“The quality of the signals is sacrificed a little by the electrodes being in a blood vessel, rather than directly on brain tissue. But it’s good enough to allow the two participants in the study to accurately type up to 20 characters per minute with predictive text disabled, and do online shopping and banking, all without lifting a finger or using voice commands. “

Source: New Stent-like Electrode Allows Humans to Operate Computers With Their Thoughts – IEEE Spectrum