Brain ultrasound: which startup is ahead?

Why is brain ultrasound attracting so much attention right now?

Brain ultrasound is becoming one of the most interesting areas of neurotechnology, with Insightec already treating patients, Carthera testing a new approach to brain cancer, and Merge Labs raising $252 million to develop ultrasound-based brain-computer interfaces.

Several developments have brought the industry into focus. Insightec recently passed 30,000 patients treated worldwide, Carthera is running a large randomized brain-cancer trial, and OpenAI-backed Merge Labs has entered a field previously dominated by smaller research organizations. New companies such as Bridge Neurotech and Aleph Neuro are also trying to read brain activity through the skull without implanted electrodes.

The excitement comes from what ultrasound could potentially do. Focused sound waves can destroy precisely targeted brain tissue, temporarily open the blood-brain barrier, influence neural activity, or help researchers observe changes in brain function.

These applications are at very different stages. Some are already used in hospitals, while others have barely moved beyond laboratory demonstrations. A company with an impressive technology announcement may still be years behind another in actual medical adoption.

Who is actually winning the brain ultrasound race today?

Insightec is the clear leader in clinical brain ultrasound today, although Carthera and Merge Labs are among the strongest competitors in two very different emerging applications.

Insightec develops ultrasound systems for treating movement disorders. Carthera uses ultrasound to help chemotherapy drugs enter the brain. Merge Labs is working toward interfaces that could potentially read and influence neural activity without conventional implanted electrodes.

Those distinctions change how we should judge each company. Clinical approvals, patient numbers and treatment outcomes tell us a great deal about Insightec. For Merge, technical demonstrations and independently verified decoding performance are more relevant because its proposed brain-computer interface has yet to reach the commercial market.

Here is where the main competitors stand based on what they have demonstrated so far.

Company	Main application	Current position
Insightec	Focused ultrasound treatment	Clinical market leader
Carthera	Ultrasound drug delivery	Advanced clinical development
NaviFUS	Non-invasive drug delivery	Early clinical competitor
Merge Labs	Ultrasound brain-computer interfaces	Major financial backing
Bridge Neurotech	Non-invasive brain interfaces	Early human research
Aleph Neuro	Transcranial brain imaging	Promising technical demonstrations
Forest Neurotech	Functional ultrasound interfaces	Specialized research and engineering
BrainSonix	Ultrasound neuromodulation	Research-stage stimulation technology
Openwater	Ultrasound stimulation and optical imaging	Experimental research platform

Insightec wins on demonstrated medical use. Merge is one of the companies to watch for a possible new category of brain interface, but no startup has yet established a clear technical lead in fully non-invasive ultrasound-based neural decoding.

If you want more recent data on this point, see the latest figures in our Neurotech report ↓.

Is Insightec still the clear leader in brain ultrasound treatment?

Insightec remains comfortably ahead in clinical brain ultrasound, with more than 30,000 patients treated worldwide and a network of 226 treatment centers, according to its September 2026 company update.

Its Exablate Neuro platform uses MRI-guided focused ultrasound to create small, precisely targeted lesions in the brain. The FDA first approved the system for medication-refractory essential tremor in 2016, and its approved applications have expanded since then.

The recent adoption figures show how far the technology has moved beyond its early clinical use. Insightec reported 10,000 patients treated across Europe, the Middle East and Africa, with more than 62 centers operating across 20 countries.

Treatment volume in that region more than doubled over the preceding three years. That's impressive for a technology that has been commercially available for roughly a decade. Hospitals are still adding equipment, and more patients are gaining access.

Insightec also announced national reimbursement in France for essential tremor treatment in March 2026, followed by the publication of new Parkinson's disease clinical evidence in June. Both developments help explain why the company's growth has continued well beyond its initial approval.

Can Insightec's ultrasound treatment really replace brain surgery?

Insightec's focused ultrasound already provides an alternative to certain invasive brain procedures, although deep brain stimulation remains an important treatment option for patients who need adjustable therapy.

With Exablate Neuro, clinicians use MRI guidance to concentrate ultrasound energy on a small target inside the brain. The treatment requires no surgical incision or permanently implanted electrodes.

