Best Student Paper for IEEE RCAR2016

Our paper titled “Towards Magnetically Actuated Guide-wire Steering in Arteriovenous Fistula Angioplasty Procedures” was awarded for the Best Student Paper at IEEE Conference on Real-time Computing and Robotics (RCAR), June 6 to 10, 2016, at Angkor Wat, Cambodia.


Ultrasound Assisted Guidance with Force Cues for Intravascular Interventions

Project Goals

Image guidance during minimally invasive cardiovascular interventions is primarily achieved based on X-ray fluoroscopy, which has several limitations including limited 3D imaging, significant doses of radiation to operators, and lack of contact force measurement between the cardiovascular anatomy and interventional tools. Ultrasound imaging may complement or possibly replace 2D fluoroscopy for intravascular interventions due to its portability, safety, and the ability of providing depth information. However, it is a challenging work to perfectly visualize catheters and guidewires in the ultrasound images. In this paper, we developed a novel method to locate the position and orientation of the catheter tip in 2D ultrasound images in real time by detecting and tracking a passive marker attached to the catheter tip. Moreover, the contact force can also be measured due to the length variation of the marker in real time. An active geometrical structure model based method was proposed to detect the initial position of the marker, and a KLT (Kanade-Lucas-Tomasi) based algorithm was developed to track the position, orientation, and the length of the marker. The ex vivo experimental results indicate that the proposed method is able to automatically locate the catheter tip in the ultrasound images and sense the contact force, so as to facilitate the operators’ work during intravascular interventions.


People Involved

Research Fellow: Jin Guo
Project Investigator: Hongliang Ren

Related Publications


Gold award in BES10SM Design Competition

Congratulations to the Gold award in the Biomedical engineering Society 10th Scientific Meeting (BES10SM) at Singapore, 14th May 2016, for our lab’s research led by FYP student, Yoew Bok Seng, on the project of Magnetic Robotic Intervention, for the design (undergraduate) category.

Best Paper Finalist award at CSCWD 2016 Conference

Our team’s research paper titled “Human-Compliant Body-Attached Soft Robots Towards Automatic Cooperative Ultrasound Imaging” paper was presented and shortlisted for the Best Conference Paper at 2016 20th IEEE International Conference on Computer Supported Cooperative Work in Design (CSCWD 2016), May 4-6, 2016, Nanchang, China.

Magnetically Actuated Guide-wire Steering

Project Goals

Guide wires are commonly used to assist surgeons during vascular surgery. Guide wires are usually the first to be placed, eventually allowing easy exchange of surgical tools to the target site. The surgeon has to manually control and manipulate the guide wire to the target region. This process is complicated by the tortuous nature of the vasculature and is made worse as the surgeon has limited vision (constant need to switch between overlay angiographs) and control over the guide wire tip (controlling the distal tip from the proximal end). For the first time towards minimally invasive Arteriovenous Fistula Angioplasty Procedures, we aim to improve the controllability of the in vivo guide wire via the attachment of a magnetic tip to the distal end of the guide wire, which under the control of external magnetic field generators can deflect the magnetic tip. This controlled deflection translates to the selection of entrance angle for the guide wire tip, affording distal control.
This is especially useful for navigating around stenosis which is common for patients with Arteriovenous(AV) Fistula. The repeated use of the fistula during dialysis has been claimed as a cause for the high occurrence of stenosis (due to tissue scaring from access). Fistulas and their grafts are however still preferred over other renal access in most situation due to its lower risk of infections. Our proposed system here can improve the controllability, safety and speed of current procedures and can enable AV-Fistula Angioplasty Procedures to be shifted to out-patient clinics.


People Involved

Student: Bok Seng Yeow
Research fellow: Jinji Sun
Project Investigators: Hongliang Ren, Jackie Ho

Related Publications

Yeow, B. S.; Sun, J.; Ho, J. & Ren, H. Towards Magnetically Actuated Guide-wire Steering in Arteriovenous Fistula Angioplasty Procedures IEEE Conference on Real-time Computing and Robotics (RCAR), IEEE, 2016, best student paper.

Body-Attached Soft Robot for Ultrasound Imaging

Project Goals

Ultrasound imaging procedures are deemed as one of the most convenient and least invasive medical diagnostic imaging modalities and have been widely utilized in health care providers, which are expecting semiautomatic or fully-automatic imaging systems to reduce the current clinical workloads. This paper presents a portable and wearable soft robotic system which has been designed with the purpose of replacing the manual operation to cooperatively steer the ultrasound probe. This human-compliant soft robotic system, which is equipped with four separated parallel soft pneumatic actuators and is able to achieve movements in three directions. Vacuum suction force is introduced to attach the robot onto the intended body location. The design and fabrication of this soft robotic system are illustrated. To our knowledge, this is the first body-attached soft robot for compliant ultrasound imaging. The feasibility of the system is demonstrated through proof-of-concept experiments.


Developing a wearable soft robotic system (Figure 1), which is capable of mimicking the procedure of probe steering and optimizing the contact force and angle according to the specific conditions, has great significance of reducing the reliance of the ultrasound imaging on the experience of operators and obtaining images with high quality.

