Bridge Neurotech has raised $13.5 million from General Catalyst, reMind Capital, Sunflower Capital, Scott Sandell, and other investors to advance a non-invasive brain-computer interface designed to decode human brain activity using functional ultrasound imaging.
The Silicon Valley-based company was founded by Will Biederman, Ph.D., who previously developed the neural interface chip used by Neuralink for its first implants and spent nearly a decade at Verily and Google designing healthcare technology.
Biederman also co-founded Forest Neurotech, where he led development of what he described as the first miniaturized functional ultrasound imaging device designed to image the human brain.
Bridge Neurotech is now seeking to apply advances across neuroscience, semiconductors and artificial intelligence to create a brain-computer interface that does not require surgery or an implanted device.
Existing implantable BCIs have demonstrated the ability to create direct links between neural activity and computers, potentially allowing people with severe physical disabilities to communicate with or control external systems.
However, Biederman noted that implantable systems require neurosurgery and have so far reached only around 100 people.
Bridge’s goal is to create an alternative that could eventually make brain-computer interfaces accessible to a much larger population.
The company is building its technology around functional ultrasound imaging, which uses ultrasound to observe changes associated with neural activity.
Biederman believes recent progress in three areas has made a practical non-invasive ultrasound-based BCI increasingly feasible.
The first is neuroscience. Functional ultrasound research has demonstrated the ability to decode human neural activity through openings in the skull while achieving spatial resolutions that Biederman says are not possible with functional magnetic resonance imaging.
The second is semiconductor technology. Ultrasound arrays and the electronics supporting them can increasingly be integrated into compact chips, while the computing resources available to process resulting data have improved substantially over the past several years.
The third is artificial intelligence.
Bridge expects increasingly capable decoding models to identify useful neural signals within data that previously might have been treated as noise, potentially improving the ability to interpret brain activity over time.
The fundamental technical challenge is the human skull.
Bone both scatters and absorbs sound, and the characteristics differ between individuals. Bridge aims to overcome those variations to produce and decode functional images of the brain in real time without surgically creating an opening in the skull.
If successful, the technology could provide a new approach to brain-computer interfaces that avoids one of the largest barriers associated with current systems: invasive brain surgery.
For people whose physical movement has been significantly impaired, the company sees BCIs as a potential means of giving the mind another way to interact with the external world.
Bridge also believes the technology could eventually have applications beyond patients with severe physical limitations by creating new ways for people to interact with computers and other systems.
The company has begun its first research study in Redwood City, California.
Bridge is currently enrolling adults who have undergone a cranioplasty using a PEEK or Longeviti implant, as well as healthy adults age 18 and older.
The study represents an early step toward determining whether Bridge can generate and decode the functional brain imaging required for its non-invasive approach.
The new $13.5 million in funding will help move the technology into its next stage of research and development as the company works toward an ultrasound-based interface capable of reading brain activity through the skull.
Bridge describes its long-term objective as building “a non-invasive interface for the mind, built with sound.”
