Note 10 - Net Loss Per Share (Tables)

9 Months Ended

Sep. 30, 2021

Notes Tables

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

	Three Months Ended September 30,						Nine Months Ended September 30,
	2021			2020			2021			2020
Numerator
Net loss attributable to common shareholders	$	(5,197,145	)	$	(3,491,071	)	$	(15,774,462	)	$	(10,344,633	)
Denominator
Weighted average common shares outstanding used to compute net loss per share, basic and diluted		126,537,544			10,162,770			113,689,961			9,496,222
Net loss per share of common stock, basic and diluted:	$	(0.04	)	$	(0.34	)	$	(0.14	)	$	(1.09	)

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

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Options to purchase common stock		10,043,575		7,158,387		8,682,997		5,825,082
Series B convertible preferred stock		166,142		177,562		172,909		183,544
Warrants to purchase common stock		22,356,105		1,070,028		24,773,777		1,070,028
		32,565,822		8,405,977		33,629,683		7,078,654