Top 7 Digital Health Startups Revolutionizing Patient Monitoring in Japan

Japan is transforming the future of healthcare through digital health startups that put patient monitoring at the center. Amid demographic shifts and rising medical costs, these innovators are bridging hospitals, homes, and clinics using wearable sensors, AI‑driven analytics, and remote monitoring platforms. Here are the top 7 ventures, active in 2025, leading the revolution.

1. Crely – Continuous Post‑Surgical Monitoring

Crely is pioneering AI‑enabled wearable devices that continuously monitor surgical wound biomarkers to predict surgical site infections (SSI) early. Founded in 2017, its clinically-validated system captures skin temperature, heart rate, and humidity data via non-invasive patches. AI models analyze trends and alert clinicians of early infection risk before visible symptoms emerge
Why it matters: SSI is the most costly HAI type with an estimated annual cost of US$ 3.3 billion, and extends hospital length of stay by 9.7 days, with cost of hospitalization increased by more than US$ 20,000 per admission. Crely’s innovation can reduce delays in diagnosis, improve recovery outcomes, and lower readmission rates.
Example: In a small pilot in a regional hospital, Crely reduced average post‑op infection rates by 40% within 30 days, patients left with greater confidence, and staff could intervene earlier.

2. SmartScan – AI Imaging for Vascular Risk

SmartScan, founded in 2017, offers the Smart Brain Doc system, a SaaS plus AI diagnostic tool that analyzes MRI images to detect early cerebrovascular disease signs. Data is uploaded to the cloud and reviewed by radiologists and neurosurgeons, enabling early intervention.
Why it matters: Stroke and vascular dementia are serious health risks in Japan’s ageing society. SmartScan’s combination of patient monitoring and remote diagnostics brings high-quality screening to smaller clinics, democratizing access.
Example: Had over US$ 11.9 million in investment which recognizes its growth potential.

Also Read: AI Game Masters: How Japan’s Studios Are Designing Adaptive Game Worlds

3. Welby – Chronic Disease Self‑Management Apps

Founded in 2011 and listed on the Tokyo Stock Exchange in 2019, Welby provides mobile health apps for chronic diseases such as diabetes and hypertension. Users record metrics, blood sugar, blood pressure, weight, and diet, and share them securely with doctors or caregivers. This empowers remote patient monitoring and more personalized care during physician visits.
Why it matters: For clinicians, having longitudinal data before a consultation allows more targeted discussions and treatment plans.
Example: A 65-year-old diabetic patient credited Welby’s app for helping her adjust insulin dosing earlier, cutting doctor visits by a third and lowering HbA1c levels within six months. Moreover, in June 2020, the AstraZeneca and Welby jointly released an app to support patients taking the anticancer drug developed and deployed by AstraZeneca and help them self-manage their medication status.

4. Ubie – AI Symptom Checker and Hospital SaaS

Ubie, with US$ 125 million in funding, is known for its AI symptom checker and hospital SaaS platform. Patients input symptoms in natural language; the system offers likely diagnoses and triage guidance. Integrated with hospital patient monitoring systems, clinicians receive pre-consultation summaries to improve speed and accuracy of care
Why it matters: Ubie speeds up triage and supports decision-making in busy clinical environments, especially where specialist access is limited.
Example: Hospitals using Ubie reported 20% faster triage workflows and improved patient satisfaction scores.

5. AI Medical Service – Endoscopic AI Diagnostics

AI Medical Service Inc., with ¥ 8 billion in fundraising, develops AI models that detect gastric cancer in endoscopy images in real‑time. Recognized as gold‑prize startup at the GHeC pitch event in early 2025, its platform supports clinicians with live flagging of suspicious lesions during procedures.
Why it matters: Early detection of GI cancers significantly improves survival rates. AI Medical Service influences patient monitoring by introducing a data-driven safety net in endoscopic workflows.
Example: In a Yokohama pilot, physicians reported a 30% increase in early-stage detection, thanks to AI alerts, a significant impact in clinical outcomes.

6. Hacarus – Lightweight AI for Vital Signs

Hacarus, known for its AI SALUS platform, uses small‑sample, ‘sparse modeling’ AI to analyze CT, MRI, ECG, and vital signs with minimal data. Their focus is enabling low-cost vital‑sign monitoring across diagnostic and clinical scenarios
Why it matters: Hacarus’s approach is ideal for remote monitoring in rural clinics or long‑term care facilities where data volume or infrastructure is limited.
Example: With ¥ 1.3 billion in venture funding, the company is scaled for real-world deployment by mid‑2025.

7. JiMED – Brain‑Computer Interface for Neuro Monitoring

Founded in 2020, JiMED is developing wireless embedded brain‑computer interface (BCI) systems for monitoring neurological conditions. Though early‑stage, its technology holds promise for real‑time monitoring of brain activity, epilepsy tracking, and rehabilitation feedback.
Why it matters: BCIs bridge a new frontier in patient monitoring, offering clinicians direct neural activity data that may guide treatment for neurological disorders.
Example: JiMED has received a funding of US$ 2.26  million in 2020.

AI, Privacy, and Regulation

Japan’s digital health ecosystem has matured: between 2020 and 2025, about 229 digital health ventures raised US$ 2.57 billion in 491 deals, growing at ~1.4% CAGR. However, patient data privacy remains a key challenge. As reported, Japan is working on standardizing data-sharing frameworks to permit ‘pseudo-anonymous’ secondary use of data while protecting cultural expectations around privacy. These legal reforms will accelerate adoption of patient monitoring technologies by enabling safer AI usage in diagnosis and research.

Insights & Actionable Takeaways

For Healthcare Providers

• Adopt incremental monitoring tools like Crely or SmartScan to reduce complications and improve early detection.
• Integrate platforms like Welby and Ubie into routine care to capture patient-reported data and symptom analytics.
• Educate staff about privacy-compliant data sharing; stay informed on evolving MHLW guidelines.

For Investors & Policymakers

• Support clinical trial infrastructure and decentralized trials (DCTs), combining regulatory clarity and metadata sharing to fast-track spin-outs. The MHLW’s interim report encourages milestone‑based support for health startups.
• Fund next‑gen monitoring tech, especially AI-enabled wearables and BCIs, which align with global healthcare trends and aging-population needs.

For Patients & Families

• Embrace home monitoring tools: From blood pressure and glucose tracking apps to wearable patches, use home monitoring tools under physician guidance.
• Understand your rights: Japan’s privacy reforms increasingly allow controlled patient data use to enhance diagnosis and treatment.

Why These Startups Stand Out

These start-ups collectively span wearables, AI imaging, mobile health, and neural sensing, all critical elements of patient monitoring.

Conclusion

Japan’s patient monitoring revolution in 2025 is powered by these seven startups, each harnessing AI, wearable sensors, and digital platforms to transform care delivery. From surgical wards to chronic disease management and even brain‑computer interfaces, these ventures exemplify how digital health startups can reduce costs, elevate quality, and humanise healthcare.

As regulatory frameworks evolve and patient attitudes shift toward digital engagement, Japan is primed to become a global leader in patient-centered, tech-enabled care. For clinicians, investors, and patients, the message is clear: the future of patient monitoring is already here, and it’s digital, smart, and deeply humane.