The clinical evidence continues to expand. A prospective multicenter Parkinson's disease study published in The Lancet Neurology in June 2026 reported a 66.8% improvement in motor complications three months after staged bilateral focused ultrasound treatment. Researchers also followed patients through 12 months.

These results support the use of focused ultrasound in selected patients, but they do not establish that the procedure is better than deep brain stimulation.

DBS allows physicians to adjust stimulation after surgery, while the lesions created by therapeutic focused ultrasound are permanent. That's a serious distinction. The choice depends on the patient's symptoms, treatment goals, medical history and tolerance for the different risks.

Insightec's commercial advantage is already substantial: its systems are being used in routine clinical care, while most newer brain ultrasound companies are still testing whether their proposed applications work reliably.

If you want more recent data on this point, see the latest figures in our Neurotech report ↓.

Is Carthera ahead in delivering drugs into the brain with ultrasound?

Carthera is one of the strongest companies in ultrasound-assisted brain drug delivery, having moved from small human studies into a large randomized trial for recurrent glioblastoma.

Its SonoCloud technology addresses a major problem in brain-cancer treatment. The blood-brain barrier protects the brain from harmful substances but also prevents many medications from reaching brain tissue in useful concentrations.

SonoCloud uses an implanted ultrasound device and injected microbubbles to temporarily increase the barrier's permeability, potentially allowing more chemotherapy to reach tumors.

In February 2024, a multicenter phase I/II study published in Nature Communications reported results involving 38 registered patients with recurrent glioblastoma. Of those, 34 underwent tumor resection and device implantation, and 33 received at least one ultrasound procedure combined with carboplatin.

Researchers reported a median overall survival of 12 months among patients who received treatment using all nine ultrasound emitters. Earlier research also found approximately 5.9 times greater carboplatin concentrations in treated brain tissue.

The results were encouraging enough to justify further testing. However, survival findings from an early uncontrolled study cannot establish whether patients live longer because of the ultrasound treatment.

Could Carthera's SONOBIRD trial make brain ultrasound a standard cancer treatment?

Carthera's SONOBIRD trial could become a turning point for ultrasound-assisted brain cancer treatment because it directly tests whether opening the blood-brain barrier improves patient outcomes.

The randomized trial, registered under NCT05902169, compares SonoCloud-9 combined with carboplatin against standard chemotherapy approaches in recurrent glioblastoma.

Carthera announced that its first 100 participants had been enrolled in April 2025. The study's planned enrollment is approximately 560 patients across nearly 40 European and American centers, and its ClinicalTrials.gov record was still active in its September 2026 update.

The planned trial is roughly 17 times larger than the 33 patients who received ultrasound treatment in the company's published early-stage SonoCloud-9 study.

That is a big jump. Carthera is now testing whether improving drug access to brain tissue actually produces a meaningful benefit in a much larger patient population.

If SONOBIRD demonstrates better survival or other clinically important outcomes with acceptable safety, Carthera could gain a major advantage over other ultrasound drug-delivery developers. The results are the decisive missing piece.

Could NaviFUS beat Carthera by avoiding brain implants?

NaviFUS could become a serious competitor to Carthera because its ultrasound system can temporarily open the blood-brain barrier without leaving a device implanted in the skull.

The Taiwanese company uses neuronavigation-guided focused ultrasound delivered from outside the head. Its clinical research has included combining blood-brain barrier opening with bevacizumab treatment for recurrent glioblastoma.

A six-patient pilot study reported a median progression-free survival of 11 months and a six-month progression-free survival rate of 66.7%. NaviFUS highlighted the findings in February 2026 following their publication in Neurosurgery.

The company also advanced a randomized follow-on study, registered as NCT06496971, with planned enrollment of up to 32 patients at two Taiwanese sites.

Carthera currently has the stronger large-trial position. Its planned SONOBIRD enrollment is 17.5 times larger than NaviFUS's randomized study.

Still, the difference between implanted and non-invasive systems could matter enormously to hospitals and patients. Avoiding another surgical procedure may make repeated treatment easier, provided NaviFUS can achieve sufficiently precise and consistent ultrasound delivery.

