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

Abstract

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 instrument for Single-Port Access Surgery. The concept introduces a novel 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.

Magnetically Assisted Robotic Fetal Surgery for the Treatment of Spina Bifida

“…Minimally invasive approaches for the treatment of MMC have recently been considered beneficial for in utero operation, drastically reducing the risks associated with the laparotomy and open hysterotomy [16]- [19]. While open hysterotomy and laparotmy can offer a higher degree of dexterity, we believe that the risks associated with these invasive procedures outweigh their benefits for the patient.…”

Design and modelling of an anisotropic continuum robot end-effector for single-port access surgery suturing

“…This maximises the output gripping force for a given input pulling force, as will be shown in (11). Similarly, to the micro bending segment presented in Vandebroek et al, 12 the gripper is actuated via a miniature McKibben muscle and its return movement is provided by a compression spring visible in Figure 2(a). In order to establish a strong gripping force even when the jaws are closed, link © is not straight but bends at an angle γ at the level of the third joint (Figure 3).…”

“…As diameters go down instruments become more flexible. In Vandebroek et al, 12 8 requirements for the OSB repair multi-arm robot were established. They were all met except one: the earlier prototype of the bending segment failed to sustain a transversal force of 1 N. This section describes a structural optimisation conducted to maximise the force that can be delivered at the end of a flexible instrument shaft without buckling or reaching superelasticity.…”

“…Given the fragile nature and small dimensions of a foetus, this task is highly challenging. The authors have been developing a novel multi-arm continuum robotic platform to treat OSB in Vandebroek et al 12 (Figure 1). It consists of an 11 mm outer-diameter (OD) SPA-robot featuring a macro-micro approach.…”

“…14 The diameters of these instruments are too large to fit the 3 . 5 mm OD required for SPA-OSB. 12 Two small wristed designs of respectively 3 . 5 mm and 3 mm OD are presented in Fujii et al 15 and Ohdaira et al 16 but they are only suitable for straight, rigid instruments.…”