Partial Neurological Recovery using Brain-Machine Interface Rehabilitation

The researchers that brought us a mind-controlled exoskeleton to kick off the Soccer World Cup in 2014 are back in the news.  Dr. Miguel Nicolelis, in collaboration with many researchers, has been able to develop a recovery method that has returned partial motor control and perception to eight patients with complete spinal cord injury after ten months of training.

• Two exoskeletons were used as a part of a medical solution in conjunction with other technology.
• Exoskeleton technology was used to achieve a medical breakthrough.
• The announcement made the top pages of all the major news sites.

Exoskeletons as part vs. full solution:

The Brain-Machine Interfaces (BMIs) rehabilitation training utilized a Hocoma Lokomat and a custom made 12 degrees of freedom exoskeleton.  What is different is that the exoskeleton technology was used in addition and in conjunction with virtual reality, tactile stimulation, EEG, EMG and an overhead suspension system (Zego G, no connection to the zeroG spring arm).

Using an exoskeleton as part of a solution marks a growing trend in integrating exoskeletons with other technological advances.  For example, there is already research showing the potential of combining medical exoskeletons with functional electric stimulation.

The BMIs training takes this idea to the extreme and exoskeletons are used as one of many tools in the rehabilitation rather than THE rehabilitation tool.  This is part of a growing trend to use multiple exoskeletons for specific applications under the same roof.  This new type of thinking suggests that a rehabilitation gym would not have to choose between a Hocoma Lokomat, an Ekso Bionics Ekso GT, and a ReWalk Robotics ReWalk but would have all three in its rehabilitation pipeline.  The Lokomat would be a starting point for a patient with partial motor control.  They would then move to the Ekso GT for more challenging rehabilitation, and finally would be able to take a ReWalk home with them if they have improved enough and still need some functional assistance.

Exoskeletons used to achieve more than classical rehabilitation.

For years exoskeleton companies and labs have been running studies with medical exoskeleton devices.  The goal was to understand who can benefit the most and how the wearables should be used.  Now all of the research data is starting to show that exoskeleton rehabilitation is more consistent, provides higher quality and can be used to achieve much better results.

Exoskeleton technology has been around for years.  For example, there are ReWalk users that have had an exoskeleton for five or more years without showing an improvement in their spinal cord injury.  This is due to the difference and improvement in software and motor control.  Many exoskeletons focus on triggering a motion at the same time as a person wants to use their leg.  Newer rehabilitation exoskeletons provide additional strength only when the user has started the step.  The difference is riding along with the device vs. receiving assistance during the motion.   One way to visualize the difference is being pushed by a strong wind gust while standing still.  The normal reaction is to push immediately in the opposite direction.  But if you are walking and the wind gust is coming from behind you, it is a welcomed push that is integrated into the step.

Exoskeleton technology is back in the news.

Between the Brain-Machine Interface Rehabilitation and the recent Ted Talk by Dr. Karen Nolan on robotics stroke rehabilitation the dialogue on medical exoskeletons has now completely shifted.  We are no longer talking about “if” robotic rehabilitation is useful.  Now the dialogue has become “how much” more useful robotic rehabilitation is.  Now that we are starting to understand how the technology is best applied, how far can it take us?  This is clearly the inflection point in the perception of medical exoskeletons that so many have been waiting for.

Method:

Eight patients with complete spinal cord injury that has transpired between 3 and 13 years in the past were selected for the study.  The Brain-Machine Interface Rehabilitation was then divided into six parts.  First, the patients were asked to imagine themselves walking. The commands were sent using an EEG cap and confirmed using muscle flexion in the arm using EMG.  A virtual model then executed the movement which was visualized using Virtual Reality Glasses and perceived via tactile stimulation at the arm.  In the second phase,  users repeated the same while suspended upright.  In the third stage, the cohort was placed on a Lokomat.  In the fourth stage, the patients exercised while suspended by a Zero G rail system.  Fifth, the users, returned to the Lokomat and the EEG control with EMG confirmation and tactile stimulation at the arm with each step.  In the final round, the patients controlled a custom-made exoskeleton with 12 degrees of motion capable of self-balancing.  Again, the EEG control with EMG confirmation and tactile stimulation were utilized.

How is it possible for individuals with complete spinal cord injury to regain partial feeling and motor control below the level of injury?  According to the researchers, various studies suggest that as many of 5 to 27% of axons in different positions in the spinal cord can survive, but the body needs to be trained on how they can best be utilized.  In the case of spinal cord injury, there is a physical interruption of neurons at the spine and no matter the level of rehabilitation new ones will not grow after the first year of injury.  This suggests that the newly developed Brain-Machine Interface Rehabilitation could have profound effects on patients with brain damage or those with recent spinal cord injury.  This has already been eluded to by various research groups in the past, but no clinical results have been made public as of yet.

Source:

Long-Term Training with a Brain-Machine Interface-Based Gait Protocol Induces Partial Neurological Recovery in Paraplegic Patients, Ana R. C. Donati, Solaiman Shoku, Edgard Morya, Debora S. F. Campos, Renan C. Moioli, Claudia M. Gitti, Patricia B. Augusto, Sandra Tripodi, Cristhiane G. Pires, Gislaine A. Pereira, Fabricio L. Brasil, Simone Gallo, Anthony A. Lin, Angelo K. Takigami, Maria A. Aratanha, Sanjay Joshi, Hannes Bleuler, Gordon Cheng, Alan Rudolph, Miguel A. L. Nicolelis, Nature.com, Published online:11 August 2016, Scientific Reports 6, Article number: 30383 (2016), http://www.nature.com/articles/srep30383

Donati, A. R. C. et al. Long-Term Training with a Brain-Machine Interface-Based Gait Protocol Induces Partial Neurological Recovery in Paraplegic Patients. Sci. Rep. 6, 30383; doi: 10.1038/srep30383 (2016).