Top Medical Devices Startups in California, US

At Willow Innovations, Inc., our vision is to create a better world for moms. We are focused on identifying where moms need support in the motherhood journey, and building hardware- and software-based solutions around their needs. In 2014, we created the first-ever cord-free Willow™ Wearable Breast Pump, revolutionizing the industry. Fast forward to today, we are building a portfolio of physical and digital products to solve mom's most meaningful problems and improve their lives. Willow Innovations, Inc. sits at the unique and exciting intersection of HealthTech, FemTech, Consumer Goods, and Med device. Our potential for scale and impact is extraordinary—we’re just getting started. We’re looking for talented, passionate team players to help us deliver our mission and vision. If this sounds like you, we'd love to hear from you! Recent awards we’ve won include: - Great Place to Work Certified 2021–2022 - Omnis Awards, Outstanding Culture and Communication

THE PROMISE With ultrasound a doctor can see into the heart of someone in cardiac arrest or into the abdomen of a woman with an ectopic pregnancy, and save their lives. 75 years after its invention, ultrasound remains an indispensable tool for diagnosis and monitoring. THE PROBLEM 60% of the world lacks access to medical imaging because current technologies are unwieldy, expensive, and require extensive training. While doctors carry supercomputers in their pockets, they still rely on the 200-year old stethoscope​ as their primary diagnostic tool. THE SOLUTION Our mission is to democratize healthcare by making medical imaging accessible to everyone around the world. Butterfly Network has raised >$350M to develop and commercialize a handheld, smartphone-connected ultrasound probe powered by AI. We operate at the intersection of medicine, engineering, and machine learning to create breakthrough technology that becomes smarter with each new patient.

RDI is an overnight success — years in the making. We’re scaling fast (grew 4× last year), fueled by enterprise engagements with the top IVD manufacturers in the world. For a small team, we punch way above our weight. RDI has become the go-to CRO for large public diagnostics companies who rely on our creativity, tech-forward systems, and zero-excuses accountability to get trials done quickly and done right. We’re a fully integrated IVD CRO — a high-complexity CLIA lab, a technology-enabled CRO, and a national physician + lab network under one roof. This lets us run clinical trials with a level of speed and operational precision the industry isn’t used to. RDI was founded in 2008 and professionalized in 2017 through a search fund acquisition (not venture hype). We’re backed by long-term operators and growth investors — not dependent on VC burn or fundraising cycles. From 2022–2024, we expanded aggressively by doing the hard things right: building real infrastructure, earning trust from enterprise customers, and executing consistently. Our physician network was sourced from real insurance claims data and strengthened by CAP accreditation. No one has successfully started and scaled a modern CRO focused on diagnostics and medical devices in over 15 years. The industry is dominated by large, slow incumbents optimized for pharma — not speed, accountability, or precision. We’re the underdog — and we’re winning. Our goal is simple: prove our customers right, and prove the industry wrong. Get a feel for how we work: youtube.com/watch?v=3tccEbsWIl8

Neuralink is developing a fully-implanted, wireless, high-channel count brain-machine interface (BMI) with the goal of enabling people with paralysis to directly use their neural activity to operate computers and mobile devices with speed and ease. Neuralink was founded in 2016 by Elon Musk and the company is headquartered in Fremont, CA with a second location opening in Austin, TX.

We develop cutting edge medical devices that leverage machine learning and artificial intelligence for healthcare.

At 4Catalyzer we strive to transform 21st century medicine by solving today’s most challenging problems – across life science research tools, medical devices and therapeutics. We aspire to create significant societal impact and are motivated by the idea that our products will change the lives of people we love. Fundamentally, we are focused on developing new types of sensors and pairing them with deep learning to get a window into biology and medicine that nobody has ever had before. We have audacious plans – but we have an unbeatable team and a founder that has disrupted biomedical science successfully more than once. If you have experience in image reconstruction, mixed-signal IC design, high-speed electronics, nanophotonics, microfabrication, MEMs, biophysics, biochemistry, molecular biology, deep learning, cloud computing, embedded systems, or hold any dual degree with distinction along with computer science please contact us and “put a dent in the universe”.

HEAL (Healmenow Inc.) is building the first screenless, voice-first companion for medication adherence and mental wellness. Instead of another app competing for screen time, HEAL lives as a physical device in your space — you talk to it, it responds, it helps you stay on track with your care. We sit at the intersection of hardware, AI, and emotional design, because behavior change doesn't come from reminders and gamification — it comes from feeling understood. What We're Building A screenless medication adherence device paired with an AI voice companion. Say "Hey HEAL" and it dispenses your medication, logs adherence, and has a real conversation with you about how you're doing — building the kind of clinical documentation that qualifies for Medicare Remote Therapeutic Monitoring (RTM) reimbursement. V1 is built and working; we're now developing V2 using real user data, targeting a significant jump in treatment effectiveness. Our voice companion also carries a crisis-escalation layer, built with clinical oversight from a psychiatry advisor with 15+ years of experience. Hard Problems We're Solving Medication non-adherence, especially for mental health conditions, is a massive and under-addressed problem — people don't stop taking their medication because they forget, they stop because no one is checking in on how they actually feel. Existing solutions (pillboxes, reminder apps) treat this as a logistics problem, not an emotional one. We're solving three hard problems at once: designing a voice AI that can hold a caring, clinically-sound conversation without a screen; building the crisis-detection logic responsible enough to flag real risk without false alarms (the single highest-risk, highest-scrutiny part of the FDA classification question); and proving this new adherence data can actually satisfy Medicare RTM reimbursement requirements, which is what will make this sustainable at scale rather than another wellness gadget.