Real-time EEG Enables New Applications for Medical Research and Technology

"Flying Blind"

TMS is already being used successfully for neuropsychiatric diseases such as depression, chronic pain, tinnitus, obsessive-compulsive disorders (OCD) or mental and motor disorders, as a result of strokes, and is approved as a therapy method.

Although the accuracy of positioning the TMS coils over specific brain regions has generally improved, the use of these precise methods requires an even more precise therapeutic targeting. Until now, the timing of sending out the stimulation impulses has been determined more or less while "flying blind". For this reason, TMS therapy has so far not been individually tailored to individual patients.

On the one hand, this reduces the effectiveness of the application. Just like drug-assisted treatments, the method does not work equally well for every patient. On the other hand, not all health insurance companies pay for the treatment since the effectiveness cannot yet be consistently proven.

When Every Millisecond Counts

EEG in real-time is currently particularly important in medical research, where the current state of the brain must be detected in real time in order to set an impulse at exactly the right time and thus achieve a therapeutic effect. To do this, a complex signal must be recorded, processed and transmitted by the EEG within milliseconds in order to be able to trigger a TMS impulse, for example.

sync2brain has developed the solution “bossdevice´ for such research applications. The solution is a real-time digital signal processor consisting of hardware and software algorithms. It is designed to read-in a real-time raw data stream from a bio-signal amplifier (electroencephalography, EEG), to continuously analyze this data and to detect patterns based on oscillations in different frequencies. When such a specific bio-signal pattern is detected, the device indicates this through a standard output port. This enables a connected device to know with millisecond accuracy when a specific bio-signal pattern occurs.

The basis for this application is an extremely accurate and fast EEG solution. EEG amplifier systems must digitize and process a signal. In most systems, it is then sent to a PC using large data packets, for example. However, this leads to longer latencies. These are so small that they are not significant for many applications. Even with applications that are currently attracting a great deal of research and media interest, such as brain-computer interfaces, one can afford a few milliseconds of delay. However, there are research and therapy areas where the speed and regularity of the signal is crucial – for example in EEG-synchronized TMS.

To ensure the necessary accuracy and speed, Bittium NeurOne™ is used as compatible EEG. The solution was specifically designed for clinical research purposes and the needs of medical professionals and scientists to simultaneously detect high-precision neurophysiological signals from multiple channels without compromising data integrity. The real-time DigiOut functionality enables TMS stimulation at a specific point in time of the EEG wave, based on the 10 Hz alpha frequency/phase – i.e. the alpha rhythm in the occipital area or mu rhythm in the motor area.

"Bittium started very early to enrich the signal with intelligence so it can be immediately forwarded to the device. Processing takes place within the Bittium NeurOne hardware unit, without detours through a PC or other hardware and software,´ explains Antti Näykki, Senior Vice President, Medical Technologies at Bittium. "In this way, researchers gain insight into brain activity within milliseconds before the next brain wave activity."

“With the Bittium solution, the signal comes absolutely regularly with a constant delay of 3.5 milliseconds. This reliable timing, also known as low jitter, and the low latency are crucial for this application,´ confirms Dr. Zrenner.