Note 9 - Stockholders' Equity (Details Textual) - USD ($) | Feb. 28, 2019 | Feb. 26, 2019 | Feb. 18, 2019 | Mar. 31, 2019 | Feb. 28, 2019 | Mar. 31, 2019 | Mar. 31, 2018 | Feb. 25, 2019 | Dec. 31, 2018 | Feb. 28, 2018 |
Preferred Stock, Par or Stated Value Per Share | | | | $ 0.01 | | $ 0.01 | | | $ 0.01 | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance | | | | 29,441 | | 29,441 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price, Ending Balance | | | | $ 53.19 | | $ 53.19 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number | | | | 13,585 | | 13,585 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price | | | | $ 93.92 | | $ 93.92 | | | | |
Share-based Payment Arrangement, Expense | | | | | | $ 26,652 | $ 23,978 | | | |
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total | | | | $ 183,731 | | $ 183,731 | | | | |
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition | | | | | | 2 years | | | | |
Stock Issued During Period, Value Expensed During the Period, Issued for Services | | | | | | $ 126,572 | $ 28,571 | | | |
Prepaid Expense, Value of Stock Issued for Services During Period | | | | $ 72,509 | | $ 72,509 | | | | |
Series I Warrants [Member] | | | | | | | | | | |
Convertible Preferred Stock and Related Warrants Issued | | 33,334 | | | | | | | | |
Class of Warrant or Right, Exercise Price of Warrants or Rights | | $ 7.50 | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | | 66,668 | | | | | | | | |
Common Stock Purchase Warrants [Member] | | | | | | | | | | |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | | | | | | | | | | 358 |
Class Of Warrant Or Right Issued During Period | | | | | | 33,334 | | | | |
Class of Warrant or Right, Outstanding | | | | 148,032 | | 148,032 | | | | |
Class Of Warrant Or Right Outstanding Weighted Average Exercise Price | | | | $ 11.54 | | $ 11.54 | | | | |
Class Of Warrant Or Right Exercisable Number | | | | 94,698 | | 94,698 | | | | |
Class Of Warrant Or Right Exercisable Weighted Average Exercise Price | | | | $ 12.75 | | $ 12.75 | | | | |
Series G Convertible Preferred Stock and Related Warrants [Member] | | | | | | | | | | |
Convertible Preferred Stock and Related Warrants, Authorized | 1,000 | | | | | | | | | |
Proceeds from Issuance of Convertible Preferred Stock and Related Warrants, Maximum | $ 1,000,000 | $ 250,000 | | | | | | | | |
Convertible Preferred Stock and Related Warrants Issued | | 500 | | | | | | | | |
Conversion of Series C Preferred Stock Into Common Stock [Member] | | | | | | | | | | |
Conversion of Stock, Shares Converted | | | | | 587 | 587 | | | | |
Conversion of Stock, Shares Issued | | | | | 78,280 | 78,280 | | | | |
Conversion of Series F Preferred Stock Into Common Stock [Member] | | | | | | | | | | |
Conversion of Stock, Shares Converted | | | | 180 | | 180 | | | | |
Conversion of Stock, Shares Issued | | | | 40,000 | | 40,000 | | | | |
Conversion from Series C and F Convertible Preferred Stock to Common Stock [Member] | | | | | | | | | | |
Conversion of Stock, Shares Issued | | | | | | 118,280 | | | | |
Series B Convertible Preferred Stock [Member] | | | | | | | | | | |
Preferred Stock, Shares Outstanding, Ending Balance | | | | 100 | | 100 | | | 100 | |
Convertible Preferred Stock, Conversion Price1 | | | | $ 175 | | $ 175 | | | | |
Conversion of Stock, Shares Converted | | | | | | 0 | | | | |
Preferred Stock, Par or Stated Value Per Share | | | | $ 1,000 | | $ 1,000 | | | $ 1,000 | |
Series F Convertible Preferred Stock [Member] | | | | | | | | | | |
Preferred Stock, Shares Outstanding, Ending Balance | | | | 2,583 | | 2,583 | | | | |
Convertible Preferred Stock, Conversion Price1 | | | $ 7.50 | | | | | | | |
Number of Series C and Series E Preferred Stock Exchanged for Series F Convertible Preferred Stock | | | 2,763 | | | | | | | |
Preferred Stock, Par or Stated Value Per Share | | | $ 1,000 | | | | | | | |
Convertible Preferred Stock, Conversion Price, Percentage of Volume Weighted Average Price of the Common Stock | | | 90.00% | | | | | | | |
Series E Convertible Preferred Stock [Member] | | | | | | | | | | |
Preferred Stock, Shares Outstanding, Ending Balance | | | | 0 | | 0 | | | 1,200 | |
Preferred Stock, Par or Stated Value Per Share | | | | $ 1,000 | | $ 1,000 | | | $ 1,000 | |
Series G Convertible Preferred Stock [Member] | | | | | | | | | | |
Convertible Preferred Stock, Conversion Price1 | | | | | | | | $ 7.50 | | |
Conversion of Stock, Shares Converted | | | | | | 0 | | | | |
Preferred Stock, Par or Stated Value Per Share | | | | | | | | $ 1,000 | | |
Convertible Preferred Stock, Conversion Price, Percentage of Volume Weighted Average Price of the Common Stock | | | | | | | | 90.00% | | |
Series C Convertible Preferred Stock [Member] | | | | | | | | | | |
Preferred Stock, Shares Outstanding, Ending Balance | | | | 0 | | 0 | | | 2,150 | |
Preferred Stock, Par or Stated Value Per Share | | | | $ 1,000 | | $ 1,000 | | | $ 1,000 | |