Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash Flows from Operating Activities:
Net loss	$ (4,776)	$ (6,901)
Adjustments to reconcile net loss to net cash and cash equivalents used in operating activities:
Depreciation and amortization	117	85
Provision for bad debts	84	(106)
Provision for sales returns	60	90
Inventory write-offs and disposals	0	(20)
Amortization of discounts on lines of credit	24	42
Amortization of debt issuance costs	43	95
Patent litigation mark-to-market	0	89
Stock-based compensation	209	928
Changes in operating assets and liabilities:
Accounts receivable	(1,085)	(193)
Inventory	(1,682)	(700)
Prepaid expenses and other current assets	(186)	558
Accounts payable and accrued liabilities	(986)	(488)
Deferred revenue	157	22
Net cash and cash equivalents used in operating activities	(8,021)	(6,499)
Cash Flows from Investing Activities:
Purchases of property, plant, and equipment	(304)	(8)
Net cash and cash equivalents used in investing activities	(304)	(8)
Cash Flows from Financing Activities:
Proceeds from the issuance of common stock, net of offering costs	0	13,292
Payments of equity offering costs	0	(6)
Proceeds from the exercise of common stock warrants	0	16,539
Net cash and cash equivalents provided by financing activities	0	29,825
Effect of exchange rate changes	(41)	(148)
(Decrease) increase in cash, cash equivalents and restricted cash	(8,366)	23,170
Cash, cash equivalents and restricted cash, beginning of period	30,175	17,876
Cash, cash equivalents and restricted cash, end of period	21,809	41,046
Supplemental cash flow disclosure:
Cash paid for interest	377	448
Cash received for interest	10	14
Cash paid for income taxes	26	10
Cash paid for operating leases	66	66
Non-cash settlement of liability	0	510
Non-cash right-of-use assets obtained in exchange for lease obligation	444	0
Deemed dividend on preferred stock	$ 217	$ 532