What ACCEL Stars does

ACCEL Stars is a Japanese medical sleep-tech company founded in 2020 to commercialize proprietary sleep-wake classification technology developed in Professor Hiroki Ueda's laboratory at The University of Tokyo. The company holds an exclusive license to the ACCEL algorithm, which classifies sleep and wake states (and, since July 2024, REM versus non-REM sleep) using accelerometer and PPG sensor data from wrist-worn devices. PSG-validated accuracy metrics (82.2% specificity, 93.2% accuracy, 97.2% sensitivity) materially exceed those of Apple Watch, Oura, Fitbit, and Actiwatch, enabling medical-grade sleep measurement outside clinical settings. The company operates two offices — Kurume, Fukuoka (headquarters) and The University of Tokyo Entrepreneur Plaza — and is registered as a Class II medical device manufacturer/sales entity with a Class I registered device (ACCEL ATRIA, registration 40B2X10040000001).

The product portfolio spans four lines: SLEEP COMPASS (B2B/B2B2C corporate wellness subscription with 8-day wearable measurement, web questionnaires, and personalized reports), the ASAP cloud platform (AI PSG analysis and wearable data analytics sold to clinics and research institutions), ACCEL ATRIA (wristwatch-type actigraph sold as a Class I medical device to hospitals and research organizations), and ACCEL POLARIS (proprietary accelerometer-plus-PPG research device). Revenue is generated via subscription, hardware sales, per-transaction PSG analysis outsourcing, and technology licensing. Customers include ~100 organizations (May 2026) across Japanese corporations (Bridgestone, Tosho Unso, ITFOR), health insurers (Sumitomo Life), local governments (Kurume, Koriyama, East Hiroshima, Kumamoto Prefecture), healthcare providers (Sakura Jyuji, Toranomon Hospital, Fast Doctor), and academic institutions. Strategic partners include Sony Network Communications (mSafety OEM), augment AI (wena X consumer smartwatch), Takeda and Astellas (pharma digital biomarkers), and Sumitomo Life Insurance (Siaful app integration). The company has raised ¥1.68B cumulative through Series A (November 2024) and signed its first overseas MOU with Singapore SleepWake Centre in May 2026 to anchor Southeast Asian expansion.

Name

ACCEL Stars

Legal name

株式会社ACCELStars

Website

https://accelstars.com

Company type

Private

Founded year

2020

Operating status

Operating

Headcount range

11–50 employees

Short description

ACCEL Stars is a Japanese sleep-tech company commercializing a University of Tokyo–licensed AI algorithm for medical-grade sleep measurement, selling B2B wellness subscriptions, Class I medical devices, and AI PSG analysis to enterprises, insurers, hospitals, and local governments across ~100 organizations.

Ownership category

akta.pro rank

Product category

Sleep Health Technology & Medical Sleep Diagnostics

NAICS

Electromedical and Electrotherapeutic Apparatus Manufacturing (334510)

SIC

Industrial Instruments For Measurement, Display, And Control (3823)

akta.pro primary industry

Sleep Tracking Devices (Wearables & Non-wearables) (CRACAQAD)

akta.pro secondary industry

Sleep Tech Wearables (CRACAIAG)

Keywords

• Sleep measurement technology
• Medical wearable devices
• AI sleep analysis
• PSG analysis platform
• Corporate wellness programs

