Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2016

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

Summary of Stock Based Compensation Expense

Stock compensation expense was allocated between departments as follows;

	Year ended
	December 31, 2016		December 31, 2015
Research & Development	$	165,154	$	148,948
Sales & Marketing	30,418		62,533
General & Administrative	675,698		730,888
Total	$	871,270	$	942,369

Schedule of Fair Value of Award Granted Using Black-Scholes Option Pricing Model

The fair value of each award granted was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions for the year ended December 31, 2016:

	Year Ended
	December 31, 2016	December 31, 2015
Expected life (years)	6.1	6.1
Risk-free interest rate	1.3% - 1.7%	1.6%-1.7%
Volatility	65% - 73%	56% - 66%
Dividend rate	—%	—%

Summary of Stock Option Transactions

The following table summarizes stock option transactions for the years ended December 31, 2016 and 2015 as issued under the Plans:

	Shares Available for Grant		Number of Options Outstanding		Weighted-Average Exercise Price per Share		Weighted Average Remaining Contractual Term
							(in years)
Balance at December 31, 2014	606,061		1,072,011		$	6.34
Additional shares authorized	270,764		—		—
Options granted	(955,713	)	955,713		3.08
Options exercised			(83,848	)	3.50
Options canceled/forfeited	85,037		(85,037	)	5.03
Balance at December 31, 2015	6,149		1,858,839		4.82		8.75
Additional shares authorized	560,717		—		—
Amendment to plan to authorize additional shares	1,500,000		—		—
Options granted	(1,339,259	)	1,339,259		1.36
Options exercised	—		(58,419	)	1.20
Options canceled/forfeited	231,249		(231,249	)	3.09
Balance at December 31, 2016	958,856		2,908,430		$	3.42	8.48
Options vested at December 31, 2016	—		1,450,033		$	4.12	8.13
Options vested and expected to vest at December 31, 2016	—		2,908,430		$	3.42	8.48