788 resultados para Inertial sensor
Resumo:
Since the appearance of downsized and simplified TCP/IP stacks, single nodes from Wireless Sensor Networks (WSNs) have become directly accessible from the Internet with commonly used networking tools and applications (e.g., Telnet or SMTP). However, TCP has been shown to perform poorly in wireless networks, especially across multiple wireless hops. This paper examines TCP performance optimizations based on distributed caching and local retransmission strategies of intermediate nodes in a TCP connection, and proposes extended techniques to these strategies. The paper studies the impact of different radio duty-cycling MAC protocols on the end-to-end TCP performance when using the proposed TCP optimization strategies in an extensive experimental evaluation on a real-world sensor network testbed.
Resumo:
A viscometric affinity sensor has been developed to measure the interstitial glucose concentration continuously. In a pilot clinical study its performance was assessed under conditions close to everyday life. Additionally, different insertion sites were tested for their suitability to apply subcutaneous glucose sensors.
Resumo:
The purpose of this single-center study was to report our initial experience with an implantable remote pressure sensor for aneurysm sac pressure measurement in patients post-endovascular aneurysm repair (EVAR) including short-term follow-up. A pressure sensor (EndoSure, Atlanta, GA) was implanted in 12 patients treated with different commercially available aortic endografts for EVAR. Pressure was read pre- and post-EVAR in the operating room. One-month follow-up (30 days +/- 6 days) was performed including sac pressure readings and IV contrast CT scans. Variables were compared using the paired Student's t test. An intraprocedure type-I endoleak and a type-III endoleak were successfully treated resulting in decreasing sac pressures. In all patients, post-EVAR systolic sac pressure decreased by an average of 33% (P = 0.005) compared to pre-EVAR measurements. One-month follow-up demonstrated a 47% decrease in systolic sac pressure (P = 0.05). On follow-up CT scans, the average maximum aneurysm diameter pre-EVAR was 6.3 +/- 1.6 cm and post-EVAR 6.0 +/- 1.7 cm (P=0.05). The diameter of the aneurysm sac was larger only in one patient with a type-III endoleak. Remote sac pressure measurement may provide important information in addition to imaging and may help to reduce the number of follow-up CT scans.