A highly accurate and scalable approach for addressing location uncertainty in asset tracking applications

Tracking systems that use RFID are increasingly being used for monitoring the movement of goods in supply chains. While these systems are effective, they still have to overcome significant challenges, such as missing reads, to improve their performance further. In this paper, we describe an optimised tracking algorithm to predict the locations of objects in the presence of missed reads using particle filters. To achieve high location accuracy we develop a model that characterises the motion of objects in a supply chain. The model is also adaptable to the changing nature of a business such as flow of goods, path taken by goods through the supply chain, and sales volumes. A scalable tracking algorithm is achieved by an object compression technique, which also leads to a significant improvement in accuracy. The results of a detailed simulation study shows that our object compression technique yields high location accuracy (above 98% at 0.95 read rate) with significant reductions in execution time and memory usage.Rengamathi Sankarkumar, Damith C. Ranasinghe, Thuraiappah Sathya

Watchdog: a novel, accurate and reliable method for addressing wandering-off using passive RFID tags

Hospitals and residential homes have a significant need for monitoring and recognising wandering-o (e.g. elopement) older people with cognitive impairments because of the serious consequences arising from wandering-o such as disappearances and serious injuries, for example, from collisions with vehicles in parking lots. Due to increasing ageing populations across the globe we can expect wandering-o to become a signi cant problem of scale a ecting all of us. Existing technologies used to address wandering-o are inadequate for providing close supervision as they use proximity based sensing that often lead to false alarms. In this study, for the rst time, we try to mitigate false alarms by identifying the traversal direction and traversal path used by people instrumented with a single low cost batteryless UHF RFID tag. Our approach uses a particle ltering (PF) based technique with Received Signal Strength Indicator (RSSI) maps obtained from scene analysis to continuously track a person wearing an RFID tag over their attire. Using real-time spatial and temporal data obtained from the PF based tracking algorithm, we develop two algorithms: i) tag traversing di rection (TD) algorithm to identify the tag bearer's moving direction (e.g. moving out of a room); and ii) tag traversing path detection algorithm (TPD) to estimate the traversal path used by the tag bearer. Our extensive experiments with 14 young adult volunteers show that: i) our TD algorithm can identify the moving direction of a person with 100% ac- curacy; ii) our TPD algorithm reduces the false alarms to < 9%, when detecting the traversing path used while eloping; and iii) our algorithms can be implemented in a di erent environment without further scene analysis.Rengamathi Sankarkumar, Damith Ransingh

A highly accurate method for managing missing reads in RFID enabled asset tracking

RFID based tracking systems have to overcome some significant challenges such as uncertainty to improve accuracy. We describe a highly accurate and scalable location tracking algorithm achieved by integrating an object compression technique with particle filtering.Rengamathi Sankarkumar, Damith Ranasinghe, and Thuraiappah Sathya

Surgical palliation for endomyocardial fibrosis: early results.

Endomyocardial fibrosis is a fatal disease of obscure aetiology which is notably prevalent in Uganda, Brazil, Kerala State in India, and certain other parts of the world. The main disability in the disease results from fibrotic obliteration of ventricular chambers and insufficiency of the mitral and tricuspid valves. The poor response to medical treatment and the bleak prognosis of the patients led to the introduction of endocardiectomy and replacement of the atrioventricular valves as a palliative procedure by Dubost and colleagues. The present report on the early results in 17 patients from Kerala State would support the continued use of this palliative procedure in endomyocardial fibrosis with severe disability

Surgical treatment of cardiac myxoma

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Surgical treatment of endomyocardial fibrosis

Forty-six patients with endomyocardial fibrosis underwent endocardiectomy and replacement of tricuspid, mitral, or both atrioventricular valves between April, 1981, and October, 1984, at the Sree Chitra Tirunal Institute, Kerala State, India, which has a high incidence of the disease. Six patients were in New York Heart Association Functional Class III and 40 patients in Class IV. The operative mortality within 30 days of the procedure and late mortality during the first two years postoperation were 21.7% and 13%, respectively. Age under 15 years was a significant correlate of operative mortality (p = .05). Non-fatal thromboembolic episodes occurred in 6 patients during the two years of postoperative observation. The life table estimate of survival inclusive of operative mortality at two years was 67%. Despite high operative mortality, endocardiectomy with atrioventricular valve replacement is advisable for functionally disabled patients with endomyocardial fibrosis whose prognosis otherwise is dismal

A correlative study of the functional class and hemodynamic status following intracardiac repair of tetralogy of Fallot

An attempt was made to correlate the NYHA Functional class with the hemodynamic status of 196 patients at an average of 21.2 months following the intracardiac repair of tetralogy of Fallot. 171 patients were in Functional class I (87.2%), 9 in class III (4.5%), 5 in class II (2.5%) and 11 in class IV (5.6%). Right and left heart catheterisation and cardiac angiography revealed the hemodynamic status of these patients to be excellent in 92 (46.4%), good in 37 (18.8%), satisfactory in 6 (3.0%) and unsatisfactory in 61 (31.6%). Whereas all patients in Functional class II, III and IV had unsatisfactory hemodynamic findings, patients in Functional Class I were hemodynamically heterogeneous and included excellent (53.8%), good (21.6%), satisfactory (3.5%) and unsatisfactory (21%) groups. The surgical technique did not seem to determine the functional status. While early reoperation is advisable for patients with functional disability, caution is necessary in considering reoperation for patients in Functional class I who have hemodynamic findings which are classified as unsatisfactory