Condensed Consolidated Statements of Operations (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue:
Total revenue	$ 2,174,635	$ 3,390,009	$ 4,027,381	$ 5,158,494
Cost of revenue:
Total cost of revenue	1,555,246	1,813,430	2,702,288	2,654,879
Operating expense:
Research and development	2,407,692	2,098,826	4,507,803	4,465,919
Selling, general and administrative	5,056,005	3,489,974	9,846,607	6,385,378
Total operating expense	7,463,697	5,588,800	14,354,410	10,851,297
Loss from operations	(6,844,308)	(4,012,221)	(13,029,317)	(8,347,682)
Other income (expense):
Interest expense	(565,888)	(407,635)	(838,392)	(709,616)
Change in fair value of preferred stock warrants and expirations	0	1,517,723	0	2,470,921
Loss on debt extinguishment	0	(342,164)	(921,496)	(342,164)
Other expense	(249,884)	(61,673)	(718,132)	(221,015)
Total other income (expense)	(815,772)	706,251	(2,478,020)	1,198,126
Loss before income taxes	(7,660,080)	(3,305,970)	(15,507,337)	(7,149,556)
Provision for income taxes	(4,486)	(5,506)	(8,972)	(9,282)
Net loss	$ (7,664,566)	$ (3,311,476)	$ (15,516,309)	$ (7,158,838)
Net loss per share, basic and diluted (USD per share)	$ (0.71)	$ (0.98)	$ (1.47)	$ (1.37)
Weighted-average common shares outstanding basic and diluted (shares)	10,860,055	3,364,128	10,541,563	5,227,448
Product revenue
Revenue:
Total revenue	$ 2,020,398	$ 3,256,023	$ 3,707,984	$ 4,918,245
Cost of revenue:
Total cost of revenue	1,525,334	1,803,461	2,644,885	2,644,043
Other revenue
Revenue:
Total revenue	154,237	133,986	319,397	240,249
Cost of revenue:
Total cost of revenue	$ 29,912	$ 9,969	$ 57,403	$ 10,836