Dr. Patel is a founding member of CSTAR (Canadian Surgical Technologies & Advanced Robotics), a major research initiative of the London Health Sciences Centre (LHSC) and the Lawson Health Research Institute (LHRI), established with funds of approximately $17 million acquired from federal and provincial funding agencies, industry and private donors. He is an investigator or principal investigator on several of CSTAR’s multidisciplinary projects: Robotic/mechatronic technologies for minimally invasive surgery and therapy; technologies and techniques for surgical training and skills assessment; haptics and teleoperation; image-guided robot-assisted medical interventions. Dr. Patel’s most recent research work in medical robotics has focused on the application of haptics and teleoperation for stroke rehabilitation and treatment of neurological movement disorders. All of Dr. Patel’s research projects in medical robotics involve collaboration with clinicians at CSTAR or LHSC.
The following is a list of Dr. Patel’s ongoing research projects:
Novel technology and algorithms have been developed for image-guided robot-assisted active catheter insertion and control. This was the first in-depth study of the robotic issues involved in guiding a catheter through the vasculature. The outcome consisted of a bilateral haptics-enabled teleoperation scheme based on advanced sensing and actuation using “smart materials” (shape memory alloy) as well as concurrent position and force control. Continuing work focused on catheter-based intervention for cardiac ablation for the treatment of atrial fibrillation (AF). The successful outcome of the AF procedure depends primarily on the correct positioning of the catheter tip inside the heart and on maintaining a consistent contact force between the catheter tip and cardiac tissue in the presence of cardiac and respiratory motions. A technique has been developed to estimate the tip/tissue contact force by analyzing the shape of the catheter near its distal end (based on fluoroscopy imaging data) without the need for a force sensor on the catheter.
A 3D ultrasound image-guided robotic system for prostate brachytherapy with a novel macro-micro architecture has been designed. The robotic system provides clinicians with the ability to control needle deflection and tissue deformation. An important contribution was a novel control strategy based on needle rotation and force control to compensate for needle deflection. In more recent work, tissue elasticity, viscous friction along the insertion depth as well as insertion velocity were addressed. Using real-time force measurements involving a sensor at the needle base, this approach related mechanical and geometric properties of needle-tissue interaction to the net amount of deflection and estimated the resulting curvature in real-time with submillimeter accuracy.
This project is concerned with techniques for accurate lung tumor localization through the integration of intraoperative tracked and fused kinesthetic, tactile and ultrasound (US) data with patient-specific pre-operative CT data. The work involves the design and evaluation of both hand-held and robotics-based instruments. A dual modality (tactile+US) instrument has been developed for collection of intraoperative tactile and US data. The robotic version of the instrument has been designed for use with the da Vinci surgical system. This design received the Best Innovation Prize at the 2015 Surgical Robot Challenge held during the Hamlyn Symposium in London, UK.
A major contribution of this project was a haptics-enabled two-master/two-slave system, with fully force-sensorized laparoscopic instruments mounted on the slaves. The resulting haptics-enabled teleoperated dual-arm surgical test-bed is capable of fully bilateral force/position control of tool-tissue interactions. A paper based on this work received the 2014 Best Paper Award of the ASME Journal of Medical Devices. The system has been used to study the importance of haptics in surgical performance and surgical training. The research also compared the efficacy of haptics (direct force reflection) and visual force reflection (“sensory substitution”) in performing surgical tasks such as suturing and tissue palpation.
A CTR is a type of continuum robotic device consisting of a set of concentric thin tubes, shaped in different curved profiles. By rotating and translating the tubes with respect to each other, their curvatures can be used to obtain different curved profiles for the overall robot and position and orient the robot's tip at desired locations while avoiding sensitive areas. This project has focused on developing technology for installing multiple Fiber Bragg Grating (FBG) sensors on CTRs for both force and shaping sensing. Incorporating shape and force information into a teleoperated CTR systems increases the accuracy of robot control and enable high performance haptic feedback to be delivered to the user.
In this project, a novel technique has been developed for integrating FBG sensors on the interior of a da Vinci instrument without major modifications to the tool. With this technique, the sensors are well protected from the surgical environment and do not interfere with the functioning of the instrument. Validation experiments show that an instrument sensorized using this technique can provide accurate force measurements at a sampling rate of 1 kHz.
Development of robotic neuro-rehabilitation systems is a major recent step in the field of motor therapy and provides a means of accelerating recovery after brain injury or trauma such as stroke, a leading cause of motor dysfunction. A novel inherently safe, haptics-enabled telerobotic rehabilitation framework has been developed that provides a new paradigm for delivering post-stroke rehabilitation therapy. The framework gives therapists direct kinesthetic supervision over robotic rehabilitation procedures and allows for remote and ultimately in-home rehabilitation. Robotic technology for lower- and upper-limb post-stroke rehabilitation has also been developed.
The project is in collaboration with a neurologist (Dr. M. Jog) and involves patients with focal hand dystonia (FHD (writer’s cramp)). The work showed that there is a potential correlation between kinesthetic sensory input and FHD and that modulating kinesthetic input can help patients in managing the symptoms of FHD. The use of haptic manipulation and visual feedback to augment medical therapy for FHD was demonstrated.
The objective is to provide easy and frequent access to supervised and well-planned sensorimotor therapy for extended periods to ensure long-term health of seniors. The research is aimed at developing in-home sensorized and/or actuated technologies that can be used for delivering appropriate individualized daily rehabilitation and appropriately programmed exercises to seniors in their homes. The exercises will be tuned through both remote supervision by a therapist and via automated local software embedded in the in-home system. The system will be capable of recording various biomechanical measurements in order to assess the user’s progress. This data could also be used for clinical assessment of musculoskeletal and sensorimotor performance. The technology will detect deterioration in various sensorimotor and musculoskeletal functions that could lead to potential falls or injuries.