U-shaped PN junctions for efficient silicon Mach-Zehnder and microring modulators in the O-band: erratum.

We correct two minor errors in the manuscript. The effective diameter of the ring modulator should be 62.5 µm rather than 65 µm. The factor, g, in the FOM for comparing between the O- and C-band results should be 0.83 instead of 0.7.

U-shaped PN junctions for efficient silicon Mach-Zehnder and microring modulators in the O-band.

We demonstrate U-shaped silicon PN junctions for energy efficient Mach-Zehnder modulators and ring modulators in the O-band. This type of junction has an improved modulation efficiency compared to existing PN junction geometries, has low losses, and supports high-speed operation. The U-shaped junctions were fabricated in an 8" silicon photonics platform, and they were incorporated in travelling-wave Mach-Zehnder modulators and microring modulators. For the high-bandwidth Mach-Zehnder modulator, the DC VπL at -0.5 V bias was 4.6 V·mm. It exhibited a 3dB bandwidth of 13 GHz, and eye patterns at up to 24 Gb/s were observed. A VπL as low as ~2.6 V·mm at a -0.5 V bias was measured in another device. The ring modulator tuning efficiency was 40 pm·V-1 between 0 V and -0.5 V bias. It had a 3-dB bandwidth of 13.5 GHz and open eye patterns at up to 13 Gb/s were measured. This type of PN junctions can be easily fabricated without extra masks and can be incorporated into generic silicon photonics platforms.

Widely bandwidth-tunable silicon filter with an unlimited free-spectral range.

Next-generation high-capacity optical networks require flexible allocation of spectrum resources, for which low-cost optical filters with an ultra-wide bandwidth tunability beyond 100 GHz are desired. We demonstrate an integrated band-pass filter with the bandwidth continuously tuned across 670 GHz (117-788 GHz) which, to the best of our knowledge, is the widest tuning span ever demonstrated on a silicon chip. The filter also features simultaneous wavelength tuning and an unlimited free spectral range. We measured an out-of-band contrast of up to 55 dB, low in-band ripples of less than 0.3 dB, and in-band group delay variation of less than 8 ps. This result was achieved using cascaded Bragg-grating-assisted contra-directional couplers and micro-heaters on the 220 nm silicon-on-insulator platform with a very compact footprint of less than 7000 µm2. Another design with the bandwidth continuously tunable from 50 GHz to 1 THz is also presented.

Relationship between knowledge and skill for basic life support in personnel of emergency medical services, Islamic Republic of Iran.

BACKGROUND: Pre-hospital resuscitation in cardiac arrest is crucial to survival of patients, so emergency medical services personnel must have up-to-date knowledge and good skills. AIMS: This study aimed to determine the association between knowledge and skills of emergency medical services personnel of basic life support in north-west Khuzestan province, Islamic Republic of Iran. METHODS: This cross-sectional study included all personnel of emergency medical services (75 participants) in two emergency centres. Data were collected on characteristics of the participants (age, time since last retraining, academic degree, and length of experience), and their knowledge of basic life support. Skills were assessed by observing the personnel carry out basic life support and use of an automated external defibrillator on a mannequin. RESULTS: Poor knowledge was found in 31% of the personnel (mean score: 19.35 (SD 3.9); range: 0-34) and 42.7% had poor skills (mean score: 5.40 (SD 2.39); range: 0-9). Most of the staff (71%) did not use the automated external defibrillator correctly. No statistically significant relationship was found between staff knowledge and skills (P = 0.298). Staff knowledge and skills were significantly associated with correct use of the defibrillator (P = 0.039). Knowledge score was significantly associated with length of time since doing resuscitation training (P = 0.006) and academic qualification (P = 0.046). The skills score was significantly associated with time since doing training (P = 0.004). CONCLUSION: Strategies to maintain and improve the life support knowledge and skills of personnel in emergency medical services are recommended.

Effects of topical sesame (Sesamum indicum) oil on the pain severity of chemotherapy-induced phlebitis in patients with colorectal cancer: A randomized controlled trial.

BACKGROUND AND PURPOSE: Chemotherapy-induced phlebitis (CIP) is one of the most important and common complications in patients with cancer. Currently, the use of complementary methods to prevent or alleviate phlebitis symptoms has attracted great attention. In this study, we aimed to assess the effects of topical sesame oil in reducing the pain severity of CIP. MATERIALS AND METHODS: This randomized clinical trial was conducted on 60 patients with colorectal cancer afflicted with CIP. Patients received, twice a day for seven consecutive days, a 5-min massage solely (as the control group) or with 10 drops of sesame oil (as the experimental group) within the 10 cm radius of the affected site. The pain severity was evaluated by the visual analog scale on the first, third, fifth, and seventh days of the intervention. RESULTS: Mean changes of the pain severity compared to the baseline were significant on the third (P = 0.009), fifth (P < 0.001), and seventh (P < 0.001) days of the intervention in favor of the experimental group. Also, a significant reduction in the pain severity both in the experimental and control groups was observed during the seven days (F = 720.66, Ptime < 0.001); however, the decrease was more significant in the experimental group (F = 21.46, Pgroup < 0.001). CONCLUSION: Application of massage with sesame oil as a complementary method is effective in reducing the pain severity of patients with CIP.

