Soft Hybrid Actuated Hierarchical Bronchoscope Robot for Deep Lung Examination

Lungdiseases are becoming one of the world's most serious health issues. Soft bronchoscope robots can achieve safe and controllable lung navigation, which will be crucial for the future early examination of lung diseases. However, due to the single driving method, the large size, and insufficient flexibility of conventional bronchoscopes, it is challenging to examine diseases in deep lungs. In this study, a small-scale soft hybrid actuated hierarchical bronchoscope robot is proposed, which is composed of an outer tendon-actuated catheter with an outer diameter (OD) of 4.5 mm and an inner magnetic working channel with an OD of 2.4 mm. Besides, model analysis and a control strategy are proposed to characterize and control the hierarchical catheter. By experimental results, the proposed robot shows high trajectory tracking accuracy, with a mean error of 0.187 mm of the hierarchical catheter. The steering and intubation experiments show the increased flexibility of the hierarchical catheter to enter end bronchioles for lung examination. This work explores the application of hierarchical design and hybrid actuation in the examination of lung diseases and is expected to promote the development of the medical field.