We have developed a three degree of freedom robot with a custom designed video game for ankle rehabilitation of children with cerebral palsy and other neuromuscular disorders. Physical therapy is commonly used to stretch and strengthen these patients, but current treatment methods have some limitations. By developing a robotic device and associated airplane video game, we aim to improve ankle range of motion, muscle strength, and motor control in a quantitative manner that is also fun and motivating for the child. Our PedBot robot consists of three intersecting axes with a remote center of motion in the ankle joint area. The patient’s ankle is strapped to PedBot and becomes a controller for the airplane game. The patient flies the plane through a series of rings and a bell sound is made each time the plane successfully passes through the center of a ring. To date we enrolled 4 children ages 4-11 in an IRB approved trial. The children completed up to 5 sessions. All of the children said they enjoyed the therapy. A 4-year old boy who completed all five sessions showed measureable improvements in several degrees of motion. We have also begun EMG based studies to investigate muscle activity during robotic rehabilitation.
We have developed a mechanical horseback riding simulator for the rehabilitation of children with neurological and musculoskeletal disabilities, focused on improving trunk control in this population. While overseen by a physical or occupational therapist, the movement of a horse is often used as therapy for these patients (hippotherapy). However, many children never have the chance to experience hippotherapy due to geographical and financial constraints. We therefore developed a horseback riding simulator that could be used in the office setting to make hippotherapy more accessible for our patient population. The system includes a motion platform, carousel horse, and tracking system. We developed a virtual reality display which simulates a horse moving along a pier. As the horse moves forward, other horses come toward it, and the patient must lean left or right to move out of the way. The tracking system provides the position of tracking markers which are placed on the patient’s back, and this information is used to control the motion of the horse. Under an Institutional Review Board (IRB) approved trial, we have enrolled two patients with cerebral palsy to date. This was after completing testing on five healthy pediatric volunteers as required by the IRB. Early results show the feasibility of the system.
Cochlear implantation is the standard of care for infants born with severe hearing loss. Current guidelines approve the surgical placement of implants as early as 12 months of age. Implantation at a younger age poses a greater surgical challenge since the underdeveloped mastoid tip, along with thin calvarial bone, creates less room for surgical navigation and can result in increased surgical risk. We have been developing a temporal bone dissection simulator based on actual clinical cases for training otolaryngology fellows in this delicate procedure. The simulator system is based on pre-procedure CT (Computed Tomography) images from pediatric infant cases (<12 months old) at our hospital. The simulator includes: (1) simulation engine to provide the virtual reality of the temporal bone surgery environment, (2) a newly developed haptic interface for holding the surgical drill, (3) an Oculus Rift to provide a microscopic-like view of the temporal bone surgery, and (4) user interface to interact with the simulator through the Oculus Rift and the haptic device. To evaluate the system, we have collected 10 representative CT data sets and segmented the key structures: cochlea, round window, facial nerve, and ossicles. The simulator will present these key structures to the user and warn the user if needed by continuously calculating the distances between the tip of surgical drill and the key structures.
Ureteroscopy is a minimally invasive procedure for diagnosis and treatment of urinary tract pathology. Ergonomic and visualization challenges as well as radiation exposure are limitations to conventional ureteroscopy. Therefore, we have developed a robotic system to “power drive” a flexible ureteroscope with 3D tip tracking and pre-operative image overlay. The proposed system was evaluated using a kidney phantom registered to pre-operative MR images. Initial experiments show the potential of the device to provide additional assistance, precision, and guidance during urology procedures.
During prostate needle insertion, the gland rotates and displaces resulting in needle placement inaccuracy. To compensate for this error, we proposed master-slave needle steering under real-time MRI in a previous study. For MRI-compatibility and accurate motion control, the master (and the slave) robot uses piezo actuators. These actuators
however, are non-backdrivable. To cope with this issue, force sensor is required. Force sensor is also required at the slave side to reflect the insertion force to clinician’s hand through the master robot. Currently, there is no MRI-compatible force sensor commercially available. In order to generate a combination of linear and rotary motions for needle steering, this study is seeking to develop a MRI-compatible 2 Degrees of Freedom (DOF) force/torque sensor. Fiber Brag Grating (FBG) strain measuring sensors which are proven to be MRI-compatible are used. The active element is made of phosphor-bronze and other parts are made of brass. The force and torque measurements are designed to be entirely decoupled. The sensor measures -20 to 20 N axial force with 0.1 N resolution, and -200 to 200 Nmm axial torque with 1 Nmm resolution. Analytical and Finite Element (FE) analyses are performed to ensure the strains are within the measurable range of the FBG sensors. The sensor is designed to be compact (diameter =15 mm, height =20 mm) and easy to handle and install. The proposed sensor is fabricated and calibrated using a commercial force/torque sensor.