Neurotech News #2: Form Factor

Updates, research, and analysis by Dynamic Neurotech

Author

Robert Murcko
May 01, 2024

In Today’s Issue

  • Research Round-Up 

    • Mapping brain regions using ultra-high density non-invasive recordings

    • Ultrasound blood brain barrier opening

    • 3D spatiotemporally scalable in vivo neural probes

  • Funding and Acquisition Highlights - Blackrock and Science

  • Editorial: Form Factor- New Design Paradigms May Bring Non-Invasive Neural Interfaces to the Masses

  • Neurotech Survey Results

  • Further Explorations and Reading

Form Factor (Generated by Google Gemini)

Research Round Up: Recent Papers That Caught Our Interest

by Robert Murcko, Yuqing Wang

  • The central sulcus is a structural landmark in the human brain.  It separates the frontal lobe from the parietal lobe.  Zooming into a further level of detail it separates the primary somatosensory cortex from the primary motor cortex.

  • A new “ultra high density EEG system (uHD EEG)” has been utilized by researchers to localize this landmark.  The system can record from up to 1024 channels across the entire scalp.  This study utilized 256 electrodes equally spaced over the sensorimotor cortex.

    Figure 1 (Schreiner et al., 2024)

  • The system and associated algorithms were able to classify electrodes as either posterior or anterior to the central sulcus with an accuracy score of 95.2% using somatosensory evoked potentials (SSEPs).  This accuracy score rivals the levels scored on this metric via invasive intracranial recordings.

  • Importance: Continued development of uHD EEG systems paired with precise head anatomy and source localization algorithms may lead to EEG becoming an even more powerful neuroimaging technique.  The research and development shown here display promising potential improvements in EEG spatial resolution.  The technique already has a relatively strong temporal resolution. A non-invasive, relatively portable neuroimaging technique with high fidelity in both of these domains (temporal and spatial) could open up a whole new frontier in neuroimaging and neuroscience.    

  • Next Steps: Initial next steps will likely focus on advancing the mapping techniques described here and using them to analyze various other regions of the brain. As this technology continues to advance we may see benefits in applications like neurosurgery, brain-computer interfaces, neuromonitoring, diagnostics, rehabilitation, mental health, and more. 

  • COMING SOON: Our interview with contributing author Christoph Guger.

  • Researchers and clinicians have applied focused ultrasound to temporarily open the blood-brain barrier in tandem with monthly aducanumab infusions in patients with Alzheimer’s disease.

  • The trial was a proof-of-concept primarily aimed at investigating the feasibility and safety of combining aducanumab treatment and focused ultrasound stimulation.  There were a total of 3 participants.

  • The trial results were promising.  Few adverse events were reported. Outcomes thus far suggest that this method of treatment is likely both safe and feasible.   

  • While not necessarily a trial focused on treatment efficacy (that step comes later), the trial also showed exciting results related to cerebral amyloid-beta (AB) load.  Reduction in AB load was numerically enhanced in areas treated with focused ultrasound when compared to non-treated homologous regions in the contralateral hemisphere.

  • Importance: While Alzheimer’s causes and treatments are a hotly debated topic in the field of neuroscience, this study is highly important.  It potentially begins to open up the door for further research into the application of focused ultrasound both in the treatment of Alzheimer’s and a broad range of other diseases.  

  • Next Steps:  Likely next steps involve increased sample sizes and research that begins to place more focus on the efficacy of this treatment.  Longer term next steps could include optimizing or personalizing the treatment and figuring out how to apply it to other indications.   

  • COMING SOON: Our interview with contributing author Pierre-Francois D’Haese.

  • Researchers have designed and built a new type of “3D spatiotemporally scalable in vivo neural probe” that aims to improve the trade-off between sensor density and mechanical flexibility.  

  • They developed a PFPE-DMA fluorinated elastomer material with an elastic modulus much closer to that of brain tissue and is over 10k times softer than traditional plastic dielectrics.

  • Using nanofabrication lithography, the researchers created a stacked probe structure with 4 total alternating layers of metal electrode array and elastomer material. The resulting probe achieved a cross-sectional density of 7.6 electrodes per 100 micrometers.

