Soft self propelling endoscope
Dr Rob Glen
Current colon examination techniques are uncomfortable for the patient and require sedation or analgesia, and in the case of the small intestine, all anaesthesia. Fear of the procedure reduces patients taking up recommendations for examination and compromises the likelihood of early identification of major diseases such as colorectal cancer. Current endoscopes are reusable, requiring a major investment in cleaning and decontamination and they carry a risk of residual cross infection. The wholly manual advancement of current devices in the intestine, particularly if the scope is pushed against bends in the intestine and has difficulty advancing, leads to patient discomfort and distress, and a risk of damage to the intestinal wall.
The device uses a novel soft computer-assisted crawling mechanism under clinician guidance. It is of low cost construction to be single use and does not require decontamination. It can be guided through the colon safely without external pushing against the colon wall and is capable of efficiently completing a safe and painless procedure. The colonoscope could transform how colorectal cancer screening and biopsy is performed and increase the uptake of colonoscopy, ensuring patients receive effective diagnosis and treatment earlier than at present. This is a large and growing market with more than one million colonoscopies carried out each year in the UK alone.
The self-propelling endoscope (SPE) can:
Self-propel around the bends in the colon and small intestine, bending to more than 270° compared to a maximum of 210° for a standard endoscope
Control the force exerted on the intestinal wall
Conform to the shape of the colon and small intestine reducing patient discomfort
Provide all existing imaging, irrigation and surgical tool channels.
The current prototype has been designed for use in the colon but the crawling mechanism is equally suitable for the small intestine. The device comprises one or two anchoring segments, and one propelling segment, each manufactured from elastic material composite. As with traditional endoscopes /enteroscopes there is a camera at the distal end of the device. The anchoring segments can bend in any direction and also both compress and elongate.
The propelling segment can be elongated more than 200% of original length to provide effective self-propulsion. The shape of each segment can be controlled. The actuation is controlled by the clinician via an intuitive hand-held manipulator.
In an automated version, it is envisaged that the scope will use an automated computer guidance system so that the scope is able to navigate the colon without the need for significant human intervention. Each examination could be handled by a nurse with a single gastroenterologist in charge of multiple simultaneous examinations.
Prototype endoscopes and a control system have been developed in collaboration with clinicians at a leading London Hospital. These are being evaluated ex-vivo for control and internal speed as measured by time to reach the cecum. This has verified that the device is equivalent in transit time but avoids the stretching and high contact force found with conventional rigid endoscopes. Safety and operational risk reduction engineering is being undertaken in preparation for a preclinical trial. The technology is currently at TRL4 (technology validated in lab).
The device will have an initial application in colonoscopy. The endoscope is scalable in physical size and capable of adaptation for use in smaller lumens such as for enteroscopy, and with further development: bronchoscopy, and upper GI endoscopy. The inclusion of two working channels, in the device is a major requirement of gastroenterologists not achieved in most of the endoscopes commercially available because the second channel makes it too stiff to manipulate. Access to multiple functions during the examination such as a needle, knife, snare, gripper/forceps and washing can thus be provided, allowing the device to be kept in place, simplifying and shortening the procedure.
Due to the enhanced flexibility of the endoscope, the device will naturally adjust its shape when it encounters a sharp bend, allowing it to traverse the bend. Because the middle segment can actively extend but remains flexible, it will bend as it is extending when it is in a sharp bend. In such a case, a traditional endoscope is unable to advance past the bend, while this device is able to navigate it effectively. A US study found that half of the eligible population referred for colonoscopy failed to complete the procedure, due lack of belief in the risk of cancer, fear of pain, fears around modesty and the bowel preparation. It is expected that in the colon the device will allow examination to occur in more patients with significantly reduced levels of pain and increases in uptake.
It is anticipated that switching to this system in both the colon and small intestine will result in cost savings for health services. Savings will be made in each procedure as there will be no cleaning and sterilisation of the device between patients. This is currently a significant cost with a recent study in the US finding that reprocessing one flexible endoscope requires approximately 76 minutes of hands-on staff time and the cost of reprocessing ranging from $114 to $2801. There will also be savings in staff time for carrying out the procedure as only one nurse will be required to support a colonoscopy with the SPE compared to two with the standard scope. Further savings will accrue from the reduction in sedation and analgesia.
The project is currently funded for the construction of a prototypes and delivery of a preclinical trial. The Project seeks licensees, partners and/or investors to fund and support the clinical development of the device following this milestone.
WO 2018/154326, A Robotic Device.
Fig 1. Dual working channel prototype device showing flexibility feature.