Annual report pursuant to Section 13 and 15(d)

Note 8 - Common Stock (Details Textual)

v3.6.0.2
Note 8 - Common Stock (Details Textual) - USD ($)
1 Months Ended 2 Months Ended 12 Months Ended
Jun. 20, 2016
Jun. 17, 2016
Nov. 24, 2015
May 14, 2015
Mar. 31, 2015
Sep. 30, 2014
Aug. 30, 2016
Jul. 31, 2016
May 31, 2016
Apr. 30, 2016
Dec. 31, 2015
May 31, 2015
Feb. 28, 2015
Nov. 30, 2014
Dec. 31, 2016
Dec. 31, 2015
Proceeds from Issuance of Common Stock                             $ 13,886,000 $ 16,433,000
Proceeds from Issuance of Private Placement Net     $ 5,393,000 $ 11,040,000                        
Proceeds from Issuance Of Private Placement Gross     $ 6,000,000 $ 12,000,000                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights                         75,697 47,751 425,274  
Class of Warrant or Right, Exercise Price of Warrants or Rights                         $ 4 $ 4.24    
Warrant Term                           5 years    
Allocated Share-based Compensation Expense                             $ 981,000 $ 220,000
The 2016 Loan Agreement [Member]                                
Amortization of Debt Discount (Premium)                             69,000  
Debt Issuance Costs, Net                             90,000  
Unamortized Debt Issuance Expense                             $ 371,000  
Vendors And Nonemployee [Member]                                
Class of Warrant or Right Number of Securities Called by Warrants or Rights Cancelled In Period                             1,094 5,157
Warrant [Member]                                
Fair Value Assumptions, Expected Dividend Rate                         0.00% 0.00%    
Fair Value Assumptions, Expected Volatility Rate                         77.60% 61.30%    
Fair Value Assumptions, Risk Free Interest Rate                         2.14%      
Fair Value Assumptions, Expected Term                         10 years      
Warrant [Member] | Minimum [Member]                                
Fair Value Assumptions, Risk Free Interest Rate                           1.55%    
Warrant [Member] | Maximum [Member]                                
Fair Value Assumptions, Risk Free Interest Rate                           1.65%    
September 2014 Issuance Related to 2014 Loan Agreement [Member]                                
Class of Warrant or Right, Number of Securities Called by Warrants or Rights           58,962                    
Class of Warrant or Right, Exercise Price of Warrants or Rights           $ 4.24                    
Warrant Term           10 years           10 years        
Stock Issued During Period, Shares, Exercise of Warrants             17,295                  
Warrants and Rights Outstanding           $ 622,000                    
Fair Value Assumptions, Expected Dividend Rate           0.00%                    
Fair Value Assumptions, Expected Volatility Rate           77.00%                    
Fair Value Assumptions, Risk Free Interest Rate           2.50%                    
Amortization of Debt Discount (Premium)                             $ 387,000 $ 187,000
March 2015 Issuance [Member]                                
Class of Warrant or Right, Number of Securities Called by Warrants or Rights         1,454                      
Class of Warrant or Right, Exercise Price of Warrants or Rights         $ 2.72                      
Warrant Term         10 years                      
Fair Value Assumptions, Expected Dividend Rate         0.00%                      
Fair Value Assumptions, Expected Volatility Rate         78.90%                      
Fair Value Assumptions, Risk Free Interest Rate         1.94%                      
May 2015 Issuance [Member]                                
Class of Warrant or Right, Number of Securities Called by Warrants or Rights         36,229                      
Class of Warrant or Right, Exercise Price of Warrants or Rights         $ 4.24                      
Warrant Term         10 years                      
Fair Value Assumptions, Expected Dividend Rate         0.00%                      
Fair Value Assumptions, Expected Volatility Rate         80.10%                      
Fair Value Assumptions, Risk Free Interest Rate         2.28%                      
May 2015 Issuance Related to 2014 Loan Agreement [Member]                                
Class of Warrant or Right, Number of Securities Called by Warrants or Rights                       3,125        
Class of Warrant or Right, Exercise Price of Warrants or Rights                       $ 2.96        
Stock Issued During Period, Shares, Exercise of Warrants               885                
Amortization of Debt Discount (Premium)                               $ 10,000
May 2015 Issuance Second Contractor [Member]                                
