Ultra-low-cost endoscopy for gastric cancer screening in rural China We propose to optimise, assess, and validate a novel portable platform designed to enable ultra-low-cost gastroesophageal cancer screening in remote settings, with a focus on rural and underdeveloped areas of China where this disease has a very high incidence and mortality.  Gastric cancer and oesophageal cancers have the highest global mortality rates among other forms of cancer. More than one third of new cases worldwide are concentrated in China. Only in 2015, more than one million people were diagnosed with this form of cancer in China and more than 870,000 have died because from the morbidity. Screening programmes have been shown to be extremely effective in reducing the mortality rate through early detection, but are expensive and difficult to implement in low-resource settings and rural areas. This is particularly relevant in China, where inequitable distribution of medical resources to urban areas (which contain 30% of the population but receive 70% of the medical resources), shortage of doctors in rural regions and greater distance to access them translate into a very large cancer survival divide. While incidence of gastric and oesophageal cancers is about double in rural areas when compared to urban centres, the mortality rate is about three times higher.   In order to reduce the larger proportion of patients diagnosed with cancer at a later stage in rural and underdeveloped areas in China, there is a pressing need to develop cost-efficient and sustainable technologies for endoscopic gastric and oesophageal cancer screening, which are the focus of this project.  Leveraging our pioneering work in the field of robotic capsule endoscopes, our team has developed a novel disposable, soft-tethered, swallowable, endoscopic capsule, with the aim of enabling cost effective gastroesophageal cancer screening in rural areas of low- and middle-income countries. Design innovations include water-jet actuation for mobility and visualization, a portable platform, and disposable components. After each procedure, the capsule outer shell and soft tether are discarded, while the endoscopic camera is reclaimed without reprocessing. The miniature tethered "pill camera" facilitates a comfortable unsedated cancer screening exam (target cost per procedure £2 and capital cost ca. £400 vs £80,000 for existing technology). The proposed platform is designed to fit in a single suitcase (airline carry-on size, 10kg).   Building upon our preliminary results, with this study we will test the hypothesis that the clinical diagnostic capabilities of our platform are comparable to standard gastroscopy, while the reliability, usability, and portability for rural settings are significantly improved. We will pursue this goal by (1) improving the range of motion of our endoscopic capsule, (2) optimizing the controllability and the stability of the capsule, (3) using the images acquired by the on-board camera to guide autonomous exploration and detection of lesions, (4) benchmarking the proposed technology with standard gastroscopy in multiple validation scenarios, spanning from laboratory testing to pre-clinical field trials in the rural setting of Hebei province, China, (5) assembling the required pre-clinical documentation to initiate clinical trials.   Our long-term goal is to develop a gastroesophageal cancer screening programme for rural China, which builds upon the technology and the experimental evidence originating from this proposal. We aim for our research to become a platform for establishing a feasible model for upper gastrointestinal cancer screening at an ultra-low cost that can be implemented in rural and poorly resourced areas. The approach can be extended to other low- and middle-income countries (nearly 70% of gastric and oesophageal cancer cases are concentrated in these areas) or equally to modern healthcare systems, where cost savings may be achieved through performing screening in day care units. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.