Survey of Collision Avoidance Systems for Underground Mines: Sensing Protocols.

With the growing number of unintentional interactions occurring in underground mines, Collision Avoidance System (CAS) establishment and maintenance has become an urgent need for mining industries to enhance their risk profile and improve construction safety. Usually, most collision accidents can be divided into three different categories in line with the involved participants and infrastructure condition. The accidents pose a great risk of financial cost to mining companies and even cause casualties. In detail, this paper presents an intensive study survey of positioning techniques, including ranging algorithms, to accommodate the demands of various proximity sensors and improve the capability of situational awareness. Then, we exploit the importance of the communication system, prevalent low-power wide-area technologies and related communication protocols. The effectiveness of communication systems decides and facilitates the success of the final integrated system that can be used to fundamentally address the problem of collision avoidance. For the purpose of collaboration between communication systems and other executive departments, a series of systematic comparisons of pertinent technologies and algorithms is given near the end, followed by a brief discussion on the best choice among these options. In the proposed solution, the overall end-to-end delay can be minimised to a few nanoseconds and the localisation accuracy can achieve centimetre level when operating in the range of 100 m.

Blockchain and AI-Based Solutions to Combat Coronavirus (COVID-19)-Like Epidemics: A Survey.

The beginning of 2020 has seen the emergence of coronavirus outbreak caused by a novel virus called SARS-CoV-2. The sudden explosion and uncontrolled worldwide spread of COVID-19 show the limitations of existing healthcare systems in timely handling public health emergencies. In such contexts, innovative technologies such as blockchain and Artificial Intelligence (AI) have emerged as promising solutions for fighting coronavirus epidemic. In particular, blockchain can combat pandemics by enabling early detection of outbreaks, ensuring the ordering of medical data, and ensuring reliable medical supply chain during the outbreak tracing. Moreover, AI provides intelligent solutions for identifying symptoms caused by coronavirus for treatments and supporting drug manufacturing. Therefore, we present an extensive survey on the use of blockchain and AI for combating COVID-19 epidemics. First, we introduce a new conceptual architecture which integrates blockchain and AI for fighting COVID-19. Then, we survey the latest research efforts on the use of blockchain and AI for fighting COVID-19 in various applications. The newly emerging projects and use cases enabled by these technologies to deal with coronavirus pandemic are also presented. A case study is also provided using federated AI for COVID-19 detection. Finally, we point out challenges and future directions that motivate more research efforts to deal with future coronavirus-like epidemics.

Long-term follow-up of perianchor cyst formation after rotator cuff repair.

BACKGROUND: Perianchor cyst formation (PCF) can occur after arthroscopic rotator cuff repair with poly-L-lactic acid (PLLA) anchors; however, little is known about PCF after all-suture anchor (ASA) use. METHODS: We reviewed patients who underwent double-row arthroscopic rotator cuff repair from 2012 to 2017 with ASAs implanted in the medial row and PLLA anchors in the lateral row. We evaluated PCF (graded on magnetic resonance imaging) and compared physical examination and functional surveys between patients with PCF (WC) and without PCF (WoC) at long-term follow-up. RESULTS: Among twenty-two patients (23 shoulders), 93% of PLLA anchors (vs. 79% ASA) displayed a grade 0 PCF, P = .100. No PLLA anchors had a grade 3 or 4 PCF, compared to 11% of ASAs, P = .158. At a mean postoperative follow-up time of 113 weeks, there was no significant difference between WC and WoC cohorts with regard to range of motion, rotator cuff strength, American Shoulder and Elbow Surgeons survey scores, or retear rates. However, the WoC cohort had a significantly higher University of California at Los Angeles shoulder survey score at final follow-up (34.3 WoC vs. 30.9 WC, P = .024). CONCLUSION: No difference was found in PCF between ASAs and PLLA anchors. At long-term follow-up, WoC patients had significantly improved functional outcome scores, based on the University of California at Los Angeles survey, but equivalent range of motion and rotator cuff strength examinations compared with WC patients.

Chronic sarcoid arthritis presenting as an intra-articular knee mass.

Patients may present with a primary complaint of intra-articular knee masses causing mechanical symptoms of snapping or locking. If the history, physical examination, laboratory tests, and imaging studies point to a benign process, acceptable treatment consists of arthroscopic excision and postoperative pathology analysis. As reported in several case series, the final diagnosis can be pigmented villonodular synovitis, localized nodular synovitis, hemangioma, lipoma, or rheumatoid nodules. In this case presentation, a 39-year-old man with no previous medical conditions and a negative preoperative chest radiograph underwent arthroscopic surgery for a single intra-articular knee mass. The unexpected diagnosis, after pathology review and further medical work-up, was arthritis secondary to chronic sarcoidosis.

