in the human body3. Here we present an injectable, bioresorbable and wireless metastructured hydrogel (metagel) sensor for ultrasonic monitoring of intracranial signals. The metagel sensors are cubes 2 × 2 × 2 mm3 in size that encompass both biodegradable and stimulus-responsive hydrogels and periodically aligned air columns with a specific acoustic reflection spectrum. Implanted into intracranial space with a puncture needle, the metagel deforms in response to physiological environmental changes, causing peak frequency shifts of reflected ultrasound waves that can be wirelessly measured by an external ultrasound probe. The metagel sensor can independently detect intracranial pressure, temperature, pH and flow rate, realize a detection depth of 10 cm and almost fully degrade within 18 weeks. Animal experiments on rats and pigs indicate promising multiparametric sensing performances on a par with conventional non-resorbable wired clinical benchmarks.

Metasurface-based dual-sense circularly polarized antenna for MIMO/full-duplex applications.

This paper introduces a two-element antenna array with dual-sense circular polarization, wideband operation, and high isolation characteristics. The antenna consists of two conventional truncated corner patches and an extra layer of metasurface (MS) located above the radiating patches. The overall dimensions of the proposed antenna are 0.92 λ0 × 0.73 λ0 × 0.05 λ0 and the element spacings are 0.02 λ0 and 0.39 λ0 with respect to edge-to-edge and center-to-center spacings. For validation, measurements on a fabricated antenna prototype are carried out. The measured data demonstrate that the presented MS-based antenna has a wide operating bandwidth of 14.5% with high isolation of better than 26 dB. The excellent performance could be concluded from the results of the investigation, which indicates that the proposed MS-based antenna could be a good candidate for multiple-input multiple-output (MIMO) and full-duplex applications.

Design and fabrication of a microstrip triplexer with wide flat channels for multi-band 5G applications.

In this paper, a new microstrip triplexer is designed to work at 2.5 GHz, 4.4 GHz and 6 GHz for mid-band 5G applications. All channels are flat with three low group delays (GDs) of 0.84 ns, 0.75 ns and 0.49 ns, respectively. Compared to the previously reported works, the proposed triplexer has the minimum group delay. The designed triplexer has 18.2%, 13.7%, 23.6% fractional bandwidths (FBW%) at 2.5 GHz, 4.4 GHz and 6 GHz, respectively. The obtained insertion losses (ILs) are low at all channels. These features are obtained without a noticeable increase in the overall size. A novel and simple resonator is used to design the proposed triplexer, which includes two pairs of coupled lines combined with a shunt stub. A perfect mathematical analysis is performed to find the resonator behavior and the layout optimization. The type of shunt stub is determined mathematically. Also, the smallness or largeness of some important physical dimensions is determined using the proposed mathematical analysis. Finally, the designed triplexer is fabricated and measured, where the measurement results verify the simulations.

Wearable Motion Analysis System for Thoracic Spine Mobility With Inertial Sensors.

This study presents a wireless wearable portable system designed for the automatic quantitative spatio-temporal analysis of continuous thoracic spine motion across various planes and degrees of freedom (DOF). This includes automatic motion segmentation, computation of the range of motion (ROM) for six distinct thoracic spine movements across three planes, tracking of motion completion cycles, and visualization of both primary and coupled thoracic spine motions. To validate the system, this study employed an Inter-days experimental setting to conduct experiments involving a total of 957 thoracic spine movements, with participation from two representatives of varying age and gender. The reliability of the proposed system was assessed using the Intraclass Correlation Coefficient (ICC) and Standard Error of Measurement (SEM). The experimental results demonstrated strong ICC values for various thoracic spine movements across different planes, ranging from 0.774 to 0.918, with an average of 0.85. The SEM values ranged from 0.64° to 4.03°, with an average of 1.93°. Additionally, we successfully conducted an assessment of thoracic spine mobility in a stroke rehabilitation patient using the system. This illustrates the feasibility of the system for actively analyzing thoracic spine mobility, offering an effective technological means for non-invasive research on thoracic spine activity during continuous movement states.

Remote optogenetic control of the enteric nervous system and brain-gut axis in freely-behaving mice enabled by a wireless, battery-free optoelectronic device.

Wireless activation of the enteric nervous system (ENS) in freely moving animals with implantable optogenetic devices offers a unique and exciting opportunity to selectively control gastrointestinal (GI) transit in vivo, including the gut-brain axis. Programmed delivery of light to targeted locations in the GI-tract, however, poses many challenges not encountered within the central nervous system (CNS). We report here the development of a fully implantable, battery-free wireless device specifically designed for optogenetic control of the GI-tract, capable of generating sufficient light over large areas to robustly activate the ENS, potently inducing colonic motility ex vivo and increased propulsion in vivo. Use in in vivo studies reveals unique stimulation patterns that increase expulsion of colonic content, likely mediated in part by activation of an extrinsic brain-gut motor pathway, via pelvic nerves. This technology overcomes major limitations of conventional wireless optogenetic hardware designed for the CNS, providing targeted control of specific neurochemical classes of neurons in the ENS and brain-gut axis, for direct modulation of GI-transit and associated behaviours in freely moving animals.

Validity of the Hawkin Dynamics Wireless Dual Force Platform System Against a Piezoelectric Laboratory Grade System for Vertical Countermovement Jump Variables.

ABSTRACT: Dos'Santos, T, Evans, DT, and Read, DB. Validity of the Hawkin dynamics wireless dual force platform system against a piezoelectric laboratory grade system for vertical countermovement jump variables. J Strength Cond Res 38(6): 1144-1148, 2024-The aim of this study was to determine the criterion validity of the Hawkin Dynamics (HD) wireless dual force platform system for assessing vertical countermovement jump (CMJ) variables, compared with those derived from a Kistler piezoelectric laboratory grade force platform system. During a single testing session, HD force platforms were placed directly on top of 2 adjacent Kistler force platforms to simultaneously collect vertical ground reaction forces produced by 2 male recreational soccer players (age: 29.0 ± 2.8 years, height: 1.79 ± 0.01 m, mass: 85.6 ± 4.7 kg) that performed 25 vertical CMJs each. Sixteen vertical CMJ variables pertaining to jump height (JH), flight time (FT), time-to-take off (TTT), countermovement depth, body weight (BW), propulsive and braking mean, and peak powers, forces, and impulses were compared between systems. Fixed bias was observed for 6 of 16 variables (peak and mean braking power, mean propulsion force, TTT, FT, and BW), while proportional bias was present for 10 of 16 variables (peak and mean propulsive and braking force, TTT, FT, peak and mean braking power, mean propulsive power, and BW). For all variables regardless of fixed or proportional bias, percentage differences were ≤3.4% between force platform systems, with near perfect to perfect correlations (r or ρ = 0.977-1.000) observed for 15 of 16 variables. The HD dual wireless force platform system can be considered a valid alternative to a piezoelectric laboratory grade force platform system for the collection of vertical CMJ variables, particularly outcome (i.e., JH, reactive strength index modified) and strategy variables (countermovement depth).

Strain-invariant stretchable radio-frequency electronics.

Wireless modules that provide telecommunications and power-harvesting capabilities enabled by radio-frequency (RF) electronics are vital components of skin-interfaced stretchable electronics1-7. However, recent studies on stretchable RF components have demonstrated that substantial changes in electrical properties, such as a shift in the antenna resonance frequency, occur even under relatively low elastic strains8-15. Such changes lead directly to greatly reduced wireless signal strength or power-transfer efficiency in stretchable systems, particularly in physically dynamic environments such as the surface of the skin. Here we present strain-invariant stretchable RF electronics capable of completely maintaining the original RF properties under various elastic strains using a 'dielectro-elastic' material as the substrate. Dielectro-elastic materials have physically tunable dielectric properties that effectively avert frequency shifts arising in interfacing RF electronics. Compared with conventional stretchable substrate materials, our material has superior electrical, mechanical and thermal properties that are suitable for high-performance stretchable RF electronics. In this paper, we describe the materials, fabrication and design strategies that serve as the foundation for enabling the strain-invariant behaviour of key RF components based on experimental and computational studies. Finally, we present a set of skin-interfaced wireless healthcare monitors based on strain-invariant stretchable RF electronics with a wireless operational distance of up to 30 m under strain.

Lead-free dual-frequency ultrasound implants for wireless, biphasic deep brain stimulation.

Ultrasound-driven bioelectronics could offer a wireless scheme with sustainable power supply; however, current ultrasound implantable systems present critical challenges in biocompatibility and harvesting performance related to lead/lead-free piezoelectric materials and devices. Here, we report a lead-free dual-frequency ultrasound implants for wireless, biphasic deep brain stimulation, which integrates two developed lead-free sandwich porous 1-3-type piezoelectric composite elements with enhanced harvesting performance in a flexible printed circuit board. The implant is ultrasonically powered through a portable external dual-frequency transducer and generates programmable biphasic stimulus pulses in clinically relevant frequencies. Furthermore, we demonstrate ultrasound-driven implants for long-term biosafety therapy in deep brain stimulation through an epileptic rodent model. With biocompatibility and improved electrical performance, the lead-free materials and devices presented here could provide a promising platform for developing implantable ultrasonic electronics in the future.