Headquarters

HQ city

Hongo

HQ country

Japan

HQ region

Asia

Offices2 records

Markets served

GTM type

B2B

Offering type

Software

Cost components

Personnel, Technology or R&D, Marketing or Sales, Operations, Supply Chain

Revenue model

1. SLEEP COMPASS (Sleep Health Measurement Service): B2B2C subscription/service model where corporations, health insurers, and local governments purchase the service for employee/member wellness programs. Delivered via medical institutions as an add-on health examination. Includes 8-day wearable measurement + web questionnaires + personalized reports + e-learning. A lighter version (SLEEP COMPASS Light) uses only web questionnaires without devices. As of November 2024, adopted by approximately 70 organizations, growing to 98+ by late 2025 and 100+ by May 2026.
2. Medical Device Sales (ACCEL ATRIA): Sales of the wristwatch-type Actigraph Sensor ACCEL ATRIA as a registered Class I medical device to medical institutions, research institutions, and corporations. Device sold or leased for use in clinical sleep evaluation and diagnosis support.
3. AI PSG Analysis Platform (ASAP) - B2B SaaS: Cloud-based AI analysis service for PSG data and wearable device data, sold as a subscription to clinics, hospitals, and research institutions. Hospitals upload EDF files and receive AI-analyzed sleep staging, arousal, and respiratory event reports. Custom AI models for specific hospitals also offered. Pricing quote-based per institution.
4. Clinical Research Support Services: One-stop research support services for universities and pharmaceutical companies — including device provision, algorithmic analysis, research protocol drafting, ethics review, and recruitment. Engaged in over 170 collaborative research discussions with 61 approved studies. Expanding into digital biomarker development for CNS disorders, drug/device evidence generation.
5. Technology Licensing / Co-development: Capital and business partnership with augment AI for co-development of AI sleep analysis features for the wena X smartwatch. ACCELStars provides its sleep analysis technology; augment AI provides wearable device hardware and consumer distribution. This may generate licensing revenue or value through the equity stake.
6. Sleep Health Guidance Services: Sleep hygiene guidance services (睡眠衛生指導) provided to employees/members identified with sleep issues through SLEEP COMPASS. Medical professionals (doctors, public health nurses) deliver guidance. Billed as part of corporate wellness or health insurer programs.

Pricing tiers

Go-to-market motion3 records

Distribution channels7 records

Marketing channels7 records

Core offering

ACCEL Stars develops and sells a medical-grade sleep health platform combining proprietary wearable devices (ACCEL POLARIS and the registered Class I medical device ACCEL ATRIA) with an AI-powered cloud analysis platform (ASAP) for PSG data and the B2B corporate wellness service SLEEP COMPASS. The platform leverages an exclusive license to the University of Tokyo's ACCEL algorithm, providing PSG-validated sleep-wake classification for corporate health management, clinical sleep diagnostics, health insurer programs, and pharmaceutical research support.

Product overview

ACCELStars offers a comprehensive sleep health platform combining proprietary wearable hardware (ACCEL POLARIS, ACCEL ATRIA), cloud-based AI analysis platforms (ACCELStars Analysis Platform/ASAP), and consumer/enterprise services (SLEEP COMPASS, SLEEP COMPASS Light). The core technology is the proprietary ACCEL algorithm for high-precision sleep-wake detection, which powers multiple product tiers: consumer wellness services for corporate health management, clinical diagnostic services for healthcare providers, and research support services for academic institutions. The portfolio includes medical devices, SaaS platforms, and professional services spanning sleep measurement, AI-powered PSG analysis, and sleep healthcare guidance.

Differentiator

Problem solved

Functional benefit

Brands

• SLEEP COMPASS: Corporate wellness and health insurance sleep measurement service providing 8-day at-home sleep measurement using wearable devices and high-precision algorithms, with personalized reports and e-learning.
• ACCELStars Analysis Platform (ASAP)
• ACCEL ATRIA
• ACCEL POLARIS

