Note 3 - Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2019

Notes Tables

Schedule of Product Warranty Liability [Table Text Block]

	March 31,
	2019			2018
Balance, beginning of the period	$	153,723		$	40,000
Provision for product warranty		-			-
Product warranty expirations		-			-
Product warranty costs paid		(6,773	)		-
Balance, end of the period	$	146,950		$	40,000

Research and Development Expense [Table Text Block]

	Three months ended March 31,
	2019		2018
Salaries	$	6,446	$	37,026
Other costs		-		3,793
	$	6,446	$	40,819