Note 12 - Summary of Stock Options (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

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

	Year Ened December 31, 2019
						Weighted
				Weighted		Average
	Number			Average		Remaining		Aggregate
	of			Exercise		Contractual		Intrinsic
	Shares			Price		Term (years)		Value
Options outstanding, January 1, 2018		26,903		$	579.81		8.6	$	249,154
Options granted		23,542		$	351.81
Options exercised		-		$	-
Options canceled		(10,301	)	$	548.13
Options outstanding, December 31, 2018		40,144		$	455.68		7.4	$	-
Options granted		10,065,844		$	1.14
Options exercised		-
Options canceled		(18,310	)	$	403.31
Options outstanding, December 31, 2019		10,087,678		$	2.22		9.9	$	3,928,715
Vested and exercisable and expected to vest, end of period		8,966,825		$	2.36		9.9	$	3,490,722
Vested and exercisable, end of period		222,582		$	41.49		9.5	$	77,540

Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block]

							Weighted
			Number		Weighted		Average		Number		Weighted
			Outstanding		Average		Remaining		Exercisable		Average
Range of			as of		Exercise		Contractual		as of		Exercise
Exercise Prices			December 31, 2019		Price		Term (Years)		December 31, 2019		Price
$0.86	-	$0.89		10,042,500	$	0.87		9.9		198,312	$	0.87
$38.00	-	$58.00		1,650	$	55.42		9.4		-	$	-
$100.00	-	$197.00		22,385	$	140.23		8.1		9,141	$	144.93
$202.00	-	$283.00		775	$	252.06		8.0		355	$	255.75
$311.00	-	$382.00		3,833	$	355.39		6.0		2,423	$	362.12
$430.00	-	$497.00		7,870	$	453.47		6.4		5,066	$	454.44
$501.00	-	$567.00		4,215	$	536.47		5.7		3,258	$	535.73
$600.00	-	$661.00		2,372	$	601.29		3.6		2,352	$	600.78
$700.00	-	$792.00		1,974	$	768.12		6.7		1,571	$	768.19
$992.00	-	$992.00		104	$	992.00		3.1		104	$	992.00
Total:				10,087,678	$	2.22		9.9		222,582	$	41.49

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Year Ended
	December 31,
	2019	2018
Expected term (in years)	6	5
Average volatility	70%	73%
Risk-free interest rate	1.62%	2.65%
Dividend yield	0%	0%

	Year Ended
	December 31,
	2019	2018
Expected term (in years)	6	9
Average volatility	70%	69%
Risk-free interest rate	1.69%	2.69%
Dividend yield	0%	0%

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Year Ended
	December 31,
	2019		2018
Cost of revenue	$	135	$	69
Research and development		192		328
Selling, general and administrative		2,073		2,638
Total	$	2,400	$	3,035

2017 Employee Stock Purchase Plan [Member]

Notes Tables

Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]

	Year Ended
	December 31,
	2019	2018
Expected term (in years)	0.25	0.25
Average volatility	87%	72%
Risk-free interest rate	2.29%	1.92%
Dividend yield	0%	0%