Effect of Face-to-Face Education on Anxiety and Pain in Children with Minor Extremity Injuries Undergoing Outpatient Suturing in Emergency Department.

OBJECTIVE: To assess the effect of face-to-face education on anxiety and pain in children with minor extremity injuries undergoing outpatient suturing. METHODS: Children in intervention and control groups received face-to-face education (10 minutes) and no specific education, respectively. The anxiety and pain was measured using Modified-Yale Preoperative Anxiety Scale, and pain by Faces Pain Scale-Revised, respectively in 3 stages viz, pre-procedure and pre-intervention, post-procedure. RESULTS: Children in the intervention group were less anxious than the control at pre-procedure and post-intervention stage (41.1 (13.8) vs. 46.3 (19.1), respectively, P=0.03) and post-procedure and post-intervention stage (32.3 (17.2) vs. 40.2 (12.9), respectively, P=0.01). Children in the intervention group experienced less pain than the control at pre-procedure and post-intervention stage (3.9 (3.8) vs. 4.9 (3.1), respectively, P<0.001) and post-procedure and post-intervention stage (3.1 (1.2) vs. 4.0 (2.1), respectively, P=0.001). CONCLUSION: Face-to-face education could reduce anxiety and pain in children undergoing suturing in the emergency department.

A Smart Cage With Uniform Wireless Power Distribution in 3D for Enabling Long-Term Experiments With Freely Moving Animals.

This paper presents a novel experimental chamber with uniform wireless power distribution in 3D for enabling long-term biomedical experiments with small freely moving animal subjects. The implemented power transmission chamber prototype is based on arrays of parallel resonators and multicoil inductive links, to form a novel and highly efficient wireless power transmission system. The power transmitter unit includes several identical resonators enclosed in a scalable array of overlapping square coils which are connected in parallel to provide uniform power distribution along x and y. Moreover, the proposed chamber uses two arrays of primary resonators, facing each other, and connected in parallel to achieve uniform power distribution along the z axis. Each surface includes 9 overlapped coils connected in parallel and implemented into two layers of FR4 printed circuit board. The chamber features a natural power localization mechanism, which simplifies its implementation and ease its operation by avoiding the need for active detection and control mechanisms. A single power surface based on the proposed approach can provide a power transfer efficiency (PTE) of 69% and a power delivered to the load (PDL) of 120 mW, for a separation distance of 4 cm, whereas the complete chamber prototype provides a uniform PTE of 59% and a PDL of 100 mW in 3D, everywhere inside the chamber with a size of 27×27×16 cm(3).

A Single-Chip Full-Duplex High Speed Transceiver for Multi-Site Stimulating and Recording Neural Implants.

We present a novel, fully-integrated, low-power full-duplex transceiver (FDT) to support high-density and bidirectional neural interfacing applications (high-channel count stimulating and recording) with asymmetric data rates: higher rates are required for recording (uplink signals) than stimulation (downlink signals). The transmitter (TX) and receiver (RX) share a single antenna to reduce implant size and complexity. The TX uses impulse radio ultra-wide band (IR-UWB) based on an edge combining approach, and the RX uses a novel 2.4-GHz on-off keying (OOK) receiver. Proper isolation (>20 dB) between the TX and RX path is implemented 1) by shaping the transmitted pulses to fall within the unregulated UWB spectrum (3.1-7 GHz), and 2) by space-efficient filtering (avoiding a circulator or diplexer) of the downlink OOK spectrum in the RX low-noise amplifier. The UWB 3.1-7 GHz transmitter can use either OOK or binary phase shift keying (BPSK) modulation schemes. The proposed FDT provides dual band 500-Mbps TX uplink data rate and 100 Mbps RX downlink data rate, and it is fully integrated into standard TSMC 0.18- µm CMOS within a total size of 0.8 mm(2). The total measured power consumption is 10.4 mW in full duplex mode (5 mW at 100 Mbps for RX, and 5.4 mW at 500 Mbps or 10.8 pJ/bit for TX). Additionally, a 3-coil inductive link along with on-chip power management circuits allows to powering up the implantable transceiver wirelessly by delivering 25 mW extracted from a 13.56-MHz carrier signal, at a total efficiency of 41.6%.

Flexible, Polarization-Diverse UWB Antennas for Implantable Neural Recording Systems.

