Andrew Richmond paid 9.95p for the shares, giving a total cost of £24,875.
It takes his stake in the Edinburgh company to 750,000 shares, or 3.99% of its issued share capital.
Mr Richmond was previously at Collins Stewart, Phoenix Equity Partners and Covenant Healthcare Group. Mr Richmond is a lay member of the Court of Dundee University, a non-executive director at NHS Tayside and deputy chairman of the Scottish Ambulance Service.
Separately, David Cairns, portfolio director at Frontier IP, also bought 250,000 shares for 9.95p each.
That took his stake to 620,000 shares or 3.3%.
Shares closed up 0.62p, or 6.4%, at 10.38p