Condensed Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities
Net loss	$ (3,048,084)	$ (4,977,932)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization	156,335	159,863
Noncash interest expense	49,133	2,087
Share-based compensation	238,190	245,405
Gain on sale of equipment	(5,253)	0
Change in fair value of warrant liabilities	(8,166)	0
Changes in operating assets and liabilities:
Accounts receivable	218,746	163,174
Inventory	24,882	49,407
Other assets	80,197	43,346
Accounts payable	(63,048)	(215,361)
Accrued compensation and other liabilities	126,439	75,683
Deferred revenue	(1,402)	(6,164)
Net cash used in operating activities	(2,232,031)	(4,460,492)
Cash flows from investing activities
Purchases of property and equipment	0	(27,022)
Proceeds from sale of property and equipment	10,440	0
Net cash provided by (used in) investing activities	10,440	(27,022)
Cash flows from financing activities
Proceeds from issuance of common stock, net of issuance costs	0	2,122,861
Proceeds from issuance of units, net of selling costs	10,721,401	0
Payments on debt	(48,424)	(25,898)
Payments on capital lease obligations	(50,193)	(52,706)
Net cash provided by financing activities	10,622,784	2,044,257
Effects of exchange rates on cash	(13,522)	(3,756)
Net increase (decrease) in cash, cash equivalents and restricted cash	8,387,671	(2,447,013)
Cash, cash equivalents and restricted cash at beginning of period	2,090,551	4,360,704
Cash, cash equivalents and restricted cash at end of period	10,478,222	1,913,691
Supplemental disclosure of cash flow information
Cash paid for interest	8,713	10,702
Supplemental disclosures of noncash investing and financing activities:
Property and equipment purchased on credit	0	8,685
Property and equipment acquired through capital lease	87,152	0
Conversion of accounts payable to capital lease	$ 174,968	$ 0