Note I - Intangible Assets

12 Months Ended

Dec. 31, 2022

Notes to Financial Statements

Intangible Assets Disclosure [Text Block]

NOTE I—INTANGIBLE ASSETS

Intangible assets consisted of the following for the periods indicated (in thousands):

	December 31, 2022
	Gross		Accumulated			Intangible
	Amount		amortization			assets, net
Patents	$	8,994	$	(5,330	)	$	3,664
Trademarks		56		(21	)	$	35
Total intangible assets	$	9,050	$	(5,351	)	$	3,699

	December 31, 2021
	Gross		Accumulated			Intangible
	Amount		amortization			assets, net
Patents	$	8,597	$	(4,779	)	$	3,818
Trademarks		35		(17	)		18
Total intangible assets	$	8,632	$	(4,796	)	$	3,836

For the years ended December 31, 2022, 2021 and 2020, amortization expense for intangible assets, included in general and administrative expenses on the income statement, was $0.6 million, $0.5 million and $0.5 million, respectively. The remaining weighted average amortization period for intangible assets is approximately six years.

At December 31, 2022, future amortization expense for intangible assets is estimated to be (in thousands):

	December 31, 2022
2023	$	627
2024		627
2025		627
2026		627
2027		627
2028		564
thereafter		-
Total	$	3,699