Postoperative Long-Term Monitoring of Mechanical Characteristics in Reconstructed Soft Tissues Using Biocompatible, Immune-Tolerant, and Wireless Electronic Sutures.

Accurate postoperative assessment of varying mechanical properties is crucial for customizing patient-specific treatments and optimizing rehabilitation strategies following Achilles tendon (AT) rupture and reconstruction surgery. This study introduces a wireless, chip-less, and immune-tolerant in vivo strain-sensing suture designed to continuously monitor mechanical stiffness variations in the reconstructed AT throughout the healing process. This innovative sensing suture integrates a standard medical suturing thread with a wireless fiber strain-sensing system, which incorporates a fiber strain sensor and a double-layered inductive coil for wireless readout. The winding design of Au nanoparticle-based fiber electrodes and a hollow core contribute to the fiber strain sensor's high sensitivity (factor of 6.2 and 15.1 pF for revised sensitivity), negligible hysteresis, and durability over 10,000 stretching cycles. To ensure biocompatibility and immune tolerance during extended in vivo periods, an antibiofouling lubricant layer was applied to the sensing suture. Using this sensing system, we successfully monitored the strain responses of the reconstructed AT in an in vivo porcine model. This facilitated the postoperative assessment of mechanical stiffness variations through a well-established analytical model during the healing period.

Developing a Novel Prosthetic Hand with Wireless Wearable Sensor Technology Based on User Perspectives: A Pilot Study.

Myoelectric hands are beneficial tools in the daily activities of people with upper-limb deficiencies. Because traditional myoelectric hands rely on detecting muscle activity in residual limbs, they are not suitable for individuals with short stumps or paralyzed limbs. Therefore, we developed a novel electric prosthetic hand that functions without myoelectricity, utilizing wearable wireless sensor technology for control. As a preliminary evaluation, our prototype hand with wireless button sensors was compared with a conventional myoelectric hand (Ottobock). Ten healthy therapists were enrolled in this study. The hands were fixed to their forearms, myoelectric hand muscle activity sensors were attached to the wrist extensor and flexor muscles, and wireless button sensors for the prostheses were attached to each user's trunk. Clinical evaluations were performed using the Simple Test for Evaluating Hand Function and the Action Research Arm Test. The fatigue degree was evaluated using the modified Borg scale before and after the tests. While no statistically significant differences were observed between the two hands across the tests, the change in the Borg scale was notably smaller for our prosthetic hand (p = 0.045). Compared with the Ottobock hand, the proposed hand prosthesis has potential for widespread applications in people with upper-limb deficiencies.

Performance Assessment for the Validation of Wireless Communication Engines in an Innovative Wearable Monitoring Platform.

In today's health-monitoring applications, there is a growing demand for wireless and wearable acquisition platforms capable of simultaneously gathering multiple bio-signals from multiple body areas. These systems require well-structured software architectures, both to keep different wireless sensing nodes synchronized each other and to flush collected data towards an external gateway. This paper presents a quantitative analysis aimed at validating both the wireless synchronization task (implemented with a custom protocol) and the data transmission task (implemented with the BLE protocol) in a prototype wearable monitoring platform. We evaluated seven frequencies for exchanging synchronization packets (10 Hz, 20 Hz, 30 Hz, 40 Hz, 50 Hz, 60 Hz, 70 Hz) as well as two different BLE configurations (with and without the implementation of a dynamic adaptation of the BLE Connection Interval parameter). Additionally, we tested BLE data transmission performance in five different use case scenarios. As a result, we achieved the optimal performance in the synchronization task (1.18 ticks as median synchronization delay with a Min-Max range of 1.60 ticks and an Interquartile range (IQR) of 0.42 ticks) when exploiting a synchronization frequency of 40 Hz and the dynamic adaptation of the Connection Interval. Moreover, BLE data transmission proved to be significantly more efficient with shorter distances between the communicating nodes, growing worse by 30.5% beyond 8 m. In summary, this study suggests the best-performing network configurations to enhance the synchronization task of the prototype platform under analysis, as well as quantitative details on the best placement of data collectors.

Gait Pattern Analysis: Integration of a Highly Sensitive Flexible Pressure Sensor on a Wireless Instrumented Insole.

