Intangible Assets

9 Months Ended

Sep. 30, 2017

Goodwill And Intangible Assets Disclosure [Abstract]

4. Intangible Assets

Intangible assets consist of the following (in thousands):

	As of
	September 30, 2017			December 31, 2016
Patents issued	$	4,272		$	4,892
Patents pending		165			385
Trademarks		40			40
Total intangible assets		4,477			5,317
Less patent amortization		(1,396	)		(1,316	)
Intangible assets, net	$	3,081		$	4,001

The following table presents patent amortization expense included in the Condensed Consolidated Statement of Operations (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
Amortization expense	$	79	$	130	$	245	$	394

During third quarter of 2017, the Company identified certain patents with carrying values deemed to not be recoverable. Based on this evaluation, the Company recorded an impairment charge of $11,000 related to these patents. Fair value was based on expected future cash flows using Level 3 inputs under ASC 820, which are cash flows expected to be generated by the market participants, discounted at the risk-free rate of interest. Because of changing market conditions such as decreased demand and rising interest rates, it is reasonably possible that the estimate of expected future cash flows may change in the near term resulting in the need to further adjust our determination of fair value.