Simultaneous Radiofrequency Research Articles

Inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium on Black Peppercorns Using Simultaneous Radiofrequency and Nonthermal Plasma Treatment: Efficacy and Impact on Quality

Inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium on Black Peppercorns Using Simultaneous Radiofrequency and Nonthermal Plasma Treatment: Efficacy and Impact on Quality

Simultaneous radiofrequency VIM thalamotomy and Posteroventral pallidotomy for management of dystonic tremors

Simultaneous radiofrequency VIM thalamotomy and Posteroventral pallidotomy for management of dystonic tremors

Simultaneous optical and RF linear frequency sweep generation using a Fourier domain mode-locked OEO with carrier-suppressed single sideband modulation.

The linear frequency swept light source is a critical device for several sensing applications, including FMCW LiDAR, with which the maximum sensing distance is determined by the coherence length of the light source and the spatial resolution is limited by the frequency scan nonlinearity. Here, we report what we believe to be a novel approach to generate highly coherent optical linear frequency sweeps (LFS) with a Fourier domain mode-locked (FDML) opto-electronic oscillator (OEO) deploying carrier suppressed single sideband (CS-SSB) modulation enabled by a dual-parallel Mach-Zehnder modulator (DP-MZM), with the coherence length determined by the fixed frequency laser used in the OEO, without the need of an expensive high-speed arbitrary waveform generator (AWG). Concurrently, a radio frequency (RF) LFS synchronized with the optical LFS is also generated with the FDML OEO. We obtained a nearly ideal optical LFS around 1550 nm with a side-mode suppression ratio of 27.4 dB, by controlling the bias point and the RF power feeding back to the DP-MZM in the OEO loop. The resulting dual optical and RF LFS' achieved a chirp rate of 27.27 MHz/µs and a frequency tuning range of 0.6 GHz, which can be extended to 142 MHz/µs and 2.0 GHz, respectively by reducing the size of the tunable ring filter circuit inside the OEO loop. By using pre-distortion method, the residual nonlinearity is reduced to 1.9881 × 10-5, and the root mean square (RMS) value of the frequency swept nonlinearity is less than 0.764 MHz. Our dual optical and RF LFS generation with a CS-SSB FDML-OEO has the advantages of long coherence length, high tuning speed, excellent frequency tuning linearity and repeatability, and potentially low cost, which can be used to make a dual optical and RF FMCW ranging system (LiDAR and RADAR) and are attractive for many applications, such as 3D sensing and autonomous driving, as well as optical frequency domain reflectometer (OFDR), and other applications requiring fast and reliable linear frequency sweeps in either optical and RF domains.

Beat Pilot Tone (BPT): Simultaneous MRI and RF motion sensing at arbitrary frequencies.

To introduce a simple system exploitation with the potential to turn MRI scanners into general-purpose radiofrequency (RF) motion monitoring systems. Inspired by Pilot Tone (PT), this work proposes Beat Pilot Tone (BPT), in which two or more RF tones at arbitrary frequencies are transmitted continuously during the scan. These tones create motion-modulated standing wave patterns that are sensed by the receiver coil array, incidentally mixed by intermodulation in the receiver chain, and digitized simultaneously with the MRI data. BPT can operate at almost any frequency as long as the intermodulation products lie within the bandwidth of the receivers. BPT's mechanism is explained in electromagnetic simulations and validated experimentally. Phantom and volunteer experiments over a range of transmit frequencies suggest that BPT may offer frequency-dependent sensitivity to motion. Using a semi-flexible anterior receiver array, BPT appears to sense cardiac-induced body vibrations at microwave frequencies ( 1.2 GHz). At lower frequencies, it exhibits a similar cardiac signal shape to PT, likely due to blood volume changes. Other volunteer experiments with respiratory, bulk, and head motion show that BPT can achieve greater sensitivity to motion than PT and greater separability between motion types. Basic multiple-input multiple-output ( MIMO) operation with simultaneous PT and BPT in head motion is demonstrated using two transmit antennas and a 22-channel head-neck coil. BPT may offer a rich source of motion information that is frequency-dependent, simultaneous, and complementary to PT and the MRI exam.

Radiofrequency and Electrical Muscle Stimulation: A Synergistic Treatment That Achieves Lipolysis and Circumferential Waist Reduction in Noninvasive Body Contouring.