Gait phase monitoring wearable sensors play a crucial role in assessing both health and athletic performance, offering valuable insights into an individual's gait pattern. In this study, we introduced a simple and cost-effective capacitive gait sensor manufacturing approach, utilizing a micropatterned polydimethylsiloxane dielectric layer placed between screen-printed silver electrodes. The sensor demonstrated inherent stretchability and durability, even when the electrode was bent at a 45-degree angle, it maintained an electrode resistance of approximately 3 Ω. This feature is particularly advantageous for gait monitoring applications. Furthermore, the fabricated flexible capacitive pressure sensor exhibited higher sensitivity and linearity at both low and high pressure and displayed very good stability. Notably, the sensors demonstrated rapid response and recovery times for both under low and high pressure. To further explore the capabilities of these new sensors, they were successfully tested as insole-type pressure sensors for real-time gait signal monitoring. The sensors displayed a well-balanced combination of sensitivity and response time, making them well-suited for gait analysis. Beyond gait analysis, the proposed sensor holds the potential for a wide range of applications within biomedical, sports, and commercial systems where soft and conformable sensors are preferred.

Wireless system for recording evoked potentials.

Experiments measuring evoked potentials require flexible and rapid adjustment of stimulation and recording parameters. In this study, we have developed a recording system and an associated Android application that allow making such adjustments wirelessly. The system consists of 3 units: for stimulation, recording and control. Most of the modules in this system are custom made, although the stimulator and tablet are off-the-shelf products. When installed on the tablet, our Android application allows wireless communication with the control unit from a distance of 5 m. In testing, the recording unit had low internal noise and displayed signals faithfully. Upon receiving commands from the control unit, the stimulation unit produced precisely timed pulse outputs. Using this system, we were able to record evoked field potentials in the dentate gyrus of a rat; responses increased as expected with increasing stimulation pulse amplitude and duration.

Robotic wireless capsule endoscopy: recent advances and upcoming technologies.

Wireless capsule endoscopy (WCE) offers a non-invasive evaluation of the digestive system, eliminating the need for sedation and the risks associated with conventional endoscopic procedures. Its significance lies in diagnosing gastrointestinal tissue irregularities, especially in the small intestine. However, existing commercial WCE devices face limitations, such as the absence of autonomous lesion detection and treatment capabilities. Recent advancements in micro-electromechanical fabrication and computational methods have led to extensive research in sophisticated technology integration into commercial capsule endoscopes, intending to supersede wired endoscopes. This Review discusses the future requirements for intelligent capsule robots, providing a comparative evaluation of various methods' merits and disadvantages, and highlighting recent developments in six technologies relevant to WCE. These include near-field wireless power transmission, magnetic field active drive, ultra-wideband/intrabody communication, hybrid localization, AI-based autonomous lesion detection, and magnetic-controlled diagnosis and treatment. Moreover, we explore the feasibility for future "capsule surgeons".

Internet of Things-Enabled Patch With Built-in Microsensors and Wireless Chip: Real-Time Remote Monitoring of Patch Treatment.

Purpose: We aimed to design, develop, and evaluate an internet of things-enabled patch (IoT patch) for real-time remote monitoring of adherence (or patch wear time) during patch treatment in child participants in clinical trials. This study provides healthcare providers with a tool for objective, real-time, and remote assessment of adherence and for making required adjustments to treatment plans. Methods: The IoT patch had two temperature microsensors and a wireless chip. One sensor was placed closer to the skin than the other, resulting in a temperature difference depending on whether the patch was worn. When the patch was worn, it measured temperatures every 30 seconds and transmitted temperature data to a cloud server via a mobile application every 15 seconds. The patch was evaluated via 2 experiments with 30 healthy adults and 40 children with amblyopia. Results: Excellent monitoring accuracy was observed in both adults (mean delay of recorded time data, 0.4 minutes) and children (mean, 0.5 minutes). The difference between manually recorded and objectively recorded patch wear times showed good agreement in both groups. Experiment 1 showed accurate monitoring over a wide range of temperatures (from 0 to 30°C). Experiment 2 showed no significant differences in wearability (ease-of-use and comfort scores) between the IoT and conventional patches. Conclusions: The IoT patch offers an accurate, real-time, and remote system to monitor adherence to patch treatment. The patch is comfortable and easy to use. The utilization of an IoT patch may increase adherence to patch treatment based on accurate monitoring. Translational Relevance: Results show that the IoT patch can enable real-time adherence monitoring in clinical trials, improving treatment precision, and patient compliance to enhance outcomes.

Rapid and on-site wireless immunoassay of respiratory virus aerosols via hydrogel-modulated resonators.

