Note 9 - Share-based Compensation (Tables)

6 Months Ended

Jun. 30, 2019

Notes Tables

Schedule of Share-based Compensation, Expense [Table Text Block]

	Three months ended June 30,				Six months ended June 30,
	2019		2018		2019		2018
Cost of goods sold	$	46	$	36	$	92	$	66
Research and development		251		264		494		461
Selling, general and administrative		399		438		800		826
Share-based compensation expense	$	696	$	738	$	1,386	$	1,353

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Options outstanding
	Number of shares			Weighted average exercise price
Balance, December 31, 2018		608,485		$	25.16
Stock options granted		14,000			10.05
Stock options exercised		—			-
Stock options canceled		(4,119	)		45.10
Balance, June 30, 2019		618,366		$	24.75
Exercisable and vested, June 30, 2019		362,368		$	24.57

Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]

				Weighted
				average
				grant date
	Number of			fair value
	shares			per share
Stock options canceled		29,694		$	25.56
RSUs granted		-			-
RSUs vested		(2,268	)	$	99.36
RSUs forfeited		-			-
Balance, June 30, 2019		27,426		$	19.45