Condensed Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating activities
Net loss	$ (11,953,881)	$ (16,580,237)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	568,380	1,039,989
Accretion of discount on NuvoGen obligation	(9,206)	(9,771)
Provision for excess inventory	60,143	5,649
Amortization of QNAH Convertible Note issuance costs		6,505
Amortization of MidCap Credit Facility discount and issuance costs		101,482
Amortization of SVB Term Loan discount and issuance costs	351,068	121,168
Stock-based compensation expense	1,000,368	1,163,742
Employee stock purchase plan expense	41,950	15,972
Non-cash operating lease expense	359,014	465,504
Accrued interest on available-for-sale securities investments	(18,394)	(101,996)
Stock compensation expense in connection with LP Purchase Agreement		205,538
Gain on forgiveness of PPP Loan	(1,735,792)
Loss on extinguishment of Midcap Credit Facility and QNAH Convertible Note		522,394
Loss on abandonment and disposal of assets, net	178,925	77,498
Changes in operating assets and liabilities:
Accounts receivable	(597,489)	1,793,975
Inventory	(892,655)	(255,718)
Prepaid expenses and other	(300,469)	457,504
Deferred offering costs		140,320
Accounts payable	(50,230)	(778,706)
Accrued liabilities	205,015	(474,521)
Contract liabilities	53,062	(74,700)
Operating lease liabilities	(378,355)	(583,828)
Net cash used in operating activities	(13,118,546)	(12,742,237)
Investing activities
Purchase of property and equipment	(590,736)	(418,712)
Maturities of available-for-sale securities	9,000,000	25,450,000
Purchase of available-for-sale securities	(17,871,203)	(11,565,882)
Net cash (used in) provided by investing activities	(9,461,939)	13,465,406
Financing activities
Proceeds from issuance of SVB Term Loan		10,000,000
Payment of SVB Term Loan issuance costs		(115,193)
Proceeds from ATM Offering, net of commissions of $0.3 million	10,665,819	6,387,982
Proceeds from LP Purchase Agreement	599,979
Proceeds from PPP Loan		1,717,000
Proceeds from Series A convertible preferred stock in private placement		562,955
Payments on NuvoGen obligation	(379,431)	(539,323)
Proceeds from exercise of pre-funded warrants		31,768
Proceeds from shares purchased under stock purchase plans	53,437	25,133
Payments on financing leases	(18,040)	(32,553)
Proceeds from exercise of stock options	326
Taxes paid for net share settlement of restricted stock awards	(2,571)	(12,824)
Payments on 2021 and 2020 Insurance Notes	(494,352)	(324,301)
Net cash provided by financing activities	10,425,167	7,262,021
Effect of exchange rates on cash	(12,848)	9,283
Increase (decrease) in cash, cash equivalents and restricted cash	(12,168,166)	7,994,473
Cash, cash equivalents and restricted cash at beginning of period	22,397,812	10,889,995
Cash, cash equivalents and restricted cash at end of period	10,229,646	18,884,468
Supplemental disclosure of noncash investing and financing activities
Issuance of Series A convertible preferred stock in exchange for outstanding common stock		2,424,900
Issuance of common stock upon conversion of Series A convertible preferred stock		1,622,500
Issuance of common stock from cashless exercise of pre-funded warrants	145
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	1,302,457	21,078
Carrying value of demonstration units transferred from property and equipment to inventory	16,128	18,817
2021 and 2020 Insurance Notes issued for insurance premiums	746,360	735,195
Gain on forgiveness of PPP Loan	1,735,792
Supplemental cash flow information
Cash paid for interest	450,344	719,676
Cash paid for taxes	$ 12,665	9,961
QNAH Convertible Note
Financing activities
Payments for extinguishment of debt		(3,000,000)
MidCap Credit Facility
Financing activities
Payments for extinguishment of debt		$ (7,438,623)