Endoscope localization and gastrointestinal feature map construction based on monocular SLAM technology.

Aiming at the real intestinal environment, the commonly used feature extraction algorithms are compared and analyzed. The performances of SIFT, BRISK, ORB and FREAK are evaluated from three aspects: feature extraction time, correct matching rate and attitude estimation accuracy under rotation and scaling transformation. ORB binary feature operator has the advantages of fast feature extraction, high correct matching rate, and small estimation error. Based on the measured data of gastrointestinal endoscopy, the classical SLAM algorithm is modified in the aspects of pose adjustment and spatial point location calculation. A framework of gastrointestinal SLAM (Simultaneous Localization and Mapping) algorithm is constructed by introducing the local pose optimization algorithm based on visual correlation graph and triangular measurement algorithm with the minimum geometric distance. In order to tackle the problem of a large amount of accumulated data of spatial points and keyframes, a keyframe judgment strategy and spatial map point deletion strategy is designed to control the growth of keyframes and map points. The feature map of the human colon is reconstructed based on endoscopic video data, and the trajectory of the endoscope is estimated, which verifies the feasibility of the algorithm in the actual intestinal environment. In order to get the real value of map and trajectory conveniently, a simulated gastrointestinal system is built to validate the effectiveness of the algorithm, and the effects of the image frame rate and a number of keyframes on positioning accuracy and feature map accuracy are evaluated. Based on the simulated gastrointestinal system, the SLAM algorithm of the gastrointestinal tract is compared with the traditional visual mileage calculation method. When the endoscope moves in a straight line, keyframe storage of the proposed algorithm is only 1/8 of that of the latter, and the positioning accuracy is improved three times.

Monitoring and Control of Medical Air Disinfection Parameters of Nosocomial Infection System Based on Internet of Things.

To include the two key parameters of circulating air volume and instantaneous ultraviolet illuminance, as well as the minor influencing factors such as temperature, humidity, comings and goings of personnel and other parameters into the scope of conventional monitoring, and monitor and alarm each parameter, the key problem is to design the data transmission of sensors of existing products and debug the network management system, and solve every problem in the research process through the cycle of experiment-trial-experiment. The specific functions of a single instrument and system software can be achieved by solving the key links such as type selection of various sensors, circuit interface, guarantee measures for measurement accuracy of various parameters, research and development of networked air disinfection management system software, design of WiFi interface, cost control of single machine and system and so on. And ultraviolet luminance sensors can be used to monitor the ultraviolet intensity in the machine in real time, and monitor 7 parameters, including circulating air volume, ozone concentration, comings and goings of personnel, temperature, humidity and leaked ultraviolet intensity.

Efficacy and safety of image-guidance radiotherapy by helical tomotherapy in patients with lung cancer.

This study aimed to explore the efficacy and toxicity of image-guided stereotactic body radiotherapy (IGSBR) by helical tomotherapy in patients with lung cancer among Chinese Han population.A total of 21 patients with stage I lung cancer were included. They received a total of 60 Gy factions IGSBR. The outcomes included complete response (CR), partial response (PR), stable disease (SD), progress disease (PD), overall response rate (ORR), and overall survival (OS). In addition, toxicities were also recorded in this study.Three-year CR, PR, SD, PD, ORR, and OS were 47.6%, 38.1%, 9.5%, 4.8%, 85.7%, and 48.0 months, respectively. Additionally, mild toxicities were found in this study.This study demonstrated that IGSBR is efficacious for patients with stage I lung cancer with mild toxicities among Chinese Han population.