NOTE 5. INTANGIBLE ASSETS

Intangible assets consist of the following at September 30, 2021:

Amortization expense for the nine-month period ended September 30, 2021 and 2020 was $298,098 and $128,488, respectively, and is included in general and administrative expenses in the consolidated statements of operations.

Estimated future amortization expense for device technology intangible assets is as follows: