Note 2 - Balance Sheet Details - Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accrued warranty	$ 365	$ 322
Accrued outside commissions	41	69
Accrued professional fees	100
Accrued deferred rent	22	29
Other accrued liabilities	31	34
Total other accrued liabilities	$ 559	$ 454