Surgeons and providers in aesthetic medicine seek noninvasive devices that can be utilized for safe, efficient, and effective body contouring. Patient demand has propelled the development of novel devices that can simultaneously improve skin laxity, adipolysis along with stimulation of muscle hypertrophy. To determine the efficacy of body contouring after 3 treatments using the noninvasive Transform (InMode, Lake Forest, CA) device. A prospective, multicenter study was performed. Outcomes evaluated include: standardized caliper and ultrasound measurements of abdominal skin/soft-tissue thickness, waist circumference, histologic evaluation, patient comfort, and satisfaction assessments. Forty-four patients were successfully enrolled in the study and completed the series of 3 treatments which involved combined electrical muscle stimulation (EMS) and noninvasive bipolar radiofrequency (RF). Abdominal ultrasound measurements reveal a decrease in soft-tissue thickness (average 3.1 mm; P = .001), there was a significant decrease in caliper measurements of periumbilical skin thickness (P < .003), and the average reduction of abdominal circumference was 1.9 cm (P < .0001) 3 months after the treatment series. Histology confirmed subcutaneous adipolysis without damaging the dermal layer. Patients reported a high degree of satisfaction with the overall result (P = .003) and that each of the 3 treatments were progressively more comfortable (P < .005). This study demonstrates that a series of simultaneous noninvasive RF with EMS treatments to the abdomen decreases subcutaneous soft-tissue thickness of the treated area. These comfortable treatments ultimately result in a high degree of patient satisfaction at 3 months.

Treatment with synchronized radiofrequency and facial muscle stimulation: Histologic analysis of human skin for changes in collagen and elastin fibers.

Skin's exposure to intrinsic and extrinsic factors causes age-related changes, leading to a lower amount of dermal collagen and elastin. This study investigated the effects of a novel facial muscle stimulation technology combined with radiofrequency (RF) heating on dermal collagen and elastin content for the treatment of facial wrinkles and skin laxity. The active group subjects (N = 6) received four 20-min facial treatments with simultaneous RF and facial muscle stimulation, once weekly. The control subject (N = 1) was untreated. Skin biopsies obtained at baseline, 1-month and 3-month follow-up were evaluated histologically to determine collagen and elastin fibers content. A group of independent aestheticians evaluated facial skin appearance and wrinkle severity. Patient safety was followed. In the active group, collagen-occupied area reached 11.91 ± 1.80 × 106 μm2 (+25.32%, p < 0.05) and 12.35 ± 1.44 × 105 μm2 (+30.00%, p < 0.05) at 1-month and 3-month follow-up visits. Elastin-occupied area at 1-month and 3-month follow-up was 1.64 ± 0.14 × 105 μm2 (+67.23%, p < 0.05), and 1.99 ± 0.21 × 105 μm2 (+102.80%, p < 0.05). In the control group, there was no significant difference (p > 0.05) in collagen and elastin fibers. Active group wrinkle scores decreased from 5 (moderate, class II) to 3 (mild, class I). All subjects, except the control, improved in appearance posttreatment. No adverse events or side effects occurred. Decreased dermal collagen and elastin levels contributes to a gradual decline in skin elasticity, leading to facial wrinkles and unfirm skin. Study results showed noticeable improvement in facial appearance and increased dermal collagen and elastin content subsequent to simultaneous, noninvasive RF, and facial muscle stimulation treatments.

Remodeling of facial soft tissue induced by simultaneous application of HIFES and synchronized radiofrequency provides nonsurgical lift of facial soft tissues.

The application of radiofrequency (RF) and HIFES on the body provides improvement in skeletal muscle tissue, reduction in fatty tissue, reorganization of connective tissue, and skin texture improvement. However, overall facial appearance relies on both skin and underlying structures, specifically muscles and connective tissue which have to be treated as one unit to achieve proper care while preserving fatty layers that define youth facial appearance. The aim of this study is to find whether the effect of novel RF + HIFES is safe and can induce the lifting of soft tissue and overall improvement in facial appearance. In this study, 21 subjects were enrolled. The therapy was administered in four 20-min treatments on the forehead and cheeks. Photographs were evaluated by a Global Aesthetic Improvement Score (GAIS) and linear measurements of facial tissue lifting at 1- and 3-month follow-ups. Volumetric changes in the cheek area were investigated as well. The patients' satisfaction, safety, and comfort were documented throughout the study. The data indicated improvement in overall facial appearance, and 23% of average lifting was found in brows (p = 3.14 × 10-12 ) and cheeks (p = 6.00 × 10-15 ). The assessment of digital photographs showed an improvement in 100% of patients at 3-month follow-up. The treatments were safe, accompanied by high therapy comfort and subject satisfaction of 98%. The treatment by simultaneous RF and HIFES technology produces significant changes to the overall facial appearance, characterized by the lifting of facial tissues.

