Stockholders' equity (deficit) (Tables)

9 Months Ended

Sep. 30, 2019

Schedule of Company Recognized Stock-Based Compensation Expense

For the three and nine months ended September 30, 2019 and 2018, the Company recognized stock-based compensation expense as follows:

	Three Months Ended September 30,					Nine Months Ended September 30,
	2019		2018			2019		2018
Cost of services	$	584	$	(2,807	)	$	1,146	$	924
Research and development		20,175		56,961			55,635		187,512
General and administrative		65,318		141,974			202,696		434,314
Sales and marketing		5,090		10,523			15,694		35,981
	$	91,167	$	206,651		$	275,171	$	658,731

Schedule of Warrants to Purchase Shares of Common Stock

At September 30, 2019 and December 31, 2018, the following warrants to purchase shares of common stock were outstanding:

				Outstanding at
Issuance	Exercise Price		Expiration	September 30, 2019 (1)		December 31, 2018 (1)
November 2009	$	3,955.00	November 2019		17		17
January 2010	$	3,955.00	January 2020		17		17
March 2010	$	3,955.00	March 2020		7		7
November 2011	$	3,955.00	November 2021		15		15
December 2011	$	3,955.00	December 2021		2		2
March 2012	$	54,950.00	March 2019		—		8
February 2015	$	3,300.00	February 2025		451		451
May 2015	$	3,300.00	May 2020		6,555		6,555
May 2016	$	656.00	May 2021		9,483		9,483
June 2016	$	656.00	May 2021		4,102		4,102
June 2017	$	390.00	June 2022		938		938
July 2017	$	345.00	July 2022		318		318
July 2017	$	250.00	July 2022		2,501		2,501
July 2017	$	212.60	July 2022		50,006		50,006
February 2018	$	81.20	February 2023		9,232		9,232
February 2018	$	65.00	February 2023		92,338		92,338
					175,982		175,990

(1)

Warrants to purchase fractional shares of common stock resulting from the reverse stock split on August 29, 2019 were rounded up to the next whole share of common stock on a holder by holder basis.