Class of Warrant or Right, Number of Securities Called by Warrants or Rights                       21,585     21,585  
Class of Warrant or Right, Exercise Price of Warrants or Rights                       $ 4.24     $ 4.24  
Warrant Term                       5 years        
Fair Value Assumptions, Expected Dividend Rate                       0.00%        
Fair Value Assumptions, Expected Volatility Rate                       64.40%        
Fair Value Assumptions, Risk Free Interest Rate                       1.54%        
December 2015 Issuance [Member]                                
Class of Warrant or Right, Number of Securities Called by Warrants or Rights                     26,875         26,875
Class of Warrant or Right, Exercise Price of Warrants or Rights                     $ 5.60         $ 5.60
Warrant Term                     10 years          
Fair Value Assumptions, Expected Dividend Rate                     0.00%          
Fair Value Assumptions, Expected Volatility Rate                     76.80%          
Fair Value Assumptions, Risk Free Interest Rate                     2.27%          
Distributor Warrants, March 2016 Issuance [Member]                                
Class of Warrant or Right, Number of Securities Called by Warrants or Rights                   25,000         25,000  
Class of Warrant or Right, Exercise Price of Warrants or Rights                   $ 6.08         $ 6.08  
Warrant Term                   10 years            
Fair Value Assumptions, Expected Dividend Rate                   0.00%            
Fair Value Assumptions, Expected Volatility Rate                   72.10%            
Fair Value Assumptions, Risk Free Interest Rate                   1.78%            
Allocated Share-based Compensation Expense                             $ 162,000 $ 537,000
Contractor Warrants, May 2016 Issuance [Member]                                
Class of Warrant or Right, Number of Securities Called by Warrants or Rights                 5,000           5,000  
Class of Warrant or Right, Exercise Price of Warrants or Rights                 $ 7.74           $ 7.74  
Warrant Term                 5 years              
Fair Value Assumptions, Expected Dividend Rate                 0.00%              
Fair Value Assumptions, Expected Volatility Rate                 61.60%              
Fair Value Assumptions, Risk Free Interest Rate                 1.20%              
June 2016 Issuance Related to 2016 Loan Agreement [Member]                                
Class of Warrant or Right, Number of Securities Called by Warrants or Rights 100,402                           100,402  
Class of Warrant or Right, Exercise Price of Warrants or Rights $ 4.98                           $ 4.98  
Warrant Term 10 years                              
Warrants and Rights Outstanding $ 350,000                              
Fair Value Assumptions, Expected Dividend Rate 0.00%                              
Fair Value Assumptions, Expected Volatility Rate 63.00%                              
Fair Value Assumptions, Risk Free Interest Rate 1.67%                              
June 2016 Offering [Member]                                
Stock Issued During Period, Shares, New Issues   3,105,000                            
Share Price   $ 5                            
Proceeds from Issuance of Common Stock   $ 15,525,000                            
Proceeds From Issuance of Common Stock, Net   $ 13,886,000                            
November 2015 Private Placement Offering [Member]                                
Stock Issued During Period, Shares, New Issues     1,071,679                          
Share Price     $ 5.60                          
Proceeds From Issuance of Common Stock, Gross     $ 6,000,000                          
Proceeds from Issuance of Private Placement Net     $ 5,393,000                          
May 2015 Issuance [Member]                                
Stock Issued During Period, Shares, New Issues       4,054,062                        
Proceeds From Issuance of Common Stock, Net       $ 11,040,000                        
Proceeds From Issuance of Common Stock, Gross       12,000,000                        
Proceeds from Issuance Of Private Placement Gross       $ 2.96                        
Private Placement [Member]                                
Stock Issued During Period, Shares, New Issues     1,071,679 4,054,062                        
Share Price     $ 5.60 $ 2.96                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights           117,535                    
Class of Warrant or Right, Exercise Price of Warrants or Rights           $ 4.24                    
Warrant Term           5 years                    
Class of Warrants or Rights, Exercises in Period                             25,268 735
Stock Issued During Period, Shares, Exercise of Warrants                             23,560