Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2017

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

Share-based Compensation Arrangement by Share-based Payment Award Options and Warrants Vested and Expected to Vest Outstanding and Exercisable [Table Text Block]

The Black-Scholes assumptions used in the nine months ended September 30, 2017 and 2016 are as follows:

	Nine months ended September 30,
	2017	2016
Exercise price	$0.83 - $0.87	$1.08 - $2.66
Expected dividends	0%	0%
Expected volatility	90% - 92 %	102% - 117%
Risk free interest rate	1.67% - 1.75 %	1.40% - 1.57 %
Expected life of option	4.2 - 4.3 years	7.0 years

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

A summary of stock option activities for the nine months ended September 30, 2017 and for the year ended December 31, 2016 is as follows:

			Weighted		Weighted Average		Aggregate
			Average Exercise		Remaining		Intrinsic
	Options		Price		Contractual Life		Value
Balance - December 31, 2015		8,941,930	$	2.14		5.67 years	$	2,900,000
Granted		3,861,425		0.98
Exercised		(445,334)		1.83			$	137,488
Expired		(338,529)		1.96
Forfeited		(383,265)		2.26
Balance - December 31, 2016		11,636,227		1.77		5.49 years	$	194,355
Granted		543,927		0.85
Exercised		(418,773)		0.40			$	163,050
Expired		(450,962)		2.00
Forfeited		(91,404)		2.00
Balance - September 30, 2017 - outstanding		11,219,015	$	1.76		5.29 years	$	548,588
Balance - September 30, 2017 - exercisable		7,205,382	$	2.02		4.77 years	$	204,437
Grant date fair value of options granted -  September 30, 2017			$	308,000
Weighted average grant date fair value - September 30, 2017			$	0.57
Grant date fair value of options granted - December 31, 2016			$	3,091,000
Weighted average grant date fair value - December 31, 2016			$	0.80