  • This stacked probe retains the elastomer's tissue-level flexibility (E_d) while greatly increasing electrode density compared to previous works. This results in less neural scarring and a lower immune response in vivo, allowing neural activity to be tracked in mice for extensive amounts of time (up to months) without adversely affecting animal behavior.

    Figure 3G (Le Floch et al., 2023)

  • Importance: This allows for a more specific mapping of the long-term activity of the CNS in stable states.

  • Next steps: More rigorous testing of probe flexural rigidity due to elastic modulus mismatch of the metal and elastomer layers. Further work exploring increased electrode density and methods to decrease rigidity caused by stacked metal layers.

  • Our interview with first author Paul Le Floch.

Funding/Acquisition Highlights - Blackrock and Science

There have been two incredibly interesting deals that recently occurred in the world of neurotech. The impacts/implications will be explored in future issues. For now, relevant press releases and analysis found at the links below.

Form Factor: New Design Paradigms May Bring Non-Invasive Neural Interfaces to the Masses

by Robert Murcko

Wearable technology is seeing a boom in recent years and this trend doesn’t seem to be slowing down anytime soon.  According to Grandview Research the global wearable tech market was valued at around $61.3 Billion as of 2022 and is expected to see significant growth over the rest of this decade.  Grandview predicts a worldwide CAGR of 14.6% through 2030 and a CAGR of 12.9% in North America.  The graph of projections below speaks for itself.

Chart via Grandview Research

As seen in the chart, wrist-wear is the most popular modality of wearable tech and will likely be remaining in the top spot for the near future.  My hypothesis is that wrist-wear is (thus far) the most intuitive form factor for wearable tech.  Wearing wristwatches or bracelets has been a popular trend for decades and the wrist-wear sector of wearable tech is a familiar form for users.  Wrist-wear-able tech allows users to add significant technological utility to a device they’ve been using for years.  All while maintaining the device’s original function (timekeeping or fashion).

It's clear that a growing portion of the general public understands, or at least appreciates the benefits of this type of technology especially when it comes to utilities like fitness tracking, sleep tracking, and other related health metrics.  Many pieces of wearable technology also offer functionality that had in a previous era been delivered to users in other forms (like the ability to check messages, answer calls, browse the internet, and more).  

The robust wearable technology sector signals a big opportunity for consumer facing, non-invasive neural interfaces.  But there is a key obstacle in actualizing this opportunity, and that is the form factor.  It may be true that we can obtain data that is much more detailed (and less noisy) from research grade, non-invasive neural interfaces with high channel counts and design focused primarily on utility - but even if the problem of cost is solved for consumers, they will likely be reluctant to adopt wearing these sorts of devices.

I think it's safe to say that the “accessory” set-up in the screenshot above or the “BCI dress” in the image below is unlikely to become a mainstream fashion trend anytime soon. So that begs the question: how do non-invasive, neural interfaces eventually get adopted by the masses? Unsurprisingly, several companies and labs are already working on this.  It seems to be the consensus that to get the general population to dip their toes into the sea of neuro-technological innovation, the technology needs to be delivered to them in a form that fits in with their existing lifestyles.

Different groups are approaching this in different ways.  Wisear, for example, is developing a neurotechnology enabled set of earphones (among other technology and systems) for the consumer facing, non-invasive neurotech space.  I spoke with their co-founder and CEO (Yacine Achiakh) and he stressed the importance of integrating this technology into items or systems that people are already using.

It appears that Apple shares Wisear’s mindset on this matter.  They’ve submitted a patent to include EEG sensors on their highly popular “AirPods.” 

Figure from Apple’s patent application for “Biosignal Sensing Device Using Dynamic Selection of Electrodes.”

Another entrant into the EEG enabled headphones space is Neurable.  They’ve partnered with audio brand Master and Dynamic to launch a pair of “smart” EEG enabled headphones. The initial application of these headphones is to help customers optimize their focus.  Neurable’s MW75 Neuro is an over the ear headphone, unlike the smaller ear-pods of the other companies that I mentioned.

