Note 9 - Net Loss Per Share (Tables)

3 Months Ended

Mar. 31, 2020

Notes Tables

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

	Three Months Ended March 31,
	2020			2019
Numerator
Net loss attributable to common shareholders	$	(2,947,420	)	$	(4,073,307	)
Denominator
Weighted average common shares outstanding used to compute net loss per share, basic and diluted		9,130,984			6,565,514
Net loss per share of common stock, basic and diluted:	$	(0.32	)	$	(0.62	)

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

	Three Months Ended March 31,
	2020		2019
Options to purchase common stock		4,308,383		783,383
Series B convertible preferred stock		190,617		458,994
Warrants to purchase common stock		1,070,028		3,369,468
		5,569,028		4,611,845