NEXSTIM - Key Persons


Gustaf Järnefelt

Job Titles:
  • Member of the Management Team
  • Vice President, R & D
Gustaf Järnefelt has served as the Vice President, R&D since joining Nexstim in 2008. Prior to joining Nexstim, he spent 18 years with Instrumentarium then GE Healthcare serving several Manager, Director and General Manager roles in design, R&D, Engineering and Business Integration. He has spent more than five years abroad on assignment in the United States leading the Configured Patient Monitoring Business unit for Instrumentarium in Louisville Colorado. Järnefelt is alone or with others an inventor in fifteen patent families. He has an education background from both Karlsruhe Germany Universität TH Karlsruhe (Institut für Werkzeugmaschinen und Betriebstechnik) and Helsinki University of Technology and holds a Master of Science from Helsinki University of Technology, Finland.

Henri Hannula - VP of Sales

Job Titles:
  • Member of the Management Team
  • Vice President, Sales and Marketing
Henri Hannula has risen through the ranks holding key leadership positions since joining Nexstim in 2001. He assumed the role of Vice President, Sales Europe in 2013. Henri assumed the position of VP, Sales and Marketing in December 2022, making him responsible for these functions globally following a corresponding role in EU & ROW sales and marketing. Henri has been vital in the growth of Nexstim and has authored multiple articles on navigated transcranial magnetic stimulation published in peer-reviewed journals. He holds a Master of Science degree from Helsinki University of Technology, Finland.

Jarmo Laine - VP

Job Titles:
  • Member of the Management Team
  • Vice President
  • Vice President, Medical Affairs
Jarmo Laine, MD, brings an extensive background as a licensed physician, with board certification in pediatrics, and management of R&D and laboratory services. He holds an M.D. and PhD from the University of Helsinki, Finland and an MBA from Helsinki University of Technology. Jarmo worked and trained throughout various hospitals in Finland and completed his post-doctoral research fellowship at Harvard Medical School in Boston, Massachusetts. Prior to joining Nexstim in 2008, Jarmo held several leadership positions with the Finnish Red Cross Blood Service. Dr. Laine has over sixty publications in international journals in the fields of organ/cell transplantation, pediatric nephrology, cell biology and Navigated Brain Stimulation. In addition, he holds seven patents, with additional patents submitted in the field of stem cell therapies and navigated transcranial magnetic stimulation.

Joonas Juokslahti - CFO

Job Titles:
  • CFO
  • Member of the Management Team
Joonas Juokslahti started as Nexstim's CFO in February 2020. He joined Nexstim in May 2014 as Business Controller and has been a key part of the Nexstim finance team. He holds a Master of Science with a major in Accounting and Finance from Turku School of Economics, Finland.

Leena Niemistö - Chairman

Job Titles:
  • Chairman of the Board
  • Member of the Board of Directors
  • Chairman of the Nexstim Board
Leena Niemistö has been Chair of the Nexstim Board since November 2019. She is a healthcare professional with over 30 years of clinical and leadership experience. Niemistö holds an M.D. from the University of Helsinki and has specialized in physical and rehabilitation medicine. She also has a doctorate in the treatment of chronic back pain. Leena Niemistö also holds a Dr. Admin. Sc. hc from Vaasa University. Niemistö worked as CEO of a private healthcare company Dextra (years 2003-2016) and deputy CEO in a social and healthcare company Pihlajalinna (years 2013-2016). Currently she is a member of the Board of Directors in several publicly listed companies. She is also an active investor in several healthtech growth companies. Niemistö's investment company is the largest shareholder of Nexstim.

Martin Forss

Job Titles:
  • Member of the Board
  • Member of the Board of Directors
Martin Forss has been a member of the Board since November 2019. He is an entrepreneur, investor and board professional. He is known as an experienced service business executive. His latest operative responsibility was as CEO of the private dentistry company Oral Hammaslääkärit. Martin holds a Master of Science degree (Econ) and has experience working with both listed companies and many private equity owned companies throughout his executive operative career.

Mikko Karvinen - CEO

Job Titles:
  • CEO
  • Member of the Management Team
Mikko Karvinen started as Nexstim's CEO in February 2020. He joined Nexstim as CFO in August 2014. Mikko has previously held CFO and deputy CEO positions at two Nasdaq Helsinki

Tero Weckroth

Job Titles:
  • Member of the Board
  • Member of the Board of Directors
Tero Weckroth has been a member of the Board since May 2021. He is an experienced professional in the fields of finance and the pharmaceutical industry. Currently, he runs his own investment and consultancy company WRCC Invest Oy and serves as a board member in multiple growth companies. Tero has extensive experience of managing international teams in the pharmaceutical and financial industries. Tero's expertise is in solving complex management issues regarding regulatory/legal challenges and business interests. Tero holds degrees in Business Administration (MBA) and Pharmacy (M.Sc.) plus additional studies in natural sciences and international politics.

Timo Hildén

Job Titles:
  • Member of the Board
  • Member of the Board of Directors
Timo Hildén has been a member of the Board since May 2021. He is a medical technology professional with decades of experience from various health technology companies. In the most recent years, Timo has worked as CEO and more recently Advisor for Revenio Group Oyj. Currently Timo serves Koite Health Oy and Hublet Oy as a board member. Timo spent over 20 years in various leadership positions at Thermo Fisher Scientific. Timo holds a Master of Science degree from the Helsinki School of Economics. He has an impressive track record especially in international sales, product management and conducting profit growth strategies.