Note 6 - Shareholders' Equity - Stock Option Activity (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares
Balance, number of shares (in shares) | shares	1,664,014
Balance, weighted average exercise price (in dollars per share) | $ / shares	$ 2.07
Balance, weighted average remaining contractual life (Year)	6 years 5 months 1 day	6 years 7 months 20 days
Balance, aggregate intrinsic value | $	$ 51,822	$ 405,223
Granted, number of shares (in shares) | shares	91,500
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 1.66
Exercised, number of shares (in shares) | shares	(67,500)
Exercised, weighted average exercise price (in dollars per share) | $ / shares	$ 1.16
Forfeited, number of shares (in shares) | shares	(65,604)
Forfeited, weighted average exercise price (in dollars per share) | $ / shares	$ 1.77
Expired, number of shares (in shares) | shares	(63,213)
Expired, weighted average exercise price (in dollars per share) | $ / shares	$ 3.29
Balance, number of shares (in shares) | shares	1,559,197	1,664,014
Balance, weighted average exercise price (in dollars per share) | $ / shares	$ 2.05	$ 2.07
Vested and expected to vest, number of shares (in shares) | shares	1,524,158
Vested and expected to vest, weighted average exercise price (in dollars per share) | $ / shares	$ 2.06
Vested and expected to vest, weighted average remaining contractual life (Year)	6 years 4 months 17 days
Vested and expected to vest, aggregate intrinsic value | $	$ 50,527
Exercisable, number of shares (in shares) | shares	1,097,797
Exercisable, weighted average exercise price (in dollars per share) | $ / shares	$ 2.26
Exercisable, weighted average remaining contractual life (Year)	5 years 10 months 6 days
Exercisable, aggregate intrinsic value | $	$ 31,799