6. PATENTS

12 Months Ended

Sep. 30, 2018

Accounting Policies [Abstract]

6. PATENTS

Patents consisted of the following at September 30:

	2018			2017
Patents	$	1,644,759		$	1,535,087
Accumulated amortization		(1,386,666	)		(1,311,920	)
Patents, net	$	258,093		$	223,167

During the years ended September 30, 2018 and 2017,there was no impairment of patent costs. Amortization expense for the years ended September 30, 2018 and 2017 totaled approximately $75,000 and $40,000, respectively. The total estimated future amortization is as follows:

Years ending September 30,
2019	$	42,000
2020		38,000
2021		35,000
2022		31,000
2023		21,000
Thereafter		91,000
	$	258,000