Stock Benefit Plans and Equity Transactions (Tables)

3 Months Ended

Mar. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Total Stock Based Compensation

Stock-Based Compensation

Total stock-based compensation for the three months ended March 31, 2021 were as follows (in thousands):

	Three Months Ended
	March 31,
	2021		2020
Cost of revenues	$	95	$	107
Research and development		498		390
Sales, general and administrative		3,881		3,071
Total	$	4,474	$	3,568

Summary of Common Stock Reserved for Future Issuance

As of March 31, 2021, the Company’s shares of common stock reserved for future issuance were as follows (in thousands):

Stock options outstanding	3,898
Unvested restricted stock award	8,866
Employee stock purchase plan	216
Series A convertible preferred stock	29
Warrants outstanding	21,594
Authorized for future grant under the Distributor and    Development Services plans	7,751
Authorized for future grant under the Management    Objective Strategic Incentive Plan	345
Authorized for future grant under the Company equity    plans	3,963
Total	46,662

Summary of All Outstanding Warrants for Common Stock

A summary of all outstanding warrants for common stock as of March 31, 2021 were as follows:

	Number of Warrants		Strike Price		Expiration
2017 PIPE Warrants		2,962,000	$	2.00	June 2022
2018 PIPE Warrants		9,231,903	$	3.50	May 2023
SafeOp Surgical Merger Warrants		1,194,943	$	3.50	May 2023
2018 Squadron Medical Warrants		845,000	$	3.15	May 2027
2019 Squadron Medical Warrants		4,838,710	$	2.17	May 2027
2020 Squadron Medical Warrants		1,075,820	$	4.88	May 2027
Executive Warrants		1,327,434	$	5.00	December 2022
Other*		117,812	$	3.85	Various through May 2023
Total		21,593,622

(1) Represents weighted average exercise price.