Note 11 - Net Loss Per Share (Tables)

9 Months Ended

Sep. 30, 2020

Notes Tables

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

	September 30,
	2020		2019
Stock options to purchase common stock		1,078,813		837,308
Unvested restricted stock units		8,200		36,981
Common stock warrants		2,435,807		2,435,807
Total		3,522,820		3,310,096