Exoskeletons using electrical stimulation and reading muscle signals are taking great strides in helping partially paralysed people regain their mobility.
In 10 seconds? Motorized suits interacting with part-paralysed users' muscle contractions are the next step in post-stroke rehabilitation aiding people to re-learn how to walk. (Read the science)
So, why are they better than sci-fi robots? Well, the giant robots in films like Pacific Rim are just there to make able-bodied heroes stronger, while new exoskeletons help stroke patients re-learn how to walk. What makes them cutting-edge is ‘shared control’, which makes machines react to residual muscular contractions from the user and that's way ahead of the glorified armour seen in the movies! (Read more)
Shared control? What's that? It marries FES, or Functional Electrical Stimulation with intuitive robotics. During rehabilitation patients repeat thousands of movements to correct ‘drop-foot’ and re-learn correct gait. This can take months as both patient and therapist will get tired during sessions. My research team is working on a technology that adapts to the patient’s characteristics and helps carry on with the exercises. (Read more)
And what’s new in it? It boosts the benefits of separate therapies. FES, for example, relies on the patient’s muscle power, which can't control complex joint movements. Robots are not good at interacting with patients and adapting to their anatomy. But combined, they can use the ‘assistance-as-needed’ principle, which makes therapy personalised and more efficient. (Find out more)
So the exoskeleton adapts to the patient? Yes, for example, a newly developed exoskeleton monitors the patient’s performance and muscle fatigue and adjusts the force in the device’s motor only adding the precise amount of boost to perform a correct step. Using EEG signals, it identifies motion intent from the patient and lets them control when they want to move, which is a great motivator! (More on this)
But is it safe? What if people fall over? Well, the therapist is always around! Meanwhile, scientists are creating devices that match the user’s anatomy better and are more in tune with all the rotations and concealed translations of human joints. One solution is a weight support lower-extremity-exoskeleton (LEE). It uses deformable rings, resulting in a more precise bodyweight and knee support, promising to help people get moving again faster. (Read more)
Getting on your feet in post-stroke therapy
Approximately two-thirds of post-stoke patients experience walking impairment and 20% develop drop-foot walking – the inability to properly flex the ankle joint while swinging the leg forward.
This is the result of the weakness of muscles involved in lifting the foot.
Walking ability is also limited by weakness of the knee flexion and ‘push-off’ at the beginning of a step.
Physiotherapists work with people and teach them how to get their limbs moving again though compex exercises, but they could use some help.
Some US healthcare providers have now started using powered exoskeletons combined with FES to enable faster recovery of mobility with promising results.