CHICAGO – An 18 millimeter capsule colonoscope, outfitted with an internal magnet and guided by an external magnet attached to a robotic arm, may represent the next generation of colonoscopy technology, according to findings presented at Digestive Disease Week (DDW) 2017 in Chicago.
"Colonoscopy saves lives through colon cancer screening, in that it can both identify and remove precancerous lesions and tumors," observed Keith Obstein, associate professor of medicine at Vanderbilt University Medical Center. "Unfortunately, a large segment of the population foregoes age-recommended colon cancer screening."
The reasons are well known to clinicians, principally fear of undergoing sedation, of submitting to the procedure itself or of experiencing discomfort or a rare adverse event.
Obstein and colleagues sought to bring down these barriers by designing a system that uses a very small package to attain the desired goal. Unlike existing capsule technology, which relies on gravity and peristalsis – the natural movement of the gastrointestinal (GI) tract – to travel through the body, the so-called "capsule robot" is manipulated by synchronizing the internal and external magnets.
The research team developed an algorithm that senses the position and orientation of the capsule relative to the magnet in the robotic arm, which is programmed to maneuver the capsule robot appropriately inside the colon.
"This is important because people are unable to make these calculations quickly and precisely enough on their own," Obstein explained.
During a presentation Monday at DDW, Obstein reported findings from a study in which the system was tested 30 times in vivo in the colon of a pig. The device autonomously completed retroflexion – bending backwards at the touch of a technician's button – in every attempt, giving the endoscopist a more complete reverse view of the colon wall. On average, the device completed retroflexion in 12 seconds, within the expectations of the research team.
Moreover, "since the external magnet pulls the capsule robot from the front or head of the capsule, instead of having a physician push the colonoscope from behind as in traditional endoscopy, we're able to avoid much of the physical pressure that is placed on the patient's colon, possibly reducing the need for sedation or pain medication," said Obstein, the study's corresponding author.
By operating a system that essentially mimics a front-wheel drive car, the capsule robot also overcomes the potential for looping of the rear-wheel drive colonoscope shaft – one of the biggest challenges involving the current procedure.
The study was supported by the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health.
The capsule robot offers both diagnostic and therapeutic potential, he added. The system, which includes a tether that is smaller in diameter than conventional endoscopes, can be maneuvered through the GI tract for examination purposes and potentially outfitted with biopsy forceps, snares, clips and/or injection needles to perform activities that current capsule devices cannot manage.
"The capsule robot is designed to perform the same therapeutic applications as current colonoscopy," Obstein told Medical Device Daily. "Our therapeutic channel is the same as current colonoscopes that are used every day. Whatever agent you can place down those you could also place through our capsule colonoscope."
Ultimately, the goal is to maneuver the capsule robot through the human GI tract in about the same amount of time needed to perform a standard colonoscopy.
The next step in developing the device is to pursue studies in humans, expected to begin at the end of next year. The plan is for Vanderbilt, which filed a patent on the technology, to complete feasibility tests before either placing the invention into a start up or out-licensing it.
"Our team continues to optimize the programming and control properties of the robotic arm to improve performance and maneuvering, Obstein said.
The researchers also are assessing what clinical skills, training and equipment will be needed to operate the system.
"This technology allows us to choose maneuvers that may be challenging to traditional colonoscopy and automate them so they can be performed with the push of a button," Obstein said. "There will certainly be a learning curve involved in the process as we move forward."
Although the team started in the colon space, "the same technology can be anticipated to be used potentially in the upper gastrointestinal tract or in avenues such as bronchoscopy or cystoscopy," he added, once the system is miniaturized.