Note 15 - Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2017

Notes Tables

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	Years ended December 31 ,
	201 7			201 6			201 5
Numerator :
Net los s	$	(12,308	)	$	(10,310	)	$	(6,697	)
Denominator :
Weighted average shares used to compute net loss per share, basic and dilute d		38,160,543			8,368,284			1,560,293
Net loss per share, basic and diluted	$	(0.32	)	$	(1.23	)	$	(4.29	)

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

	December 31 ,
	201 7		201 6		201 5
Convertible preferred stoc k		-		-		9,208,376
Notes convertible into share s		-		-		8,731,657
Convertible preferred stock warrant s		-		-		194,383
Stock options to purchase common stoc k		4,213,100		3,491,937		1,149,040
Unvested restricted stock unit s		97,996		-		-
Tota l		4,311,096		3,491,937		19,283,456