Streamlining Iliac Bone Harvest for Maxillary Reconstruction With Novel Use of Arthrex Osteochondral Autograft Transfer System.

This study introduces a novel application of the Osteochondral Autograft Transfer System (OATS) for autologous bone grafting during alveolar cleft repair. Approximately 75% of patients with cleft lip and palate have an alveolar cleft, which often necessitates secondary bone grafting from common donor sites such as the iliac crest. Traditional harvesting techniques, although effective, can be labor-intensive and increase the risk of donor site injury. Here the authors describe the use of OATS, which has primarily been used in orthopedic procedures like anterior cruciate ligament reconstruction, for the first time in alveolar cleft repair. It involves a minimally invasive, single-use transfer system for harvesting osteochondral autografts from the anterior iliac crest, and thereby reduces harvest time compared with traditional open approaches. The procedure is detailed from pre-operative evaluation through long-term follow-up and highlights the technique's benefits related to surgical time, ease of use, and maintenance of sizable autograft volumes. Similarly, the authors discuss other advantages of OATS, including its single-use and cordless nature, which is believed to contribute to a lower contamination risk and better intraoperative ergonomics.

Evaluation of 5G Positioning Performance Based on UTDoA, AoA and Base-Station Selective Exclusion.

Accurate and reliable positioning solution is an important requirement for many applications, for instance, emergency services and vehicular-related use cases. Positioning using cellular signals has emerged as a promising solution in Global Navigation Satellite System (GNSS) challenging environments, such as deep urban canyons. However, harsh working conditions of urban scenarios, such as with dense multipath and Non-Line of Sight (NLoS), remain as one of the key factors causing the detriment of the positioning estimation accuracy. This paper demonstrates that the use of joint Uplink Time Difference of Arrival (UTDoA) and Angle of Arrival (AoA) gives a significant improvement in the position accuracy thanks to the use of antenna arrays. The new advances of this technology enable more accurate user locations by exploiting angular domains of propagation channel in combination with time measurements. Moreover, it is shown that a better localization is achieved by combining the joined UTDoA and AoA with a base-station selective exclusion method that is able to detect and eliminate measurements affected by NLoS. The proposed approach has been tested through simulations based on a deep urban deployment map, which comes with an experimental data file of the user's position. A sounding reference signal of 5G new radio operating in the centimeter-wave band is used. The obtained results add value to the use of advance antennas in 5G positioning. In addition, they contribute towards the fulfillment of high-accuracy positioning requirements in challenging environments when using cellular networks.

Methodology for Simulating 5G and GNSS High-Accuracy Positioning.

This paper focuses on the exploitation of fifth generation (5G) centimetre-wave (cmWave) and millimetre-wave (mmWave) transmissions for high-accuracy positioning, in order to complement the availability of Global Navigation Satellite Systems (GNSS) in harsh environments, such as urban canyons. Our goal is to present a representative methodology to simulate and assess their hybrid positioning capabilities over outdoor urban, suburban and rural scenarios. A novel scenario definition is proposed to integrate the network density of 5G deployments with the visibility masks of GNSS satellites, which helps to generate correlated scenarios of both technologies. Then, a generic and representative modeling of the 5G and GNSS observables is presented for snapshot positioning, which is suitable for standard protocols. The simulations results indicate that GNSS drives the achievable accuracy of its hybridisation with 5G cmWave, because non-line-of-sight (NLoS) conditions can limit the cmWave localization accuracy to around 20 m. The 5G performance is significantly improved with the use of mmWave positioning with dominant line-of-sight (LoS) conditions, which can even achieve sub-meter localization with one or more base stations. Therefore, these results show that NLoS conditions need to be weighted in 5G localization, in order to complement and outperform GNSS positioning over urban environments.