"Dr Riddell has been a key force in driving Feedback forward in recent years and on behalf of the board, we are grateful for his guidance and advice,” said Oakley.
Riddell will be replaced by Professor Rory Shaw, who will quit his role as medical director immediately to initially fulfil the role of deputy chairman.
Shaw previously held the same job at Healthcare UK within the Department of International Trade. Over the previous 15 years he was Medical Director of three NHS Trusts and in 2001 he was appointed the first chairman of the National Patient Safety Agency.
Shaw is described as being vital in helping develop the company’s Bleepa technology, a medical-grade messaging service that can be used on smartphone, tablet and desktop.
"With his appointment as deputy chairman and in due course, to chairman, we will continue to benefit from his valuable clinical and business expertise," said CEO Oakley.