or mobility . I can ’ t help recalling the most inspiring and famous story of Professor Stephen Hawking , who was diagnosed with motor neuron disease at the young age of 21 ; beating all odds , he managed to become one of the most respected physicists of the century . Many of you may have watched the movie The Theory of Everything ( 2014 ) portraying his life and accomplishments . His book A Brief History of Time : From the Big Bang to the Black Holes 2 remains one of the most popular science titles . He lost his speaking ability apparently after undergoing tracheotomy in 1985 but managed to communicate with the use of a voice synthesizer . For his writing , initially he used a spelling card to choose the correct letter or word by raising his eyebrows . Later he used a computer program called “ Equalizer ” which allowed him to select letters , words or phrases from a collection of 2,500-3,000 words by pressing a switch with his thumb . This coupled with the voice synthesizer allowed him to deliver many of his famous lectures and speeches .
Progressive hand weakness impaired the ability to use the thumb switch technique and he had to depend upon the intact facial muscles around his cheek and eyes . An infrared switch mounted on his spectacles sensitive even to minimal movements of those muscles allowed communication with his computer , a tablet mounted on the arm of his wheelchair . An adaptive word predictor , developed specifically by storing words from many of his scientific papers , made the process faster . Professor Hawking passed away at the age of 76 in 2018 , but the technology that allowed him to communicate has benefited many others with similar disability . I can only imagine how thrilled my teacher with ALS would have been , if similar devices were available then .
While many of these augmentative and alternative communication ( AAC ) devices are quite useful , the more exciting field is the rapidly developing brain-computer interface ( BCI ) technology . BCI has the potential to use one ’ s own brain activity to operate external devices - which very much sounds like telekinetic ( psychokinetic ) power portrayed by Matilda and other fictional characters . In principle , brain electric activity is used as a medium of communication with a computer . The computer output is designed to initiate and control an external device like a prosthetic or a robotic arm . The term BCI was introduced by Vidal in 1973 3 and his goal was to use signals from human electroencephalogram ( EEG ) to control objects , equivalent to an “ EEG switch .” Brain electric activity at rest and during motor imagery can be collected by non-invasive ( scalp-recorded EEG ) or by more invasive techniques : placing electrodes over the cerebral cortex ( electrocortical ) or within the cortex close to the neurons ( Intracortical ) recording . A variety of brain electric signals such as the alpha rhythm , mu rhythm , contingent negative variation and P300 are being explored .
Motor imagery , the mental simulation of movements , can be used as a BCI stimulus , where the thought of movement by the user can be translated into a real movement , helping patients with motor disability . Several BCI systems have been developed by neuroscientists in the recent years . In 2021 the FDA designated a form of BCI as “ Breakthrough Device ” for the first time ; the device called “ IpsiHand ” system is designed to improve hand function in stroke patients . Dr . Eric Leuthardt and his team at Washington University School of Medicine were instrumental in developing the device . 4 It consists of a wearable robotic exoskeleton that is placed over the paralyzed hand , which is operated by motor imagery . The electric activity of the intact side ( ipsilateral ) of the brain evoked by motor imagery is used to provide mobility to the paralyzed hand using the “ IpsiHand .” In this setup EEG signals are gathered non-invasively using a head cap with numerous electrodes . More recently “ MoveAgain ,” a BCI system with an array of implanted electrodes to pick up neuronal activity , transmits wirelessly to an external device such as a cursor or wheelchair or a prosthetic device . In “ BrainGate ” technology 100 microelectrodes placed within the motor cortex serve to pick up the brain electric activity . Yet another device , “ Stentrode ” uses a stent to deliver intracranial electrodes through the jugular vein and place them close to the motor cortex in the superior sagittal sinus , avoiding the need for craniotomy . Two recent papers report very few adverse events in quadriplegic patients in whom BrainGate or Stentrode was used to regain lost motor functions such as typing or controlling a robotic hand . 5 , 6
Have we achieved the power of telekinesis yet ? The answer : we are almost there , but many more innovations are needed . It is good for neuroscientists developing BCIs to follow Thomas Edison ’ s great advice : “ There is a way to do it better – find it .”
References :
1
Matilda . Roald Dahl . 1988 . Jonathan Cape , UK
2
A Brief History of Time . Stephen Hawking . 1996 , Bantam Books . New York
3
Vidal JJ . Toward direct brain-computer communication . Annual Review of biophysics and bioengineering 1973 ( 2 ) 157-180
4
Bundy DT et al . Contralesional brain-computer interface control of a powered exoskeleton for motor recovery in chronic stroke survivors . Stroke 2017 ( 48 ) 1908-1915
5
Robin DB et al . Interim safety profile from the feasibility study of the BrainGate neural interface system . Neurology 2023 Epub 2023 Han 13
6
Mitchel P et al . Assessment of safety of a fully implanted endovascular brain-computer interface for severe paralysis in 4 patients : The Stentrode with thought-controlled digital switch study . JAMA Neurol 2023 Epub 2023 Jan 9
Dr . Iyer practices at the Neurodiagnostic Center of Louisville and is a retired professor of neurology at the University of Louisville School of Medicine .
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