Note 2 - Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2017

Notes Tables

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

	Nine Months Ended
	September 30,
	2017		2016
Stock options to purchase common stock		2,489,979		1,315,808
Warrants to purchase common stock		642,622		425,274
Restricted common stock awards		-		64,405