National University of Singapore

Regaining mobility after a stroke or other neurological conditions such as spinal cord injuries, traumatic brain injuries, and Parkinson’s disease is often a struggle. To help these patients regain motor functions, they are usually required to undergo physical therapy sessions. To ease the transition, a team of engineers from the National University of Singapore (NUS) has invented a novel robotic walker that can help patients carry out therapy sessions to regain their leg movements and natural gait. They say that the system also increases productivity of physiotherapists and improves the quality of the rehabilitation sessions.

Fig. 1 – A team of researchers at the Department of Biomedical Engineering at the National University of Singapore Faculty of Engineering practice with the robotic walker.
Designed by a team of researchers led by Assistant Professor Yu Haoyong of the NUS Department of Biomedical Engineering, the robotic walker can support a patient’s weight while providing a proper amount of force at the pelvis of the patient to help the patient walk with a natural gait. In addition, the device gathers quantitative data during the therapy sessions so that doctors and physical therapists can monitor the progress of the patient’s rehabilitation.

How It Works

The robotic walker is composed of six modules: an omni-directional mobile platform, an active body weight support unit, a pelvic and trunk motion support unit, a suite of body sensors, a functional electrical stimulation unit, and an intuitive user control interface.

The sensors measure the gait of the patient so that the walker can provide the right amount of support to help the patient walk more naturally. The electrical stimulation unit can deliver a targeted electrical current to stimulate the correct muscle at the right timing to facilitate joint movement. The walker can also provide assistive force, resistive force, and disturbance force, depending on the training requirements set by the therapists.

Using the device, patients can transition through a variety of training sessions that are often difficult to achieve manually. The patient interacts with the walker through a force sensor that detects the user’s intent. An intelligent control system uses this information, as well as the gait information provided by the body sensors, to control the movement of the walker.

Another unique feature of this walker is that it allows the patient to practice gait movements by walking on flooring instead of on a treadmill. This allows the gait training to be conducted in a more natural way for the patients.

Yu explained, “This robotic walker allows patients to practice their gait movements continuously to optimize their therapy. When patients repeat the movements in a natural setting, the routine can be imprinted into their brains, which gradually learn to correct from the damage resulting from their medical conditions.”

In addition, the robotic walker is capable of collecting data on the gait kinematics and muscle activation pattern of the patient. Such information is useful for doctors and therapists to monitor the progress of the patients’ recovery.

Currently, gait training requires one or two therapists to support the patient’s body weight and trunk, and an additional assistant may be needed to move the patient’s leg. This is labor intensive for the therapists, and can limit the quality, duration, and frequency of rehabilitation sessions.

With the robotic walker, manual therapy can be taken over by the robotic system, while physical therapists can focus on providing better assessment and training guidance for patients. The device also reduces the number of physiotherapists needed to conduct each rehabilitation session, thereby increasing productivity and reducing the cost of care.

What’s Next

Yu is collaborating with a company called Hope Technik to fine-tune and commercialize the robotic walker. He plans to conduct clinical studies to validate the training effects on patients and to develop novel therapy regimes together with clinicians at the National University Hospital.

“Our vision is for the robotic walker to be installed at outpatient clinics and rehabilitation centers to benefit patients who need therapy sessions. There is also a possibility that patients can perform exercises in the comfort of their own homes,” said Yu.