Note 11 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Notes Tables

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	2015			2014
Deferred tax assets:
Net operating loss carryforward	$	23,822,431		$	22,806,391
Research and development tax credit carryforward		893,797			825,896
Stock-based compensation expense		2,419,892			2,396,805
Total deferred tax assets		27,136,120			26,029,092
Deferred tax liabilities
Depreciation		(5,086	)		(7,149	)
Total deferred tax liabilities		(5,086	)		(7,149	)
Net deferred tax assets		27,131,034			26,021,943
Valuation allowance		(27,131,034	)		(26,021,943	)
	$	-0-		$	-0-

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	2015			2014			2013
U.S. federal statutory rate applied to pretax loss	$	(936,936	)	$	(906,830	)	$	(776,881	)
Permanent differences		2,914			1,734			3,138
Research and development credits		67,901			26,648			14,047
Change in valuation allowance		866,121			878,448			759,696
Reported income tax expense	$	-0-		$	-0-		$	-0-