Surgical Robotics
- Design and build new surgical robot platforms to provide enhanced performance of surgical operations, seeking to offer unparalleled capabilities in terms of dexterity, accuracy, and reliability.
- Modeling and control of these robot systems to execute complex procedures with minimal human intervention, reducing the risk of errors and enhancing the consistency of surgical outcomes.
MR-guided Robotic Catheterization
Recent progress in ablation therapy leverages magnetic resonance imaging (MRI) for higher contrast visual feedback, and additionally utilizes a guiding sheath with an actively deflectable tip to improve the dexterity of the catheter inside the heart. We presents the design and validation of an MR-conditional robotic module for automated actuation of both the ablation catheter and the sheath. The robotic module features a compact design for improved accessibility inside the MR scanner bore and is driven by piezoelectric motors to ensure MR-conditionality. Path following experiments were conducted to validate the actuation module and control scheme, achieving < 2 mm average tip position error.
MR-Conditional Concentric Tube Robot for Intracerebral Hemorrhage (ICH)
About 1 in 50 people suffer from Intracerebral Hemorrhage (ICH) in their lifetime. ICH occurs when blood leaked from a ruptured vessel accumulates and forms a blood clot (hematoma) in the cerebrum. The objective of this research is to create and validate a minimally-invasive Magnetic Resonance (MR) – compatible concentric tube robot for ICH evacuation. We will develop dexterous robot hardware, enable accurate real-time image guidance, and perform system-level evaluations in live animals.
Liver Ablation Robot
Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related death in the world with a five-year survival rate as low as 4%. Laser ablation has been shown to be an effective method of treating HCC. However, with current clinical practices it is rather difficult to place the ablation needle within the target volume due to the respiratory-induced dynamic movement of the liver. We propose a novel robotic platform that will enable accurate needle deployment under intraoperative CT image guidance. The robot consists of upper and lower XY-carriages that allow for 4-DOF in aiming the needle and this is coupled with a 3D printed flexible fluidic actuator that creates a step-like grasp-insert-release method of actuation.
Surgical Autonomy based on dVRK system
Surgical robots, such as Intuitive Surgical’s da Vinci Surgical System, have brought about more efficient surgeries by improving the dexterity and reducing fatigue of the surgeon through teleoperational control. Research in surgical task automation has been growing to improve patient throughput, reduce variations in the quality-of-care during surgeries, and possibly enable automated surgeries in the future. We use Reinforcement Learning (RL) based methods to push forward the task-level autonomy including soft tissue manipulation.
Soft and Continuum Robot
- Control and modeling of pneumatic soft robot arm
- Modeling and planning of tendon-driven continuum robots/concentric tube robots
- Bio-inspired soft robot locomotion and manipulation
Pneumatic soft robot arm
Soft robots can undergo large elastic deformations and adapt to complex shapes. However, they lack the structural strength to withstand external loads due to the intrinsic compliance of fabrication materials. We present a novel stiffness modulation approach to a tendon-actuated soft bending robot that controls the robot stiffness on-demand without permanently affecting the intrinsic compliance of the elastomeric body.
We also aim to investigate the control method that not only takes into account the known dominant dynamics of the robot but also maintain the superior trajectory tracking in the presence of parametric uncertainty. We also proposed a stable closed-loop controller using a gain-scheduled algorithm in the redundancy resolution algorithm that enables simultaneous position and orientation control while avoiding joint limits.
Continuum and Concentric Tube robot
We focus on the contact and friction modeling of continuum robots. We proposed a formulation through linear complementarity problems that accommodated various effects caused by the contact, including static friction and hysteresis behavior. The future work is to generalize the contact model for concentric tube robots and tendon-driven robots.
Soft Robot Harvesting
Berries in the US have reached a market value of $1.4 billion in 2015. Fresh-market berries typically are manually harvested either for pick-your-own operations or retail markets. The cost of manual picking represents a significant percentage of the total cost of berry production. With the projected trend of labor shortage, there is an urgent need to create alternative methods for cheap and efficient berry harvesting. We use a tendon actuated soft robotic gripper on a multi-degree of freedom robot arm to provide an automated harvesting method for blackberries. The berries will be harvested using force control for the gripper to provide the optimal contact force, image processing for berry location, and an off-road chassis for navigating the assembly along the floricane rows.