Note 11 - Short-term Debt	12 Months Ended
Dec. 31, 2018
Notes to Financial Statements
Short-term Debt [Text Block]	Note 11. Short-term Debt In March 2017, we entered into amendments with the holders of certain outstanding warrants issued on April 17, 2015 and July 30, 2015 to eliminate certain anti-dilution provisions in such warrants, which caused us to reflect an associated liability of $5.3 million on our balance sheet as of December 31, 2016. Such amendments were contingent upon and did not take effect until the closing of the public offering. For each warrant share underlying the warrants so amended, the holder received the right to purchase an additional .2 shares of common stock. Two of the holders of such warrants, which owners hold warrants to purchase an aggregate of 11,049 shares of common stock, did not agree to the amendment. The warrant holders agreeing to the amendment include Acuitas and another accredited investor, who received additional warrants to purchase 31,167 and 13,258 shares of our common stock. In addition, several warrant agreements that had anti-dilution protection had a provision in the agreement that upon an up-listing to NASDAQ, the anti-dilution protection would be removed. The up-listing to NASDAQ occurred on April 26, 2017. The elimination of the anti-dilution provision resulted in the write-off of $6.2 million of the warrant liability as of December 31, 2017. In January 2017, we entered into a Subscription Agreement (the "Subscription Agreement") with Acuitas, pursuant to which we received aggregate gross proceeds of $1,300,000 (the "Loan Amount") in consideration of the issuance of (i) an 8% Series B Convertible Debenture due March 31, 2017 ( the "January 2017 Convertible Debenture") and (ii) 254,904 five -year warrants to purchase shares of the Company's common stock which is equal to one hundred percent ( 100% ) of the initial number of shares of common stock issuable upon the conversion of the January 2017 Convertible Debenture, at an exercise price of $5.10 per share (the "January 2017 Warrants"). In addition, any warrants issued in conjunction with the December 2016 Convertible Debenture currently outstanding with Acuitas have been increased by an additional 25% warrant coverage, exercisable for an aggregate of 137,883 shares of the Company's common stock. Acuitas agreed to extend the maturity date of the January 2017 Convertible Debenture to April 30, 2017 or until we completed a public offering, whichever came first. In April 2017, we used the net proceeds from the public offering to repay the Loan Amount including interest of $1.3 million.

Note

11.

Short-term Debt

March 2017,

we entered into amendments with the holders of certain outstanding warrants issued on

April 17, 2015

and

July 30, 2015

to eliminate certain anti-dilution provisions in such warrants, which caused us to reflect an associated liability of

$5.3

million on our balance sheet as of

December 31, 2016.

Such amendments were contingent upon and did

not

take effect until the closing of the public offering. For each warrant share underlying the warrants so amended, the holder received the right to purchase an additional

shares of common stock. Two of the holders of such warrants, which owners hold warrants to purchase an aggregate of

11,049

shares of common stock, did

not

agree to the amendment. The warrant holders agreeing to the amendment include Acuitas and another accredited investor, who received additional warrants to purchase

31,167

and

13,258

shares of our common stock. In addition, several warrant agreements that had anti-dilution protection had a provision in the agreement that upon an up-listing to NASDAQ, the anti-dilution protection would be removed. The up-listing to NASDAQ occurred on

April 26, 2017.

The elimination of the anti-dilution provision resulted in the write-off of

$6.2

million of the warrant liability as of

December 31, 2017.

January 2017,

we entered into a Subscription Agreement (the "Subscription Agreement") with Acuitas, pursuant to which we received aggregate gross proceeds of

$1,300,000

(the "Loan Amount") in consideration of the issuance of (i) an

Series B Convertible Debenture due

March 31, 2017 (

the

"January 2017

Convertible Debenture") and (ii)

254,904

five

-year warrants to purchase shares of the Company's common stock which is equal to

one hundred

percent (

100%

) of the initial number of shares of common stock issuable upon the conversion of the

January 2017

Convertible Debenture, at an exercise price of

$5.10

per share (the

"January 2017

Warrants"). In addition, any warrants issued in conjunction with the

December 2016

Convertible Debenture currently outstanding with Acuitas have been increased by an additional

25%

warrant coverage, exercisable for an aggregate of

137,883

shares of the Company's common stock. Acuitas agreed to extend the maturity date of the

January 2017

Convertible Debenture to

April 30, 2017

or until we completed a public offering, whichever came first. In

April 2017,

we used the net proceeds from the public offering to repay the Loan Amount including interest of

$1.3

million.