Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash Flows From Operating Activities
Net loss	$ (27,128)	$ (19,925)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation of leasehold improvements and equipment	890	871
Amortization of intangibles	225	243
Amortization of right of use assets	511	399
Share-based compensation expense	6,195	6,936
Provision for doubtful trade receivables	46	36
Loss from investment in long-term assets	0	395
Loss from impairment of intangibles	0	4
Non-cash financing costs	108	94
Changes in operating assets and liabilities:
Trade receivables	(2,578)	(555)
Inventories	(1,918)	(148)
Implementation costs for cloud computing arrangement	(278)	(142)
Prepaid expenses and other assets	(810)	(427)
Accounts payable	978	(181)
Accrued expenses	348	1,717
Deferred revenue	(95)	568
Customer deposits and other	(116)	106
Principal payments on operating leases	(541)	(591)
Net cash used in operating activities	(24,163)	(10,600)
Cash Flows From Investing Activities
Purchases of leasehold improvements and equipment	(409)	(124)
Purchases of intangible assets	0	(18)
Investment in other long-term assets	0	(23)
Net cash used in investing activities	(409)	(165)
Cash Flows From Financing Activities
Proceeds from issuance of common stock, net	26,740	4,856
Proceeds from exercise of stock options	9,495	4,115
Payment of debt issuance costs	(110)	(49)
Principal payments on finance leases	(31)	(272)
Net cash provided by financing activities	36,094	8,650
Net increase (decrease) in cash and cash equivalents	11,522	(2,115)
Cash and cash equivalents, including restricted cash of $0.2 million for both 2021 and 2020 - beginning of period	16,697	18,812
Cash and cash equivalents, including restricted cash of $0.2 million for both 2021 and 2020 - end of period	28,219	16,697
Supplemental Disclosures of Cash Flow Information
Cash payments for interest on finance leases	1	13
Supplemental Schedule of Noncash Operating Activity
Right-of-use assets and operating lease obligations incurred for entering into lease amendment	3,637	734
Supplemental Schedule of Noncash Investing Activity
Financing lease obligation incurred for purchase of computer equipment and software	0	47
Retirement of fully depreciated equipment - cost	0	5
Retirement of fully depreciated equipment - accumulated depreciation	$ 0	$ 5