460 Assessment of long-term arrhytmic sequelae in patients recovering from COVID-19 infection

Aims COVID-19 has been associated with acute cardiac complications including cardiac arrhythmias. We aimed to assess the prevalence of long-term cardiac arrhythmias in patients recovering from severe COVID-19 infection with proved or suspected of cardiac involvement. Methods and results All patients with COVID-19 infection discharged from the cardiology department of our institution from the 1 March to the 30 April 2020 were considered eligible for this study. Patients were fitted out with an adhesive patch and a wireless single-lead 24-h electrocardiogram (ECG) Holter monitor (Rooti Rx® System, Rooti Labs Ltd, Taipei, Taiwan). RootiRx® is a small device consisting of an integrated sensor system, a microelectronic board with memory storage, and an internal rechargeable battery. This system can provide continuous ECG and was set to monitor heart rhythm for 24 h. The Holter system provides also blood pressure measurements and sleep apnea data which are evaluated through chest wall motion/cyclic variation of heart rate and reported along with the sleep efficiency (percentage of time spent asleep while in bed). Arrhythmic findings, sleep apnea detections, and residual COVID-19 symptoms were reported. The study follow-up was performed 174 (range = 166–190) days after hospital discharge in a cohort of 63 (76% males, median age 66 years) patients. New diagnosis of atrial fibrillation (AF) was performed in three sinus rhythm patients (4.8%). Eleven (18%) patients had asymptomatic bradycardia (<45 b.p.m.) with no pauses lasting more than 3 s. Non-sustained ventricular tachycardia (<30 s) episodes were recorded in two (3.2%) patients, while no sustained ventricular arrhythmia was documented. The Holter system indicated the presence of moderate-to-severe obstructive sleep apnea episodes in 33 (53%) patients without known history of sleep disorders. Some previously unrecognized long-lasting COVID-19 symptoms were also described: fatigue (10, 16%), myalgia (3, 4.8%), and impaired attention (1, 1.6%). Conclusions Six months after the infection, we performed new diagnoses of AF in patients who recovered from severe COVID-19 infection with proved or suspected cardiac involvement using 24-h Holter monitoring. No other arrhythmias were observed, but the Holter system identified obstructive sleep apnea episodes in half of the patients. A relevant percentage of patients also described persisting symptoms of COVID-19 infection. These findings suggest further prospective studies to better describe long-term arrhythmic manifestations and residual symptoms in patients hospitalized with COVID-19 infection.

Development of Inverter Circuits with Dual Control Subchannel Areas of Integral CMOS Sensor Element

The use of an integrated sensor element as an addition of inverter, which converts the resistance of a sensitive element into the level of the output pulse signal, is investigated. Inverter circuits with different control options for sub-channel areas of MOS transistors are modeled in the LTSpice program. Based on the simulation results, dependencies graphs of the output signal amplitude on the resistance of a sensitive element and sensor’s sensitivity are drawn, and the shapes of the output signals are shown.

Higher-order Lamb waves with quasi-zero surface displacement components on a GaAs piezoelectric plate

Higher-order Lamb waves with quasi-zero surface displacement components are reported on (100)-cut GaAs propagating along the <110> direction where the total displacement at the surface of the plate is less than 10% of the maximum total displacement. The dispersion curves and the displacement component profiles show the reduction of total displacement at the surface of the plate starting when the phase velocities of the higher-order modes are crossing the shear bulk acoustic wave velocity to the value as low as 5%. Due to the concentration of acoustic energy inside the plate, the reported quasi-zero plate acoustic waves (QZ-PAW) further reduce the radiation of acoustic when the plate surface is in contact with liquid. The experimental results validate the occurrence of QZ-PAW with a reduction of viscous damping insertion loss compared to previously reported quasi-longitudinal Lamb waves (QL-LW). The results demonstrate the potential QZ-PAW mode for emerging applications such as dual-mode PAW sensors, PAW devices with integrated sensor and actuator, thin-film and ultra-high frequency (UHF) PAW sensors in highly viscous liquid media.

Highly responsive screen-printed asymmetric pressure sensor based on laser-induced graphene

Graphene-based pressure sensors have received extensive attention in wearable devices. However, reliable, low-cost, and large-scale preparation of structurally stable graphene electrodes for flexible pressure sensors is still a challenge. Herein, for the first time, laser-induced graphene (LIG) powder are prepared into screen printing ink, and shape-controllable LIG patterned electrodes can be obtained on various substrates using a facile screen printing process, and a novel asymmetric pressure sensor composed of the resulting screen-printed LIG electrodes has been developed. Benefit from the 3D porous structure of LIG, the as-prepared flexible LIG screen-printed asymmetric pressure sensor has super sensing properties with a high sensitivity of 1.86 kPa−1, low detection limit of about 3.4 Pa, short response time, and long cycle durability. Such excellent sensing performances give our flexible asymmetric LIG screen-printed pressure sensor the ability to realize real-time detection of tiny body physiological movements (such as wrist pulse and pronunciation action). Besides, the integrated sensor array has a multi-touch function. This work could stimulate an appropriate approach to designing shape-controllable LIG screen-printed patterned electrodes on various flexible substrates to adapt the specific needs of fulfilling compatibility and modular integration for potential application prospects in wearable electronics.

