Biotronic NeuroNetwork, a portfolio company of Great Point Partners, has promoted Bill Gecsey to CEO from president and CFO. The appointment is effective immediately. Gecsey first joined the firm in 2010 as CFO. Based in Ann Arbor, Michigan, Biotronic is a provider of intraoperative neurophysiological monitoring.

CDI Computer Dealers, which is backed by H.I.G. Growth Partners, has promoted Erez Pikar to president from chief operating officer. Pikar began at the firm as a director of operations. Headquartered in Markham, Ontario, CDI is a refurbisher and remarketer of IT equipment to educational institutions.

Growth equity investor Edison Partners has promoted Ryan Ziegler to general partner and Lenard Marcus and Sever Totia to partner. Ziegler joined Edison 11 years ago while Marcus joined in 2004 and Totia in 2007.

Small business development company Plexus Capital has appointed Michael Painter as managing partner. Painter, one of five founding partners, succeeds Bob Anders, who has served as managing partner since the firm’s inception in 2005.

Response Biomedical Corp has appointed Lewis J. Shuster as chairman of its board of directors. The outgoing chairman, Dr. Peter A Thompson, will remain on the board. Shuster, CEO of Shuster Capital, an adviser to emerging growth and turnaround situation life science companies and to investors in life science company equity and debt, joined the Response board in 2011. Headquartered in Vancouver, British Columbia, Response is a maker of on-site diagnostic tests.