Note 5 - Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2018

Notes Tables

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

	Three Months Ended March 31,
	201 8		201 7
Employee and non-employee stock options		1,097,960		700,960
Common shares issuable upon conversion of notes payable		322,947		307,838
Common shares issuable under common stock purchase warrants		403,700		361,550
		1,824,607		1,370,298