Note 9 - Collaboration and Device Development Payable - Significant Input Assumptions of Warrant Valuation (Details) - Series E Warrants [Member]	Dec. 07, 2018
Measurement Input, Price Volatility [Member]
Measurement input	1.03
Measurement Input, Expected Term [Member]
Measurement input	5
Measurement Input, Risk Free Interest Rate [Member]
Measurement input	0.027

Value of input used to measure outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

Name:	us-gaap_WarrantsAndRightsOutstandingMeasurementInput
Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant