Note 9 - Share-based Compensation (Tables)

9 Months Ended

Sep. 30, 2019

Notes Tables

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

	Three months ended September 30,				Nine months ended September 30,
	2019		2018		2019		2018
Cost of goods sold	$	38	$	39	$	130	$	105
Research and development		293		250		787		711
Selling, general and administrative		425		441		1,224		1,267
Share-based compensation expense	$	756	$	730	$	2,142	$	2,083

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		254,785			5.28
Stock options exercised		—			-
Stock options canceled		(15,122	)		14.16
Balance, September 30, 2019		848,148		$	18.90
Exercisable and vested, September 30, 2019		390,199		$	24.17

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

				Weighted
				average
				grant date
	Number of			fair value
	S hares			per share
Balance, December 31, 2018		29,694		$	25.56
RSUs granted		34,713		$	4.75
RSUs vested		(2,272	)	$	99.36
RSUs forfeited		-			-
Balance, September 30, 2019		62,135		$	10.55