Note 2 - Significant Accounting Policies (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Oct. 31, 2016	Oct. 24, 2016	Aug. 22, 2016	Dec. 31, 2014
Retained Earnings (Accumulated Deficit)	$ (60,142,000)	$ (49,832,000)
Cash and Cash Equivalents, at Carrying Value	21,352,000	3,557,000		$ 24,000,000		$ 3,184,000
Allowance for Doubtful Accounts Receivable, Current	2,000	4,000
Deferred Offering Costs Incurred in 2015		1,586,000
Write-off of Deferred Offering Costs		1,634,000
Impairment of Long-Lived Assets Held-for-use	0	0
Sales Returns Reserve	$ 1,000	3,000
Standard Product Warranty, Term	2 years
Standard Product Warranty Accrual	$ 0	0
Income Tax Examination, Penalties and Interest Accrued	0	0
Cost of Goods Sold [Member]
Shipping, Handling and Transportation Costs	$ 7,000	$ 11,000
Proceeds from Convertible Notes [Member]
Cash and Cash Equivalents, at Carrying Value			$ 4,400,000
Tiger X [Member]
Cash and Cash Equivalents, at Carrying Value					$ 19,000,000