Development of an Automated Ultrasound Signal Indicator of Lung Interstitial Syndrome.

The number and distribution of lung ultrasound (LUS) imaging artifacts termed B-lines correlate with the presence of acute lung disease such as infection, acute respiratory distress syndrome (ARDS), and pulmonary edema. Detection and interpretation of B-lines require dedicated training and is machine and operator-dependent. The goal of this study was to identify radio frequency (RF) signal features associated with B-lines in a cohort of patients with cardiogenic pulmonary edema. A quantitative signal indicator could then be used in a single-element, non-imaging, wearable, automated lung ultrasound sensor (LUSS) for continuous hands-free monitoring of lung fluid. In this prospective study a 10-zone LUS exam was performed in 16 participants, including 12 patients admitted with acute cardiogenic pulmonary edema (mean age 60 ± 12 years) and 4 healthy controls (mean age 44 ± 21). Overall,160 individual LUS video clips were recorded. The LUS exams were performed with a phased array probe driven by an open-platform ultrasound system with simultaneous RF signal collection. RF data were analyzed offline for candidate B-line indicators based on signal amplitude, temporal variability, and frequency spectrum; blinded independent review of LUS images for the presence or absence of B-lines served as ground truth. Predictive performance of the signal indicators was determined with receiving operator characteristic (ROC) analysis with k-fold cross-validation. Two RF signal features-temporal variability of signal amplitude at large depths and at the pleural line-were strongly associated with B-line presence. The sensitivity and specificity of a combinatorial indicator were 93.2 and 58.5%, respectively, with cross-validated area under the ROC curve (AUC) of 0.91 (95% CI = 0.80-0.94). A combinatorial signal indicator for use with single-element non-imaging LUSS was developed to facilitate continuous monitoring of lung fluid in patients with respiratory illness.

Lectura y almacenamiento de recursos bibliográficos empleando tecnología RFID de ultra alta frecuencia con internet de las cosas

Libraries supervisors have the administrative duty of control and keep safe their inventories, such as books, documents, manuals, and theses, facilitating access to their users to this information and helping them loan and return, internal or external, in case it’s permitted. We wanted to design and build a prototype for a device capable of complementing these tasks in a low cost. We go through the processes in the design of a prototype for a simultaneous Radio Frequency Identification Reader using Ultra High Frequencies with Internet of Things technologies for data storage and communication between multiple stations, to do so we use a decision matrix method to select hardware tools, and software programming languages and libraries, needed to build such device, comparing, and weighting the characteristics that fit our needs. The resulting hardware selection was the Raspberry Pi and the RedBoard with a 59,7% and 12,4% respectively, and NodeJS with WebSockets for the software selection with a 53,8%. Finally, we present the designed architecture and a working prototype of the device that was built. Obtained response times from the reader and the database storage were as low as 10 milliseconds and as high as 20 milliseconds.

Precision Joint RF Measurement of Inter-Satellite Range and Time Difference and Scalable Clock Synchronization for Multi-Microsatellite Formations.

The rapid development of multi-satellite formations requires inter-satellite radio frequency (RF) measurement to be both precise and scalable. The navigation estimation of multi-satellite formations using a unified time reference demands the simultaneous RF measurement of the inter-satellite range and time difference. However, high-precision inter-satellite RF ranging and time difference measurements are investigated separately in existing studies. Different from the conventional two-way ranging (TWR) method, which is limited by its reliance on a high-performance atomic clock and navigation ephemeris, asymmetric double-sided two-way ranging (ADS-TWR)-based inter-satellite measurement schemes can eliminate such reliance while ensuring measurement precision and scalability. However, ADS-TWR was originally proposed for ranging-only applications. In this study, by fully exploiting the time-division non-coherent measurement characteristic of ADS-TWR, a joint RF measurement method is proposed to obtain the inter-satellite range and time difference simultaneously. Moreover, a multi-satellite clock synchronization scheme is proposed based on the joint measurement method. The experimental results show that when inter-satellite ranges are hundreds of kilometers, the joint measurement system has a centimeter-level accuracy for ranging and a hundred-picosecond-level accuracy for time difference measurement, and the maximum clock synchronization error was only about 1 ns.

