Stock Incentive Plans - Stock-Based Compensation (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Stock Based Compensation
Total stock-based compensation expense	$ 446,368	$ 464,454	$ 872,876	$ 736,697
Research and development expense
Stock Based Compensation
Total stock-based compensation expense	148,844	145,035	215,948	224,749
Sales and marketing expense
Stock Based Compensation
Total stock-based compensation expense	12,251	18,167	46,093	20,552
General and administrative expense
Stock Based Compensation
Total stock-based compensation expense	285,273	$ 301,252	610,835	$ 491,396
Stock options and RSUs
Stock Based Compensation
Unrecognized stock-based compensation expense	$ 1,817,839		$ 1,817,839
Expected weighted average period to be recognized			1 year 6 months 22 days
Minimum | Employee stock options
Estimated grant-date fair value of stock options calculated using the Black-Scholes option-pricing model
Weighted-average volatility (as a percent)			108.30%	87.40%
Weighted-average expected term (years)			5 years 9 months 22 days	5 years 1 month 6 days
Risk-free interest rate (as a percent)			2.50%	2.60%
Maximum | Employee stock options
Estimated grant-date fair value of stock options calculated using the Black-Scholes option-pricing model
Weighted-average volatility (as a percent)			108.50%	95.30%
Weighted-average expected term (years)				5 years 9 months 18 days
Risk-free interest rate (as a percent)			2.60%	2.90%