Condensed Consolidated Statements of Cash Flows - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Cash flows from operating activities
Net loss			$ (6,446,127)	$ (6,380,297)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization			450,952	317,652
Noncash interest expense			43,371	94,594
Stock compensation expense			184,004	452,080
Loss (gain) on sale of equipment			9,904	(5,253)
Change in fair value of warrant liability			(67)	(8,155)
Impairment of right-of-use asset	$ 0	$ 0	520,759	0
Changes in operating assets and liabilities:
Accounts receivable			(399,528)	291,273
Inventory			(23,824)	(81,321)
Other assets			429,558	(235,835)
Accounts payable			(301,376)	(219,565)
Accrued compensation and other liabilities			(285,953)	226,611
Deferred revenue			(5,831)	(10,320)
Net cash used in operating activities			(5,824,158)	(5,558,536)
Cash flows from investing activities
Purchases of property and equipment			(24,680)	(4,457)
Proceeds from sale of equipment			29,250	10,440
Net cash provided by investing activities			4,570	5,983
Cash flows from financing activities
Proceeds from issuance of common stock, net of issuance costs			4,782,509	192,320
Proceeds from issuance of units, net of selling costs			0	10,728,131
Proceeds from debt, net of issuance costs			15,481	309,900
Payments on debt			(237,414)	(55,582)
Payments on finance leases			(235,600)	(107,871)
Net cash provided by financing activities			4,324,976	11,066,898
Effects of exchange rates on cash			(1,321)	5,587
Net (decrease) increase in cash, cash equivalents and restricted cash			(1,495,933)	5,519,932
Cash, cash equivalents and restricted cash at beginning of period			4,737,207	2,090,551	$ 2,090,551
Cash, cash equivalents and restricted cash at end of period	$ 3,241,274	$ 7,610,483	3,241,274	7,610,483	$ 4,737,207
Supplemental disclosure of cash flow information
Cash paid for interest			97,599	17,785
Supplemental disclosures of noncash investing and financing activities:
Right-of-use assets acquired through finance leases			291,936	281,153
Conversion of accounts payable to finance lease			$ 63,600	$ 174,968