Piramidal builds a foundation model for the brain trained on EEG, with a first clinical product in ICU / continuous EEG interpretation. The bet is a general brain model that transfers across people and devices.
Founded 2023
team@apexlogos.ai · 27 days ago
Piramidal research note (2026-09-09)
Company
Piramidal Inc. (YC W24). Site https://piramidal.ai/ . EEG foundation model (“brain language”); first product now a clinical ICU / continuous EEG co-pilot (YC launch was an epilepsy-diagnosis copilot). Bet: a general brain model that transfers across people, montages, sampling rates, and devices, then constrained under clinician “harnesses.” Legal: UK PIRAMIDAL LIMITED (Companies House 15423483; officers 2024-01-18; 1 Buarth Owen, Wonastow, Monmouth NP25 4DL); FR SAS PIRAMIDAL (SIREN 989601463, Paris, 2025-07; Kanishk Pahuja président / Dimitrios Sakellariou DG). PitchBook: 28 Marcy Avenue, New York, NY 11211. YC HQ New York; jobs also London. WIRED/Becker’s: San Francisco; IntraNerve/Forbes: New York. Founded 2023 (WIRED, IntraNerve, Forbes) vs 2024 (YC, LinkedIn, PitchBook — likely incorporation/batch). Team ~10. Named after pyramidal neurons.
Listings
- Site: https://piramidal.ai/
- YC: https://www.ycombinator.com/companies/piramidal (Launch https://www.ycombinator.com/launches/KVc-piramidal-foundation-model-for-the-brain )
- LinkedIn: https://www.linkedin.com/company/piramidalai (HQ “San Fransisco”; 2–10; founded 2024). Widget showed Seed US$1.5M on 2025-01-15 via Crunchbase — unconfirmed; not entered.
- PitchBook: https://pitchbook.com/profiles/company/593005-51 ($6M seed 21-Aug-2024; $6.5M total; 13 investors; 10 employees)
- Tracxn: https://tracxn.com/d/companies/piramidal/__uBFEvKBnC3dkudCQv9nv2O0d4pZUzJcz3Kpp-N19DNQ ($6.5M in 3 rounds; latest Seed 21-Aug-2024; 9 institutions + 1 angel)
- CB Insights: https://www.cbinsights.com/company/piramidal/financials ($6.5M / 4 rounds; Seed VC-II $6M on 2024-08-21)
- Caplight: https://www.caplight.com/company/piramidal ($6.5M; Seed 21-Aug-2024; Accelerator 1-Mar-2024)
- Neurofounders: https://www.neurofounders.co/startups/piramidal (USA; 2024; Seed; investigational)
- Golden CB slug fragment piramidal-8584: https://golden.com/wiki/Piramidal-WXZE89Z/structured_data — Crunchbase HTML was Cloudflare-blocked here. Golden’s $6.0M-only total is weaker than PitchBook/CBI/Tracxn $6.5M.
- UK officers: https://find-and-update.company-information.service.gov.uk/company/15423483/officers
Materials
- WIRED 2025-08-11 (Emily Mullin): https://www.wired.com/story/an-ai-model-for-the-brain-is-coming-to-the-icu-cleveland-clinic-piramidal/ — Cleveland Clinic ICU partnership; $6M seed prior year; YC.
- Forbes 2025-08-10 (Reichental): https://www.forbes.com/sites/jonathanreichental/2025/08/10/doctors-use-large-neuro-model-to-decode-brain-activity/ — “large neuro model”; Clinic ICU rollout over months.
- TechCrunch 2024-08-23 (Coldewey): https://techcrunch.com/2024/08/23/piramidals-foundation-model-for-brainwaves-could-supercharge-eegs/ — $6M co-led Adverb + Lionheart; YC + angels; four ICU pilots planned (as of Aug 2024).
- SiliconANGLE 2024-08-21: https://siliconangle.com/2024/08/21/piramidal-raises-6m-advance-ai-brainwave-analysis-improve-diagnoses-neurological-conditions/ — YC “led”; Adverb, Lionheart; unnamed angels “founders of Intercom, PlanGrid and Guilded.”
- Pulse2 / Pahuja interview: https://pulse2.com/piramidal-profile-kris-pahuja-interview/ ; VentureBeat quotes (via Outpost) King’s College + St Thomas’ England pilots.
- YC LinkedIn $6M: https://www.linkedin.com/posts/y-combinator_piramidal-yc-w24-has-just-raised-6m-in-activity-7234228510855159809-QN9a
- CEO $6M post: https://www.linkedin.com/posts/sacellarius_excited-to-announce-our-6m-funding-round-activity-7234183521395703811-HED7
- Cleveland Clinic Consult QD 2026-04-07: https://consultqd.clevelandclinic.org/harnessing-ai-to-bring-real-time-eeg-interpretation-to-the-icu — retrospective ~90% sens/spec for seizure detection/lateralization; vendor-agnostic; hub in new Neuro Institute (~early 2027). Najm: FDA approval “expected within the coming months.”
