Single-port surgical robots have gained popularity due to less patient trauma and quicker post-surgery recovery. However, due to limited access provided by a single incision, the miniaturization and maneuverability of these robots still needs to be improved. In this research, we propose the design of a single-port, multi-arm robotically steerable endoscope containing one steerable major cannula and two steerable minor cannulas. By integrating the proposed nine degrees-of-freedom (DoFs) robotically steerable endoscope with an industrial robotic arm and a joystick controller, this robotic system can potentially achieve intuitive, and remote multi-arm manipulation capability. We present the design of the robotically steerable endoscope consisting of tendon-driven joints controlled by a compact actuation system and derive the kinematic and static models.

(A) Peripheral vascular intervention remains a challenging procedure mainly due to the tortuosity of the vessels needing to be traversed by guidewires and catheters. In addition, handling long guidewires while navigating tortuous vasculature requires extensive time and skill from the surgeon. In this work, a compact guidewire advancement mechanism is proposed that is able to dispense guidewires up to 150 cm in length. The mechanism is adapted to actuate a prototype of the modified COaxially Aligned STeerable (COAST) guidewire robot to perform follow-the-leader (FTL) motion. The design of this mechanism consists of a spool, with actuation components nested inside to vary the bending length, actuate the tendon, and deflect the tip of the guidewire. The spool is mounted onto a lead screw that dispenses the guidewire with a tolerance of ±2mm. A modified bending joint kinematics and statics model is developed to characterize and validate the relationship between the tendon stroke and the desired curvature. The model is further used in a control system to navigate the distal tip through an ex vivo porcine aorta.

(B) Many intravascular procedures are prefaced by the placement of a slender wire called a guidewire. Steering these guidewires is met with challenges in controlling the distal end along with the possibility of damaging vessel walls, or even perforation, which can be fatal. To this end, utilizing robotic guidewires can improve steerability and enable force feedback through intrinsic force sensing. Enabling force sensing contains challenges such as discrete sensor placements in continuous structures and non-unique force distributions for a given deflection. In this work, we utilize image feedback and a Cosserat rod model to estimate and localize forces along the body of a micro-scale tendon-driven guidewire robot. This includes additional modeling of friction and hysteresis that is often neglected for force sensing. The model is tested on a variety of notched nitinol tubes under gravity loading with the shape predictions having an average RMSE of 0.46 mm. Utilization of friction and hysteresis models provide shape predictions with an RMSE of 1.22 mm compared to an uncompensated model (RMSE = 1.62 mm) for approximately 180° bends. The methods presented are able to localize forces with an average error of 4.79 mm (5.15% of the length) while force magnitudes are estimated with an average error of 13.03 mN.

Mitral regurgitation (MR) is the most common type of valvular heart disease, affecting over 2% of the world population, and the gold-standard treatment is surgical mitral valve repair/replacement. Compared to open-heart surgeries, minimally invasive surgeries (MIS) using transcatheter approaches have become popular because of their notable benefits such as less postoperative pain, shorter hospital stay, and faster recovery time. However, commercially available catheters are manually actuated, causing over-exposure of clinical staff to radiation and increased risk of human error during medical interventions. To tackle this problem, in this project, we propose a telerobotic transcatheter delivery system, which consists of a robotic catheter (5.7 mm OD), a reinforced guide tube (1.11 m length), and an actuation system. We present the robotic system design, fabrication of key components, and static model of reinforced quadlumen tube. The robot interface design enables the user to intuitively control the robot. We demonstrate the effectiveness of the telerobotic transcatheter delivery system and reinforced quadlumen tube in a realistic human cardiovascular phantom for preclinical evaluation. Additionally, we validated the proposed system using an in vivo pig.

Stroke is a leading cause serious long-term disability in adults. Every year, more than 795,000 people in the United States have a stroke. In individuals who have suffered a stroke, approximately 80% survive the acute phase. Among them, while most regain their ability to walk, 30% to 66% of survivors experience lasting impairment in the use of their affected arm. Moreover, a significant portion of the stroke population experiences impaired hand grasp function, with studies showing that over 80% of stroke patients have difficulty with finger grasping, impacting their ability to perform daily activities due to upper limb paresis. Due to the complexity of arm and hand movements, impairments in the upper extremities can significantly impact activity participation and reduce the quality of life in stroke survivors. However, existing solutions primarily address these challenges through caregivers who assist disabled individuals 24 hours a day due to their inability to perform activities of daily living. Aside from the social issues surrounding the shortage of caregivers, relying on a caregiver cannot fully satisfy an individual's desire for independence. Many disabled individuals wish to regain the ability to complete basic tasks such as eating, drinking, and opening doors by themselves. To address this issue, in this project, we aim to develop and validate an innovative portable soft robotic glove platform for home-based daily neurorehabilitation, surpassing the capabilities of existing tools. Furthermore, this platform can be widely used for spinal cord injuries, cerebral palsy, and other hand function disabilities.

Serial and Cable-Driven Parallel Robots (CDPRs) are two types of robots that are widely used in industrial applications. Usually, the former offers high position accuracy at the cost of high motion inertia and small workspace envelope. The latter has a large workspace, low motion inertia, and high motion accelerations, but low accuracy. In this research, redundant Hybrid Cable-Driven Robots (HCDRs) are proposed to harness the strengths and benefits of serial and CDPRs. Although the study has been directed at warehousing applications, the developed techniques are general and can be applied to other applications (e.g., applied in biomimetics/rehabilitation/medicine/industry).