Rapid and accurate detection of respiratory virus aerosols is highlighted for virus surveillance and infection control. Here, we report a wireless immunoassay technology for fast (within 10 min), on-site (wireless and battery-free), and sensitive (limit of detection down to fg/L) detection of virus antigens in aerosols. The wireless immunoassay leverages the immuno-responsive hydrogel-modulated radio frequency resonant sensor to capture and amplify the recognition of virus antigen, and flexible readout network to transduce the immuno bindings into electrical signals. The wireless immunoassay achieves simultaneous detection of respiratory viruses such as severe acute respiratory syndrome coronavirus 2, influenza A H1N1 virus, and respiratory syncytial virus for community infection surveillance. Direct detection of unpretreated clinical samples further demonstrates high accuracy for diagnosis of respiratory virus infection. This work provides a sensitive and accurate immunoassay technology for on-site virus detection and disease diagnosis compatible with wearable integration.

Wearable wireless continuous vital signs monitoring on the general ward.

PURPOSE OF REVIEW: Wearable wireless sensors for continuous vital signs monitoring (CVSM) offer the potential for early identification of patient deterioration, especially in low-intensity care settings like general wards. This study aims to review advances in wearable CVSM - with a focus on the general ward - highlighting the technological characteristics of CVSM systems, user perspectives and impact on patient outcomes by exploring recent evidence. RECENT FINDINGS: The accuracy of wearable sensors measuring vital signs exhibits variability, especially notable in ambulatory patients within hospital settings, and standard validation protocols are lacking. Usability of CMVS systems is critical for nurses and patients, highlighting the need for easy-to-use wearable sensors, and expansion of the number of measured vital signs. Current software systems lack integration with hospital IT infrastructures and workflow automation. Imperative enhancements involve nurse-friendly, less intrusive alarm strategies, and advanced decision support systems. Despite observed reductions in ICU admissions and Rapid Response Team calls, the impact on patient outcomes lacks robust statistical significance. SUMMARY: Widespread implementation of CVSM systems on the general ward and potentially outside the hospital seems inevitable. Despite the theoretical benefits of CVSM systems in improving clinical outcomes, and supporting nursing care by optimizing clinical workflow efficiency, the demonstrated effects in clinical practice are mixed. This review highlights the existing challenges related to data quality, usability, implementation, integration, interpretation, and user perspectives, as well as the need for robust evidence to support their impact on patient outcomes, workflow and cost-effectiveness.

A wirelessly programmable, skin-integrated thermo-haptic stimulator system for virtual reality.

Sensations of heat and touch produced by receptors in the skin are of essential importance for perceptions of the physical environment, with a particularly powerful role in interpersonal interactions. Advances in technologies for replicating these sensations in a programmable manner have the potential not only to enhance virtual/augmented reality environments but they also hold promise in medical applications for individuals with amputations or impaired sensory function. Engineering challenges are in achieving interfaces with precise spatial resolution, power-efficient operation, wide dynamic range, and fast temporal responses in both thermal and in physical modulation, with forms that can extend over large regions of the body. This paper introduces a wireless, skin-compatible interface for thermo-haptic modulation designed to address some of these challenges, with the ability to deliver programmable patterns of enhanced vibrational displacement and high-speed thermal stimulation. Experimental and computational investigations quantify the thermal and mechanical efficiency of a vertically stacked design layout in the thermo-haptic stimulators that also supports real-time, closed-loop control mechanisms. The platform is effective in conveying thermal and physical information through the skin, as demonstrated in the control of robotic prosthetics and in interactions with pressure/temperature-sensitive touch displays.

Wireless wearable potentiometric sensor for simultaneous determination of pH, sodium and potassium in human sweat.

This paper reports on the development of a flexible-wearable potentiometric sensor for real-time monitoring of sodium ion (Na+), potassium ion (K+), and pH in human sweat. Na0.44MnO2, polyaniline, and K2Co[Fe(CN)6] were used as sensing materials for Na+, H+ and K+ monitoring, respectively. The simultaneous potentiometric Na+, K+, and pH sensing were carried out by the developed sensor, which enables signal collection and transmission in real-time to the smartphone via a Wi-Fi access point. Then, the potentiometric responses were evaluated by a designed android application. Na+, K+, and pH sensors illustrated high sensitivity (59.7 ± 0.8 mV/decade for Na+, 57.8 ± 0.9 mV/decade for K+, and 54.7 ± 0.6 mV/pH for pH), excellent stability, and good batch-to-batch reproducibility. The results of on-body experiments demonstrated that the proposed platform is capable of real-time monitoring of the investigated ions.