Rice University Engineers Develop Miniature Brain Stimulator for Safer and Less-invasive Neuromodulation

Published in the April 12 issue of the journal Science Advances, researchers and engineers from Rice University have achieved a groundbreaking feat in neuromodulation technology with the development of the smallest implantable brain stimulator ever demonstrated in a human patient. The device, called Digitally-programmable Over-brain Therapeutic (DOT) microstimulator, is only 9 millimeters in width, marking a significant advancement in the treatment of drug-resistant depression and various neurological disorders.

Developed in collaboration with Motif Neurotech, together with clinicians Dr. Sameer Sheth (from Baylor College of Medicine) and Dr. Sunil Sheth (from McGovern Medical School at UTHealth Houston), this pea-sized battery-free device offers a wireless and less invasive solution to stimulate the brain through the dura mater (dura), the thick protective membrane made of connective tissue that surrounds the skull.

Related article: Neuralink Ground-breaking Brain Implant Makes its First Stride in Human: Potential for Paralysis Recovery

Overcoming Limitations in Existing Neuromodulation Technologies

Neuromodulation technology involves the alteration or adjustment of nerve activity by delivering pharmaceutical agents or sending electrical signals directly to target nerves. One possible way to achieve this is the use of implantable devices that electrically stimulate the central or peripheral nervous system. Applications of these devices in treating psychiatric, movement, and pain disorders, as well as restoration of movement after spinal cord injuries are on the rise around the world. 

However, traditional implantable neuromodulation devices face challenges such as patient perception of risk, high procedural costs, and long wait lists for complex surgical procedures. According to Dr. Jacob Robinson, Professor of Electrical and Computer Engineering and of Bioengineering at Rice University, one of the key milestones of this innovation lies in eliminating the need for large batteries and extensive surgical procedures by utilizing wireless power transfer technology that converts magnetic fields into electrical pulses. With dimensions as small as 9 mm in width, the DOT can deliver a stimulation voltage of 14.5 V, corresponding to stimulation pulses of approximately 6.75 to 14.5 mA of current.

On the one hand, this breakthrough streamlines the implantation process, which only takes a 30-minute minimally-invasive procedure that does not require hospitalization. On the other hand, the innovative technology ensures reliable and efficient power delivery to the device, avoiding drawbacks of invasive procedures (such as craniotomies) or battery-related complications.

Joshua Woods, graduate student in Prof. Robinson’s lab and the lead author on the study, highlighted the DOT’s unique capability to stimulate cortical activity, noting that, “this has not been done before because the quality and strength of the signal needed to stimulate the brain through the dura were previously impossible with wireless power transfer for implants this small.”

A Glimpse into the Future of Neuromodulation Therapies

By enabling precise neuromodulation with less-invasive surgical intervention, the DOT also holds promise to significantly expand the accessibility of bioelectronic therapies. Following successful demonstrations of acute motor cortex activation in human patients and reliable chronic activation in pig models, the platform paves the way for simpler surgical procedures and personalized treatment regimens. 

Dr. Sameer Sheth, Professor and Vice Chair of Research of the Department of Neurosurgery at Baylor College of Medicine, underscored the potential impact of this innovation on mental health care. By offering a minimally invasive alternative to traditional deep brain stimulation, the DOT could overcome barriers to adoption and reach a broader population in need of effective neuromodulatory therapies.

Also the founder and CEO of Motif Neurotech, Prof. Robinson expressed optimism about a future where patients can administer neurostimulation treatments from the comfort of their homes, simply following the prescription and guidance from their physicians. “The patient would put on their hat or wearable to power and communicate with the implant, push ‘go’ on their iPhone or their smartwatch and then the electrical stimulation from that implant would activate a neuronal network inside the brain,” he said.

Moreover, the DOT excels in its versatility of applications, including indications requiring the device be on permanently or most of the time like epilepsy, and those only necessitating daily stimulation over several minutes for desired effects, such as depression and obsessive compulsive disorder (OCD).

Rice University engineers have developed a novel implantable brain stimulator that is only 9 mm in width, the smallest ever demonstrated in a human patient. (Source: Rice University)

Motif Pursues a Human Clinical Trial Following Successful Series A Financing 

As a neurotechnology company formed through the Rice University Biotech Launch Pad, Motif Neurotech is actively probing the potential of brain-computer interfaces (BCIs) to transform treatments for neurological disorders. In late January, the Houston-based startup managed to raise $18.75 million in an oversubscribed Series A financing round, providing the company with necessary funds for advancing the development of its lead product, the DOT microstimulator. As Motif is seeking FDA approval for a long-term clinical trial, the future of neuromodulation therapy looks promising, with the DOT leading the way towards personalized and accessible treatments for mental health and neurological conditions. 

Author

Richard Chau