Carthera is ahead on clinical development today. NaviFUS has a potentially more convenient treatment approach, but six patients are nowhere near enough to establish that its system can outperform an implanted alternative.

If you want more recent data on this point, see the latest figures in our Neurotech report ↓.

Is Merge Labs already the biggest brain ultrasound startup?

Merge Labs is one of the most heavily financed new entrants in ultrasound-based brain-computer interfaces, having raised approximately $252 million at a reported $850 million valuation in January 2026.

The startup attracted attention partly because of its founding team, which includes Sam Altman, Mikhail Shapiro, Tyson Aflalo and Sumner Norman. Its investors include OpenAI and Bain Capital.

Merge wants to develop interfaces that combine ultrasound, biological engineering and artificial intelligence to communicate with brain activity. Its long-term goal goes considerably beyond conventional ultrasound imaging, potentially including communication between biological and artificial intelligence systems.

The company has also been moving to secure specialized hardware. In September 2026, Merge signed a multiyear agreement with Butterfly Network to use its Poseidon family of ultrasound-on-chip technology.

That gives Merge access to a semiconductor-based ultrasound platform without having to develop every hardware component internally.

The difficulty is judging how much of the company's technical ambition has already been demonstrated. Merge has substantial capital, experienced researchers and access to specialized hardware, but there is still no publicly established record of a commercially usable, high-bandwidth, fully non-invasive brain interface.

Its financing makes it an important contender. Clinical performance will decide whether that early advantage lasts.

Does Merge Labs have technology that other brain ultrasound startups cannot copy?

Merge Labs is pursuing a particularly ambitious combination of ultrasound and molecular engineering, but there is no convincing public evidence yet that competitors cannot reproduce its proposed capabilities.

Conventional functional ultrasound measures changes in cerebral blood flow associated with neural activity. That approach has important limitations because blood-flow changes occur more slowly than the electrical activity of neurons.

Merge's research strategy includes investigating whether engineered biological systems could improve the way ultrasound interacts with neural tissue, potentially enabling richer communication than conventional blood-flow imaging.

This could eventually give Merge a meaningful advantage over startups working primarily on ultrasound hardware and signal processing.

However, the company has not publicly demonstrated the complete system at a level that would support clear performance comparisons.

Its partnership with Butterfly Network is also interesting because Butterfly retains the right to license its ultrasound technology to other brain-interface developers. Merge has access to advanced hardware, but competitors can pursue related semiconductor-based solutions.

So hardware access alone is unlikely to become Merge's strongest defense against competitors. Any lasting technical advantage will probably come from how its biological engineering, acoustic methods and decoding models work together. And that combination still has to prove itself.

If you want more recent data on this point, see the latest figures in our Neurotech report ↓.

Can Bridge Neurotech challenge Merge Labs with just $13.5 million?

Bridge Neurotech is already a credible early challenger to Merge Labs, despite launching with roughly 19 times less disclosed funding.

Founded by Will Biederman, Bridge emerged publicly in October 2026 with $13.5 million in financing, including investment from General Catalyst.

The startup is developing a non-invasive brain-computer interface using functional ultrasound to detect brain activity through the skull. Its initial approach is more narrowly focused than Merge's broader research into biological interfaces and bidirectional communication.

Bridge began enrolling participants for its first human research study around its public launch. It also announced a development agreement with Butterfly Network to use ultrasound-on-chip technology.

There is an interesting connection between the competitors. Biederman was involved in Forest Neurotech, a nonprofit research organization established in 2023 to advance miniaturized functional ultrasound technology. Researchers associated with Forest later became central to Merge Labs.

Several emerging competitors therefore share elements of the same scientific and engineering background.

Bridge's smaller funding round may be sufficient for its initial research goals, particularly if it can demonstrate practical decoding through intact skull bone using existing ultrasound hardware.

We have not yet seen enough comparable human performance data to judge whether Bridge is technically ahead of Merge. The financing gap is clear; the performance gap remains unknown.

Has Aleph Neuro already solved ultrasound brain imaging through the skull?

Aleph Neuro has demonstrated promising transcranial ultrasound imaging, but publicly available results do not yet show that it has developed a complete brain-computer interface.

