Development of a skill learning system for advanced body balance control by sound feedback

科学研究費助成事業 研究成果報告書：挑戦的萌芽研究2011-2013 課題番号：2365040

A 92-year-old man with retropharyngeal hematoma caused by an injury of the anterior longitudinal ligament

AbstractTraumatic retropharyngeal hematoma is a rare condition and may be lethal in some cases. In patients with this condition, the absence of a vertebral fracture or a major vascular injury is extremely rare. We present the case of a 92-year-old man who hit his forehead by slipping on the floor in his house. He had no symptoms at the time; however, he experienced throat pain and dyspnea at 6 hours after the injury. On arrival, he complained of severe dyspnea; therefore, an emergency endotracheal intubation was performed. A lateral neck roentgenogram after intubation showed dilatation of the retropharyngeal and retrotracheal space and no evidence of a cervical vertebral fracture. Cervical computed tomography (CT) with contrast medium revealed a massive hematoma extending from the retropharyngeal to the superior mediastinal space but no evidence of contrast medium extravasation or a vertebral fracture. However, sagittal magnetic resonance imaging (MRI) revealed an anterior longitudinal ligament (C4-5 levels) injury. We determined that the cause of the hematoma was an anterior longitudinal ligament injury and a minor vascular injury around the injured ligament. Therefore, we recommend that patients with retropharyngeal hematoma undergo sagittal cervical MRI when roentgenography and CT reveal no evidence of injury

Arterial embolization in patients with grade-4 blunt renal trauma: evaluation of the glomerular filtration rates by dynamic scintigraphy with 99mTechnetium-diethylene triamine pentacetic acid

<p>Abstract</p> <p>Background</p> <p>High-grade blunt renal trauma has been treated by arterial embolization (AE). However, it is unknown whether AE preserves renal function, because conventional renal function tests reflect total renal function and not the function of the injured kidney alone. Dynamic scintigraphy can assess differential renal function.</p> <p>Methods</p> <p>We performed AE in 17 patients with grade-4 blunt renal trauma and determined their serum creatinine (sCr) level and glomerular filtration rate (GFR; estimated by dynamic scintigraphy) after 3 months. In 4 patients with low GFR of the injured kidney (<20 ml·min^-1·1.73 m^-2), the GFR and sCr were measured again at 6 months. Data are presented as median and interquartile range (25th, 75th percentile).</p> <p>Results</p> <p>The median GFR of the injured kidney, total GFR, and median sCr at 3 months were 29.3 (23.7, 35.3) and 96.8 (79.1, 102.6) ml·min^-1·1.73 m^-2and 0.6 (0.5, 0.7) mg/dl, respectively. In the patients with low GFR (ml·min^-1·1.73 m^-2), the median GFR of the injured kidney, total GFR, and median sCr (mg/dl) were 16.2 (15.7, 16.3), 68.7 (61.1, 71.6), and 0.7 (0.7, 0.9), respectively, at 3 months and 34.5 (29.2, 37.0), 90.9 (79.1, 98.8), and 0.7 (0.7, 0.8), respectively, at 6 months.</p> <p>Conclusions</p> <p>The function of the injured kidney was preserved in all patients, indicating the efficacy of AE for the treatment of grade-4 blunt renal trauma.</p

Predicting Successful Throwing Technique in Judo from Factors of Kumite Posture Based on a Machine-Learning Approach

