PATENTS

12 Months Ended

Sep. 30, 2022

PATENTS

PATENTS

6. PATENTS

Patents consist of the following at September 30:

	2022			2021
Patents	$	893,833		$	910,523
Accumulated amortization		(681,632	)		(634,657	)
Patents, net	$	212,201		$	275,866

During the years ended September 30, 2022 and 2021, there was no impairment of patent costs.  Amortization expense for the years ended September 30, 2022 and 2021 totaled approximately $49,000 and $52,000, respectively.   The total estimated future amortization is as follows:

Years ending September 30,
2023	$	38,000
2024		30,000
2025		28,000
2026		24,000
2027		21,000
Thereafter		71,000
	$	212,000