Note 3 - Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2018

Notes Tables

Schedule of Product Warranty Liability [Table Text Block]

	September 30,			December 31,
	2018			2017
Balance, beginning of the period	$	40,000		$	240,980
Provision for product warranty		115,000			40,000
Product warranty expirations		-			(238,967	)
Product warranty costs paid		(24,630	)		(2,013	)
Balance, end of the period	$	130,370		$	40,000

Research and Development Expense [Table Text Block]

	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Salaries	$	7,047	$	68,158	$	69,727	$	159,237
Other costs		14,000		12,193		38,401		39,645
	$	21,047	$	80,351	$	108,128	$	198,882