Equity Incentive Plans (Tables)

12 Months Ended

Dec. 31, 2021

Equity Incentive Plans [Abstract]

Stock Option Plan Activity

Activity under the stock option plans was as follows:

	Number of options			Weighted average exercise price
Balances at December 31, 2019		983,889		$	3.69
Granted		—			—
Exercised		(53,056	)		2.88
Expired		—			—
Forfeited		(187,206	)		4.23
Balances at December 31, 2020		743,627		$	3.60
Granted		—			—
Exercised		(44,698	)		2.83
Expired		(556	)		27.00
Forfeited		(8,378	)		5.43
Balances at December 31, 2021		689,995		$	3.58

Options Outstanding and Vested and Currently Exercisable by Exercise Prices

The options outstanding and vested and currently exercisable by exercise prices as of December 31, 2021 were as follows:

Option outstanding						Options vested and exercisable
Exercise price		Outstanding (in shares)		Weighted average remaining life years		Number of options vested		Exercise price		Weighted average remaining life years
$	1.71		227,780		4.21		116,669	$	1.71		4.21
	3.24		279,837		5.50		279,837		3.24		5.50
	3.96		66,949		6.21		55,283		3.96		6.20
	4.50		1,667		6.87		834		4.50		6.87
	4.95		44,445		7.24		22,223		4.95		7.24
	6.12		57,092		7.95		28,763		6.12		7.95
	27.00		12,225		0.57		12,225		27.00		0.57
			689,995		5.37		515,834				5.38

Share-based Compensation Expense

The following table shows stock-based compensation expense related to vested stock option grants to employees, directors and nonemployees by financial statement line item on the accompanying statement of comprehensive loss for the year ended December 31:

	2021		2020
Research and development	$	106,469		159,308
Sales and marketing		3,759		11,616
General and administrative		83,138		147,716
Total share-based compensation expense	$	193,366		318,640