- IntraNerve PR 2026-04-22: https://www.prnewswire.com/news-releases/intranerve-neuroscience-and-piramidal-partner-to-develop-scalable-eeg-monitoring-through-ai-302749815.html — first remote-monitoring partner; models “not cleared or approved by the FDA and are not intended for use in clinical decision-making at this time.”
- AHA 2025-08-26: https://www.aha.org/aha-center-health-innovation-market-scan/2025-08-26-4-takeaways-cleveland-clinics-new-ai-co-pilot-brain-icu-care (Axios + WIRED + Clinic press quoting Najm). Becker’s 2025-08-11 cites an Aug 10 news release.
- Neurofounders 2026-09-07: https://www.neurofounders.co/articles/inside-the-frontier-of-brain-foundation-models — Sakellariou + Arctop’s Dan Furman.
- No Piramidal peer-reviewed paper or arXiv found. WIRED: accuracy data to be published later. TechCrunch: work not yet published. Consult QD 90% is not a paper.
Data / corpus (company or press claims; not audited)
- WIRED 2025-08-11 (Sakellariou): nearly a million hours from “dozens of thousands” of patients (healthy + unhealthy); public datasets + Cleveland Clinic + other partners.
- Neurofounders 2026-09-07 (Sakellariou): pretrained on >3 million hours EEG, ~450 TB. Later company claim; ~3x the WIRED figure.
- Consult QD: public EEG pretrain, Cleveland Clinic fine-tune; 3 senior readers + 3 physicians annotated thousands of hours. 90%/90% is retrospective, seizures/lateralization only; PLEDs/triphasic/BIPDs still validating.
- TechCrunch: siloed open-source EEG being aggregated; hospitals to add thousands of hours.
- YC launch: “massive and diverse corpus”; no hour count.
Rounds entered
- roundId 10548 — YC W24 convertible note, 2024-02-04, USD 500000, Y Combinator lead. Date = CB Insights Convertible Note 2024-02-04; amount = public W24 standard deal, consistent with $6.5M total vs $6M seed. PitchBook accelerator 2024-01-01; Caplight 2024-03-01.
- roundId 10549 — Seed USD 6000000, 2024-08-21. Leads: Lionheart Ventures (David Langer) and Adverb Ventures (Jessica Verrilli, April Underwood). Participants: Y Combinator, Ajira Ventures. Date from SiliconANGLE 2024-08-21 / PitchBook / CBI; TechCrunch 2024-08-23.
Lead discrepancy
CEO LinkedIn + TechCrunch: co-led Lionheart + Adverb; YC participating. Homepage: “$6M Seed led by” YC, Lionheart, Adverb. SiliconANGLE: led by YC. Schema follows CEO + TechCrunch (Lionheart + Adverb isLead; YC not lead on the $6M).
Unconfirmed / not entered
PitchBook/CBI/Tracxn/Diffbot without primary confirmation: AHN Ventures, CoreNest Capital, Futureland Ventures, Gaingels, Niremia Collective, Ritual Capital, Founderful, FAST — by GETTYLAB, 10 Bond, Kahlil Lalji. Employbl/Diffbot $1.5M (2024-12-14) and $8M total — ignore. LinkedIn/CB $1.5M Seed 2025-01-15 — no primary announcement. Angels “founders of Intercom, PlanGrid and Guilded” unnamed — not entered as people. YC thanks Surbhi Sarna, Jared Friedman, Wayne Crosby as mentors, not check-writers. Carl Saab thanked; not on the site advisor list.
Team / advisors
Founders entered: Dimitris Fotis Sakellariou (Founder/CEO; https://www.linkedin.com/in/sacellarius/ ; X https://x.com/dsacellarius ); Kris Pahuja / Kanishk Pahuja (Co-Founder/CPO on site/YC; IntraNerve quotes CBO; https://www.linkedin.com/in/kris-pahuja-a59a905b/ ). Kris resigned UK director 2026-01-29; still listed founder/CPO on YC/site. Advisors on site (not entered as investors): Michalis Koutroumanidis (ex-Head of Epilepsy, St Thomas’ London); Mark Richardson (Vice Dean for Neuroscience, KCL); Imad Najm (Vice Chairman of Neurology, Cleveland Clinic — also partnership clinical lead); Walter Greenleaf (Stanford Medical Mixed Reality).
Regulatory
IntraNerve 2026-04-22: not FDA-cleared; investigational. Consult QD same month: Najm says FDA approval expected “within the coming months.” Treat clearance as unconfirmed. Product shifted epilepsy copilot (YC 2024) → ICU cEEG co-pilot (2025–26).
Schema gaps
Cannot store advisor-only ties, hospital partnerships (Cleveland Clinic, IntraNerve, King’s/St Thomas’), or US Inc vs UK Ltd vs FR SAS. No fields for FDA status, dataset hours, or accuracy. Check sizes unknown. Angel identities unnamed. CPO vs CBO; founded 2023 vs 2024; HQ NY vs SF. Site is a static founders/advisors/investors page (no product demo URL). YC $500k is standard-deal inference plus $6.5M−$6M remainder, not a Piramidal press release. SHOW MORE
team@apexlogos.ai · 27 days ago
COMPETITION 
Dimitris Fotis SakellariouFounder and CEO
Kris PahujaCo-Founder and Chief Product Officer