Stockholders' equity (Tables)

3 Months Ended

Mar. 31, 2017

Stockholders Equity Note [Abstract]

Schedule of Company Recognized Stock Compensation Expense

For the three months ended March 31, 2017 and 2016, the Company recognized stock compensation expense as follows:

	Three Months Ended March 31,
	2017		2016
Cost of services	$	1,823	$	4,312
Research and development		57,778		62,218
General and administrative		152,476		172,103
Sales and marketing		33,328		22,864
	$	245,405	$	261,497

Schedule of Warrants to Purchase Shares of Common Stock

Stock purchase warrants

At March 31, 2017 and December 31, 2016, the following warrants to purchase shares of common stock were outstanding:

				Outstanding at
Issuance	Exercise Price		Expiration	March 31, 2017		December 31, 2016
August 2007	$	7.91	August 2017		8,921		8,921
March 2008	$	790.54	March 2018		46		46
November 2009	$	7.91	November 2019		6,674		6,674
January 2010	$	7.91	January 2020		6,674		6,674
March 2010	$	7.91	March 2020		1,277		1,277
November 2011	$	7.91	November 2021		5,213		5,213
December 2011	$	7.91	December 2021		664		664
March 2012	$	109.90	March 2019		4,125		4,125
February 2015	$	6.60	February 2025		225,011		225,011
May 2015	$	6.60	May 2020		3,457,750		3,457,750
May 2016	$	1.31	May 2021		4,739,348		4,739,348
June 2016	$	1.31	May 2021		2,050,821		2,050,821
					10,506,524		10,506,524