People Involved

PhD Student: Xiaoyi Gu
FYP Student: Koon Lin Tan
Project Investigator: Hongliang Ren

Related Publications

Ren, H.; Gu, X. ; Tan, K. L. Human-Compliant Body-Attached Soft Robots Towards Automatic Cooperative Ultrasound Imaging 2016 20th IEEE International Conference on Computer Supported Cooperative Work in Design (CSCWD 2016), IEEE, 2016, –

Positions for part-time undergraduate Research Assistants (RA)

The part-time research positions are to support a funded project on the study of a computer integrated surgery system. The successful applicants will involve hands-on development for surgical robot prototype or surgical navigation system study based on their backgrounds. The successful applicants will also be exposed to the other interesting research projects in surgical robotic system development.

Position Responsibilities:

Assist in the development of a computer integrated surgery system.
Closely collaborates with the PI and other research assistants throughout the study.
Write experiment reports.
Learn to manage the project.


Prior clinical knowledge is not required but would be a plus.
Experience with mechanical design or computer programming.
Willing to learn and work independently.
Strong problem-solving, interpersonal, and analytic skills.
To apply, please email a detailed CV (including education background, courses, experiences, and skills) to:
Dr. REN, Hongliang

BN5209-6209 Neurosensors and Signal Processing/Neurotechnology AY15/16

BN5209/BN6209 Neurosensors and Signal Processing / Neurotechnology Semester 2, 2015/2016


Lecture Time:

  • Tuesday: 3 pm – 6 pm (EA-06-03)


Note: Information contained in this syllabus may be subject to change.

Week Topic
Intro to the Course (NT)
Intro to Neurotechnology  (NT)
Introduction of BioSignal Processing  (HR)
L1-CFT; L2-Stochastic Process/R.V./Moments/PSD
Neural recording methods: Neural circuits, amplifiers, telemetry, stimulation (NT)
Prepare Student Seminarspaper selection
Time-Frequency-Spatial Analysis  STFT (HR)
Feb9 (CNY)
Neural signals (clinical applications)- EEG, evoked potentials (HR)
Lab tutorial for Project I: Neural Signals and Analysis
Recess Feb22
Multiple Dimensional  Signal Processing (HR)
Lab Project II: Application in neural systems
Student Reading Seminars (HR)
Neuro Diagnostic and Therapeutic Devices by NT
Brain machine interfaces  (NT)
Neuromorphic Engineering – Brain Inspired Robotics by SK
Neuroimaging and Image Processing (HR)
Neuroimaging fMRI (HR)
Advanced Neurosignal Processing / Neurosurgical systems (HR)
Apr12 (makeup)
Project Reports (due before final) & presentations (HR, NT)


Course Projects

1. EEG for brain state monitoring
2. EEG/EMG Feature Identification Extension


This module teaches students the advanced neuroengineering principles ranging from basic neuroscience introduction to neurosensing technology as well as advanced signal processing techniques. Major topics include: introduction to neurosciences, neural recording methods, neural circuits, amplifiers, telemetry, stimulation, sensors for measuring the electric field and magnetic field of the brain in relation to brain activities, digitization of brain activities, neural signal processing, brain machine interfaces, neurosurgical systems and applications of neural interfaces. The module is designed for students at Master and PhD levels in Engineering, Science and Medicine.


Basic probability
Basic circuits
Linear algebra (matrix/vector)
Matlab or other programming
Recommended Textbooks: Neural Engineering, Edited by Bin He
Seminar papers


The majority of the course will be in lecture-tutorial format. Some advanced topics will be in the formats of seminar and research presentations.


Take Home Tests (5 for 50%)
Labs/Projects Reports + Presentations (20%)
Seminars (10%)
Take Home Final Exam(20%)

Finding the Kinematic Base Frame of a Robot by Hand-Eye Calibration Using 3D Position Data


When a robot is required to perform specific tasks defined in the world frame, there is a need for finding the coordinate transformation between the kinematic base frame of the robot and the world frame. The kinematic base frame used by the robot controller to define and evaluate the kinematics may deviate from the mechanical base frame constructed based on structural features. Besides, by using kinematic modeling rules such as the product of exponentials (POE) formula, the base frame can be arbitrarily located, and does not have to be related to any feature of the mechanical structure. As a result, the kinematic base frame cannot be measured directly. This paper proposes to find the kinematic base frame by solving a hand-eye calibration problem using 3D position measurements only, which avoids the inconvenience and inaccuracy of measuring orientations and thus significantly facilitates practical operations. A closed-form solution and an iterative solution are explicitly formulated and proved effective by simulations. Comprehensive analyses of the impact of key parameters to the accuracy of the solution are also carried out, providing four guidelines to better conduct practical operations. Finally, experiments on a 7-DOF industrial robot are performed with an optical tracking system to demonstrate the superiority of the proposed method using position data only over the method using full pose data.

More information

Full-text and more information

Soft Robotic Manipulators: fabrication & applications


Flexible robotic manipulators have been widely used in minimally invasive surgery (MIS) and many other applications requiring closer inspection and operation. Although a variety of manipulators enabled by different mechanism have been developed, few of them can preserve softness, thinness and decent bending capability simultaneously. We develop miniature soft robotic manipulators made of hyper-elastic silicone rubber. Along with the manipulator design, novel fabrication methods are proposed and elaborated. Detailed characterizations are specified to show the bending capability of the manipulator given different air pressure. Specifically, our manipulator, as thin as 6 mm, is able to achieve 360° directional bending, and, when given pressure over 70kPa, it can reach 180° bending angle and around 5mm bending radius easily. Due to its innate compliance and small dimension, this type of robotic manipulator can deliver safe and comfortable interactions with the subjects. More significantly, the novel fabrications in this paper diversify the fabrication methods for soft pneumatic robots and actuators (SPRA) and further scale down their sizes.
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