Intangible Assets

6 Months Ended

Jun. 30, 2022

Intangible Assets, Net (Excluding Goodwill) [Abstract]

Intangible Assets

10. INTANGIBLE ASSETS: 

Intangible assets consist of the following:   

	June 30, 2022							December 31, 2021
(In thousands)	Gross Carrying Amount		Accumulated Amortization			Net		Gross Carrying Amount		Accumulated Amortization			Net
Patents	$	2,044	$	(1,715	)	$	329	$	1,972	$	(1,614	)	$	358
Software	206		(206		)	—		206		(206		)	—
Marketing assets and customer relationships	86		(73		)	13		86		(69		)	17
Total intangible assets	$	2,336	$	(1,994	)	$	342	$	2,264	$	(1,889	)	$	375

Amortization expense in the three and six months ended June 30, 2022 and June 30, 2021 was as follows:   

	Three Months Ended June 30,				Six Months Ended June 30,
(In thousands)	2022		2021		2022		2021
Patents	$	51	$	44		101		87
Software		—		—		—		6
Marketing assets and customer relationships		2		2		4		4
Total amortization expense	$	53	$	46		105		97

Estimated aggregate amortization expense based on current intangible assets for the next four years is expected to be as follows: $102,000 for the remainder of 2022; $165,000 in 2023; $69,000 in 2024; and $6,000 in 2025.