Swallowable capsule with air channel for improved image-guided cancer detection in the esophagus

A new type of endoscope has been developed and tested in the human esophagus, a tethered-capsule endoscope (TCE) that requires no sedation for oral ingestion and esophageal inspection. The TCE uses scanned red, green, and blue laser light to image the upper digestive tract using a swallowable capsule of 6.4mm in diameter and 18mm in length on a 1.4mm diameter tether. The TCE has been modified for image-guided interventions in the lower esophagus, specifically for more effective detection and measurement of the extent of Barrett's esophagus, a precursor to esophageal cancer. Three modifications have been tested in vivo: (1) weighting the capsule so it is negatively buoyant in water, (2) increasing the frame rate of 500-line images to 30 Hz (video rate), and (3) adding a 1.0mm inner diameter working channel alongside the tether for distending the lower esophagus with air pressure during endoscopy. All three modifications proved effective for more clearly visualizing the lower esophagus in the first few human subjects. The air channel was especially useful because it did not change tolerability in the first subject for unsedated endoscopy and the air easily removed bubbles obscuring tissue from the field of view. The air provided a non-invasive intervention by stimulating the mechanosensor of the lower esophageal sphincter at the precise time that the TCE was positioned for most informative imaging. All three TCE modifications proved successful for improved visualization of esophageal pathology, such as suspected Barrett's esophagus, without the use of sedation.