Leo 🫧

If you’re interested in tFUS, I encourage you to check out the tFUS deep dive I’ll be posting on my blog (link in bio) later this week, and to reach out to me in my X/Twitter or Substack DMs with any questions.

The promise of tFUS is the ability to activate or deactivate any brain region safely, without surgery or implants. Lucid dreaming is just one of the many interesting brain states that tFUS may be able to induce. tFUS could become a key treatment for severe illnesses like addiction, depression, and anxiety. I hope that Prophetic publishes a lot more safety data before they ship this product, because otherwise they risk not only the safety of their customers, but also the reputation of tFUS as a whole.

Is it legal? My guess is that Prophetic wants this device to be classified a “general wellness” product, rather than a medical device. The relevant FDA guidance defines general wellness products as “products that meet the following two factors: (1) are intended for only general wellness use, as defined in this guidance, and (2) present a low risk to the safety of users and other persons.” Prophetic does not refer to any diseases or conditions in their marketing, so the first condition is fulfilled. The second condition is less clear to me. They would probably claim that, if they are below the FDA general safety guidelines for ultrasound devices, that the device is sufficiently low risk to be considered a general wellness product. In my opinion, we would need to see a lot more safety testing of this specific device before we know whether it is actually low-risk.

Is it safe? In perfect conditions, when ultrasound parameters are within the ITRUSST guidelines, tFUS is probably safe. But even if the intention is to stay within those guidelines, there are many things that could go wrong. If they accidentally set the intensity levels too high, or if they leave the device on for too long, they could heat up the brain and cause serious damage. Also, the intensity levels at the targeted brain region depend a lot on the individual that is receiving the stimulation; if one person has a thicker skull than another, the intensity level at the target can be very different. We have no idea how much they’ve tested this on humans, or what their methodology was. Without that information, there is no way of knowing whether this device is safe.

Does the device actually work? A chart comparing the dream reports of the stimulation and control groups.📷 The only effectiveness information that Prophetic has shared is this bar chart of the self-reports of testers. We don’t know anything about their methodology or how many people they’ve tested it on. Without any peer-reviewed, published research, we basically have no idea whether it actually works.

Is the device priced fairly? The $449/$1299 price points are both extremely low compared to the cost of a research-grade ultrasound system, but research devices serve a different purpose than this device. Price comparisons are difficult because there literally aren’t any other consumer devices of this kind to compare it to.

How are the two versions of the device different? The “Dual” device is probably a simpler ultrasound array, which is focused through a lens, and produces a beam that can’t be steered as much. The “Phase” device is probably a phased array transducer, which allows for realtime steering of the ultrasound beam, and the ability to change the shape of the focal point that is being stimulated.

How does the device stimulate the brain? The device uses a technology called tFUS to stimulate the brain. This means aiming a beam of ultrasound (sound that is too high-pitched for humans to hear) at a particular point in the brain. In theory, this is safe because the intensity levels of the ultrasound are similar to the intensity levels of ultrasound imaging, which is one of the safest imaging methods used in medicine. tFUS is a new technology that is in the early stages of adoption—as far as I know, this is the first consumer tFUS device on the market. The same technology is currently being used in a number of clinical trials as a potential treatment for various mental illnesses, but it has not yet been FDA approved for any medical uses. I’ll also publish a deep dive on tFUS on my blog sometime in the next week.

How will the device induce lucid dreaming? Lucid dreaming is thought to be correlated with higher-than-normal activity in the prefrontal cortex during REM sleep. Prophetic believes that by stimulating more activity in that region during REM, they can cause lucidity to increase.

What does the device look like? The device has two components: a headband that you wear while sleeping, and a small box of electronics that connects to the headband through a wire.

What is lucid dreaming? Lucid dreaming is the ability to be aware that you are dreaming during a dream, and to control what is happening in the dream. There are also reliable ways to induce lucid dreaming without brain stimulation—I have a blog post that explains how you can do this yourself.

Prophetic just launched a new brain stimulation device. But if you want to avoid damaging your brain, I strongly encourage you to read this thread this before you buy it:

What is Prophetic? Prophetic was founded in 2023 in New York, and has been developing a tFUS device for lucid dreaming since their inception. You can follow their technical progress by looking back at the X/Twitter feeds of the company account and of their cofounders, @EricWollberg and @weslouisberry . They have raised over $3.4 million according to Pitchbook.

Summarizing the announcement: Prophetic is launching two versions of a device that aims to induce lucid dreaming. The device looks like a headband that you wear while sleeping, plus a box of electronics that connects to the headband with a long wire. The device uses a technology called transcranial focused ultrasound. They claim to have tested this on humans, with the group that received stimulation reporting higher levels of lucidity while dreaming compared to a control group. You can preorder the “Dual” version of the device for $449, and the “Phase” version for $1299. The first will start shipping at the end of 2026, and the second starts shipping mid-2027.

My quick take: I support the mission of the company, and I think the device is very cool, but I am concerned by the lack of safety data. I would not use the device myself until its safety has been studied much more rigorously and transparently.

My credentials: I founded tFUS Society, a group of people that are working on transcranial focused ultrasound (tFUS), which is the same technology that powers the Prophetic device. I’ve also met some members of the Prophetic team, and they seem friendly and well-intentioned.

@OwenBrakes @matlabdogboy they would probably claim that it's a "wellness device," but there's no precedent for whether ultrasound neuromodulation is considered a low safety risk by the FDA

@matlabdogboy I am not fluent in this space, did a bit of tFUS work. I believe it's a grey market, many doctors have told me about people in the bay area frying their brains with tDCS machines.

How can you launch a tFUS device without safety data? If you mismodulate in the brain you literally melt the tissue.

@davidspiegs indeed

@leozaroff “Number of Bitcoin traded” is an interesting (and questionable?) growth metric lol Seems they turned out alright though..

the craziest thing about the epstein files that nobody noticed is that you can read all the pitch decks and investor updates of the companies he invested in like coinbase

autoresearch reminds me of how right before reasoning models started coming out, lots of developers were using non-RLed chain of thought themselves as a simple prompting technique and finding that it was achieving noticeably better results than standard prompting. wouldn’t be surprised if autoresearch means we are in that precursor moment but for agentic loops (for constrained optimization problems), and soon the labs will come out with a more sophisticated implementation with RL/scaling.