Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash Flows From Operating Activities:
Net loss	$ (14,082)	$ (19,220)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	574	336
Product line exit expense	0	747
Gain on sale of assets	0	(17)
Warranty provision	55	23
Software impairment charge	0	170
Change in contingent liability	0	(23)
Non-cash lease expense	75	67
Share-based compensation	2,628	4,310
Common shares issued for services	0	239
Provision for doubtful accounts	61	27
Changes in assets and liabilities:
Accounts receivable	1,576	(1,414)
Inventories	(1,396)	(160)
Prepaid expenses and other current assets	268	231
Accounts payable	(834)	271
Operating lease liability	(65)	(71)
Customer deposits	(43)	19
Accrued liabilities and other	175	502
Warranty settlement	(63)	10
Deferred revenue	35	224
Net cash used in operating activities	(11,036)	(13,729)
Cash Flows From Investing Activities:
Purchase of short-term investments	(23,119)	(30,014)
Proceeds from maturities of short-term investments	33,300	25,000
Capital expenditures for property and equipment	(201)	(811)
Payments for Other Deposits	(3)
Proceeds from long-term deposits		4
Net cash provided by (used in) investing activities	9,844	(6,511)
Cash Flows From Financing Activities:
Proceeds from exercise of warrants	0	12,048
Proceeds from exercise of stock options	83	1,678
Repayment of debt	0	(275)
Net cash provided by financing activities	83	13,451
Net (decrease) increase in cash and cash equivalents	(1,109)	(6,789)
Cash and cash equivalents, beginning of period	4,937	16,647
Cash and cash equivalents, end of period	3,828	9,858
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Change in unrealized gain on short-term investments	62	(2)
Right-of-use asset and liability recorded during period	260	(66)
Patents and Trademarks [Member]
Cash Flows From Investing Activities:
Purchase of intangible assets	(133)	(129)
Intangibles Other than Patents and Trademarks [Member]
Cash Flows From Investing Activities:
Purchase of intangible assets	$ 0	$ (561)