Locked in connections

Season five, episode nineteen of House MD speaks about a patient who, following a cycling accident, suffers from Locked-In Syndrome. In brief, it is a syndrome where a person is only able to communicate through blinking, as they do not have any control over their paralysed muscles.

I do apologise to spoil the episode for anyone, but at some moment, the medical team messes up, and the patient loses his blinking ability, and the doctors can no longer determine if he is braindead or not. Their twisted solution? A BCI: Brain-Computer Interface.

The way it worked in the episode, was that the patient was asked to try to move an arrow on a screen, up meant Yes, down meant No. It took a while, but eventually the patient managed to pull it off, showing thus that he was still mentally present.

Of course, House MD is a TV series, however BCIs are considered to be the way to aid in cases such as the locked-in syndrome. In fact, as early as 2002, a BCI was successfully used to get a patient suffering from the syndrome to answer yes / no questions, instead of the traditional “blink once for yes, twice for no” method. In 2006, the technology was already so advanced to allow someone to use a web browser using a BCI [1].

The usage of BCIs is of course not limited to people suffering from the locked-in syndrome, and many different neurological diseases benefit from their usage. In biref, there are three major types of BCIs. Invasive, partially invasive and non invasive ones.

Invasive ones concist in electrodes that get implanted into the brain itself, thus resulting in highest quality signals, but having complications associated with them, as our brain is not supposed to have electrodes in them (nature said so). Partially invasive ones are still within the skull, but rather on the surface of the brain, not inside of it. Non invasive ones make use of external neuroimaging using various techniques, and therefore do not require surgery.

The way these systems work are of course complex and deserve an entire post on their own, however the key takeaway from this topic should be that even the faintest neurological signals can be somehow processed and exploted in a way to manipulate a computer. We have come a long way, and the tehnologies keep evolving thanks to highly specialised research field. Hopefully in the future, neurological diseases that once isolated people from society can reintegrate them, if not physically then at least mentally.

[1] Karim AA, Hinterberger T, Richter J, Mellinger J, Neumann N, Flor H, Kübler A, Birbaumer N. “Neural internet: Web surfing with brain potentials for the completely paralyzed”. Neurorehabilitation & Neural Repair. 40 (4): 508–515