Share-Based Payments (Tables)

6 Months Ended

Oct. 31, 2017

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,
	2017		2016		2017		2016
General and administrative	$	96	$	469	$	519	$	1,298
Sales and marketing	7		18		41		187
Research and development	42		45		122		130
TOS cost of sales	3		3		28		47
POS cost of sales	—		—		1		2
Total stock-based compensation expense	$	148	$	535	$	711	$	1,664

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, 2017 and 2016 were as follows:

	Three Months Ended October 31,		Six Months Ended October 31,
	2017	2016	2017	2016
Expected term in years	6	6	6	2.6 - 6
Risk-free interest rates	1.98%	1.48%	1.98%	0.75% - 1.48%
Volatility	87.1%	87.32%	87.1%	73.2% - 95.6%
Dividend yield	—%	—%	—%	—%

Summary of Stock Option Activity

The Company’s stock options activity for the six months ended October 31, 2017 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, 2017	50,000	2,258,704		2,308,704		$	2.86	6.1	$	1,282,000
Granted	—	194,977		194,977		2.51		9.7
Exercised	—	—		—		—
Forfeited	—	(6,042	)	(6,042	)	7.58
Canceled	—	—		—		—
Expired	—	(2,709	)	(2,709	)	8.44
Outstanding, October 31, 2017	50,000	2,444,930		2,494,930		2.82		5.9	$	2,512,000
Vested and expected to vest as of October 31, 2017	50,000	2,444,930		2,494,930		2.82		5.9	$	2,512,000
Exercisable as of October 31, 2017	33,336	2,391,889		2,425,225		2.81		5.9	$	2,484,000

Summary of Warrant Activity

Activity related to these warrants, which expire at various dates through March 2020, is summarized as follows:

	Number of Shares	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding, May 1, 2017	2,004,284	$	5.57	2.8	$	—
Granted	—	—		—	—
Exercised	—	—		—	—
Expired	—	—		—	—
Outstanding, October 31, 2017	2,004,284	$	5.57	2.3	$	—