Design and Modelling of a Continuum Robot for Lung Sampling in Critical Care

We designed and manufactued a novel robotic bronchoscope for sampling of distal lung in mechanically-ventilated (MV) patients in critical care units. The mortality rate for MV patients with suspected pneumonia approaches 40%. Despite the high cost and attributable morbidity and mortality, sampling of the distal lung in MV patients suffering form lung diseases such as Covid-19 is not standardised, lacks reproducibility and requires expert operators. We propose a robotic bronchoscope that enables repeatable targeting of deeply nested pathologies inside the lung by addressing the main challenges in bronchoscopy of MV patient, namely, limited dexterity and relatively large size of the bronchoscope.

We developped a robotic bronchoscope with 7 Degrees of Freedom (DoF), an outer diameter of 4.5mm and inner working channel of 2,mm. The prototype is a push/pull actuated continuum robot capable of dexterous manipulation inside the lung and visualisation/sampling of the inner airways. A prototype of the robot is engineered and a mechanics-based model of the robotic bronchoscope is developed. Furthermore, we developped a novel numerical solver that improves the computational efficiency of the model and facilitate the deployment of the robot. Experiments were performed to verify the design and evaluate accuracy and computational cost of the model. Results demonstrated that the model can predict the shape of the robot in less than 0.011sec with a mean error of 1.76mm, enabling future deployment of robotic bronchoscope in MV patients.