Multiple Moving Speaker Tracking by Microphone Array on Mobile Robot

Real-world applications often require tracking multiple moving speakers for improving human-robot interactions and/or sound source separation. This paper presents multiple moving speaker tracking using an 8ch microphone array system installed on a mobile robot. This problem is difficult because the system does not assume that sound sources and/or the microphone array are fixed. Our solutions consist of two key ideas – time delay of arrival estimation, and multiple Kalman filters. The former localizes multiple sound sources based on beamforming in real time. Non-linear movements are tracked by using a set of Kalman filters with different history lengths in order to reduce errors in tracking multiple moving speakers under noisy and echoic environments. For quantitative evaluation of the tracking, motion references of sound sources and a mobile robot, called SIG2, were measured accurately by ultrasonic 3D tag sensors. As a result, we showed that the system tracked three simultaneous sound sources even when SIG2 moved in a room with large reverberation due to glass walls. 1

Onset of Chronic Expanding Hematoma 25 Years After Total Hip Arthroplasty

Chronic expanding hematoma (CEH) is a rare anatomical condition that gradually expands due to trauma or surgery. We report the case of a 56-year-old woman who developed CEH 25 years after metal-on-polyethylene total hip arthroplasty. She presented with swelling and radiating pain in the right inguinal region. Tocilizumab was administered for treating rheumatoid arthritis and renal amyloid A amyloidosis. Diagnostic imaging and partial resection revealed a soft tissue mass and a CEH, respectively. The symptoms recurred 6 months later; dialysis was initiated, and the CEH was resected under general anesthesia, leading to improvement. This case report emphasizes the importance of prompt diagnosis and intervention in CEH management for preventing further complications and improving the patient's quality of life

Weekend onset of acute myocardial infarction does not have a negative impact on outcome in Japan.

Background Studies from North America indicate that patients admitted during the weekend with acute myocardial infarction (AMI) have a worse outcome than weekday-admitted patients, probably reflecting a lower rate of invasive procedures. However, it is unclear whether the same is true in Japan, which has a different healthcare system. Methods and Results Using the Japanese Acute Coronary Syndrome Study (JACSS) database, this study included 4,805 consecutive patients who were admitted within 48 h of onset of AMI (3,526 [73.4%] patients with weekday onset [Monday through Friday] and 1,279 [26.6%] with weekend onset [Saturday and Sunday]). There were no significant differences between the 2 groups in patient background and clinical features. The proportions of patients who underwent emergency catheterization (88.4% vs 88.0%) and reperfusion therapy (81.5% vs 81.4%) were also similar. There were no differences between the 2 groups in the in-hospital, 30-day, and 1-year mortality rates. Even after various adjustments, there was no difference in the risk of death associated with weekend versus weekday onset of AMI. Conclusion There were no obvious differences in outcome for Japanese AMI patients in the weekday- or weekend-onset group, suggesting the quality of the Japanese healthcare system is similar for the entire week. (Circ J 2007; 71: 1841 - 1844)出版者照会後に全文公

Japanese Acute Coronary Syndrome Study (JACSS) Investigators.Long-term nitrate therapy after acute myocardial infarction does not improve or aggravate prognosis.

Background There is conflicting information about whether nitrate treatment aggravates long-term prognosis, so the present retrospective study was designed to determine the effects of long-term nitrate therapy on major adverse events after acute myocardial infarction (AMI) in the coronary interventional era. Methods and Results Using the Japanese Acute Coronary Syndrome Study database, 1,236 consecutive patients who were hospitalized within 48 h of onset of symptoms of AMI from January to December 2003 were evaluated. All-cause mortality, cardiac events and cardiovascular events were lower in patients treated with nitrates than in the untreated controls. However, these crude comparisons included several confounding factors on nitrate prescription. To minimize the effect of selection bias on outcomes, the technique of propensity score matching for clinical characteristics was used and distortion of effective nitrate treatment was excluded as much as possible. The results of propensity score matching showed that nitrate therapy had no impact on all-cause mortality, cardiac events and cardiovascular events at 30, 60 or 90 days, 6 months, 1 year, and 2 years follow-up. Conclusions Long-term nitrate therapy after AMI neither improves nor aggravates prognosis. Prospective randomized clinical trials are warranted to determine the effects of long-term nitrate therapy for secondary prevention of AMI. (Circ J 2007; 71: 301 - 307)出版者照会後に全文公