Annual report pursuant to Section 13 and 15(d)

Note 17 - Income Taxes (Details Textual)

v3.19.1
Note 17 - Income Taxes (Details Textual) - USD ($)
 12 Months Ended
Dec. 22, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Deferred Tax Assets, Gross, Total   $ 41,572,772 $ 39,708,697  
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent 35.00% 21.00% 34.00%  
Revaluation of Deferred Tax Asset, Decrease     $ 26,400,000  
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount     26,400,000  
Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax   $ 621,240 1,229,979  
Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax, Percentage Reclassified to Income Tax Receivable   50.00%    
Cardiosonix [Member] | Subsidiaries [Member]        
Net Income (Loss) Attributable to Parent, Total     (5,000)  
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]        
Operating Loss Carryforwards, Total   $ 130,878,700 131,800,000  
Operating Loss Carryforwards Stock-based Compensation       $ 15,100,000
Net Operating Loss Carryforwards Expired in Period   0 0  
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]        
Tax Credit Carryforward, Amount   8,678,986 9,700,000  
Tax Credit Carryforward, Amount Expired During Period   1,200,000 0  
State and Local Jurisdiction [Member]        
Operating Loss Carryforwards, Total   $ 20,300,000 20,400,000  
Foreign Tax Authority [Member] | Israel Tax Authority [Member] | Cardiosonix [Member] | Subsidiaries [Member]        
Operating Loss Carryforwards, Total       $ 7,700,000
Other Noncurrent Assets [Member]        
Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax     $ 1,200,000