Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net loss	$ (17,145,170)	$ (20,870,218)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	721,246	1,346,560
Accretion of discount on NuvoGen obligation	(12,288)	(12,936)
Provision for excess inventory	174,589	53,298
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	470,281	243,541
Stock-based compensation expense	1,317,355	1,584,785
Employee stock purchase plan expense	57,669	21,186
Bad debt expense	20,315
Non-cash operating lease expense	458,001	629,501
Accrued interest on available-for-sale securities investments	(25,018)	(72,503)
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	180,008	105,063
Changes in operating assets and liabilities:
Accounts receivable	(805,736)	1,575,409
Inventory	(1,365,384)	(256,940)
Prepaid expenses and other	619,226	284,921
Deferred offering costs		140,320
Accounts payable	453,337	(23,801)
Accrued liabilities	616,447	(409,035)
Contract liabilities	(38,314)	(683,716)
Operating lease liabilities	(469,326)	(783,731)
Net cash used in operating activities	(16,508,554)	(16,292,377)
Investing activities
Purchase of property and equipment	(644,381)	(453,552)
Maturities of available-for-sale securities	12,600,000	31,650,000
Purchase of available-for-sale securities	(18,620,363)	(12,465,341)
Net cash (used in) provided by investing activities	(6,664,744)	18,731,107
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	7,545,838
Proceeds from LP Purchase Agreement	899,980	976,545
Proceeds from PPP Loan		1,717,000
Proceeds from Series A convertible preferred stock in private placement		562,955
Payments on NuvoGen obligation	(530,656)	(645,949)
Proceeds from exercise of pre-funded warrants		31,768
Payments on financing leases	(22,563)	(41,134)
Proceeds from exercise of stock options	326
Taxes paid for net share settlement of restricted stock awards	(3,239)	(14,049)
Cash in lieu of fractional shares related to reverse stock split		(560)
Proceeds from shares purchased under stock purchase plans	125,828	40,976
Payments on 2021 and 2020 Insurance Notes	(743,873)	(570,096)
Net cash provided by financing activities	10,391,622	9,049,478
Effect of exchange rates on cash	(16,186)	19,609
Increase (decrease) in cash, cash equivalents and restricted cash	(12,797,862)	11,507,817
Cash, cash equivalents and restricted cash at beginning of year	22,397,812	10,889,995
Cash and cash equivalents at end of year	9,599,950	22,397,812
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 warrants in connection with SVB Term Loan		420,000
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	447,987
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
Reclassification of contract liability to refund liability		281,722
Disposal of fully depreciated assets	635,870
Gain on forgiveness of PPP Loan	1,735,792
Supplemental cash flow information
Cash paid for interest	599,922	869,857
Cash paid for taxes	$ 12,665	17,514
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)