We are on a mission to democratize quality assistive products so that none are left behind.


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Benefit Corporation


Great medical devices can be affordable. Today, 80% of medical devices are designed for only 20% of the people who need them. To fit tighter budgets and rougher environments, our product design process and company structure are different.

Participant is for-profit company registered as a Benefit Corporation. Here are a few of our commitments to social impact.

  • Our products are evaluated by outside experts to confirm that they pass international quality standards.

  • We monitor and report the actual efficacy of our products. Our participants tell us if we are succeeding!

  • Our management is evaluated by our board using environmental and social metrics - as are all employees.

  • All products have lifecycle impact assessments. We do not do ‘planned obsolescence’.

  • 5% of our profits are donated to our non-profit partners so they can serve more people.

  • We all participate in the company's success. All employees are owners regardless of where they live.

Learn more about B Corp


Keoke King
CEO, Co-founder




We are experienced industry veterans. Between the founders, we’ve designed 200 assistive products, served thousands wheelchair users in over 20 countries, and have a combined 10 decades of experience serving people with disabilities.

Dave Calver

Chief Clinical Officer 

Dave  Calver is a Canadian Occupational Therapist who has dedicated his career to working  with wheelchair seating and in wheelchair development in less resourced countries.  He is a wheelchair user who participates in a great variety of outdoor sports and enjoys introducing other individuals to the outdoors, particularly fellow wheelchair users.  He has been living and working overseas for more than 25 years and currently calls Nicaragua home.  Dave on LinkedIn


Wayne Hanson

Product Developer, Co-Founder

Wayne grew up in Montana and currently lives in Bozeman, Montana with his wife Lee Ann. Nearby are Wayne’s two children and five grandchildren. Wayne loves developing and delivering innovative products for children with disabilities to help them reach their greatest potential. Wayne and his wife co-founded their first wheelchair company, Kid-Kart Cares About Kids in 1990. Kid-Kart was a pioneer in providing freedom of mobility and therapeutic support for children with disabilities during their formative years from age one to age five. Wayne has since developed numerous products that serve children and adults with disabilities worldwide, including innovative dynamic seating systems that provide freedom of movement for children in their wheelchair. Wayne is the co-founder and currently the Executive Director of Reach Out and Care (ROC Wheels), a non-profit organization dedicated to providing seating and mobility products for people with disabilities in less resourced countries. Wayne has joined Participant because he believes in doing everything he can to help mobilize people with disabilities throughout the world. Wayne on LinkedIn


Keoke King

Cheif executive officer, Co-Founder

Keoke’s first encounter with disability was while being cared for by his grandmother. Her assistive products, a cane and a rudimentary wheelchair, were bulky and did not function well for her daily activities, especially outdoors. To design projects, Keoke brings a user-centered approach and attention to affordability. He loves to find market-based, scalable solutions that serve basic needs and his career in international development has taken him to seventeen countries for roles in marketing, supply chain, product development, and sales. In his last role, Director of Social Enterprises at UCP Wheels for Humanity, he launched CLASP, which is a supply chain solution designed to improve the access and affordability of appropriate assistive products globally. Previously, Keoke was Marketing Director at Whirlwind Wheelchair after his MBA studies at San Francisco State University. Keoke lives in San Francisco with his wife, Chris. Keoke on LinkedIn


Ryota Yamada

Cheif of design and innovation, Co-Founder

Ryota is one of the leading wheelchair designers in the world. He has developed over 130 wheelchairs from quick court chairs for basketball, to skate-park big jump chairs with suspension, to stylish daily use chairs, and some of the most robust chairs available today.  He weaves simplicity and user understanding into designs. And, he has a knack for achieving a balance between high performance, user satisfaction, and low unit production cost. He enjoys bicycling and craft beers of all kinds. We have Yoda on our team!  Ryota on LinkedIn

Advisory Board

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Eli Anselmi

Eli has over 25 years of experience in pediatric seating and positioning, with a focus in complex seating evaluation. He has been involved in Product Development, Continuing Education & Product training, and Sales Operations. He lives in Bozeman, MT, and has 3 sons. He has worked with many wheelchair companies, has evaluated over 1500 clients domestically & internationally, and is an accomplished conference speaker. He loves the outdoors, skiing, riding his motorcycle and a good book.

Eli on LinkedIn

Greg Barrett

Greg brings rigorous finance and accounting standards to Participant's books. As a CPA, he is building a career in medical devices and life sciences companies, including Bolt Threads in the SF Bay Area. Building the finance systems of scrappy startups into well oiled machines is his forte. "Human health and wellbeing are pillars of any great society. In my day to day, we push forward the leading edge of new health technology. It is satisfying to me to work with Participant to also bring underserved and vulnerable people forward toward good life and inclusion."

Greg on LinkedIn

Mark Burger

Mark’s background includes wealth management, institutional trading, and co-managing a hedge fund.  He has been active in finance both on the advisory side and as an angel investor in numerous companies over the past 35 years.  Mark holds a B.S. in Genetics from the University of California, Berkeley and an M.B.A. , awarded with honors, from the Graduate School of Economics and Business Administration at Saint Mary’s College. Additionally, he completed a Certificate in Accounting for Financial and Business Analysts, awarded with distinction, from the extension program at the University of California, Berkeley.

Mark on LinkedIn

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Ralf Hotchkiss

The struggle for disability rights and equality has taken Ralf far off the beaten path. "I was recognized with the MacArthur Genius Award for advancing independent living for wheelchair users by localizing wheelchair manufacturer. At the time, in 25 locations, now they have replicated and we've lost count." Ralf is co-founder of Whirlwind Wheelchair and lives in Oakland with his family. "Participant is carrying forward a vision for inclusion for all that is both self-evident and disruptive."

Ralf on LinkedIn

Sara Munera

Sara is a Physical therapist, she has a master’s degree in rehabilitation sciences at the University of Pittsburgh. She has experience in providing wheelchairs in the USA, Kenya, South Africa, Colombia and Mexico. She is a Wheelchair Service Provider (ISWP), certified trainer, and is an ATP-RESNA. Sara is the founder of Whee, a social enterprise that supports the inclusion of people with disabilities through education in assistive technology.

Sara on LinkedIn


Lal Ninan

Lal Ninan, Ph.D., is an experienced technical and regulatory professional with over 16 years of experience in the medical device and pharmaceutical industry. An engineer by training, he is passionate about enabling life science businesses develop global products that heal and restore health and quality of life in an affordable manner. Lal is excited to join the advisory board and contribute to realizing Participant’s vision of providing quality assistive products to disabled children worldwide.

Lal on LinkedIn


Sarah Vanier

Sarah has over 15 years of marketing experience with startups and big companies, doing both domestic and international marketing. She excels in building marketing infrastructure, pipeline, and in building top performing teams from the ground up. She brings a data based approach to Participant’s marketing by establishing metrics and testing protocols that reveal the tactics that best contribute to our sales pipeline.

Sarah on LinkedIn


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