The device is both wirelesses as well as autonomous, which means that once it becomes trained to recognize abnormal electrical current in the brain, it is capable of delivering suitable electrical impulses automatically to prevent the undesirable and debilitating movements.
Additionally, it is a closed-loop system meaning it is able to simultaneously record and deliver electrical impulses in real time as stated above. Details of the WAND and how it functions appear in the journal Nature Biomedical Engineering
About the WAND in Brief
"In order to deliver closed-loop stimulation-based therapies, which is a big goal for people treating Parkinson's and epilepsy and a variety of neurological disorders, it is very important to both perform neural recordings and stimulation simultaneously, which currently no single commercial device does,"
- WAND can record electrical activity at 128 different points in the brain compared to currently available closed loop systems which detects impulses only at eight points. The team demonstrated the working of WAND to detect and delay the occurrence of specific arm movements in rhesus macaques.
- Currently, closed loop systems either stop recording brain activity while delivering impulses or record at a different site other than where current is delivered. This closed loop system can be programmed for use in several clinical as well as research applications.
said former UC Berkeley postdoctoral associate Samantha Santacruz, who is now an assistant professor at the University of Texas in Austin.
- The engineers who created the WAND have incorporated a chip design that enables recording of the full signal from both abnormal the brain current as well as the stimulation impulse delivered.
- The chip design helps to accurately record the brain electrical activity by subtracting the signals arising from the stimulatory electrical current
According to Rikky Muller, who led the team that designed the WAND custom integrated circuits, "Because we can actually stimulate and record in the same brain region, we know exactly what is happening when we are providing a therapy."
- Current devices can only record signals from the smaller brain waves and are overshadowed by the bigger stimulation pulses, making this kind of precise signal reconstruction impossible.
Testing the WAND in Humans
"While delaying reaction time is something that has been demonstrated before, this is, to our knowledge, the first time that it has been demonstrated in a closed-loop system based on a neurological recording only,"
- The WAND was tested by the study team in human subjects to evaluate its efficacy.
- The subjects were asked to use a joystick to move a cursor on the computer screen to a specific location.
- Following an initial training period, the WAND was able to detect the electrical impulses in the brain that were generated as the subjects became ready to perform the above movement (shifting the cursor), and it delivered an appropriate electrical stimulation that delayed this motion.
For future research, the team plans to build intelligent devices with a closed loop system that can be gradually trained to treat the patient on its own without the constant need for a doctor's intervention.
The WAND is another example of how artificial intelligence could be applied in medicine to treat and improve the quality of life of patients. References :
- A wireless and artefact-free 128-channel neuromodulation device for closed-loop stimulation and recording in non-human primates - (http://dx.doi.org/10.1038/s41551-018-0323-x)