Thin-Film Electrodes for Brain Surgery Reach the Market

In the next few months, as many neurological surgeries are likely to be rescheduled in the aftermath of the COVID-19 lockdown, thin film electrode technology is poised to reach the market.
 
Developers and manufacturers of medical devices should take note and understand the potential benefits of this patented technology—thin film electrodes may reduce patient complications during neurosurgery procedures, provide better signal clarity in recording brain activity, and potentially lower the cost of care if the device allows for shorter patient stays in the hospital. Furthermore, thin film electrodes have the potential to improve patient comfort during and after surgical procedures due to the product’s lightweight feature.
 
Designed to record brain activity and stimulate brain tissue for up to 30 days, we expect this technology to generate significant interest from neurologists and neurosurgeons managing patients with epilepsy and brain tumors.
 
Given its thin-film properties, this cortical electrode technology may enable minimally invasive delivery through a reduced size craniotomy. This capability is a significant improvement over current, commercially available silicone electrodes, which are heavier and thicker than the new thin film electrodes. Further, the silicone electrodes are generally handmade, making them costly and time-consuming to manufacture, and the silicone base of existing electrode technology does not optimally conform to the brain as well as thin film polyimide material does. The current technology is also limited in its ability to increase the recording resolution due to the signal artifacts caused by the swelling in the brain. In contrast, new polyimide thin film technologies may provide higher resolution recording for more advanced clinical applications.
 
Customization
Thin film electrodes utilize technology advances to generate high-density electrode arrays that may be customizable per physician request. The flexible design should allow a less invasive placement onto the brain compared to the large craniotomy method used for currently available electrodes. Furthermore, the potential to significantly increase the resolution of brain recordings may enable the usage of powerful computing techniques, such as machine learning and artificial intelligence.
 
Developers of this innovative technology anticipate that the replacement of current silicone electrodes with polyimide substrate electrodes for the acquisition of intracranial EEG could provide enhanced clinical electrophysiological value with reduced cost, infection risk, and patient discomfort. Due to its potential to be placed with minimal invasiveness, along with its single tail design, thin film electrode technology may mean fewer post-procedure complications and should reduce the risk of infection.
 
Potentially Important Advance for Epilepsy Market
According to the World Health Organization’s (WHO) report on epilepsy in 2017, nearly 50 million people have been diagnosed with the disorder around the word. In the U.S., approximately 3.4 million people suffer from epilepsy, and an additional 150,000 people are diagnosed every year. The CDC estimates that epilepsy costs the U.S. $15.5 billion per year. Approximately 30% (720,000) of people with epilepsy in the U.S. are not receptive to pharmaceutical treatment, making them appropriate candidates for surgical treatment.
 
Currently, a person with epilepsy is typically treated with medications. If the pharmacological therapy is not successful, the patient may then undergo an invasive surgical procedure to help identify the areas of the brain that are causing the seizures. This procedure, referred to as iEEG or sEEG, is the practice of recording electroencephalographic signals via cortical or depth electrodes. After the diagnostic procedure, a second therapeutic surgical procedure is performed to treat the seizure onset location. The success rate of seizure freedom after surgery ranges between 30% to 70% depending on the seizure location and surgical treatment.
 
Because of the invasiveness of a craniotomy, neurosurgeons that perform epilepsy surgery predominantly use sEEG electrodes since they can be placed less invasively through a stereotactic procedure. There are clinical scenarios where implanting cortical electrodes and sEEG would potentially provide a more complete map of the brain by obtaining recordings from the surface and deep structures of the cortex. Physicians also recognize the potential of thin film electrodes for applications with Parkinson’s disease, dystonia, essential tremors, and pain management for failed back surgery syndrome.
 
Better for the Brain
Today, about 30% to 40% of people with epilepsy are candidates for surgery but only 3% undergo surgery. Companies, such as NeuroOne, are now able to provide thin film electrode arrays for clinical practice and human research. This could lead to more people opting for surgery because of the potentially less invasive—and less alarming—nature of the surgery.
 
Leveraging thin film technology could be a defining moment in the world of medical devices by allowing the patient to receive “optimal mapping” of the brain. This enables the evaluation of activity both deep in the brain and from the surface by utilizing both cortical and depth electrodes simultaneously.
 
Thin film strip, grid and depth electrodes made with lithographic polymer film technology are an effective way to increase mechanical flexibility and reduce mass. This is better for the brain because they weigh less than traditional electrodes and conform more completely to the brain for more direct contact.
 
Polyimide thin film electrodes are thinner, lighter, and offer fewer electrode tails exiting the brain—thereby potentially reducing the risk of infection. Given their flexibility and versatility, it’s no surprise that this technological advance is attracting considerable interest from hospitals and research centers around the globe.
 
Furthermore, this technology’s hi-definition recording may enable the doctor to be more precise in identifying the problematic tissue. Contacts on the electrodes may be scaled down in size, improving the ability to increase resolution, as well as customize electrode configurations to meet physician requests. Given its automated manufacturing system, this technology also shows promise for reducing lead times to customers.