Condensed Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (2,598,060)	$ (2,345,402)
Adjustments to reconcile net loss to net cash used in operations:
Depreciation	21,627	14,599
Stock-based compensation	207,605	336,355
Bad debt expense	16,275
Excess and obsolete inventory reserve		(645)
Change in fair value of derivative liabilities	(41,970)	(15,307)
Loss on disposal of asset	320
Changes in operating assets and liabilities:
Accounts receivable	(33,912)	145,594
Inventories	(131,871)	(63,923)
Prepaid expenses and other	(128,256)	15,182
Accounts payable and other accrued expenses	(432,998)	(327,390)
Deferred revenue	23,850	(24,423)
Other current liabilities	(22,492)
Net cash used in operating activities	(3,119,882)	(2,265,360)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of equipment	(5,404)	(64,924)
Net cash used in investing activities	(5,404)	(64,924)
CASH FLOWS FROM FINANCING ACTIVITIES
Payments of issuance costs	12,606
Net settlement of vested restricted stock units to fund related employee statutory tax withholding	156,517	(63,149)
Proceeds from exercise of warrants		3,550,490
Proceeds from public offering	5,648,928
Net cash provided by financing activities	5,818,051	3,487,341
Net increase in cash, cash equivalents and restricted cash	2,692,765	1,157,057
Cash, cash equivalents and restricted cash, beginning of period	6,615,794	13,011,373
Cash, cash equivalents and restricted cash, end of period	9,308,559	14,168,430
SUPPLEMENTAL DISCLOSURE CASH FLOW INFORMATION
Inventory capitalized as sales demo equipment	2,108	$ 27,944
Issuance of warrants recorded as a derivative liability	$ 196,236