Macro-Micro Multi-Arm Robot for Single-Port Access Surgery

Minimally invasive surgery is now a well established field in surgery but continuous efforts are made to reduce invasiveness even further. This paper proposes a novel concept of small-diameter multi-arm robot for Single-Port Access Surgery. The concept introduces a combination of backbone and actuation principles in a macro-micro fashion to achieve an excellent decoupling of the triangulation platform (macro) and of the end-effectors (micro). Concentric tube robots are used for the triangulation platform, while compliant fluidic-actuated bending segments are used as end-effectors. The fluidic actuation is advantageous as it minimally interferes with the triangulation platform. The triangulation platform on the other hand provides a stable base for the end-effectors such that large distal actuation bandwidth can be achieved. A specific embodiment for Spina Bifida repair is developed and proposed. The surgical and technical requirements as well as the mechanical design are presented in details. A first prototype is built and characterization experiments are conducted to evaluate its performance.