Chronic pain, hearing loss, sleep apnea, Parkinson’s disease, epilepsy, paralysis from stroke or spinal cord injury. These are among a growing array of medical conditions that physicians are now treating with neurotechnology devices, which deliver electrical stimulus to limbs and organs. One Battelle Labs device under development even uses the brain itself to activate muscles in a paralyzed patient’s hand via an electronic “Neurobridge” sleeve worn on the forearm.

For Hunter Peckham, a PhD engineer and biomedical professor at Case Western Reserve University, the growth in neurotechnology is nothing short of astounding. A co-founder of Cleveland’s Functional Electrical Stimulation (FES) Center and one of the nation’s leading experts in the field, Peckham spoke with Engineering360 editorial contributor Larry Maloney about progress being made in a technology he helped to pioneer more than four decades ago.

Maloney: How has neurotechnology changed over the last 40 years?

Peckham: The field has simply exploded, whether you’re talking about the conditions being treated, the kinds of devices being developed or the number of companies getting involved.

Hunter PeckhamHunter PeckhamWhen we first started our work in developing FES devices for patients with spinal cord injury, there were only a few products out there. Then, in the early 1990s, we saw a notable pick up in cochlear implants, which involve electrical stimulation of the auditory nerves. And in the last decade, there’s been an explosion of new technology to stimulate the spinal cord, the peripheral nerves that control limbs and organs and now even the brain itself.
President Obama has announced the BRAIN Initiative, which promotes innovative neurotechnology to advance brain research. Such developments make this field one of the fastest growing areas of the medical device industry.

Maloney: To what extent is neurotechnology becoming a realistic alternative to other modes of treatment, such a surgery or medication?

Peckham: It depends on the medical condition. For example, you can’t give a medication to restore hearing, thus the strong interest in cochlear implants. For other conditions, such as Parkinson’s disease, a physician typically will treat the patient with medication until that approach is no longer effective. Then, deep brain neurostimulation may be called for. Neurostimulation of the sacral nerve for bladder control also is increasingly being used when other therapies fall short.

The challenge we have in FES for spinal cord injury is that the patient population is relatively small. That’s a stumbling block when it comes to underwriting marketable devices. The largest single application, in terms of numbers of patients, is neurostimulation of the spinal cord for those suffering from chronic pain, with devices from such medical giants as Medtronic, St. Jude and Boston Scientific.

Maloney: What are the common features of today’s neurotechnology products?

Peckham: Like electronic products in other fields, such as computers and smartphones, neurostimulation devices have become more compact, more ergonomic and at the same time much more complex and powerful. The software and control schemes that govern these devices are getting ever more sophisticated, and battery life is much longer. And while early neurotechnology devices typically featured implantable electrodes linked through the skin to external stimulators and controllers, most devices today are fully implantable. You can even reprogram the software and recharge batteries wirelessly without ever having to remove the implant.

Even so, there are still many applications that use an external device for short-term stimulation, such as those that relieve shoulder pain in stroke patients. With the large population of stroke patients, the Cleveland FES Center is devoting about half its research to neurotechnology for stroke victims.

Maloney: Can you cite an important new technology under development at the FES Center?

Peckham: A good example is the Networked Neural Prosthesis for patients with spinal cord injuries. It’s a fully implantable, rechargeable device that is also scalable, depending on the number of muscles that need to be stimulated or organs to be sensed for such functions as hand grasp or arm movement. For a patient with an upper extremity spinal cord injury, the system would typically include a power module and a myoelectric sensor module connected by cables to muscle-based stimulators. Through myoelectric signals from the muscles, this device senses the patient’s desire to move a hand or arm and then provides the needed electrical stimulus.

We view this device as a network platform that could be used for a variety of stimulus implications, from hand or leg movement to bladder control. We are completing our work for an FDA (Food and Drug Administration) Investigational Device Exemption so that we can begin clinical trials in humans.

Maloney: But aren’t you still faced with a tough challenge in getting such a device to market?

Peckham: That’s the case with many neurotechnology devices, which is why we are trying a new approach. About a year and a half ago, I stepped down as director of the Cleveland FES Center, which is now headed by my long-time engineering colleague, Robert Kirsch, to focus on ways to get these new technologies out the research door and into the marketplace.

To that end, I founded a new Institute for Functional Restoration, based at Case Western Reserve, which is dedicated to taking the risk out of bringing such products at the Networked Neural Prosthesis to market. By raising money through philanthropy, as well as through sales and grants, this nonprofit institute will underwrite much of the development and clinical trial work of technologies coming out of the FES Center. We believe this new approach will make neurotechnology less risky to companies that might later partner with us or license our technology.

Maloney: What’s the potential of devices aimed at using a patient’s brain to enhance a paralyzed patient’s motor skills, as in Battelle’s “Neurobridge” system?

Peckham: It’s an area that is attracting a lot of attention. Many research centers are doing work on brain-computer interfaces, including a project at the FES Center. Borrowing from pioneering work by a company called CyberKinetics, these interfaces seek to harness signals from the brain to allow severely motor-impaired patients to control a computer, appliances or a prosthetic arm.

This technology is still in its infancy, but current systems typically consist of electrodes implanted in the brain and connected to a pedestal containing an amplifier and signal conditioning. The pedestal, which can be located on top of the skull or just beneath the scalp, interfaces with a computer.
Whatever the neurotechnology device, a major design challenge is to create effective interfaces with the body’s own sophisticated neurological pathways. You must capture these neurological signals, dissect them or amplify them, depending on the application. That’s why so much work is being done in developing better electrode interfaces.

A good example of the progress being made in closed loop systems is a new epilepsy product called the RNS Stimulator, approved last year by the FDA. Consisting of a small stimulator implanted just under the scalp and connected to electrodes placed in the area of the brain where epileptic seizures originate, the device senses abnormal electrical activity and responds by delivering stimulation to prevent seizures.

Maloney: What other evidence do you see of neurotechnology’s growth?

Peckham: Many more companies are getting involved, not just the giants but also start-ups, including several in Northeast Ohio that are staffed by engineers and others who gained experience in neurotechnology at Case Western Reserve, MetroHealth Medical Center and the Louis Stokes VA Hospital, which all participate in the FES Center.

For example, NDI Medical developed an electrical stimulator for bladder control that it sold to Medtronic. SPR therapeutics, an NDI spinoff, develops neuorostimulators for pain relief. Neuros Medical also focuses on pain control, using an electrical nerve block, while Synapse Biomedical’s stimulator aids breathing in patients suffering from ALS and spinal cord injury. Such companies in turn have spawned all sorts of supplier firms that make the specialized components that go into neurostimulators, such as connectors and leads.

More universities have also begun engineering programs in neurotechnology, such as the University of Minnesota and the University of Louisville. The National Science Foundation has a big program called Engineering Research Centers, and one of these – at the University of Washington – is devoted to neurotechnology. The field is particularly attractive to young engineers, especially women, who have a strong interest in helping patients. Half of the graduate students in our biomedical engineering program at Case Western Reserve are women.

Maloney: How about acceptance by the medical community?

Peckham: Doctors and other clinicians are far more accepting than they were 40 years ago, and continued progress in this field depends on a close working relationship between clinicians and engineers. In fact, the whole environment has changed for the better, including the FDA approval process and government funding from such bodies as NIH and the Veteran’s Administration. Patients, too, are much more open to this technology, having already embraced such innovations as artificial joints, cardiac pacemakers and heart stents.

Additional Resources:

Cleveland FES Center

Kentucky Spinal Cord Research Center

National Science Foundation Engineering Research Centers