Photonic-Assisted Reconfigurable LO Harmonic Downconverter With RF Self-Interference Cancellation and Image-Rejection

A photonic-assisted reconfigurable LO harmonic downconverter with simultaneous image-rejection and RF self-interference cancellation (SIC) for in-band full-duplex communication is proposed and experimentally investigated based on a dual-polarization dual-parallel Mach–Zehnder modulator (DP-DPMZM). The received signal from the antenna, which includes the radio frequency (RF) signal, image signal (IM) and self-interference (SI) signal, is input into one sub-MZM of the X-DPMZM. The self-reference (SR) signal is input into the other. The Y-DPMZM is used to load the LO signal and is properly biased to obtain the high-order sideband of the LO signal, which was then set as the LO signal of the reconfigurable harmonic frequency downconverter. By matching the power and delay of the SR signal and changing the main bias of the X-DPMZM, the SI signal can be eliminated directly in optical domain. With power splitting after the output of the DP-DPMZM, the quadrature IF signals can be obtained by a photonics-based continuously adjustable phase shifter. Then, photonics image-rejection down-conversion based on phase cancellation is realized after a low-frequency electrical 90° hybrid coupler (HC) combines the quadrature IF signals. Both theoretical and experimental investigations are performed. The results show that the SIC has a cancellation depth more than 32 dB for the 10-MHz bandwidth and greater than 19 dB for the 500-MHz bandwidth, the image-rejection has an image-rejection ratio larger than 31 dB for 10-MHz bandwidth and larger than 22 dB for the 100-MHz bandwidth, both in 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> - and 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> -order harmonic down-conversion mode. Experiments are also carried out on the reconfigurable LO harmonic downconverter with simultaneous SIC and image-rejection. A 16-quadrature amplitude modulation (16-QAM) -modulated RF signal is successfully down-converted to a 1-GHz intermediate frequency (IF) signal with self-interference and image frequency cancelled. It is verified that the RF signal can be well recovered from SI and IM signals by the proposed system.

Analytical Evaluation of Power-Amplifier-Based Charging Methodology and Energy Efficiency Optimization Framework for Aerial Base Stations

In this article, a radio-frequency (RF) power-amplifier (PA) system configuration for the on-board energy conversion is proposed for unmanned aerial vehicle base station’s (UAV-BS’s) battery charging. First, the PA system utilizes the internal RF source for energy conversion so that perpetual battery charging is possible without external power sources. Therefore, a continuous battery charging of the UAV-BS is possible while providing wireless network coverage by hovering over the target location. In addition, the proposed PA system offers a higher RF power control resolution than the existing PA works, which is desirable for precise power control of the UAV-BS. The objective of simultaneous RF power control and battery charging by the PA system is achieved by activating one Wilkinson power divider (WPD) with a specific power splitting ratio in the power divider bank. The simulations show that the dynamic activation of ten distinct unequal split WPDs of the proposed PA system improves the RF power control resolution by $157$ and $396{\,}\%$ compared to the existing PAs. Additionally, the simulations show that the PA’s power added efficiency fluctuation is reduced by $54$ and $82{\,}\%$ compared to the existing PAs. In addition, it will be shown that the proposed on-board battery charging increases the hovering time by $7.4{\,}\%$. Furthermore, an energy-efficiency optimization framework for UAV-BS’s is proposed considering real-world communication system’s hardware imperfections, and the proposed result suggests that UAV-BS’s flight time may decrease by $50{\,}\%$ depending upon the type of UAV-BS RF components.

