Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash Flows From Operating Activities
Net loss	$ (19,925,000)	$ (32,147,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation of leasehold improvements and equipment	871,000	762,000
Amortization of intangibles	243,000	246,000
Amortization of right of use assets	399,000	515,000
Share-based compensation	6,936,000	7,172,000
Allowance for doubtful trade receivables	2,576,000	2,228,000
Loss from investment in long-term assets	395,000	0
Loss from impairment of intangibles	4,000	0
Loss from disposal of equipment	0	7,000
Amortization of convertible notes issuance costs and discount	0	846,000
Non-cash financing costs	94,000	134,000
Changes in operating assets and liabilities:
Trade receivables	2,057,000	(44,000)
Inventories	(148,000)	(3,286,000)
Implementation costs for cloud computing arrangement	(142,000)	0
Prepaid expenses and other assets	(427,000)	(191,000)
Accounts payable	(181,000)	78,000
Accrued expenses	1,717,000	103,000
Deferred revenue	568,000	3,873,000
Customer deposits and other	106,000	(106,000)
Payments on operating leases	(591,000)	(629,000)
Net cash used in operating activities	(10,600,000)	(20,439,000)
Cash Flows From Investing Activities
Proceeds from disposal of assets held at escrow	0	553,000
Purchases of leasehold improvements and equipment	(124,000)	(743,000)
Purchases of intangible assets	(18,000)	(10,000)
Investment in other long-term assets	(23,000)	(49,000)
Net cash used in investing activities	(165,000)	(249,000)
Cash Flows From Financing Activities
Proceeds from issuance of common stock, net	4,856,000	6,772,000
Proceeds from sale of convertible notes	0	10,000,000
Payment of convertible notes issuance costs	0	(565,000)
Payment of debt issuance costs	(49,000)	(113,000)
Proceeds from exercise of stock options	4,115,000	1,066,000
Principal payments on finance leases	(272,000)	(276,000)
Net cash provided by financing activities	8,650,000	16,884,000
Net decrease in cash	(2,115,000)	(3,804,000)
Cash Beginning of Year, including restricted cash of $0.2 million for both 2020 and 2019	18,812,000	22,616,000
Cash Ending of Year, including restricted cash of $0.2 million for both 2020 and 2019	16,697,000	18,812,000
Supplemental Disclosures of Cash Flow Information
Cash payments for interest on finance leases	13,000	33,000
Supplemental Schedule of Noncash Operating Activity
Finance lease obligation incurred on licensing fees	0	99,000
Right of use assets transferred	0	62,000
Operating lease obligation transferred	0	65,000
Operating lease obligation incurred for entering into lease amendment	734,000	0
Supplemental Schedule of Noncash Investing Activity
Finance lease obligation incurred for purchase of computer equipment and software	47,000	143,000
Operating lease obligation incurred for tenant improvement credit received	0	64,000
Retirement of fully depreciated equipment - cost	5,000	0
Retirement of fully depreciated equipment - accumulated depreciation	5,000	0
Supplemental Schedule of Noncash Financing Activity
Issuance of common stock for conversion of debt and accrued interest	$ 0	$ 10,123,000