INTANGIBLE ASSETS
 12 Months Ended
Dec. 31, 2016
INTANGIBLE ASSETS [Abstract]  
INTANGIBLE ASSETS
7.
INTANGIBLE ASSETS

Intangible assets consist of the following:

    
December 31,
    
Weighted
Average
Amortization
  
Period
 
2016
  
2015
  
(in Years)
 
Patents
 
$
958,604
  
$
958,604
   
0.4
 
Trademarks
  
55,824
   
50,208
   
1.8
 
License rights
  
6,718
   
6,718
   
0.0
 
Total
  
1,021,146
   
1,015,530
     
Less accumulated amortization
  
(1,012,338
)
  
(944,444
)
    
Intangible assets, net
 
$
8,808
  
$
71,086
     

Amortization expense for the years ended December 31, 2016 and 2015 was approximately $68,000 and $192,000, respectively. Amortization expense on existing intangible assets is estimated to be $8,000 for 2017, and $1,000 for 2018.

Included in total amortization expense are approximately $13,000 and $6,700 for the years ended December 31, 2016 and 2015, respectively, related to discontinued operations.