(ShareCast News) - Ron Zwanziger has resigned as non-executive director of EKF Diagnostics with immediate effect.The AIM-listed point-of-care business confirmed the news in a statement on Monday.Last week, EKF appointed Christopher Mills as non-executive chairman with immediate effect. Mills is chief executive and the sole shareholder of Harwood Capital Management Limited and founder of JO Hambro.He is a fund manager of Oryx International Growth Fund Limited and North Atlantic Smaller Companies Investment Trust PLC and has been and continues to serve as a director of many public and private companies.At 1215 BST, EKF shares were up 2.97% or 0.38p to 13.00p.