In June 2026, Butterfly Network announced that Aleph had produced what the research group described as exceptionally high-resolution three-dimensional images of the human brain obtained from outside the skull.

Aleph was founded by Marley Xiong, Raffi Hotter and Lev Chizhov. Its system uses Butterfly's programmable semiconductor ultrasound technology as part of a research platform for brain imaging.

The achievement targets one of the hardest problems in the field. Skull bone distorts and weakens ultrasound signals, making high-quality measurements much harder than imaging soft tissue elsewhere in the body.

Still, anatomical imaging and neural decoding are different challenges. A system might produce detailed brain images without being able to recognize intended movements, identify communication signals or control an external device.

Aleph has provided a useful demonstration of imaging capability. Its position in the brain-interface race will depend on whether that capability translates into reliable measurements of brain function.

Why is Butterfly Network working with so many brain ultrasound startups?

Butterfly Network is becoming an important technology supplier to the ultrasound brain-interface industry, with Aleph Neuro, Merge Labs and Bridge Neurotech all announcing relationships with the company in 2026.

The three announcements came within approximately four months. Aleph disclosed its imaging research in June, Merge signed a multiyear agreement in September, and Bridge announced a development partnership in October.

Butterfly's Ultrasound-on-Chip platform uses semiconductor technology to create compact, programmable ultrasound systems. That is attractive to startups trying to build smaller and more flexible devices than conventional medical ultrasound equipment.

The partnerships also reveal something about the emerging market. Several well-funded research teams have decided to build around commercially available acoustic hardware rather than independently create every part of their systems.

This could speed up development, especially for smaller companies. It may also make the technology more accessible to new entrants.

For Butterfly, the potential business includes licensing payments, hardware sales and possible future royalties. Its Merge agreement specifically includes upfront and milestone-based licensing payments, hardware commitments and potential commercial royalties.

Butterfly could therefore benefit from growing interest in brain ultrasound regardless of which startup wins the brain-interface race. That's a pretty attractive position for a hardware supplier in a market with no established interface winner.

Can ultrasound brain interfaces really compete with Neuralink?

Ultrasound brain interfaces could eventually offer a less invasive alternative to Neuralink-style implants, but they have not yet demonstrated comparable real-world communication performance.

Neuralink uses electrodes implanted close to neurons to measure electrical activity. Functional ultrasound usually measures changes in cerebral blood flow, which respond more slowly than electrical signals.

The difference affects what each system can potentially do. Implanted electrodes can capture neural events on millisecond timescales, while blood-flow responses generally develop over seconds.

A study published in Science Translational Medicine in 2024 demonstrated that functional ultrasound could decode movement-related information in a human participant using an acoustically transparent cranial implant.

That experiment supported the idea that ultrasound can extract useful information from brain activity. However, it still required a specialized implant, leaving the challenge of fully non-invasive recording through intact skull bone unresolved.

Merge, Bridge and Aleph are approaching that problem with different combinations of ultrasound hardware, computational models and biological research.

The most realistic early applications may involve tasks where slower signals are acceptable. Implanted electrodes are likely to retain an advantage in applications requiring particularly fast, precise neural measurements unless ultrasound developers produce a major technical breakthrough.

There is a big potential upside to avoiding brain surgery. But until ultrasound interfaces demonstrate useful decoding speeds and accuracy through an intact skull, Neuralink-style electrode systems have the stronger case for high-performance communication.

If you want more recent data on this point, see the latest figures in our Neurotech report ↓.

Could brain ultrasound stimulation become a bigger business than brain imaging?

Ultrasound neuromodulation could become a substantial medical market before non-invasive ultrasound brain-computer interfaces reach commercial maturity, although the evidence for many newer treatments remains preliminary.

BrainSonix develops low-intensity focused ultrasound technology designed to influence activity in selected brain regions without creating permanent lesions.

Openwater is also researching low-intensity focused ultrasound, alongside optical imaging technology. Its Open-LIFU and Open-Motion platforms are investigational systems rather than FDA-cleared clinical treatments.

