Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash Flows From Operating Activities:
Net loss	$ (19,220)	$ (9,024)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	336	90
Product line exit expense	747	0
Gain on sale of assets	(17)	0
Warranty provision	23	17
Software impairment charge	170	0
Change in contingent liability	(23)	0
Non-cash lease expense	67	91
Share-based compensation	4,310	1,563
Common shares issued for services	239	0
Provision for doubtful accounts	27	10
Changes in assets and liabilities:
Accounts receivable	(1,414)	(985)
Inventories	(160)	294
Prepaid expenses and other current assets	231	(50)
Accounts payable	271	355
Operating lease liability	(71)	(95)
Customer deposits	19	(216)
Accrued liabilities and other	502	255
Warranty settlement	10	2
Deferred revenue	224	0
Net cash used in operating activities	(13,729)	(7,693)
Cash Flows From Investing Activities:
Purchase of short-term investments	(30,014)	(24,980)
Proceeds from maturities of short-term investments	25,000	0
Capital expenditures for property and equipment	(811)	(202)
Proceeds from long-term deposits	4	0
Net cash used in investing activities	(6,511)	(25,283)
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	12,048	24,480
Offering costs paid on exercise of warrants	0	(1,017)
Proceeds from exercise of stock options	1,678	566
Proceeds from bank note	0	414
Repayment of debt	(275)	0
Net cash provided by financing activities	13,451	36,110
Net (decrease) increase in cash and cash equivalents	(6,789)	3,134
Cash and cash equivalents, beginning of period	16,647	16,984
Cash and cash equivalents, end of period	9,858	20,118
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Change in unrealized gain on short-term investments	(2)	7
Patents and Trademarks [Member]
Cash Flows From Investing Activities:
Payments for intangible assets	(129)	(101)
Intangibles Other than Patents and Trademarks [Member]
Cash Flows From Investing Activities:
Payments for intangible assets	$ (561)	$ 0