Find Us On:

Linked In


Join Our Mailing List


We won't spam you or ever share your information.

New Illinois-ADSC technology enables at-home rehab care


To regain full functioning, many stroke or trauma patients must continue physical or occupational therapy even after returning home from the hospital. But often, their progress diminishes once they are home, said Rama Ratnam, a senior research scientist at the University of Illinois at Urbana-Champaign.

Rama Ratnam
Rama Ratnam
“Patients almost always do well in a hospital, where there’s someone who monitors them to make sure they do their exercises,” said Ratnam, who is also a researcher at Illinois’ Advanced Digital Sciences Center in Singapore. “Home-based rehab has not been as successful because once patients go home, there’s much less accountability in making sure patients are performing their exercises,”

Ratnam is leading a group of Illinois and ADSC researchers who have developed a new system that makes it easier for a doctor or therapist to keep tabs on a patient’s progress remotely. The technology employs Kinect cameras, which capture 3D motion data, and then adds a mathematical layer that eliminates noise and produces a smooth motion, giving health care providers an accurate picture of how a patient is performing an exercise.

A major advantage of the system is that data is stored in the form of a stick-figure representing major joints and body segments, and not as a detailed video that can reveal the identity of the person. This reduces the data bandwidth while ensuring privacy. The system, called Salus (after the Roman Goddess of Wellness), was initially developed by ADSC engineer Alex Khromenkov. The ADSC team includes Vignesh Ramkrishnan and Stefan Winkler, who are continuing to develop the technology and target specific applications.

The research comes at a time when health care costs are driving therapy patients to reduce time spent in in-patient rehabilitation care and return home before regaining full functioning. In addition, as people continue to live longer, there may not be enough providers to care for patients in traditional settings in years to come.

Ratnam’s at-home rehab care system would help overcome these challenges by allowing physicians to access video of patients’ therapy at a convenient time. After the patient performs an exercise, physicians could then download the data from a cloud server and play back the video. The interface also includes a calendar that would enable physicians to schedule specific exercises on certain days.

The Salus system
The Salus system
According to Ratnam, the mathematical layer is what makes the system unique. Kinect cameras excel at capturing motion in 3D, but do not have a holistic concept of the human body. They only see a series of points in space. The algorithms developed by Ratnam’s team imposes constraints on the data that rules out movements that humans are physically incapable of doing.   

“You can’t rotate your neck 180 degrees like in ‘The Exorcist,’” he said. “The camera also doesn’t assume that a person’s arm length doesn’t change from frame to frame. It’s important to smooth out unwanted noise and make sure the system understands what is possible and what isn’t.”

In order to get a good picture of what a movement should look like, Ratnam is working with colleagues at the University of Illinois to apply the technology in specific populations. For example, Prof. Jacob Sosnoff, a professor of kinesiology and human health, is using the system to assess and identify elderly at a high risk of falling. Another kinesiology professor, Robert Motl, is working to develop home-based exercises and remotely monitor compliance in multiple sclerosis patients. Ian Rice and Laura Rice, whose research focuses on wounded veterans, are collaborating with Ratnam and Jake Sosnoff to monitor wheelchair transitions, such as a patient moving from a wheelchair to a chair or a bed, with the aim of minimizing shoulder problems. Each of these populations has specific needs, and the Salus system along with the body model functions as the core engine in powering the various applications.

Researchers are currently working to develop a prototype, which they hope to test at Illinois and in Singapore.

“While there are some limitations to what this technology can do, it is non-invasive, touch-free, and guarantees privacy while monitoring movements,” Ratnam said. “We intend for the system to relieve the burden currently on health care professionals by enabling remote physical rehab in the home along with the crucial capability to monitor compliance.”