Implanted antennas for implant-to-air data communications must be composed of material compatible with biological tissues. We design single and dual-polarization antennas for wireless ultra-wideband neural recording systems using an inhomogeneous multi-layer model of the human head. Antennas made from flexible materials are more easily adapted to implantation; we investigate both flexible and rigid materials and examine performance trade-offs. The proposed antennas are designed to operate in a frequency range of 2-11 GHz (having S11 below -10 dB) covering both the 2.45 GHz (ISM) band and the 3.1-10.6 GHz UWB band. Measurements confirm simulation results showing flexible antennas have little performance degradation due to bending effects (in terms of impedance matching). Our miniaturized flexible antennas are 12 mm×12 mm and 10 mm×9 mm for single- and dual-polarizations, respectively. Finally, a comparison is made of four implantable antennas covering the 2-11 GHz range: 1) rigid, single polarization, 2) rigid, dual polarization, 3) flexible, single polarization and 4) flexible, dual polarization. In all cases a rigid antenna is used outside the body, with an appropriate polarization. Several advantages were confirmed for dual polarization antennas: 1) smaller size, 2) lower sensitivity to angular misalignments, and 3) higher fidelity.

A Wearable Microwave Antenna Array for Time-Domain Breast Tumor Screening.

In this work, we present a clinical prototype with a wearable patient interface for microwave breast cancer detection. The long-term aim of the prototype is a breast health monitoring application. The system operates using multistatic time-domain pulsed radar, with 16 flexible antennas embedded into a bra. Unlike the previously reported, table-based prototype with a rigid cup-like holder, the wearable one requires no immersion medium and enables simple localization of breast surface. In comparison with the table-based prototype, the wearable one is also significantly more cost-effective and has a smaller footprint. To demonstrate the improved functionality of the wearable prototype, we here report the outcome of daily testing of the new, wearable prototype on a healthy volunteer over a 28-day period. The resulting data (both signals and reconstructed images) is compared to that obtained with our table-based prototype. We show that the use of the wearable prototype has improved the quality of collected volunteer data by every investigated measure. This work demonstrates the proof-of-concept for a wearable breast health monitoring array, which can be further optimized in the future for use with patients with various breast sizes and tissue densities.

Biological channel modeling and implantable UWB antenna design for neural recording systems.

Ultrawideband (UWB) short-range communication systems have proved to be valuable in medical technology, particularly for implanted devices, due to their low-power consumption, low cost, small size, and high data rates. Neural activity monitoring in the brain requires high data rate (800 kb/s per neural sensor), and we target a system supporting a large number of sensors, in particular, aggregate transmission above 430 Mb/s (∼512 sensors). Knowledge of channel behavior is required to determine the maximum allowable power to 1) respect ANSI guidelines for avoiding tissue damage, and 2) respect FCC guidelines on unlicensed transmissions. We utilize a realistic model of the biological channel to inform the design of antennas for the implanted transmitter and the external receiver under these requirements. Antennas placement is examined under two scenarios having contrasting power constraints. Performance of the system within the biological tissues is examined via simulation and experiment. Our miniaturized antennas, 12 mm ×12 mm, need worst-case receiver sensitivities of -38 and -30.5 dBm for the first and second scenarios, respectively. These sensitivities allow us to successfully detect signals transmitted through tissues in the 3.1-10.6-GHz UWB band.

Capacity of UWB wireless channel for neural recording systems.

Ultra wide-band (UWB) short-range communication systems are valuable in medical technology, particularly for implanted devices, due to their low-power consumption, low cost, small size and high data rates. Monitoring of neural responses in the brain requires high data rate if we target a system supporting a large number of sensors. In this work, we are interested in the evaluation of the capacity of the ultra wide-band (UWB) channel that we could exploit using a realistic model of the biological channel. The channel characteristics are examined under two scenarios that are related to TX antenna placements. Using optimal power spectrum allocation (OPSA) at the transmitter side, we have computed this capacity by taking into account the fading characteristics of the channel. The results show the pertinence of the optimal power spectrum allocation for this type of channel. An improvement by a factor of 2 to 3 over a uniform power spectrum allocation (UPSA) when the SNR <; 0 dB was obtained. When the SNR is > 40 dB, both approaches give similar results. Antennas placement is examined under two scenarios having contrasting power constraints.

Realistic modeling of the biological channel for the design of implantable wireless UWB communication systems.

Several emerging medical applications require that a miniature data acquisition device be implanted into the head to extract and wirelessly communicate brain activity to other devices. Designing a reliable communication link for such an application requires a realistic model of the surrounding biological tissues. This paper exploits a realistic model of the biological channel to design a suitable wireless ultra wideband communication link in a brain monitoring application. Two scenarios for positioning the implanted transmitting antenna are considered. The 1(st) scenario places the antenna under the skull, whereas the 2(nd) scenario places the antenna under the skin, above the skull. The propagation characteristics of the signal through the tissues of the human head have been determined with full-wave electromagnetic simulation based on Finite Element Method. The implantable antenna and the external antenna are key components to establish an electromagnetic link between an implanted transmitter and an external receiver. The average specific absorption rate (ASAR) of the implantable antennas are evaluated and compared for the two proposed scenarios. Moreover, the maximum available power from the implanted antenna is evaluated to characterize the performance of the communication link established between the implantable antenna and the external antenna, with respect to spectrum and safety regulations. We show how sensitive the receiver must be in order to implement a reliable telemetry link based on the proposed model of the channel.