Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2018

Stockholders' Equity Note [Abstract]

Summary of stock-based compensation expense

The following table summarizes stock-based compensation expense and the impact it had on operations for the periods presented (in thousands):

	Three months ended September 30,				Nine months ended September 30,
	2018		2017		2018		2017
Cost of sales	$	8	$	10	$	27	$	40
Product development	31		16		86		45
Selling, general, and administrative	237		166		593		540
Total stock-based compensation	$	276	$	192	$	706	$	625

Schedule of valuation assumptions

Estimates utilized in the calculation include the expected life of the option, risk-free interest rate, and expected volatility, and are further comparatively detailed as follows:

	Nine months ended September 30,
	2018			2017
Fair value of options issued	$	1.41		$	2.66
Exercise price	$	1.97		$	3.55
Expected life of options (in years)	5.9			5.8
Risk-free interest rate	2.6		%	2.1		%
Expected volatility	84.2		%	91.9		%
Dividend yield	0.0		%	0.0		%

Summary of option activity

A summary of option activity under all plans for the nine months ended September 30, 2018 is presented as follows:

	Number of Options		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Life (in years)
Balance at December 31, 2017	248,512		$	5.76
Granted	100,746		1.97
Exercised	—		—
Canceled/forfeited	(43,787	)	7.17
Expired	(10,000	)	20.00
Balance at September 30, 2018	295,471		$	3.78	7.5
Vested and expected to vest at September 30, 2018	269,153		$	3.93	7.3
Exercisable at September 30, 2018	144,191		$	5.20	5.7

Restricted stock units

A summary of restricted stock unit activity under all plans for the nine months ended September 30, 2018 is presented as follows:

	Restricted Stock Units		Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Life (in years)
Balance at December 31, 2017	306,142		$	3.37
Granted	553,657		2.38
Released	(213,795	)	3.14
Canceled/forfeited	(76,950	)	2.99
Balance at September 30, 2018	569,054		$	2.55	2.0