Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash Flows From Operating Activities
Net loss	$ (9,613,000)	$ (16,092,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation of leasehold improvements and equipment	432,000	363,000
Amortization of intangibles	122,000	122,000
Amortization of right of use assets	187,000	279,000
Share-based compensation expense	3,584,000	3,788,000
Allowance for doubtful trade receivables	(2,730,000)	(8,000)
Amortization of convertible notes issuance costs	0	552,000
Non-cash financing costs	51,000	0
Changes in operating assets and liabilities:
Trade receivables	952,000	(1,373,000)
Contract assets	0	4,000
Inventories	(804,000)	(2,465,000)
Prepaid expenses and other assets	322,000	50,000
Accounts payable	154,000	(224,000)
Accrued expenses	830,000	(671,000)
Deferred revenue	(53,000)	3,873,000
Customer deposits and other	78,000	18,000
Principal payments on operating leases	(289,000)	(285,000)
Net cash used in operating activities	(6,777,000)	(12,069,000)
Cash Flows From Investing Activities
Purchases of leasehold improvements and equipment	(107,000)	(308,000)
Purchases of intangible assets	0	(10,000)
Investment in other long-term assets	(15,000)	(47,000)
Net cash used in investing activities	(122,000)	(365,000)
Cash Flows From Financing Activities
Proceeds from issuance of common stock, net	4,856,000	0
Proceeds from sale of convertible notes	0	10,000,000
Payment of convertible notes issuance costs	0	(565,000)
Proceeds from exercise of stock options	2,312,000	271,000
Payment of debt issuance costs	(30,000)	0
Principal payments on finance leases	(161,000)	(128,000)
Net cash provided by financing activities	6,977,000	9,578,000
Net increase (decrease) in cash	78,000	(2,856,000)
Cash Beginning of Period, including restricted cash of $0.2 million for both 2020 and 2019	18,812,000	22,616,000
Cash Ending of Period, including restricted cash $0.2 million for both 2020 and 2019	18,890,000	19,760,000
Supplemental Disclosures of Cash Flow Information
Cash payments for interest on finance leases	9,000	17,000
Supplemental Schedule of Noncash Operating Activity
Financing lease obligation incurred for prepayment of licensing fees	0	99,000
Supplemental Schedule of Noncash Investing Activity
Financing 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