Identifying the key points of a movement performed by an expert is required for beginners who want to acquire a motor skill. By repeating a learning cycle, the beginner tries the movement, focusing on the key points. We can find many guiding methods for adopting motor skills in the fields of coaching and training for sports. However, the methods strongly depend on the experience of trainers and coaches, who need to select the appropriate methods for different types of athletes. Although methods based on objective information obtained from videos and sensors applicable to individual movements have been proposed in order to overcome the subjectivity of these approaches, we cannot apply those to movements that include external factors, such as pushing and/or attacks from an opponent, as seen in combat sports. Furthermore, such sports require fast feedback of the analysis to the athletes in order to find the key factors of offensive/defensive techniques at the training site. Focusing on judo throwing techniques, this paper proposes a novel real-time prediction method called RT-XSM (Real-Time Extraction method for Successful Movements) that predicts which throwing technique is most likely to be successful based on Kumite posture just before the throw. The RT-XSM uses logistic regression to analyze datasets consisting of the factors of Kumite posture (a standing posture when both players grip each other) and throwing technique classification. To validate the proposed method, this paper also demonstrates experiments of the RT-XSM using datasets acquired from video scenes of the World Judo Championships

Design and Implementation of a Stream-based Distributed Computing Platform using Graphics Processing Units

Anonymous use of computing resources spread over the world becomes one of the main goals in GRID environments. In GRID-based computing, the security of users or of contributors of computing resources is crucial to execute processes in a safe way. This paper proposes a new method for streambased processing in a distributed environment and also a novel method to solve the security matter under this kind of processing. It also presents the design of the distributed computing platform developed for stream-based processing, including the description of the local and remote execution methods, which are collectively designated by Caravela platform. The proposed flow-model is mapped on the distributed processing resources, connected through a network, by using the Caravela platform. This platform has been developed by the authors of this paper specifically for making use of the Graphics Processing Units available in recent personal computers. The paper also illustrates application of the Caravela platform to different types of processing, namely scientific computing and image/video processing. The presented experimental results show that significant improvements can be achieved with the use of GPUs against the use of general purpose processors

Statistical Extraction Method for Revealing Key Factors from Posture before Initiating Successful Throwing Technique in Judo

Many methods such as biomechanics and coaching have been proposed to help people learn a certain movement. There have been proposals for methods to discover characteristics of movement based on information obtained from videos and sensors. Especially in sports, it is expected that these methods can provide hints to improve movement skills. However, conventional methods focus on individual movements, and do not consider cases where external factors influence the movement, such as combat sports. In this paper, we propose a novel method called the Extraction for Successful Movement method (XSM method). Applying the method, this paper focuses on throwing techniques in judo to discover key factors that induce successful throwing from the postures right before initiating the throwing techniques. We define candidate factors by observing the video scenes where the throwing techniques are successfully performed. The method demonstrates the significance of the key factors according to the predominance of factors by χ2 test and residual analysis. Applying the XSM method to the dataset obtained from the videos of the Judo World Championships, we demonstrate the validity of the method with discussing the key factors related to the successful throwing techniques

Stream-Based Visually Lossless Data Compression Applying Variable Bit-Length ADPCM Encoding

Video applications have become one of the major services in the engineering field, which are implemented by server–client systems connected via the Internet, broadcasting services for mobile devices such as smartphones and surveillance cameras for security. Recently, the majority of video encoding mechanisms to reduce the data rate are mainly lossy compression methods such as the MPEG format. However, when we consider special needs for high-speed communication such as display applications and object detection ones with high accuracy from the video stream, we need to address the encoding mechanism without any loss of pixel information, called visually lossless compression. This paper focuses on the Adaptive Differential Pulse Code Modulation (ADPCM) that encodes a data stream into a constant bit length per data element. However, the conventional ADPCM does not have any mechanism to control dynamically the encoding bit length. We propose a novel ADPCM that provides a mechanism with a variable bit-length control, called ADPCM-VBL, for the encoding/decoding mechanism. Furthermore, since we expect that the encoded data from ADPCM maintains low entropy, we expect to reduce the amount of data by applying a lossless data compression. Applying ADPCM-VBL and a lossless data compression, this paper proposes a video transfer system that controls throughput autonomously in the communication data path. Through evaluations focusing on the aspects of the encoding performance and the image quality, we confirm that the proposed mechanisms effectively work on the applications that needs visually lossless compression by encoding video stream in low latency