Virtual Wireless Sensor Networks: Adaptive Brain-Inspired Configuration for Internet of Things Applications.

Many researchers are devoting attention to the so-called "Internet of Things" (IoT), and wireless sensor networks (WSNs) are regarded as a critical technology for realizing the communication infrastructure of the future, including the IoT. Against this background, virtualization is a crucial technique for the integration of multiple WSNs. Designing virtualized WSNs for actual environments will require further detailed studies. Within the IoT environment, physical networks can undergo dynamic change, and so, many problems exist that could prevent applications from running without interruption when using the existing approaches. In this paper, we show an overall architecture that is suitable for constructing and running virtual wireless sensor network (VWSN) services within a VWSN topology. Our approach provides users with a reliable VWSN network by assigning redundant resources according to each user's demand and providing a recovery method to incorporate environmental changes. We tested this approach by simulation experiment, with the results showing that the VWSN network is reliable in many cases, although physical deployment of sensor nodes and the modular structure of the VWSN will be quite important to the stability of services within the VWSN topology.

[The Effectiveness of Epidural Droperidol for Prophylaxis of Postoperative Nausea and Vomiting: A Comparative Study of Droperidol and Adrenaline].

BACKGROUND: Intravenous droperidol has strong evidence for antiemetic efficacy in high risk patients for prevention of postoperative nausea and vomiting (PONV). However it is not clear whether continuous epidural administration of doroperidol prevent PONV. It has been reported that epidural adrenaline decreases PONV; therefore we prospectively compared the effectiveness of epidural droperidol and adrenaline for prophylaxis of PONV. METHODS: Eighty-six patients were scheduled for abdominal gynecological surgery under general-epidural anesthesia in the study. Patients were randomly assigned to droperidol group or adrenaline group. We investigated the incidences of PONV, the frequency of using the antiemetics. RESULTS: There was no statistical difference between the groups. The incidences of PONV were 27.9% (doropeidol group) and 58.1% (adrenaline group), respectively (P = 0.0046). The frequency of the anti-emetics use were 18.6% and 41.9%, respectively (P = 0.0189). There was one patient who needed cancellation of continuous epidural administration for vomiting in adrenaline group, but no patient in doropeidol group. CONCLUSIONS: The results suggest that epidural droperidol effectively decreases PONV in high risk patients. However epidural adrenaline might be ineffective.

Evaluation of noninvasive positive pressure ventilation after extubation from moderate positive end-expiratory pressure level in patients undergoing cardiovascular surgery: a prospective observational study.

BACKGROUND: It remains to be clarified if the application of noninvasive positive pressure ventilation (NPPV) is effective after extubation in patients with hypoxemic respiratory failure who require the sufficient level of positive end-expiratory pressure (PEEP). This study was aimed at examining the effect and the safety of NPPV application following extubation in patients requiring moderate PEEP level for sufficient oxygenation after cardiovascular surgery. METHODS: With institutional ethic committee approval, the patients ventilated invasively for over 48 h after cardiovascular surgery were enrolled in this study. The patients who failed the first spontaneous breathing trial (SBT) at 5 cmH2O of PEEP, but passed the second SBT at 8 cmH2O of PEEP, received NPPV immediately after extubation following our weaning protocol. Respiratory parameters (partial pressure of arterial oxygen tension to inspiratory oxygen fraction ratio: P/F ratio, respiratory ratio, and partial pressure of arterial carbon dioxide: PaCO2) 2 h after extubation were evaluated with those just before extubation as the primary outcome. The rate of re-intubation, the frequency of respiratory failure and intolerance of NPPV, the duration of NPPV, and the length of intensive care unit (ICU) stay were also recorded. RESULTS: While 51 postcardiovascular surgery patients were screened, 6 patients who met the criteria received NPPV after extubation. P/F ratio was increased significantly after extubation compared with that before extubation (325 ± 85 versus 245 ± 55 mmHg, p < 0.05). The other respiratory parameters did not change significantly. Re-intubation, respiratory failure, and intolerance of NPPV never occurred. The duration of NPPV and the length of ICU stay were 2.7 ± 0.7 (SD) and 7.5 (6 to 10) (interquartile range) days, respectively. CONCLUSIONS: While further investigation should be warranted, NPPV could be applied effectively and safely after extubation in patients requiring the moderate PEEP level after cardiovascular surgery.