I’ve listed several companies working on neural interfaces as a component of headphones, but there are surely other ways to develop this type of technology in an intuitive form.  Many people wear sleep masks to help block out external light while they try to get some shut eye.  Enter the team at Bia Neuroscience, who want to make the sleep mask “smart.” They use fNIRS to track data such as sleep stages and even incorporate neurofeedback into their product.

Speaking of non-EEG neural sensing modalities, let's talk about Meta.  In 2019 Meta (then called Facebook) acquired a neural interface startup called CTRL-Labs. Fast forward almost five years, and work born out of this partnership is making waves. A group of engineers at Meta recently released a preprint discussing “a generic noninvasive neuromotor interface for human-computer interaction.”

The interface discussed in this paper used surface electromyography (sEMG) to pick up motor signals sent from the brain to the nerves and muscles in the wearer’s upper extremities.  With a form factor not much bigger than a wristwatch, this device can decode gestures at between 0.5 and 0.9 gestures per second depending on the task.  It can also decode handwriting at 17.0 words per minute.  All of the performance metrics described above are when the device is operating in a generalized and generic manner. This means that the device and algorithm do not need to be calibrated/recalibrated for each person and can work across a set of numerous people.  Generalizability is a big step in the world of neural interfaces. (Note: When the decoding algorithms are personalized, performance boosts using Meta’s neuromotor interface have been seen to approach a 30% bandwidth increase.)

In addition to all the forays into the consumer sector in various forms that I’ve described already, its clear to see that consumer neurotech and VR/AR/MR can have an incredibly symbiotic fit. While I won’t dive too deeply into the details (a topic for a future editorial), some of the most valuable companies of our generation are tinkering in this space. Meta’s technology described above is likely envisioned (at least in part) as a control system for their future metaverse products and applications. Apple also has been working to patent a “health sensing retention band” that appears to include electrodes in the head-strap of their new “Apple Vision Pro.” There are plenty of startups (inlcuding OpenBCI) working at this intersection too. If you’re going to be wearing something on your face/head anyways, why not add some electrodes and make your experience even more immersive.

Don’t worry, I’ll stop there, I’m not going to go on and list non-invasive neurotech companies and projects all day.  But I do think it's important to talk about some of the key obstacles to building non-invasive neurotechnology in an intuitive manner.  Generally, the most intuitive (and likely to be adopted) form factor for these types of products is “small” or “sleek.”  This inherently limits the amount of electrodes that can be placed and the spread of data that can be captured.  We may only be getting signals from certain brain (or body) regions, not to mention all the noise (both electromagnetic and otherwise) out there in the real world.  Another challenge is the dynamic nature of real life.  It is unlikely that people will wear their devices in precisely the same manner each time.  Thus, sensor placement will drift from day to day.

In my view this trend of consumer grade neurotechnology being merged with products that are already commonly used will be the first step in what may eventually lead to mass adoption of neurotech.  As more and more people experience the deep and useful insights that can come from non-invasive neural recordings/stimulation and the convenience that can come with decoding this neural data (and using it to control various devices), they may start to realize that an expanded form comes with expanded features. 

While for the general public there may currently still be some stigma associated with wearing relatively bulky neurotech devices around in public, I believe this stigma will quickly start to fall away as the massive utility of these devices becomes greater understood. 

Concurrently, with the decrease in stigma and increase in user awareness of consumer neurotech - the technology will continue to improve .  These improvements will be seen both from a hardware (materials and form) and software (decoding and generalizability) standpoint. This may lead to a reduction in the factors limiting adoption of consumer neurotech from a another vector. 

Be sure to keep a close eye on this sector over the next few years. A unique mix of market forces, technology development, and consumer behavior appear to be on the horizon. I don’t know what will happen, but I know it will be interesting.

Survey Says: Polls of Our Community

Survey by Robert Murcko, Graphs by Neil Raman

Further Explorations and Reading

Disclaimers: This newsletter is for informational and entertainment purposes only. Do not make any medical or financial decisions based on information contained in this newsletter.  Opinions expressed here are solely my own and those of my collaborators.  They do not necessarily represent the opinions of the organizations that we are involved with or affiliated with. Errors in reporting may be present - if errors are identified, corrections will be published in future issues.