Rational engineering of morphology modulated Ti-ZnO thin films coupled monolayer Ti3C2 MXene for efficient visible light PEC water splitting activity

• Morphology modulated Ti 3 C 2 /Ti-ZnO composite constructed. • Well-dispersed grain-like morphology of Ti-ZnO anchored on monolayer Ti 3 C 2 MXene. • Ti 3 C 2 /Ti-ZnO composite show improved visible light PEC activity. • Ti 3 C 2 /Ti-ZnO composite promote the long-term PEC activity for 21 min. • The charge transport mechanism under visible light PEC activity is evaluated. Novel morphology modulated monolayer 2D Ti 3 C 2 MXene coupled Ti-doped ZnO (Ti 3 C 2 /Ti-ZnO) photoelectrode developed for exploring interfacial charge transfer and visible-light photoelectrochemical (PEC) water splitting. Here, we altered the flake-like ZnO into grain-like morphology by selective Ti (2 at.%) doping into ZnO under simultaneous radio frequency (RF) and direct-current (DC) magnetron sputtering. This study describes the versatility of the Ti 3 C 2 /Ti-ZnO (monolayer/grain-like) interface. Transmission electron microscopy findings suggest that Ti 3 C 2 MXene developed in a monolayer. Moreover, scanning electron microscopy proved a consistent grain-like Ti-ZnO thin film interface with monolayer Ti 3 C 2 MXene. We also find Hall effect measurements to uncover the interfacial impact on charge carrier generation. The fabricated monolayer/grain-like interface modulated the band gap towards visible region. With all the above benefits, Ti 3 C 2 /Ti-ZnO achieved stable visible water splitting for 21 min. Overall, these findings provide the potentiality of Ti 3 C 2 /Ti-ZnO photoelectrode to extend the PEC activity towards the visible region.

RF Self-Interference Cancellation and Frequency Downconversion With Immunity to Power Fading Based on Optoelectronic Oscillation

We report a photonic approach to achieve simultaneous radio frequency (RF) self-interference cancellation (SIC) and frequency downconversion with immunity to power fading based on an optoelectronic oscillator (OEO) for an in-band full-duplex (IBFD) radio-over-fiber (ROF) system. A dual-drive Mach–Zehnder modulator (DDMZM) in a polarization-division multiplexing Mach–Zehnder modulator (PDM-MZM) is used to cancel the RF self-interference (SI) signal and generate optical carrier-suppressed double sidebands (CS-DSBs) of the signal of interest (SOI). Meanwhile, another DDMZM in the PDM-MZM is used to construct an OEO loop to generate optical CS-DSBs of the local oscillation (LO) signal. After detection at a photodetector (PD), a frequency downconverted signal is recovered with the RF self-interference cancellation (SIC). The proposed scheme can directly cancel the RF SI signal in the optical domain, meaning that it can overcome the limitation of SIC in the electrical domain. With the phase compensation introduced by a polarization controller, the desired signal is unaffected by the power fading over fiber transmission, which is significant for IBFD ROF systems. In addition, instead of an external microwave source, an OEO loop is used to generate an LO signal with a high spectral purity, which is very promising for integrated microwave photonics systems.

Evaluation of a Hydrogel Liquid Embolic Agent in a Porcine Mesenteric Hemorrhage Model

PurposeTo evaluate the ability to achieve hemostasis of a new liquid embolic agent in a porcine mesenteric artery hemorrhage model. Materials and MethodsAn anticoagulated porcine mesenteric artery hemorrhage model was created using a transarterial approach. Arterial hemorrhage was the result of aspiration needle punctures and simultaneous radiofrequency current application. Ten injured mesenteric arteries in 8 swine were treated. The hydrogel liquid embolic agent under investigation, an aqueous-based and in situ polymerizing liquid embolic agent, was used to treat actively bleeding sites. At 7 days, confirmation angiography was performed, followed by necropsy. ResultsThe mesenteric arterial injuries produced persistent and angiographically visible hemorrhage before initiating embolic therapy. Arteriovenous fistulae were observed in 4 cases. Embolization led to hemostasis in 10 of the 10 bleeds (100%). The mean embolic agent delivery time was 5.3 minutes (range, 1–15 minutes) with a mean embolic agent volume of 2.9 mL (range, 0.8–5.2 mL) delivered to achieve hemostasis. Notably, 40% of the treatments embolized the injury in the artery at the treatment site while leaving the native arterial lumen patent for the 7-day term of survival. All animals survived with no clinical evidence of hemorrhage through 7 days. Necropsy did not reveal evidence of ischemia within the bowel, liver, or lung. ConclusionsA new hydrogel liquid embolic agent was found to achieve rapid and durable hemostasis in an animal model of acute mesenteric hemorrhage.

