Note 6 - Derivative Obligations (Tables)

3 Months Ended

Mar. 31, 2018

Notes Tables

Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]

	Series A
	March 31, 2018		December 31, 2017
Market price of common stock	$	2.01	$	3.00
Expected volatility		111%		107%
Contractual term (years)		2.9		3.2
Discount rate		2.38%		1.99%
Dividend rate		0%		0%
Exercise price	$	8.00	$	8.00

Fair Value Measurements, Recurring and Nonrecurring [Table Text Block]

	Derivative Obligation
	March 31, 2018		December 31, 2017
Balance	$	338,000	$	597,000
Level 1	$	-	$	-
Level 2	$	-	$	-
Level 3	$	338,000	$	597,000

Derivative Instruments, Gain (Loss) [Table Text Block]

	Amount
Balance – December 31, 2017	$	597,000
Change in fair value of derivative obligation		259,000
Balance – March 31, 2018	$	338,000