Note 4 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Components of net deferred income tax assets

	December 31,
	2017			2016
Deferred tax assets:
Federal net operating loss carryforward	$	15,949,000		$	19,819,000
Other		—			1,634,000
Patent amortization		(6,000	)		(11,000	)
Deferred tax assets before valuation		15,943,000			21,422,000
Valuation allowance		(15,943,000	)		(21,422,000	)
Net deferred income tax assets	$	—		$	—