Novel multifunctional robotically assisted bipolar instrument for simultaneous radiofrequency sealing and transection: preclinical and single-center experience

BackgroundA novel robotic-assisted bipolar radiofrequency (RF) multifunctional vessel seal-and-transection instrument (SynchroSeal, Intuitive Surgical, Inc., Sunnyvale, CA) has been developed. The objective of the current paper is to describe the design of SynchroSeal based on bench studies, assess the safety of SynchroSeal in ex vivo and in vivo porcine studies, and provide early clinical context.MethodsSynchroSeal grasping, energy activation time, and jaw temperature were evaluated with those of the Harmonic Ace+7. Data were analyzed with descriptive statistics, with Mann–Whitney for comparisons and statistical significance p < 0.05. Ex vivo and in vivo animal safety assessments of tissue after SynchroSeal use were evaluated for burst pressure, thermal spread, and acute sealing. Last, a single-center analysis of the technical metrics of SynchroSeal and Vessel Sealer Extend (robotically assisted seal-and-transection instrument) in bariatric cases is provided.ResultsBench studies of SynchroSeal and Harmonic Ace+7 evidenced SynchroSeal’s greater slip resistance force (8.4 ± 1.0 vs. 3.1 ± 0.4 N; p = 0.0002), lower grip pressure (3.0 ± 0.2 vs. 4.2 ± 0.5 kg/cm2; p = 0.0002), faster seal time (1.5 ± 0.4 vs. 11.6 ± 2.5 s; p < 0.0001), lower mean jaw temperature (109.7 ± 7.2 vs. 247.4 ± 8.6 °C; p = 0.0051), and faster cooling to 40 °C (53.6 ± 2.1 vs. 68.0 ± 3.5 s; p = 0.0051). SynchroSeal’s mean burst pressures after seal-and-transection and seal only modes were, respectively, 1169.1 ± 393.1 mmHg and 1159.2 ± 454.6 mmHg. Mean thermal spreads were, respectively, 1.2 ± 0.6 mm and 1.5 ± 0.55 mm. In the chronic animal study, 102 vessels were sealed; at 3 weeks post-procedure, there was no evidence of leakage or adverse events, such as non-target tissue thermal spread or tissue damage. In bariatrics cases, SynchroSeal was activated more frequently per case; however, its mean activation time was significantly shorter than Vessel Sealer Extend. No adverse events were reported for either device.ConclusionsSynchroSeal’s multifunctional design provides enhanced sealing and transection capabilities with an acceptable safety profile.

Simultaneous RF Self-Interference Cancellation, Local Oscillator Generation, Frequency up- and down-Conversion in an Integrated In-Band Full-Duplex 5G RF Transceiver Front-End

Wideband radio-frequency (RF) self-interference cancellation (SIC), local oscillator (LO) generation, frequency up-, and down-conversion are all crucial for an in-band full-duplex (IBFD) 5G RF transceiver front-end. In this paper, a microwave photonic approach enabled by only one optical dual-polarization IQ modulator (DP-IQMZM) is proposed to simultaneously realize wideband RF SIC, LO generation, frequency up- and down-conversion. Note that, the LO signal with high spectral purity and low phase noise is produced by a dual-loop optoelectronic oscillator (OEO) using a self-polarization stabilization structure, and the generated LO signal is applied for frequency up- and down-conversion. Besides, the optical single-sideband signal is produced at the output of this 5G RF transceiver for uplink transmission from the remote antenna unit (RAU) to the baseband unit (BBU), so the power fading induced by fiber dispersion could be completely suppressed. A proof-of-concept experiment is performed, and the LO signal with the central frequency of 10&#x00A0;GHz, the phase noise performance of &#x2212;108.97&#x00A0;dBc&#x002F;Hz at a frequency offset of 10&#x00A0;kHz is achieved. A 5 &#x00D7; 20&#x00A0;MHz Long Term Evolution (LTE) 16&#x002F;64-ary quadrature amplitude modulation-orthogonal frequency division multiplexing (16&#x002F;64QAM-OFDM) signal with the central frequency of 12.6&#x00A0;GHz is down-converted to 2.6&#x00A0;GHz. Meanwhile, the cancellation ratio of 30.22&#x00A0;dB and 26.26&#x00A0;dB could be achieved when the bandwidth of the self-interference signal is 150&#x00A0;MHz and 300&#x00A0;MHz, respectively. Moreover, a 3 &#x00D7; 20&#x00A0;MHz LTE 64QAM-OFDM signal with a central frequency of 2.6&#x00A0;GHz is up-converted to 12.6&#x00A0;GHz, and the electrical signal-to-noise ratio of the generated RF signal can achieve 31.34&#x00A0;dB. The measured error vector magnitude performance shows that the generated down- and up-converted signal both meet the 3^rd Generation Partnership Project (3GPP) requirements for 5G systems.

