Note 4 - Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2021

	Nine Months Ended September 30, 2021
	Number of Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value
Outstanding, January 1, 2021		549,970		$	8.81		8.0	$	209,280
Granted		234,500			2.53
Exercised		(2,000	)		1.06
Cancelled/Forfeited		(67,600	)		4.01
Expired		(2,090	)		61.75
Outstanding, September 30, 2021		712,780		$	7.07		7.6	$	128,765
Exercisable, September 30, 2021		222,882		$	13.27		5.6	$	47,381

	Nine Months Ended September 30, 2021
	Number of Shares			Weighted Average Grant-Date Fair Value
Unvested, January 1, 2021		60,000		$	2.90
Granted		15,000			2.17
Vested		(36,667	)		2.40
Unvested, September 30, 2021		38,333		$	3.10