Stock Benefit Plans and Equity Transactions (Tables)

6 Months Ended

Jun. 30, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Total Stock Based Compensation

Total stock-based compensation for the three and six months ended June 30, 2019 and 2018 is as follows (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2019		2018		2019		2018
Cost of revenues	$	28	$	11	$	56	$	33
Research and development		293		129		533		13
Sales, general and administrative		2,030		1,008		3,374		1,721
Total	$	2,351	$	1,148	$	3,963	$	1,767

Summary of Common Stock Reserved for Future Issuance

As of June 30, 2019, the Company had reserved shares of its common stock for future issuance as follows (in thousands):

	June 30, 2019
Stock options outstanding		4,253
Unvested restricted stock award		6,641
Employee stock purchase plan		132
Series A convertible preferred stock		164
Warrants outstanding		26,885
Authorized for future grant under the Distributor and Development Services plans		3,923
Authorized for future grant under the Company equity plans		2,014
Total		44,012

Summary of Outstanding Warrants

A summary of all outstanding warrants is as follows:

	Number of Warrants		Strike Price
2017 Common Stock Warrants		3,657,000	$	2.00
2017 Banker Warrants		148,554	$	2.50
2018 Common Stock Warrants		13,860,851	$	3.50
Merger Warrants		2,200,000	$	3.50
Executive		1,327,434	$	5.00
Squadron Capital		845,000	$	3.15
Squadron Capital		4,838,710	$	2.17
Other		7,812	$	19.20
Total		26,885,361