Share-Based Payments (Tables)

6 Months Ended

Oct. 31, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Allocation of Share Based Compensation Expense

Stock-based compensation expense was recognized as follows (table in thousands):

	Three Months Ended October 31,				Six Months Ended October 31,
	2016		2015		2016		2015
General and administrative	$	469	$	674	$	1,298	$	1,112
Sales and marketing	18		25		187		145
Research and development	45		46		130		213
TOS cost of sales	3		2		47		26
POS cost of sales	—		1		2		27
Total stock-based compensation expense	$	535	$	748	$	1,664	$	1,523

Valuation Assumptions for Stock Options

Black-Scholes assumptions used to calculate the fair value of options granted during the three and six months ended October 31, 2016 and 2015 were as follows:

	Three Months Ended October 31,		Six Months Ended October 31,
	2016	2015	2016	2015
Expected term in years	6	6	2.6 - 6	5 - 6
Risk-free interest rates	1.48%	1.63% - 1.72%	0.75% - 1.48%	1.57% - 1.72%
Volatility	87.32%	87.46% - 87.81%	73.2% - 95.6%	87.46% - 92.32%
Dividend yield	—%	—%	—%	—%

Summary of Stock Option Activity

The Company’s stock options activity for the six months ended October 31, 2016 was as follows:

	Non- Employees		Directors and Employees		Total		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding, May 1, 2016	51,250		2,161,507		2,212,757		$	5.58	6.1	$	10,000
Granted	—		2,320,681		2,320,681		1.98		7.4	—
Exercised	—		—		—		—
Forfeited	—		(9,063	)	(9,063	)	10.18
Canceled	—		(1,996,821	)	(1,996,821	)	4.63
Expired	(16,664	)	(61,137	)	(77,801	)	7.34
Outstanding, October 31, 2016	34,586		2,415,167		2,449,753		2.87		6.9	$	—
Vested and expected to vest as of October 31, 2016	34,586		2,415,167		2,449,753		2.87		6.9	$	—
Exercisable as of October 31, 2016	34,586		1,806,295		1,840,881		3.21		5.9	$	—

Summary of Warrant Activity

Activity related to these warrants, which expire at various dates through January 2019, is summarized as follows:

	Number of Shares	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding, May 1, 2016	2,109,840	$	5.54	3.6	$	—
Granted	—	—		—	—
Exercised	—	—		—	—
Expired	—	—		—	—
Outstanding, October 31, 2016	2,109,840	$	5.54	3.1	$	—