Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss	$ (10,279)	$ (7,886)
Adjustments to reconcile net loss to net cash used in operating activities:
Other income	(30)	(876)
Capitalized interest on promissory notes payable	40	0
Gain on forgiveness of PPP loan	0	(801)
Depreciation	159	188
Stock-based compensation	117	429
Provision for doubtful accounts receivable	14	6
Provision for slow-moving and obsolete inventories	32	156
Provision for warranties	(111)	68
Amortization of loan discounts and origination fees	364	230
Loss on impairment	338	0
Change in operating assets and liabilities:
Accounts receivable	783	783
Inventories	2,358	(2,381)
Short-term deposits	120	257
Prepaid and other assets	247	669
Accounts payable	(1)	(423)
Accrued and other liabilities	(596)	(380)
Deferred revenue	(268)	196
Total adjustments	3,566	(1,879)
Net cash used in operating activities	(6,713)	(9,765)
Cash flows from investing activities:
Acquisitions of property and equipment	(41)	(443)
Proceeds from the sale of property and equipment	25	0
Net cash used in investing activities	(16)	(443)
Cash flows from financing activities:
Proceeds from the issuance of common stock and warrants	3,500	9,500
Proceeds from the exercise of warrants	0	801
Offering costs paid on the issuance of common stock and warrants	(334)	(969)
Principal payments under finance lease obligations	(1)	(3)
Proceeds from exercise of stock options and purchases through employee stock purchase plan	6	80
Common stock withheld in lieu of income tax withholding on vesting of restricted stock units	0	(1)
Proceeds from related party promissory notes payable	800
Payments for deferred financing costs	(114)	(30)
Net payments on credit line borrowings - Credit Facilities	(768)	(181)
Net cash provided by financing activities	4,099	10,712
Net increase in cash	(2,630)	504
Cash, beginning of year	2,682	2,178
Cash, end of year	52	2,682
Supplemental information:
Cash paid in year for interest	364	381
Cash paid in year for income taxes	1	4
Non-cash investing and financing activities:
Debt-to-equity exchange transactions	304	0
2021 Streeterville Note
Cash flows from financing activities:
Payments on the 2021 Streeterville Note	(1,640)	0
Proceeds from notes payable	0	1,515
2022 Streeterville Note
Cash flows from financing activities:
Proceeds from notes payable	2,000	0
Promissory Note Payable
Cash flows from financing activities:
Proceeds from notes payable	$ 650	$ 0