Note 6 - Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accrued sales tax	$ 18	$ 435
Accrued professional fees	30	41
Accrued travel expenses	89	74
Accrued product warranty costs	214	272
Accrued clinical trial costs	101	111
Accrued restructuring charge		98
Other accrued liabilities	202	418
	$ 654	$ 1,449