The main goal of this research is to develop integrated control systems to reduce vibrations and improve the position accuracy of HCDRs. For the proposed HCDRs, the research includes system modeling, redundancy resolution, optimization problem formulation, integrated control system development, and simulation and experimental validation.

• Ronghuai Qi, Amir Khajepour, and William W. Melek, “Redundancy Resolution and Disturbance Rejection via Torque Optimization in Hybrid Cable-Driven Robots (HCDRs),” IEEE Transactions on Systems, Man and Cybernetics: Systems, vol. 52, no. 7, pp. 4069-4079, July 2022, doi: 10.1109/TSMC.2021.3091653.

• Ronghuai Qi, Amir Khajepour, and William W. Melek, “Modeling, Tracking, Vibration and Balance Control of an Underactuated Mobile Manipulator (UMM),” Control Engineering Practice, vol. 93, pp. 104159, 2019.  PDF  Video

• Ronghuai Qi, Mitchell Rushton, Amir Khajepour, and William W. Melek, “Decoupled Modeling and Model Predictive Control of a Hybrid Cable-Driven Robot,” Robotics and Autonomous Systems, vol. 118, pp. 1–12, 2019.  PDF  Video 1  Video 2

• Ronghuai Qi, Amir Khajepour, and William W. Melek, “Generalized Flexible Hybrid Cable-Driven Parallel Robot: Modeling, Control, and Analysis,” IEEE Transactions on Systems, Man and Cybernetics: Systems, Under Review.  arXiv

For the study of soft robotics, I was inspired by living organisms and constructed robots from highly compliant materials for dealing with unstructured environment and dynamic tasks. My research focused on design and control to enhance robots' mobility, manipulation performance, and adaptability. 

In this research, a low-cost and lightweight inflatable robot finger is designed for safe human-robot interaction and adaptive gripping. The proposed soft inflatable robot finger is different from traditional designs. It uses a common and low cost inflatable material and can be easily and massively manufactured. The proposed soft inflatable finger only weighs 0.8 grams, but can well realize swift movement which is actuated by low pressure air. Numerous analyses and experiments have been conducted for key parameters selection of the mechanical design.

• Ronghuai Qi, Tin Lun Lam, and Yangsheng Xu, “Design and Implementation of a Low–Cost and Lightweight Inflatable Robot Finger,” in Proc. IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Chicago, USA, Sep. 14–18, 2014, pp. 28–33.  PDF  Video

In this research, a novel soft inflatable arm is proposed for humanoid robots. The new proposed structure of the arm is achieved by a very common and low-cost inflatable material and it is very light, weighing only about 50 g. However, it can realize agile movement by driving six tiny cables installed in the shoulder and elbow joints. The soft inflatable arm can work by pumping air at a very low pressure (7.32 ± 3.45 kPa) and allows direct and soft human contact without any external force sensors. This research proposes joint compressed models, joint kinematic models, and kinematic models for the whole inflatable robot arm. These models can be easily applied to multijoint arms. In addition, a new redundancy resolution method is also developed for the inflatable arm, which makes it easier to control resolution and is less complex than other traditional approaches. Numerous experiments have been conducted, including performances of accuracy, repeatability, motion trajectories, human-safe interaction, and remote interaction.

• Ronghuai Qi, Amir Khajepour, William W. Melek, et al., “Design, Kinematics, and Control of a Multijoint Soft Inflatable Arm for Human-Safe Interaction,” IEEE Transactions on Robotics, vol. 33, no. 3, pp. 594–609, 2017.  PDF  Video 1  Video 2

• Ronghuai Qi, Tin Lun Lam, and Yangsheng Xu, “Mechanical Design and Implementation of a Soft Inflatable Robot Arm for Safe Human–Robot Interaction,” in Proc. IEEE International Conference on Robotics and Automation (ICRA), Hong Kong, China, May 31–June 7, 2014, pp. 3490–3495.  PDF 

• Ronghuai Qi, Tin Lun Lam, and Yangsheng Xu, “Kinematic Modeling and Control of a Multi–joint Soft Inflatable Robot Arm with Cable–Driven Mechanism,” in Proc. IEEE International Conference on Robotics and Automation (ICRA), Hong Kong, China, May 31–June 7, 2014, pp. 4819–4824.  PDF

With the advancing globalization, people travel needs become more and more frequent. Nonetheless, travels spend a lot of effort, time and money, which is one of the major problems for modern urbanities. In addition, frequent use of transport also increased the carbon emissions. To cope with these problems, a Telepresence Robot is presented.

In smart cities, users in anywhere can connect remote telepresence robots via the internet and control it to move around freely and interact with people and objects. It acts as a user's real-world avatar. The application includes remote parties, meetings, consultations, school and inspection which are particularly suitable for those with busy life or mobility problems. 

To enhance users' and remote participants' telepresence experience, in addition to the capability of move, transmitting sounds and images, telepresence robot has a feature of presenting users' facial expressions and body language.

This project has published seven patents and three software packages.