Introducing chaos behavior to kernel relevance vector machine (RVM) for four-class EEG classification.

This paper addresses a chaos kernel function for the relevance vector machine (RVM) in EEG signal classification, which is an important component of Brain-Computer Interface (BCI). The novel kernel function has evolved from a chaotic system, which is inspired by the fact that human brain signals depict some chaotic characteristics and behaviors. By introducing the chaotic dynamics to the kernel function, the RVM will be enabled for higher classification capacity. The proposed method is validated within the framework of one versus one common spatial pattern (OVO-CSP) classifier to classify motor imagination (MI) of four movements in a public accessible dataset. To illustrate the performance of the proposed kernel function, Gaussian and Polynomial kernel functions are considered for comparison. Experimental results show that the proposed kernel function achieved higher accuracy than Gaussian and Polynomial kernel functions, which shows that the chaotic behavior consideration is helpful in the EEG signal classification.

Metoclopramide or domperidone improves post-pyloric placement of spiral nasojejunal tubes in critically ill patients: a prospective, multicenter, open-label, randomized, controlled clinical trial.

INTRODUCTION: The use of prokinetic agents on post-pyloric placement of spiral nasojejunal tubes is controversial. The aim of the present study was to examine if metoclopramide or domperidone can increase the success rate of post-pyloric placement of spiral nasojejunal tubes. METHODS: A multicenter, open-label, randomized, controlled trial was conducted in seven hospitals in China between April 2012 and February 2014. Patients admitted to the intensive care unit and requiring enteral nutrition for more than three days were randomly assigned to the metoclopramide, domperidone or control groups (1:1:1 ratio). The primary outcome was defined as the success rate of post-pyloric placement of spiral nasojejunal tubes, assessed 24 hours after initial placement. Secondary outcomes included success rate of post-D1, post-D2, post-D3 and proximal jejunum placement and tube migration distance. Safety of the study drugs and the tubes during the entire study period were recorded. RESULTS: In total, 307 patients were allocated to the metoclopramide (n = 103), domperidone (n = 100) or control group (n = 104). The success rate of post-pyloric placement after 24 hours in the metoclopramide, domperidone and control groups was 55.0%, 51.5% and 27.3%, respectively (P = 0.0001). Logistic regression analysis identified the use of prokinetic agents, Acute Physiology and Chronic Health Evaluation (APACHE) II score <20, Sequential Organ Failure Assessment (SOFA) score <12 and without vasopressor as independent factors influencing the success rate of post-pyloric placement. No serious drug-related adverse reaction was observed. CONCLUSIONS: Prokinetic agents, such as metoclopramide or domperidone, are effective at improving the success rate of post-pyloric placement of spiral nasojejunal tubes in critically ill patients. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-TRC-12001956 . Registered 21 February 2012.