A New Dynamic Optimal M2M RF Interface Setting in Relay Selection Algorithm (DORSA) for IoT Applications

Machine-to-Machine (M2M) communication is an important type of communication in the Internet-of-Things (IoT). How to send data in these high-density communications using relay selection can help improve the performance of this type of communication in various applications. In addition, the possibility of simultaneous use of different Radio Frequency (RF) interfaces helps to use the spectrum more efficiently. In this work, we try to further use machine communication RF equipment and improve the average data rate of networks in some applications such as the IoT, which have their own bandwidth requirements. Therefore, we provide an optimization algorithm for relay selection as well as the simultaneous and dynamic multiple M2M RF interface setting that is called Dynamic Optimal Relay Selection and RF interfaces Setting Algorithm (DORSA). The simulation results show that the average data rate of DORSA with three interfaces (DORSA&#x005F;W-B-Z) can be improved up to 10&#x0025; compared to the existing methods such as optimal direct transmission and relay selection algorithms with static RF interface setting.

Catch Your Breath: Simultaneous RF Tracking and Respiration Monitoring with Radar Pairs

Continuous respiration monitoring is significant for real-life healthcare applications, but realizing it is extremely hard as wearable sensors are cumbersome and contact-free sensors largely fail to tolerate user movements. Meanwhile, tracking users indoors mostly demands user-held devices, while device-free localization can barely tell what and who it tracks. Fortunately, as both contact-free respiration monitoring and device-free localization may rely on Radio-Frequency (RF) sensing, fusing them together creates a novel system capable of continuously tracking users while recovering their fine-grained respiratory waveforms. To this end, we propose BreathCatcher as a continuous human respiration tracking system for indoor applications. To build this system, we employ commercial-grade compact radar pairs to capture RF reflections containing respiratory signals. We then propose a hybrid human respiration and position tracking algorithm to locate and identify respiratory signals from complex RF reflection mixtures. Finally, we design an encoder-decoder deep neural network driven by variational inference to recover fine-grained respiratory waveforms. Essentially, BreathCatcher cannot only obtain respiratory waveforms from multiple walking users, but also identify each user according to the latent properties of the respiratory signals. We evidently demonstrate the accuracy of both tracking and respiration monitoring via experiments involving 12 subjects and 80 man-hour data.

Role of radiofrequency ablation and cement injection for pain control in patients with spinal metastasis

BackgroundThe study aimed to investigate the effects and reliability of simultaneous vertebroplasty and radiofrequency ablation or radiofrequency ablation applied alone for pain control in patients with painful spine metastasis, and to investigate the effect of preventing tumor spread in long-term follow-up.MethodsPatients with painful vertebrae metastasis in the Afyonkarahisar Health Sciences University, Medical Faculty, Hospital Neurosurgery Clinic between 01.01.2015 and 01.06.2020 were recruited. They were divided into groups according to the surgical procedures applied. Group 1 included 26 patients who underwent radiofrequency ablation only, and group 2 included 40 patients who underwent vertebroplasty with radiofrequency ablation. Computed tomography and magnetic resonance imaging were performed in all patients pre-operation. The patients were followed for at least 6 months. Magnetic resonance imaging was performed at the end of the 6th month in neurologically stable patients. The metastatic lesion, pain, and quality of life were evaluated with Visual Analog Scale and Oswestry Disability Survey before and after the procedure.ResultsThe mean VAS score before the procedure was 8.3 ± 1.07 in the RFA group, and a statistically significant difference was observed in VAS scores at all post-procedural measurement time-points (p < 0.001). The pain scores decreased at a rate of 58.8 and 69.6% of patients showed significant improvements in the QoL in the RFA-only group. The mean VAS score was 7.44 ± 1.06 in group RFA + VP before the procedure; the difference in the mean VAS scores was statistically significant at all measurement time-points after the procedure (p < 0.001). The mean pre-treatment Oswestry Index (to assess the QoL) was 78.50% in the RFA + VP group, which improved to 14.2% after treatment.ConclusionAblation + vertebroplasty performed to control palliative pain and prevent tumor spread in patients with painful vertebral metastasis is more successful than vertebroplasty performed alone.