Note 4 - Accrued Liabilities - Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Customer advance payments	$ 1,418	$ 20
Accrued professional fees	432	388
Accrued bonuses	164	613
Accrued vacation	121	68
Accrued clinical trial costs	89	112
Other accruals	184	92
Total accrued liabilities	$ 2,408	$ 1,293	[1]

[1] The condensed consolidated balance sheet as of December 31, 2015 has been derived from the audited consolidated financial statements as of that date.