Note 5 - Accrued Liabilities - Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Accrued sales commission	$ 817		$ 1,743
Customer contracts liabilities	679		686
Accrued interest	675		683
Accrued payroll and other related expenses	670		877
Accrued bonuses	613		837
Accrued professional fees	492		978
Current operating lease liabilities	238	$ 230
Accrued clinical trial costs	127		84
Travel and entertainment	114		280
Accrued sales & use tax	102		259
Other accruals	275		339
Total accrued liabilities	$ 4,802	$ 6,996	$ 6,766