Note 2 - Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2018

Notes Tables

Cumulative Effect of Adjustments for New Accounting Pronouncements on Balance Sheet [Table Text Block]

	Balance as of December 31, 2017			Adjustment Due to Adoption of ASC 606				Balance as of January 1, 2018
Consolidated Balance Sheet:
Liabilities
Accrued liabilities	$	4,605		$	18		(1)	$	4,623
Other noncurrent liabilities	$	327		$	(195	)	(2)	$	132
Equity
Accumulated deficit	$	(105,581	)	$	177		(3)	$	(105,404	)

Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]

	For three months ended June 30, 2018									For six months ended June 30, 2018
	As Reported			Balances Without Adoption of ASC 606			Effect of Change Higher/(Lower)			As Reported			Balances Without Adoption of ASC 606			Effect of Change Higher/(Lower)
Consolidated Statement of Operations
Revenue	$	5,525		$	5,405		$	120	(1)	$	9,224		$	8,894		$	330	(1)
Cost of revenue	$	2,711		$	2,705		$	6	(2)	$	5,063		$	5,048		$	15	(2)
Gross profit	$	2,814		$	2,700		$	114	(3)	$	4,161		$	3,846		$	315	(3)
Loss from operations	$	(10,295	)	$	(10,409	)	$	114	(3)	$	(21,635	)	$	(21,950	)	$	315	(3)
Comprehensive and net loss	$	(11,516	)	$	(11,630	)	$	114	(3)	$	(24,185	)	$	(24,500	)	$	315	(3)
Net loss per share:
Basic and diluted	$	(0.37	)	$	(0.37	)	$	-		$	(0.85	)	$	(0.86	)	$	0.01

	As of June 30, 2018
	As Reported			Balances Without Adoption of ASC 606			Effect of Change Higher/(Lower)
Consolidated Balance Sheets
Liabilities
Accrued liabilities	$	5,258		$	5,302		$	44		(1)
Other noncurrent liabilities	$	305		$	753		$	448		(2)
Equity
Accumulated deficit	$	(129,589	)	$	(130,081	)	$	(492	)	(3)

Revenue from External Customers by Geographic Areas [Table Text Block]

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2018		2017		2018		2017
United States	$	4,552	$	1,895	$	7,158	$	3,791
Asia Pacific		630		690		1,521		1,433
Europe and Middle East		329		456		531		568
Latin America		14		35		14		325
Total	$	5,525	$	3,076	$	9,224	$	6,117

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	Six Months Ended
	June 30,
	2018		2017
Stock options to purchase common stock		4,209,355		2,287,572
Warrants to purchase common stock		642,622		642,622
Restricted common stock awards		66,250		6,250