DEPARTMENT OF DEFENSE - CONGRESSIONALLY DIRECTED MEDICAL RESEARCH PROGRAMS

Safety and efficacy validation of the Stentrode: Translation of a novel brain-machine-interface into clinical application

Principal Investigator: OPIE, NICHOLAS L
Institution Receiving Award: MELBOURNE, UNIVERSITY OF
Program: SCIRP
Proposal Number: SC160158
Award Number: W81XWH-17-1-0210
Funding Mechanism: Translational Research Award
Partnering Awards:
Award Amount: $1,131,080.00


PUBLIC ABSTRACT

At present, there is no cure for the millions of people worldwide paralyzed by spinal cord injury. For many of these people, the portion of the brain responsible for limb movement remains intact and functional. However, due to spinal cord damage, neural signals cannot be delivered from the brain to limbs to actuate movement.

We are developing a technology that can potentially extract thoughts, in the form of neural signals, from the brains of people with paralysis. These neural signals can in turn be used to control prosthetic limbs, computers, exoskeletons, and vehicles. Recent research has demonstrated that electrodes implanted in the brain can be used to extract brain signals to enable control of external equipment. This research may eventually have a significant impact on the quality of life for people with paralysis, offering hope for the return of mobility and independence. However, in order to access the brain to implant the necessary electrodes, surgery is required to remove part of the skull. Twenty-six percent of these invasive, open-brain-surgery procedures have complications that result in bleeding, infections, or death. Furthermore, implantation of these needle-like electrode arrays require pneumatic insertion directly into brain tissue at high speed and force, which has been shown to cause damage to the tissue and renders many electrodes useless after a period of months. These complications have significantly hampered clinical translation. Our technology offers a solution that obviates the need for skull removal because the electrodes can be implanted through blood vessels using minimally invasive techniques that are routinely practiced clinically to remove clots in people suffering from a stroke. The complication rate of this technique is less than 1%.

We have developed an electrode array that can be implanted to the brain through blood vessels. This removes the risk of invasive surgery and damage to the brain caused from direct implantation. We have conducted proof-of-concept trials in a large animal model and have demonstrated that we can implant a brain recording electrode array safety over the part of the brain that controls movement. Further, we have shown that we can use the device to extract and decode brain signals related to intentional movement. We have also demonstrated preliminary safety of our device, with no adverse events observed in animals implanted for durations of up to 190 days. Our current objective is to conduct preclinical safety trials that will enable translation of this research into clinical application. We will first outsource fabrication of our prototype brain sensor to a US Food and Drug Administration (FDA)-approved medical device manufacturer. The prototype will be assembled using proven biocompatible materials and will utilize a commercially available, FDA-approved stent as a scaffold on which to mount the recording electrodes. We will conduct mechanical tests to validate the capacity of the prototype to tolerate forces generated during device implantation and movements encountered over the lifetime of the patient. Preclinical animal tests will be conducted to demonstrate that the prototype devices can be implanted reliably and repeatedly without damaging vessels or neighboring tissue. Additional tests, conducted for up to 6 months, will be performed to demonstrate the durability of our manufactured prototype system and the capacity to safely record brain activity from awake and freely moving animals. Upon successful completion of this project, we will have developed a prototype electrode array that is suitable for long-term implantation in humans.

We aim to implant our technology in a first-in-human clinical trial in 2019. Our technology has the potential to enable people with spinal cord injury to control computers, exoskeletons, and vehicles using direct brain control. Provided there is no substantial damage to the brain and there are no vascular abnormalities, the level of the spinal injury or lesion is irrelevant. Our initial pilot trial will identify and optimize the training protocols required for an implanted pilot to control electromechanical equipment; however, prior research conducted with invasive arrays has indicated this may be achievable in as little as 2 weeks. We anticipate that following success of our human pilot trial and the proceeding global clinical trial, our technology may be clinically available as early as 2022.