Note 10 - Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

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

	Year Ended December 31,
	2019			2018
Numerator
Net loss	$	(17,239,777	)	$	(11,404,934	)
Deemed dividend attributable to preferred stock		-			(11,479,308	)
Net loss attributable to common shareholders	$	(17,239,777	)	$	(22,884,242	)
Denominator
Weighted average common shares outstanding used to compute net loss per share, basic and diluted		8,496,964			4,157,746
Net loss per share of common stock, basic and diluted:	$	(2.03	)	$	(5.50	)

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

	Year Ended December 31,
	2019		2018
Options to purchase common stock		3,013,370		487,941
Series B convertible preferred stock		258,230		774,983
Warrants to purchase common stock		1,637,013		3,054,481
		4,908,613		4,317,405