Note 4 - Stockholders' Equity (Deficit), Stock Options and Warrants (Tables)

12 Months Ended

Dec. 31, 2018

Notes Tables

Share-based Compensation, Activity [Table Text Block]

	Stock Options					Warrants
	Number of Shares			Average Exercise Price		Number of Shares			Average Exercise Price
Outstanding at December 31, 2016		165,643		$	11.22		871,101		$	52.22
Issued		2,612,070			1.45		1,082,946			1.49
Expired		(12,730	)		10.39		(2,790	)		281.46
Exercised		-			-		-			-
Outstanding at December 31, 2017		2,764,983		$	2.00		1,951,257		$	23.74
Issued		1,098,858			1.01		2,336,154			1.07
Expired		(194,564	)		2.00		(10,706	)		199.55
Exercised		-			-		(650,062	)		1.00
Outstanding at December 31, 2018		3,669,277		$	1.70		3,626,643		$	4.17

Schedule of Share-based Compensation Shares Authorized Under Stock Option and Warrant Plans by Exercise Price Range [Table Text Block]

Range of Exercise Prices	Shares		Weighted Average Remaining Life
Options:
$0.619		201,908		10.00
$0.82		60,000		9.91
$0.91		10,000		9.30
$0.965		3,000		9.38
$0.97		191,753		9.02
$1.01		149,110		9.12
$1.06		23,585		9.76
$1.10		86,958		9.46
$1.13		195,931		9.55
$1.15		21,740		9.59
$1.16		66,451		9.59
$1.18		30,000		9.61
$1.20		41,668		9.59
$1.21		30,000		9.61
$1.35		111,112		9.20
$1.454		17,200		8.75
$1.47		2,305,790		8.48
$2.10		14,286		8.25
$2.25		293		7.65
$2.42		20,640		7.64
$2.80		57,145		8.01
$3.75		4,000		7.50
$4.125		3,636		7.75
$4.1975		7,147		7.72
$4.25		3,529		7.25
$5.125		3,902		7.69
$65.75		190		6.81
$73.50		1,157		7.01
$77.50		2,323		6.50
$80.25		187		6.75
$86.25		232		6.25
$131.25		81		3.69
$148.125		928		4.21
$150.00		1,760		3.63
$162.50		123		6.01
$206.25		121		5.75
$248.4375		121		4.54
$262.50		130		4.54
$281.25		529		4.04
$318.75		3		4.35
$346.875		72		5.25
$431.25		306		5.19
$506.25		188		5.00
$596.25		42		4.75
Total		3,669,277
Warrants:
$0.836		221,292		4.92
$1.00		1,063,935		3.76
$1.07		697,946		3.85
$1.155		1,071,776		4.75
$1.3125		86,086		4.75
$2.25		385,000		3.06
$123.75		94,084		1.67
$243.75		2,529		0.59
$309.375		2,850		0.61
$309.50		222		0.85
$506.25		59		0.12
$609.375		862		0.09
Total		3,626,643

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]

Year	Shares		Price
2011		173			281.25
2012		1,841		131.25	–	150.00
2013		1,553		148.13	–	596.25
2014		836		162.50	–	431.25
2015		4,088		65.75	–	86.25
2016		100,294		2.25	–	5.13
2017		2,461,634		1.01	–	2.10
2018		1,098,858		0.62	–	1.35
Total		3,669,277		$0.62	–	596.25

Year	Shares		Price
2014		6,455		243.75	–	609.38
2015		94,151		0.00	–	243.75
2016		252,333			1.00
2017		1,082,946		1.07	–	2.25
2018		2,190,758		0.84	–	1.3125
Total		3,626,643		$0.00	–	609.38