Note 10 - Share-based Compensation (Tables)

6 Months Ended

Jun. 30, 2022

Notes Tables

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

				Weighted Average
	Options on					Remaining		Aggregate
	Common			Exercise		Contractual		Intrinsic
	Shares			Price		Term		Value
Outstanding January 1, 2022		3,935,883		$	5.24		4.79
Granted		2,559,639		$	2.92
Exercised		(50,000	)	$	1.50
Forfeited, cancelled, expired		(757,246	)	$	7.87
Outstanding June 30, 2022		5,688,276		$	3.88		6.32	$	232,778
Exercisable June 30, 2022		2,351,826		$	4.38		2.32	$	232,778

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

	For the Six Months
	Ended June 30,
	2022			2021
Expected stock price volatility		49	%		50	%
Risk-free interest rate		1.09	%		0.92	%
Forfeiture rate		0	%		0	%
Expected dividend yield		0	%		0	%
Expected life of options - years		1.82			5.70
Weighted-average fair value of options granted	$	1.32		$	2.46

Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]

				Weighted Average		Weighted Average
	Service-Based			Grant Date		Vesting
	RSU's			Fair Value		Period (Years)
Unvested at January 1, 2022		269,303		$	6.47
Granted - service based		619,817		$	2.73
Vested		(90,216	)	$	5.03
Forfeited and cancelled		(28,357	)	$	5.00
Unvested at June 30, 2022		770,547		$	3.69	2.35

Disclosure of Share-Based Compensation Arrangements by Share-Based Payment Award [Table Text Block]

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Selling, general and administrative	$	591	$	2,027	$	1,485	$	2,629
Research and development		136		121		271		378
Total share-based expense	$	727	$	2,148	$	1,756	$	3,007