Note 5 - Share-based Compensation (Tables)

3 Months Ended

Mar. 31, 2023

Notes Tables

Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

Risk-Free interest rate	3.90% - 3.93%
Expected dividend yield	—%
Expected stock price volatility	62.2%
Expected life of options (in years)	5.50 - 6.25

Share-Based Payment Arrangement, Option, Activity [Table Text Block]

						Weighted-Average
				Weighted-Average		Remaining Contractual		Aggregate Intrinsic
	Shares			Exercise Price		Term (Years)		Value
Outstanding at December 31, 2022		5,031,097		$	3.25		5.75	$	13,000
Granted (1)		707,850			1.38
Exercised		—			—
Expired (2)		(320,000	)		1.62
Canceled		—			—
Outstanding at March 31, 2023		5,418,947		$	3.10		6.40	$	642,791
Exercisable at March 31, 2023		4,004,318		$	3.18		5.46	$	359,651

Share-Based Payment Arrangement, Activity [Table Text Block]

	Three Months Ended March 31,
	2023		2022
General and administrative	$	319,335	$	388,662
Research and development		11,304		65,129
Total	$	330,639	$	453,791

	Three Months Ended March 31,
	2023		2022
Share based compensation expense- stock options	$	276,540	$	453,791
Share based compensation expense- restricted stock units		54,099		—
Total	$	330,639	$	453,791