6. PATENTS

12 Months Ended

Sep. 30, 2017

Accounting Policies [Abstract]

6. PATENTS

Patents consisted of the following at September 30:

	2017	2016
Patents	$ 1,535,087	$ 1,528,610
Accumulated amortization	(1,311,920)	(1,272,063)
Patents, net	$ 223,167	$ 256,547

During the years ended September 30, 2017 and 2016,there was no impairment of patent costs. Amortization expense for the years ended September 30, 2017 and 2016 totaled approximately $40,000 and $38,000, respectively. The total estimated future amortization is as follows:

Years ending September 30,
2018	$ 37,000
2019	35,000
2020	32,000
2021	28,000
2022	25,000
Thereafter	66,000
	$ 223,000