Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash Flows From Operating Activities:
Net loss	$ (24,449)	$ (12,580)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	478	163
Share-based compensation	5,356	2,237
Common shares issued for services	239	0
Product line exit expense	747	0
Debt forgiveness income	0	(417)
Gain on sale of assets	(27)	0
Warranty provision	10	30
Inventory write-offs	0	(68)
Software impairment charge	170	0
Change in contingent liability	(23)	0
Non-cash lease expense	88	122
Non-cash interest expense	0	2
Provision for doubtful accounts	123	10
Changes in assets and liabilities:
Accounts receivable	(2,111)	(1,686)
Inventories	559	(343)
Prepaid expenses and other current assets	(109)	(508)
Accounts payable	546	825
Operating lease liability	(94)	(128)
Customer deposits	41	(342)
Accrued liabilities and other	(54)	493
Warranty settlement	38	4
Deferred revenue	249	(1)
Net cash used in operating activities	(18,223)	(12,187)
Cash Flows From Investing Activities:
Purchase of short-term investments	(55,014)	(34,980)
Proceeds from maturities of short-term investments	50,005	10,000
Capital expenditures for property and equipment	(995)	(249)
Business acquisition	0	(210)
Proceeds from long-term deposits	4	0
Net cash used in investing activities	(6,937)	(26,111)
Cash Flows From Financing Activities:
Sale of common stock and warrants	0	12,400
Offering costs paid on sale of common stock and warrants	0	(733)
Proceeds from exercise of warrants	12,047	26,191
Offering costs paid on exercise of warrants	0	(1,016)
Proceeds from exercise of stock options	1,678	705
Proceeds from bank note	0	414
Repayment of debt	(275)	0
Net cash provided by financing activities	13,450	37,961
Net decrease in cash and cash equivalents	(11,710)	(337)
Cash and cash equivalents, beginning of period	16,647	16,984
Cash and cash equivalents, end of period	4,937	16,647
Supplemental Disclosure of Non-Cash Investing
Business acquisition liability	0	298
Business acquisition cost in deferred revenue	0	15
Change in unrealized gain on short-term investments	(21)	15
Patents and Trademarks [Member]
Cash Flows From Investing Activities:
Payments for intangible assets	(187)	(129)
Intangibles Other than Patents and Trademarks [Member]
Cash Flows From Investing Activities:
Payments for intangible assets	$ (750)	$ (543)