Products and services

• SLEEP COMPASS B2B corporate wellness service providing 8-day at-home sleep measurement using a wristwatch-type wearable device combined with daily web questionnaires. Delivers 5-stage sleep evaluation, personalized improvement recommendations, and sleep hygiene e-learning content. Sold to enterprises, health insurers, and local governments for employee/member wellness programs.
• ACCELStars Analysis Platform (ASAP) Cloud-based AI analysis platform for automated sleep/wake classification from wearable devices and PSG data. Supports binary (Sleep/Wake) and three-state (Wake/REM/Non-REM) classification, autonomic nervous system indices (HRV), automatic AHI calculation for SAS diagnosis, and web questionnaire creation. PSG analysis reduces evaluation time from hours to minutes using AI + technologist review. Sold via subscription to clinics, hospitals, and research institutions.
• Actigraph Sensor ACCEL ATRIA Wristwatch-type medical device (Class I general medical device) with built-in accelerometer for body movement recording. Generic name: Actigraphy Sensor, Registration number: 40B2X10040000001. Used for sleep disorder evaluation in clinical and home settings. Sold or leased to medical institutions, research institutions, and corporations for clinical sleep evaluation and diagnosis support.
• ACCEL POLARIS Proprietary wristwatch-type sleep measurement device equipped with 3-axis accelerometer and PPG sensor. Enables accurate detection of mid-sleep awakenings with up to 2-week battery life. Designed for high-precision sleep research and clinical studies, supporting three-state sleep classification (Wake/REM/Non-REM).
• SLEEP COMPASS Light Simplified sleep assessment service using only web questionnaires (no wearable device required). Provides quick sleep risk identification and improvement action recommendations within 3 days. Lower-cost entry point for organizations implementing sleep health programs, typically used as a broad screening tool before offering full SLEEP COMPASS to selected employees.
• SLEEP COMPASS Sleep Apnea Screening Option Sleep apnea screening add-on for SLEEP COMPASS combining wristwatch-type device measurement with ring-type pulse oximeter to detect SAS risk. Provides personal report and medical institution submission report format.
• AI PSG Analysis Outsourcing Service Outsourced PSG test analysis service using AI. Clinical technologists' manual analysis (3-4 hours per test) is replaced with AI-powered analysis of sleep stages, arousals, and respiratory events, with quick AHI calculation for sleep apnea diagnosis. Includes human technologist review for quality assurance; custom AI models for specific hospitals are available as a premium option.
• Home PSG Service At-home polysomnography testing service for sleep apnea syndrome and other sleep disorders. Combines ACCEL Stars wearable devices with portable measurement equipment for clinical-grade diagnosis without hospital admission.
• Sleep Hygiene Guidance Service Medical professional-guided sleep improvement service (睡眠衛生指導) for individuals identified with sleep issues through measurement. Doctors and public health nurses deliver personalized sleep hygiene instructions based on wearable-measured sleep data. Billed as part of corporate wellness or health insurer programs.
• Clinical Research Support Services One-stop research support services for universities and pharmaceutical companies, including device provision, algorithmic analysis, research protocol drafting, ethics review support, and participant recruitment. Engaged in over 170 collaborative research discussions with 61 approved studies, expanding into digital biomarker development for CNS disorders and drug/device evidence generation.

Quantifiable outcome

• 82.2% specificity vs PSG gold standard (vs Apple Watch 54.1%, Oura Ring 48%, Fitbit 42.4%, Actiwatch 26.9-37.0%)
• +7 more outcomes

Named customers14 records

Segments6 records

Ideal customer profiles5 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration1 record

AI capability5 records

Feature6 records

Partnerships

14 partnerships are on record, tiered strategic, core and minor.