Product Integration of Established Crash Sensors for Safety Applications in Lightweight Vehicles

The functionality of products increases when more sensors are used. This trend also affects future automobiles and becomes even more relevant in connected and autonomous applications. Concerning automotive lightweight design, carbon fibre-reinforced polymers (CFRP) are suitable materials. However, their drawbacks include the relatively high manufacturing costs of CFRP components in addition to the difficulty of recycling. To compensate for the increased expenditure, the integration of automotive sensors in CFRP vehicle structures provides added value. As a new approach, established sensors are integrated into fibre-reinforced polymer (FRP) structures. The sensors are usually mounted to the vehicle. The integration of sensors into the structure saves weight and space. Many other approaches specifically develop new sensors for integration into FRP structures. With the new approach, there is no need for elaborate development of new sensors since established sensors are used. The present research also showed that the range of applications of the sensors can be extended by the integration. The present paper outlines the functional behaviour of the integrated sensor utilized for crashing sensing. First of all, the integration quality of the sensor is relevant. Different requirements apply to the usual mounting of the sensor. The self-sensing structure must fulfil those requirements. Moreover, unfamiliar characteristics of the new surrounding structure might affect the sensing behaviour. Thus, the sensing behaviour of the self-sensing composite was analyzed in detail. The overarching objective is the general integration of sensors in products with reasonable effort.

Miniaturized wireless, skin-integrated sensor networks for quantifying full-body movement behaviors and vital signs in infants

Early identification of atypical infant movement behaviors consistent with underlying neuromotor pathologies can expedite timely enrollment in therapeutic interventions that exploit inherent neuroplasticity to promote recovery. Traditional neuromotor assessments rely on qualitative evaluations performed by specially trained personnel, mostly available in tertiary medical centers or specialized facilities. Such approaches are high in cost, require geographic proximity to advanced healthcare resources, and yield mostly qualitative insight. This paper introduces a simple, low-cost alternative in the form of a technology customized for quantitatively capturing continuous, full-body kinematics of infants during free living conditions at home or in clinical settings while simultaneously recording essential vital signs data. The system consists of a wireless network of small, flexible inertial sensors placed at strategic locations across the body and operated in a wide-bandwidth and time-synchronized fashion. The data serve as the basis for reconstructing three-dimensional motions in avatar form without the need for video recordings and associated privacy concerns, for remote visual assessments by experts. These quantitative measurements can also be presented in graphical format and analyzed with machine-learning techniques, with potential to automate and systematize traditional motor assessments. Clinical implementations with infants at low and at elevated risks for atypical neuromotor development illustrates application of this system in quantitative and semiquantitative assessments of patterns of gross motor skills, along with body temperature, heart rate, and respiratory rate, from long-term and follow-up measurements over a 3-mo period following birth. The engineering aspects are compatible for scaled deployment, with the potential to improve health outcomes for children worldwide via early, pragmatic detection methods.

New epiretinal implant with integrated sensor chips for optical capturing shows a good biocompatibility profile in vitro and in vivo

Background Retinal degenerative diseases, e.g., retinitis pigmentosa, cause a severe decline of the visual function up to blindness. Treatment still remains difficult; however, implantation of retinal prostheses can help restoring vision. In this study, the biocompatibility and surgical feasibility of a newly developed epiretinal stimulator (OPTO-EPIRET) was investigated. The previously developed implant was extended by an integrated circuit-based optical capturing, which will enable the immediate conversion of the visual field into stimulation patterns to stimulate retinal ganglion cells. Results The biocompatibility of the OPTO-EPIRET was investigated in vitro using the two different cell lines L-929 and R28. Direct and indirect contact were analyzed in terms of cell proliferation, cell viability, and gene expression. The surgical feasibility was initially tested by implanting the OPTO-EPIRET in cadaveric rabbit eyes. Afterwards, inactive devices were implanted in six rabbits for feasibility and biocompatibility testings in vivo. In follow-up controls (1–12 weeks post-surgery), the eyes were examined using fundoscopy and optical coherence tomography. After finalization, histological examination was performed to analyze the retinal structure. Regarding the in vitro biocompatibility, no significant influence on cell viability was detected (L929: < 1.3% dead cells; R-28: < 0.8% dead cells). The surgery, which comprised phacoemulsification, vitrectomy, and implantation of the OPTO-EPIRET through a 9–10 mm corneal incision, was successfully established. The implant was fixated with a retinal tack. Vitreal hemorrhage or retinal tearing occurred as main adverse effects. Transitional corneal edema caused difficulties in post-surgical imaging. Conclusions The OPTO-EPIRET stimulator showed a good biocompatibility profile in vitro. Furthermore, the implantation surgery was shown to be feasible. However, further design optimization steps are necessary to avoid intra- and postoperative complications. Overall, the OPTO-EPIRET will allow for a wide visual field and good visual acuity due to a high density of electrodes in the central retina.