7. PATENTS

12 Months Ended

Sep. 30, 2019

Finite-Lived Intangible Assets, Net [Abstract]

7. PATENTS

Patents consist of the following at September 30:

	2019			2018
Patents	$	841,397		$	742,698
Accumulated amortization		(529,811	)		(484,605	)
Patents, net	$	311,586		$	258,093

During the years ended September 30, 2019 and 2018, there was no impairment of patent costs. Amortization expense for the years ended September 30, 2019 and 2018 totaled approximately $45,000 and $75,000, respectively. The total estimated future amortization is as follows:

Years ending September 30,
2020		51,000
2021		48,000
2022		44,000
2023		33,000
2024		26,000
Thereafter		110,000
	$	312,000