• Singapore SleepWake Centre (Tanglin) Pte. Ltd.strategicStrategic or Co-development Partner · 25 May 2026MOU signed May 2026 for clinical evaluation, performance validation, and practical usability assessment of ACCELStars' sleep-related devices and technologies in the Singapore market. Both parties will collaborate on joint research, technology improvement, data analysis, clinical application, regulatory support, and market development. ACCELStars provides devices, analysis platform operation, data analysis and technical verification. Singapore SleepWake Centre provides clinical review, comparative evaluation against existing technologies, clinical feedback, and regulatory support. This MOU represents ACCELStars' first step in Southeast Asian and broader Asian market expansion, with Singapore serving as the regional hub.
• augment AI Inc.coreStrategic or Co-development Partner · 20 March 2026Capital and business alliance between ACCELStars and augment AI for co-development of AI sleep analysis features for the wena X smartwatch. ACCELStars contributes its medical science-based sleep analysis expertise, including 4-stage sleep staging, nap detection, smart alarms, sleep scores, and personalized feedback. The wena X smartwatch (world's smallest, developed by Sony's former wena team) positions sleep and exercise as its most important health domains. The partnership enables ACCELStars to reach consumer markets through a consumer wearable device while providing augment AI with medical-grade sleep analysis technology. The partnership was announced March 20, 2026, concurrent with wena X crowdfunding launch.
• Takeda Pharmaceutical Company Limited (武田薬品工業)strategicStrategic or Co-development Partner · 13 November 2025ACCELStars selected for Takeda's 'Neuroscience Challenge' corporate partnership program focused on digital health solutions for sleep-wake disorders including narcolepsy. The partnership aims to improve QoL for patients and support physicians. ACCELStars will develop new models for sleep disorder screening and treatment support using its proprietary technologies, with joint Proof of Value (PoV) initiative.
• Portal Innovations LLCstrategicStrategic or Co-development Partner · 23 October 2025US-based life science accelerator. ACCELStars selected for the Portal Innovations × Astellas SakuLab-Tsukuba Bootcamp — a program bringing Portal Innovations' US startup acceleration model to Japan. ACCELStars will engage with US investors and Bio/MedTech partners for potential global expansion and collaboration.
• Astellas Pharma Inc. (アステラス製薬) / SakuLab-TsukubastrategicStrategic or Co-development Partner · 23 October 2025Joint bootcamp program with Portal Innovations and Astellas Pharma's SakuLab-Tsukuba. ACCELStars selected as one of the participating startups. Astellas Pharma is one of Japan's largest pharmaceutical companies, and this program supports life science startup commercialization in Japan.
• ITFOR Inc. (株式会社アイティフォー)minorStrategic or Co-development Partner · 1 September 2025Company-wide sleep habit improvement program 'SLEEP UPGRADE' combining sleep seminars, SLEEP COMPASS Light surveys, and SLEEP COMPASS device measurements for selected employees. All employees participate in the sleep awareness seminar, followed by sleep reality surveys and sleep measurement for winners. ITFOR focuses on 'human resources deepening' as a key priority.
• K-BIT Inc. (株式会社K-BIT)minorStrategic or Co-development Partner · 20 August 2025Joint project 'K-BIT Sleep Skill Power-Up Challenge 2025' adopted by Osaka Smart Health Project 'Health-O'. ACCELStars provides SLEEP COMPASS and sleep seminars to K-BIT employees to validate sleep improvement effectiveness. K-BIT is an ICT company with high rates of mental health-related absences in Japan's workforce.
• Fast Doctor Inc. (ファスト・ドクター)strategicChannel Partner/ Reseller/ Distributor · 5 August 2024Service partnership where Fast Doctor offers 'Fast Doctor Sleep Examination' combining ACCELStars' SLEEP COMPASS service with Fast Doctor's online medical consultations and mental health services. Two courses offered: Light (web questionnaire only, 3-day) and Regular (SLEEP COMPASS + web questionnaire, 8-day). Fast Doctor uses ACCELStars' high-precision sleep data to support online counseling and medical consultations for patients with sleep disorders.
• Linkage Inc. (リンケージ)minorChannel Partner/ Reseller/ Distributor · 31 May 2024Partnership to integrate SLEEP COMPASS Light (web questionnaire-based) into Linkage's specific health guidance (特定保健指導) programs. ACCELStars provides sleep measurement and analysis; Linkage provides distribution to their health insurer and corporate clients for lifestyle disease prevention programs targeting 'rest' outcomes.
• NeuroSurgicals Co., Ltd. (株式会社ニューロシューティカルズ)strategicStrategic or Co-development Partner · 7 May 2024Strategic business partnership to build a next-generation medical device industry ecosystem in Japan. ACCELStars provides high-precision sleep algorithms and medical device development capabilities. NeuroSurgicals contributes medical device development expertise, regulatory/approval process knowledge, clinical research and trial support, and talent development systems. Goal is to enable continuous generation of innovative medical devices from Japan.
• Onoff Co., Ltd. / Yurureco (株式会社オノフ / ゆるれこ)minorChannel Partner/ Reseller/ Distributor · 1 April 2024Sales partnership to integrate SLEEP COMPASS into Yurureco's femcare service for women in perimenopause (ages 40-55). Yurureco targets sleep issues caused by hormonal changes during menopause. ACCELStars provides sleep measurement technology integrated into Yurureco's app ecosystem.
• Sony Network Communications CorporationstrategicTechnology or Integration · 1 March 2024Partnership to integrate ACCELStars' sleep analysis algorithm with Sony Network Communications' mSafety B2B wearable and cloud platform. ACCELStars develops sleep analysis algorithms for data collected via mSafety's LTE-M connected wearable devices. Joint exploration of new sleep measurement and improvement services for enterprise and consumer markets, targeting partnership contract by summer 2024.
• I.M.I. Co., Ltd. (アイ・エム・アイ)minorStrategic or Co-development Partner · 29 June 2022Joint development of sleep disorder early detection services and AI-supported PSG analysis services. I.M.I. (medical device importer/distributor) brings sleep testing devices and hospital networks. ACCELStars provides its world-leading sleep measurement algorithm. Focus on SAS (sleep apnea syndrome) screening and sleep disorder diagnosis support for medical institutions.
• Sakura Jyuji Group (桜十字グループ)strategicStrategic or Co-development Partner · 16 December 2021Ongoing partnership with Sakura Jyuji Group hospitals for joint development of healthcare services combining sleep measurement with health/medical data. Includes 'Health Sleep Project' covering sleep examination and sleep hygiene guidance. 'MediMessé Sakura Jyuji' health park in Kumamoto serves as a hub. UX project collaboration with Kumamoto Prefecture. Also collaborating on sleep health in pediatric patients (ASD, ADHD) and rehabilitation.

Scale indicators7 records

Recent moves7 records

Expansion highlights6 records

Direct peers

• Whoop: Whoop is a subscription wearable focused on sleep, recovery, and strain for athletes and general wellness users. Comparable to ACCELStars on sleep tracking and recurring subscription model, with Whoop's sleep-coaching features overlapping SLEEP COMPASS guidance.
• Oura: Oura Ring is a consumer smart ring focused on sleep, readiness, and recovery tracking. Directly comparable to ACCELStars on sleep tracking use case and wearable form factor, though Oura targets consumers directly while ACCELStars leads with B2B/wellness and medical-grade accuracy claims.
• Compumedics: Compumedics manufactures PSG and EEG clinical diagnostic systems used by sleep clinics and hospitals. Comparable to ACCELStars on PSG-analysis infrastructure for sleep medicine providers.
• Dreem: Dreem is a clinical-grade sleep headband with EEG-based sleep staging aimed at consumers and researchers. Comparable to ACCELStars on the pursuit of PSG-validated accuracy in a non-clinical wearable, though using EEG rather than accelerometer/PPG.

Regional players

• Nihon Kohden: Nihon Kohden is a leading Japanese medical-device manufacturer with neurology and sleep-diagnostic equipment. Comparable as a Japanese regional player in clinical measurement instrumentation that ACCELStars could partner with or compete against.

Broad incumbents

• ResMed: ResMed is the global leader in sleep apnea and respiratory care medical devices. Comparable as a broad incumbent in the clinical sleep-disorder space where ACCELStars is expanding via PSG AI and SAS screening.
• Fitbit (Google): Fitbit is one of the mass-market consumer sleep and activity trackers cited by ACCELStars as an accuracy benchmark. Broad incumbent with significant scale but materially lower wake-detection specificity than ACCEL algorithm.
• Apple: Apple Watch offers consumer sleep tracking features that ACCELStars directly benchmarks (54.1% specificity). Apple is a broad incumbent in consumer wearables rather than a focused medical-sleep competitor.
• Philips (Respironics): Philips Respironics is an established player in sleep diagnostics (PSG, HSAT) and sleep therapy. Comparable broad incumbent in clinical sleep measurement where ACCELStars competes with ASAP and ACCEL ATRIA.

Emerging players

• S'UIMIN: S'UIMIN is a Japanese sleep-tech company offering consumer sleep analysis and corporate wellness programs. Comparable emerging player in the Japanese sleep wellness and corporate health-management space overlapping SLEEP COMPASS.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks7 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/accelstars-inc-
• Xx.com/accelstars_hr

Compliance5 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles10 records

Funding overview

Funding rounds1 record

Investors8 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about ACCEL Stars