Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (9,865,498)	$ (7,951,505)
Adjustments to reconcile net loss to net cash used in operations:
Depreciation	79,729	70,678
Stock-based compensation	411,192	740,304
Bad debt expense	29,839
Non-cash interest expense, debt discount	218,803
Amortization of original issue discount	161,869
Loss on extinguishment of debt	696,436
Change in fair value of derivative liabilities	(122,706)	(155,955)
Loss on disposal of asset	177	2,481
Other non-cash charges	(2,326)	14,634
Changes in operating assets and liabilities:
Accounts receivable	85,925	248,252
Inventories	(324,234)	(302,608)
Prepaid expenses and other current assets	30,020	(130,268)
Other assets	57,987	(2,000)
Accounts payable and accrued expenses	494,311	(191,120)
Deferred revenue	3,771	2,447
Other liabilities	165,889	(43,042)
Net cash used in operating activities	(7,878,816)	(7,697,702)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of equipment	(30,294)	(38,261)
Net cash used in investing activities	(30,294)	(38,261)
CASH FLOWS FROM FINANCING ACTIVITIES
Repayment of debt	(1,703,552)
Payment of prepayment penalty on debt	(255,533)
Net settlement of vested restricted stock units to fund related employee statutory tax withholding	(1,855)	(80,321)
Proceeds from exercise of stock options	3	16
Proceeds from exercise of warrants	161,299
Proceeds from issuance under at-market sales facility, net of offering costs	5,049,551
Proceeds from public offering, net of offering costs	13,504,812	5,603,829
Proceeds from payment of grants	6,928
Net cash provided by financing activities	16,761,653	5,523,524
Effect of foreign exchange rate changes on cash	(417)
Net increase (decrease) in cash, cash equivalents and restricted cash	8,852,126	(2,212,439)
Cash, cash equivalents and restricted cash, beginning of period	4,540,455	6,615,794
Cash, cash equivalents and restricted cash, end of period	13,392,581	4,403,355
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Inventory capitalized as sales demo equipment	2,743	17,715
Sales demo equipment transferred to rental inventory	2,514
Issuance of warrants recorded as a derivative liability		$ 196,236
Deferred issuance costs to additional paid-in capital paid in prior period	161,253
Issuance of common stock for debt	$ 2,059,573