Note 7 - Accrued Expenses and Other Current Liabilities - Accrued Liabilities and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accrued expenses	$ 406	$ 478
Accrued clinical trial costs	126
Grant liability	269	304
Customer deposits	63	66
Total	$ 864	$ 848