Journalism Forum

Curtis Wilkie, moderato

3D ActionSLAM: wearable person tracking in multi-floor environments

We present 3D ActionSLAM, a stand-alone wearable system that can track people in previously unknown multi-floor environments with sub-room accuracy. ActionSLAM stands for action-based simultaneous localization and mapping: It fuses dead reckoning data from a foot-mounted inertial measurement unit with the recognition of location-related actions to build and update a local landmark map. Simultaneously, this map compensates for position drift errors that accumulate in open-loop tracking by means of a particle filter. To evaluate the system performance, we analyzed 23 tracks with a total walked distance of 6,489 m in buildings with up to three floors. The algorithm robustly (93 % of runs converged) mapped the areas with a mean landmark positioning error of 0.59 m. As ActionSLAM is fully stand-alone and not dependent on external infrastructure, it is well suited for patient tracking in remote health care applications. The algorithm is computationally light-weight and runs in realtime on a Samsung Galaxy S4, enabling immediate location-aware feedback. Finally, we propose visualization techniques to facilitate the interpretation of tracking data acquired with 3D ActionSLAM

Tratamento das infecções pós artroplastia total de joelho: resultados com 2 anos de seguimento Treatment of infections following total knee arthroplasty: 2-year follow-up outcomes

INTRODUÇÃO: A (ATJ) Artroplastia Total do Joelho é cirurgia de grande porte e sujeita a complicações pós operatórias, sendo a infecção uma das piores e mais temidas. No Instituto de Ortopedia e Traumatologia da Faculdade de Medicina da Universidade de São Paulo, a incidência de infecção nas ATJ tem se mantido ao redor de 3% nos últimos 3 anos. O objetivo desse estudo é analisar e padronizar o protocolo de tratamento das infecções pós artroplastia total de joelho. MATERIAIS AND MÉTODOS: Dentre os anos de 2003 e 2004, vinte e nove pacientes com o diagnóstico de infecção pós artroplastia total de joelho primária foram submetidos a o protocolo de tratamento, sendo o período médio de seguimento 20 meses. Dentre os casos nove eram de infecção superficial, três de infecção profunda aguda, e dezoito de infecção profunda crônica. A classificação é baseada em critérios clínicos locais e no tempo de apresentação dos sintomas. RESULTADOS: Foram tratados oito pacientes com quadro de infecção superficial e três pacientes com infecção profunda aguda, com índice de cura de 100%, sem nenhuma recidiva. Foram tratados dezoito casos de infecção profunda crônica, com cura sem recidiva no período de seguimento em 14 pacientes. CONCLUSÃO: Consideramos nossos resultados e nosso protocolo de tratamento adequados e compatíveis com a literatura.<br>OBJECTIVE: The objective of this study is to analyze and standardize the treatment protocol of infections following total knee arthroplasty proposed by the Knee Group and the Infectology Group of IOT-HC-FMUSP. MATERIALS AND METHODS: Between 2003 and 2004, twenty-nine patients (19 women and 10 men, mean age: 67 years) diagnosed with infection after total primary knee arthroplasty were hospitalized at IOT-HC FMUSP (Institute of Orthopedics and Traumatology of Hospital das Clínicas, Medical College, University of Sao Paulo, SP, Brazil) and subjected to a treatment protocol. The mean follow-up time was 20 months. Nine cases had superficial infections, three had acute deep infections and eighteen had chronic deep infections. The classification is based on local clinical criteria and on the time of symptoms onset. RESULTS: Eight patients with superficial infection and three patients with acute deep infection were treated, showing good outcomes and no recurrence cases. Eighteen patients with chronic deep infection were treated and cured, 14 of whom with no recurrence during the follow-up period. CONCLUSION: We regard our outcomes and treatment protocol as appropriate and consistent with literature