Respiratory Compensated Robot for Liver Cancer Treatment: Design, Fabrication, and Benchtop Characterization

Abstract

Hepatocellularcarcinoma (HCC) is one of the leading causes of cancer-related deaths in the world. Radiofrequency ablation (RFA) is an effective method for treating tumors less than 5 cm. However, manually placing the RFA needle at the site of the tumor is challenging due to the complicated respiratory induced motion of the liver. This article presents the design, fabrication, and benchtop characterization of a patient mounted, respiratory compensated robotic needle insertion platform to perform percutaneous needle interventions. The robotic platform consists of a four degrees of freedom (DoF) dual-stage Cartesian platform used to control the pose of a one-DoF needle insertion module. The active needle insertion module consists of a 3-D printed flexible fluidic actuator capable of providing a steplike, grasp&#x2013;insert&#x2013;release actuation that mimics the manual insertion procedure. Force characterization of the needle insertion module indicates that the device is capable of producing 22.6 &#x00B1; 0.40 N before the needle slips between the grippers. Static phantom targeting experiments indicate a positional error of 1.14 &#x00B1; 0.30 mm and orientational error of 0.99&#x00B0; &#x00B1; 0.36&#x00B0;. Static <i>ex vivo</i> porcine liver targeting experiments indicate a positional error of 1.22 &#x00B1; 0.31 mm and orientational error of 1.16&#x00B0; &#x00B1; 0.44&#x00B0;. Dynamic targeting experiments with the proposed active motion compensation in dynamic phantom and <i>ex vivo</i> porcine liver show 66.3&#x0025; and 69.6&#x0025; positional accuracy improvement, respectively. Future work will continue to develop this platform with the long-term goal of applying the system to RFA for HCC.