Neurostimulation (a.k.a. neurostim), which uses targeted electrical pulses to alter nerve activity in order to treat a variety of conditions, sounds like a recent invention. But there are records as early as 46 A.D. of people using electric torpedo fish as an early form of transcutaneous electrical nerve stimulation (TENS) to treat people suffering from gouty arthritis. Even then, people knew a precise zap to a specific affected area provided an effective treatment for challenging conditions.
 
Today’s neurostim devices are used both externally (like TENS, though without the use of fish) or internally as implants to treat a variety of conditions. Thanks to clinical and technological innovations, neurostim devices are able to deliver targeted pulses to areas like the spinal cord (for chronic pain treatment), deep brain (Parkinson’s, depression, or epilepsy), and vagus nerve (epilepsy, depression), among many others. In many cases, using a neurostim device can provide treatment for conditions that don’t respond well to drug therapies, or else have no other effective treatments.
 
The neurostim market has flourished as proof of these devices’ effectiveness has mounted. In order to get insight on neurostim technology trends and how these devices are built, I spoke with Steven Scott, director of product development at Heraeus Medical Components, a St. Paul, Minn.-based global business unit of Heraeus Holding GmbH.

Sam Brusco: What high-level trends have you noticed in neurostimulation technology?
 
Steven Scott: We are seeing an increasing number of channels for devices that contact the brain with the intent of improving targeting capabilities for delivering therapy and/or sensing capabilities for assessing the patient’s condition for therapeutic needs. Additionally, we see an increasing number of channels for spinal cord stimulation, and expanding interest and energy around vagus nerve stimulation, along with development of cuff electrodes.

Brusco: Which components specific to neurostim technology do you manufacture? What challenges are involved in making these parts?
 
Scott: We currently supply titanium housings, conductors (cables, coils), and a variety of machined components to neurostimulation manufacturers. We also assemble finished devices from procured components using our supply chain expertise.

Brusco: What services beyond manufacturing can you offer neurostim device developers? 
 
Scott: We offer complete medical device design and development services through the engineering process and verification/validation testing. We build and evaluate prototypes, test design and development, and provide clinical input such as implantation methods and physiological impact evaluations.

Brusco: How do neurostim device makers benefit from partnering with Heraeus, as opposed to making the devices in house?
 
Scott: We are completely unique in the market because of our combination of concept and design skillset, testing services, strong process development, supply chain management practices, and scalable manufacturing capability. In addition, throughout our development process, we anticipate delivery and deployment systems challenges. We truly are developing the technology here to support our partners with all of their design and development needs.

Brusco: What advancements in or new therapeutic areas for neurostim technology/components do you anticipate in the next few years?
 
Scott: It is expected stimulation of the vagus nerve will continue as additional therapies are identified. Therefore, we expect the accepted stimulation/sensing tool, the cuff electrode, to be a focus for continued development. Along with the need for more stimulation/sensing channels, we anticipate the commensurate development of new connection methodologies for lead body configurations and electrode arrays. We also see the expanding use of non-conventional ways to access the brain, like vascular pathways. For therapies, we see the increased use of targeting technologies like directional and micro electrodes. For devices, we see the increased application of multiplexing technologies to balance high channel counts with physical limitations of the current connector technologies. Continued activity and advancements in the brain-activated functions such as prosthetic control are also anticipated.

For more information about neurostimulation technology, check out "Shock to the System: An Examination of Neurostimulation Technologies" as featured in the September issue of MPO.