Qualification of Wrist Functional Performance During Dart Thrower's Movement.

Recently, numerous comprehensive studies have been concentrating on the intricate kinematics of the wrist joint functionality captured with dart thrower's movement. It is envisaged that the wrist capability in performing daily activities can be more accurately characterized or encapsulated in the dart thrower's movement. This study examines the characteristic function of wrist movements during dart-throwing motion using only gyroscopic data measured from inertial sensors. A multi-dimensional form of dart throwing trajectory is described using quaternion representation associated with distance metric to quantitatively validate the functional wrist performance between two cohorts; healthy controls and patients. Eight normal subjects and eight patients engaged in a series of clinical trials conducted after undergoing post-surgical reconstructive procedures of the wrist joint. The discriminative results in terms of silhouette clustering evaluation show that the use of distance metric values based quaternion trajectory is well-matched consistently with subjective expert assessments. Our proposed approach captures the relative motions underpinning the wrist joint instead of relying on the traditional measure based on the range of motion measure. Therefore, this paper proposes a reliable approach to dynamically capture the wrist functionality during dart thrower's movement; a movement envisaged to describe the ability to engage in daily life activities. These quantitative outcomes in terms of measurement consistency will provide insightful information in understanding the significant changes in wrist joint signatures associated with various scenarios.

Quantifying the extent of a type II SLAP lesion required to cause peel-back of the glenoid labrum--a cadaveric study.

PURPOSE: To quantify the extent of labral disruption required to cause it to peel back when the peel-back test is performed. METHODS: Ten cadaveric shoulders were prepared by removal of the deltoid and rotator cuff muscles. The glenohumeral joint was concentrically reduced and brought into 90 degrees abduction and maximal external rotation. The peel-back of the labrum was graded 0, 1, or 2. The labrum was sequentially detached from the glenoid in the following order: biceps anchor only, 1 o'clock, 2 o'clock, 11 o'clock, and 3 o'clock positions. After each labral cut, the peel-back test was performed. Labral repair was performed with a single suture anchor placed at the 12:30 o'clock position; labral peel-back was reassessed. RESULTS: A progressive increase was noted in peel-back grade with sequential cutting of the labrum posteriorly. However, disruption of the anchor alone did not lead to a positive peel-back sign. Disruption to the 2 o'clock position resulted in a positive peel-back sign overall in 9 of 10 shoulders (5 were grade 1, and 4 were grade 2). No increase was seen in peel-back grade with anterior extension of the labral detachment. Labral repair with a single anchor placed at the 12:30 o'clock position eliminated labral peel-back in 100% of shoulders. CONCLUSIONS: Detachment of the biceps anchor alone does not cause peel-back. The labrum must be disrupted to at least the 2 o'clock position before overt (grade 2) peel-back is observed. A single suture anchor placed at 12:30 o'clock eliminated peel-back of the labrum. CLINICAL RELEVANCE: Validation of the peel-back test as an important diagnostic tool during shoulder arthroscopy.

The effect of estrogen on ovine anterior cruciate ligament fibroblasts: cell proliferation and collagen synthesis.

UNLABELLED: Estrogen has been implicated as a causal factor for anterior cruciate ligament injuries in women. Studies have demonstrated a decrease in anterior cruciate ligament fibroblast proliferation and collagen synthesis at supraphysiologic levels of estrogen in a rabbit model. HYPOTHESIS: The authors hypothesized that physiologic levels of estrogen would have no significant effect on anterior cruciate ligament fibroblast proliferation and collagen synthesis in an ovine model. METHODS: Anterior cruciate ligament fibroblasts were isolated from sheep knees using routine cell culture methods. The cells were exposed to 17beta-estradiol at physiologic concentrations of 2.2, 5, 15, 25, 250, and 2500 pg/ml. Cell proliferation was determined by cell counts on days 4 and 6. Collagen synthesis was determined by (3)H-proline incorporation on day 4. Immunohistochemistry was performed to detect estrogen receptors. RESULTS: Immunohistochemistry demonstrated the presence of estrogen receptors in ovine anterior cruciate ligament fibroblasts. There was no significant difference in anterior cruciate ligament fibroblast proliferation or collagen synthesis regardless of 17beta-estradiol concentration. CONCLUSIONS: Based on results of this study, and given the low turnover of collagen in ligaments, it is unlikely that a 2- to 3-day per month increase in circulating estrogen would result in rapid, clinically significant alterations in material properties of the anterior cruciate ligament in vivo. The etiology of noncontact anterior cruciate ligament injuries is complex and multifactorial in nature, meriting further investigation.