Development of a Robotic Companion to Provide Haptic Force Interaction for Overground Gait Rehabilitation

The aim of gait rehabilitation is to achieve independent ambulation. Somatosensory augmentation with external haptic sources can improve the subject's ability to walk or stand. This paper presents the development and evaluation of a robotic system prototype that delivers haptic forces to aid overground gait rehabilitation. This portable system is based on a compact, mobile robot that is equipped with force and LIDAR sensors. The robot is flexibly linked to the user, which allows the force interaction between the user and machine to be halted when desired. During operation, the system can dynamically transition between modes in which force is applied or distance is maintained to emulate the experience of a human walking a dog on a leash. The haptic feedback from our system was evaluated in a pilot study that involved six young, healthy subjects and one individual recovering from a hemiparetic stroke. The study comprised independent and device-assisted walking trials. When using the device, the subjects walked continuously as it transitioned between distance and force modes. Gait speed and step length increased when force was applied and decreased as the force was removed. The improvements exhibited by an individual suffering from stroke were similar to those exhibited by healthy subjects. The application of haptic forces has a high potential for improving the efficiency of overground gait training with simple interactions.