Search

The coverage of traditional wireless sensor networks (WSNs) is limited by node energy and data redundancy, forcing WSNs to be interrupted abnormally. To this end, a novel optimization cooperative coverage algorithm with controllable threshold-parameters (OCC-CT) is proposed. The algorithm first determines the location information of the focus target nodes (FTNs), and uses the genetic algorithm (GA) to give the node path planning. Second, the controllable threshold parameters and mutation parameters are used to control event domain nodes. Clustering is optimized to make the clustering of the nodes more uniform, so as to reduce the energy consumption of the nodes and improve the search ability of the global target nodes. Third, the adaptation function is used to cover the continuity of the covered target locations and the monitoring range of the nodes. Optimization is performed to achieve the goals of increasing network coverage and extending the network lifetime. Finally, simulation results show that the OCC-CT algorithm, compared with other three algorithms in this paper, improves 0.11 and 0.16 on average in terms of network coverage, network lifetime, and 0.14 in terms of network energy overhead, thereby further verifying OCC-CT algorithm has strong stability and effectiveness.

Background/purposes: Magnetic navigation capsule endoscopy (MNCE) is considered to be an important means to realize the controllable and precise examination of capsule endoscopy (CE) in the unstructured gastrointestinal (GI) tract. For the current magnetic navigation system (MNS), due to the limitation of workspace, driving force, and control method of the CE, only clinical application in the stomach has been realized, whereas the examination of other parts of the GI tract is still in the experimental stage. More preclinical studies are needed to achieve the multisite examination of the GI tract. Methods: Based on the MNS (Supiee) developed in the laboratory, an X‐ray imaging system with magnetic shielding and a commercial CE are integrated to form the MNCE system. Then, in vivo GI tract experiments with a porcine model are performed to verify the clinical feasibility and safety of this system. Moreover, the effects of different control modes on the efficiency and effect of GI tract examination are studied. Results: Animal experiments demonstrate that with the MNCE system, it is convenient to achieve steering control in any direction and multiple reciprocating movements of CE in the GI tract. Benefiting from the flexibility of the three basic control modes, the achieved swing movement pattern of CE can effectively reduce the inspection time. It is demonstrated that the esophageal examination time can be reduced from 13.2 to 9.2 min with a maximum movement speed of 5 mm/s. Conclusion: In this paper, the feasibility, safety, and efficacy of the MNCE system for a one‐stop examination of the in vivo GI tract (esophagus, stomach, and colorectum) is first demonstrated. In addition, complex movement patterns of CE such as the swinging are proved to effectively improve examination efficiency and disease detection rates. This study is crucial for the clinical application of the MNCE system. [ABSTRACT FROM AUTHOR]