Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
OPERATING ACTIVITIES
Net loss	$ (1,943)	$ (1,538)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation	403	281
Amortization	57	61
Loss on sale of equipment	0	10
Non-cash interest income on held-to-maturity securities	(132)	(433)
Provision for credit losses, net of recoveries	(4)	0
Deferred income taxes	4	(5)
Stock-based compensation, net of forfeitures	446	389
Changes in operating assets and liabilities:
Accounts receivable	(1,127)	1,039
Employee retention credit receivable	(1,677)	0
Inventories	41	(46)
Prepaid expenses, other current assets and other non-current assets	292	(6)
Accounts payable	519	(295)
Accrued liabilities and other non-current liabilities	(312)	1,239
Net cash (used in) provided by operating activities	(3,433)	696
INVESTING ACTIVITIES
Purchases of equipment and patents	(378)	(418)
Purchases of debt securities	(18,060)	(14,026)
Maturities of debt securities	12,995	8,000
Net cash used in investing activities	(5,443)	(6,444)
FINANCING ACTIVITIES
Proceeds from exercise of stock options	0	42
Taxes paid on behalf of equity award participants	(95)	0
Net cash (used in) provided by financing activities	(95)	42
Effect of exchange rate fluctuations on cash	(97)	(44)
Net decrease in cash and cash equivalents	(9,068)	(5,750)
Cash and cash equivalents at beginning of period	17,578	23,328
Cash and cash equivalents at end of period	8,510	17,578
Supplemental Cash Flow Information:
Cash income taxes paid, net	52	12
Non-cash transfer from other non-current assets to property and equipment	$ 597	$ 0