Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2019

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,
	2019		2018		2019		2018
Cost of sales	$	1	$	8	$	8	$	27
Product development	2		31		24		86
Selling, general, and administrative	31		237		525		593
Total stock-based compensation	$	34	$	276	$	557	$	706

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,
	2019			2018
Fair value of options issued	$	0.32		$	1.41
Exercise price	$	0.42		$	1.97
Expected life of options (in years)	6.3			5.9
Risk-free interest rate	1.9		%	2.6		%
Expected volatility	90.0		%	84.2		%
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, 2019 is presented as follows:

	Number of Options		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Life (in years)
Balance at December 31, 2018	292,871		$	3.78
Granted	450,000		0.42
Canceled/forfeited	(151,993	)	2.90
Expired	(27,525	)	5.33
Balance at September 30, 2019	563,353		$	1.26	9.1
Vested and expected to vest at September 30, 2019	420,864		$	1.54	8.9
Exercisable at September 30, 2019	109,837		$	4.63	6.3

Summary of restricted stock activity

A summary of restricted stock unit activity under all plans for the nine months ended September 30, 2019 is presented as follows:

	Restricted Stock Units		Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Life (in years)
Balance at December 31, 2018	546,858		$	2.54
Granted	27,187		1.04
Released	(377,894	)	2.51
Canceled/forfeited	(152,441	)	2.32
Balance at September 30, 2019	43,710		$	2.62	1.2