Chin-Boon Chng

Hand gesture guided robot-assisted surgery based on a direct augmented reality interface

Radiofrequency (RF) ablation is a good alternative to hepatic resection for treatment of liver tumors. However, accurate needle insertion requires precise hand-eye coordination and is also affected by the difficulty of RF needle navigation. This paper proposes a cooperative surgical robot system, guided by hand gestures and supported by an augmented reality (AR)-based surgical field, for robot-assisted percutaneous treatment. It establishes a robot-assisted natural AR guidance mechanism that incorporates the advantages of the following three aspects: AR visual guidance information, surgeons experiences and accuracy of robotic surgery. A projector-based AR environment is directly overlaid on a patient to display preoperative and intraoperative information, while a mobile surgical robot system implements specified RF needle insertion plans. Natural hand gestures are used as an intuitive and robust method to interact with both the AR system and surgical robot. The proposed system was evaluated on a mannequin model. Experimental results demonstrated that hand gesture guidance was able to effectively guide the surgical robot, and the robot-assisted implementation was found to improve the accuracy of needle insertion. This human-robot cooperative mechanism is a promising approach for precise transcutaneous ablation therapy.

A bioabsorbable microclip for laryngeal microsurgery: design and evaluation.

Epithelial flaps created during laryngeal microsurgery require apposition to facilitate proper healing. Current technologies are restricted by minimal access of the surgical site, posing various limitations in application. In this paper, we propose a novel magnesium-based bioabsorbable microclip, discuss our design considerations and evaluate the microclips feasibility as a miniature wound closure device. Ex vivo experiments demonstrate that the microclip fastens securely to the vocal fold, while in vivo studies show bioabsorbability and a lack of adverse side effects, suggesting that the microclips are viable as implantable devices.

Carbon Nanotube-Based Artificial Tracheal Prosthesis: Carbon nanocomposite implants for patient-specific ENT care.

We have developed the first patient-specific carbon nanotube (CNT) composite artificial tracheal implant tested on a porcine model in vivo. The experimental subject has survived with the implant with no apparent problems. Carbon nanocomposite material and the patient-specific approach have also been used to develop a voice prosthesis device as well as new microclips for wound closure. This article presents our experimental investigation with the carbon nanocomposite materials for constructing patient-specific ear, nose, and throat (ENT) implants.

Design of a Mechanical Larynx With Agarose as a Soft Tissue Substitute for Vocal Fold Applications

Mechanical and computational models consisting of flow channels with convergent and oscillating constrictions have been applied to study the dynamics of human vocal fold vibration. To the best of our knowledge, no mechanical model has been studied using a material substitute with similar physical properties to the human vocal fold for surgical experimentation. In this study, we design and develop a mechanical larynx with agarose as a vocal fold substitute, and assess its suitability for surgical experimentation. Agarose is selected as a substitute for the vocal fold as it exhibits similar nonlinear hyperelastic characteristics to biological soft tissue. Through uniaxial compression and extension tests, we determined that agarose of 0.375% concentration most closely resembles the vocal fold mucosa and ligament of a 20-year old male for small tensile strain with an R(2) value of 0.9634 and root mean square error of 344.05±39.84 Pa. Incisions of 10 mm lengthwise and 3 mm in depth were created parallel to the medial edge on the superior surface of agar phantom. These were subjected to vibrations of 80, 130, and 180 Hz, at constant amplitude of 0.9 mm over a period of 10 min each in the mechanical larynx model. Lateral expansion of the incision was observed to be most significant for the lower frequency of 80 Hz. This model serves as a basis for future assessments of wound closure techniques during microsurgery to the vocal fold.

Parallel processing for object oriented robotic simulation of tracheal-oesophageal puncture

An approach in advancing the field of medical robotics is via a more efficient preparation of robotic surgical intervention using accurate simulation. Our intra-operative virtual system for robotic tracheal-oesophageal puncture is modeled using an object oriented method. The interaction between rigid tools and flexible organs is simulated with finite element method codes integrated within the framework of multi-body dynamics codes. We investigate LogP and MLogP models for multi-core CPU computing, and propose Topology Independent Model (TIN) model for a heterogeneous computing system, which mimics parallel processing with multi-core CPU and GPU, to provide the required computational power for tool-tissue simulation.

Image-guided robotic system for radiofrequency ablation of large liver tumor with single incision

Radiofrequency (RF) ablation surgery is effective in liver tumor treatment with non-collateral damage and reduced blood loss. However, the surgery is challenging for large tumor ablation in a minimally invasive procedure. In this paper, we developed a surgical robot system incorporating medical image information and surgeons planning knowledge to realize a minimally invasive procedure for large liver tumor treatment through a single incision. The system includes a surgical robot designed with spherical arc structures, medical image processing and planning, and trajectory generation modules. With planning strategies applied to medical images, multiple trajectories are automatically generated. ex-vivo and in-vivo tests were conducted and the experimental results demonstrated that the multiple RF needle insertion could accurately reach the target area and the required needle incision ports were significantly reduced.

Experiments of carbon nanocomposite implants for patient specific ENT care

We have developed the first patient specific carbon nanotube composite artificial tracheal implant tested on a porcine model in vivo. The experimental subject has survived with the implant with no apparent problems. Carbon nanocomposite material and the patient specific approach have also been used to develop a voice prosthesis device, as well as new microclips for wound closure. This paper presents our experimental investigation with the carbon nanocomposite materials for constructing patient specific ENT implants.

Augmented Reality Guidance with Multimodality Imaging Data and Depth-Perceived Interaction for Robot-Assisted Surgery

Image-guided surgical procedures are challenged by mono image modality, two-dimensional anatomical guidance and non-intuitive human-machine interaction. The introduction of Tablet-based augmented reality (AR) into surgical robots may assist surgeons with overcoming these problems. In this paper, we proposed and developed a robot-assisted surgical system with interactive surgical guidance using tablet-based AR with a Kinect sensor for three-dimensional (3D) localization of patient anatomical structures and intraoperative 3D surgical tool navigation. Depth data acquired from the Kinect sensor was visualized in cone-shaped layers for 3D AR-assisted navigation. Virtual visual cues generated by the tablet were overlaid on the images of the surgical field for spatial reference. We evaluated the proposed system and the experimental results showed that the tablet-based visual guidance system could assist surgeons in locating internal organs, with errors between 1.74 and 2.96 mm. We also demonstrated that the system was able to provide mobile augmented guidance and interaction for surgical tool navigation.

Design and implementation of a patient-specific cognitive engine for robotic needle insertion

In order to develop an effective and user-friendly control method for surgical robotic system, we propose a new framework of cognitive engine to supervise and regulate the surgical processes. The framework aims to make the surgical processes understandable by both human operators and robots. A prototype cognitive engine was implemented using ontology and SPARQL query language on JAVA and tested in ex-vivo phantom experiments with a robotic RF needle insertion system. The prototype cognitive engine has successfully guided the robot in execution of surgical procedures.

Learning laparoscopic surgery by imitation using robot trainer

Laparoscopic surgery requires rigorous training in order to overcome physical, spatial and visual constraints. We are developing a laparoscopic robot trainer. The robot trainer can learn the motion of the master surgeon when he is performing a virtual surgery, and drive the surgical tool by mimicking the learnt trajectory during training. This paper reports our investigation on robot learning using learning by imitation for surgical training. The feasibility of implementing this innovative learning method is demonstrated with recent results on the robot trainer, and experiments involving our laparoscopic surgery trainer box and computer vision system.