These companies are working toward applications that differ from Insightec's established lesion-producing procedures. Instead of permanently targeting brain tissue, low-intensity stimulation aims to change neural activity without destroying the tissue.

That could eventually support treatments for neurological or psychiatric conditions where repeated or adjustable stimulation is preferable.

The commercial potential is significant because patients with conditions such as treatment-resistant depression already receive other forms of neuromodulation, including transcranial magnetic stimulation.

However, BrainSonix and Openwater still need stronger controlled clinical evidence showing that ultrasound-based stimulation delivers lasting benefits and acceptable safety.

Which brain ultrasound startups have the strongest evidence today?

Insightec has the strongest evidence of actual clinical adoption, while Carthera is conducting one of the most important advanced trials in ultrasound-assisted drug delivery. The newer brain-interface companies remain at a much earlier stage.

Comparing published human studies, regulatory approvals and research demonstrations reveals a large maturity gap between the leading therapeutic companies and experimental brain-computer interface developers.

Company	Strongest evidence	Current limitation
Insightec	Over 30,000 patients treated; regulatory approvals	Limited to specific clinical indications
Carthera	Published human studies; large randomized SONOBIRD trial	Survival benefit remains unproven
NaviFUS	Six-patient pilot and randomized follow-on trial	Limited clinical sample sizes
Merge Labs	Strong scientific team, funding and hardware access	Limited public product-level human validation
Bridge Neurotech	Human research enrollment and semiconductor partnership	Reliable decoding performance not yet established
Aleph Neuro	Public transcranial brain-imaging demonstrations	Complete brain-interface capability unproven
Forest Neurotech	Specialized functional ultrasound research	Research-focused organization
BrainSonix	Human neuromodulation research	Larger controlled efficacy studies needed
Openwater	Open research hardware and early neuromodulation work	No FDA-cleared clinical treatment

The comparison explains why funding rankings can be misleading. An experimental company may raise hundreds of millions of dollars while an established medical device company already has thousands of patients benefiting from its technology.

What could change the brain ultrasound leaderboard in the next few years?

The next major shift in brain ultrasound will probably come from clinical trial results or a convincing demonstration of non-invasive neural decoding, rather than another large investment round.

Carthera's SONOBIRD trial is especially important because a positive outcome could establish that ultrasound-assisted chemotherapy improves the treatment of recurrent glioblastoma.

NaviFUS faces a related challenge with its non-invasive approach. The company needs larger studies demonstrating that improved drug delivery leads to better clinical outcomes.

For Merge, Bridge and Aleph, the most useful evidence would be independently reproducible demonstrations showing how accurately their systems decode brain activity across different people.

We would want to see response times, decoding accuracy, the number of commands a participant can reliably produce, performance across different skull anatomies and results over repeated sessions.

Another important question is whether any of these systems can function without complicated setup or highly controlled laboratory conditions.

Insightec, meanwhile, is focused on expanding an existing medical technology. Further reimbursement decisions, new treatment indications and stronger long-term clinical results could increase the number of patients who qualify for its procedures.

So, which brain ultrasound startup is ahead right now?

Insightec is currently the overall leader in brain ultrasound, Carthera is one of the strongest contenders in ultrasound-assisted drug delivery, and Merge Labs is a leading candidate in the emerging brain-computer interface market.

Insightec has the clearest lead because its technology has already reached hospitals and patients at scale. More than 30,000 patients treated worldwide, a network of 226 centers and growing regional procedure volumes give it an advantage that cannot be replicated with a large funding round.

Carthera is developing a potentially important new medical application. Its SONOBIRD trial could provide the evidence needed to show that ultrasound-assisted chemotherapy improves outcomes for brain-cancer patients.

Merge Labs has the financial resources and scientific expertise to pursue a much more ambitious type of brain interface. Still, we have limited public evidence of how well its proposed system performs in humans.

Bridge Neurotech and Aleph Neuro are worth following because both are working on the difficult problem of obtaining useful brain signals through an intact skull.

For now, Insightec has the strongest claim to leadership in brain ultrasound. Merge Labs may eventually help create an entirely new market, but the evidence needed to crown a winner in non-invasive ultrasound brain-computer interfaces is still missing.