Development of robotic imaging for microrobotic surgery
Project reference: SIE_22 This project has already been allocated and is no longer available for applications
First supervisor: Christos Bergeles
Second supervisor: Sebastien Ourselin
Start date: October 2020
Project summary: We aim to develop “MAMMOBOT” for early detection of breast cancer. MAMMOBOT is a flexible steerable growing endoscopic robotic system that can safely navigate the mammary ducts, and harness imaging and sensing technologies to provide local cellular-level diagnosis. Beyond early detection, MAMMOBOT provides a novel platform for minimally invasive local therapies delivered directly to mammary duct disease. The end-goal is an integrated platform that incorporates proof-of-concept for the millimeter-scale growing robot, developed through this PhD project, and navigation algorithm, and deployed sensor array developed through our collaborators at Imperial, Leeds, Bath, and University of Edinburgh.
There are over 55,000 breast cancers diagnosed per year in the UK alone. “Early breast cancer” refers to detection of small invasive and non-invasive cancers such as ductal carcinoma in situ (DCIS). However, many “early” breast cancers require surgery, radiotherapy and chemotherapy at UK prevalent costs that reach close to £430m. Arguably, there needs to be a reframing of what constitutes “early” breast cancer with platforms for detecting and excluding the disease and its precursors at far earlier time-points, so as to increase survival rates and reduce morbidity associated with current treatments. Given its ductal origins, a robotic framework that enables navigation, interrogation and intervention within the ductal network via access through the natural orifice of the nipple could completely disrupt the way in which breast cancer is diagnosed and treated.
Ductoscopic Technology Development
Mammary ductoscopy has shown tremendous promise as a vehicle for early diagnosis excluding breast cancer in patients with cancer precursors. Despite its potential, the technique has not been widely adopted in the UK, simply because current platforms are unwieldy, inflexible, and cannot safely, swiftly and smoothly navigate down the complex treelike structure of the mammary ducts. Robotics can overcome the inherent challenges faced by the human operator, and more precisely manipulate and articulate endoscopes at scale. This project pertains to developing the robotic platform for safe ductoscopy, while additional elements will be contributed by our collaborators at Imperial College London, and Universities of Bath, Leeds and Edinburgh.
Proposed Robotic Technology
Growing robots can “unfold” inside the mammary ducts via addition of material at their tip, and therefore minimise disruption of the anatomy. Robotic catheters, on the other hand, rely on insertion through pushing, implying harmful frictional forces between the catheter and duct. This safety characteristic of growing robots matches the project’s needs for moving within the breast ducts (1-8mm) with minimal collateral damage. The different aspects of the project are as follows:
Front End: We will create a 3-chamber flexible growing robot of 1-2mm diameter. Each of the 3 chambers will be independently addressable for steerability and growing. Hydraulic pressure within each chamber would cause the unfolding of new material from the front of the respective chamber, and therefore elongation along a desired trajectory.
Back End: We will develop appropriate actuation for the flexible growing robot and manipulation of chip-on-tip cameras. For robot chamber control, independent hydraulic circuits to control the pressure of microfluidic pumps. A force-controlled winch will ensure that the encapsulated camera sensor will be in the appropriate location with respect to the growing body of the robot.
Robot Control: We will develop hydraulic controllers optimised for micro flows, using reduced order models of growing robots based on soft robotics theory. We will use the TMTDyn package, codeveloped by the Robotics and Vision in Medicine (RViM) Lab.
Risk Mitigation: To ensure the project’s goal for robotic mammary duct exploration is met, we will in parallel use existing flexible (1mm diameter) robots based on concentric tube technology. Their surfaces will be micromachined to ensure robot stiffness reduction and maximum compliance with delicate tissue.