Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Operating Activities
Net loss	$ (140)	$ (1,458)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation	161	154
Amortization	31	30
Non-cash interest income on held-to-maturity securities	(72)	(203)
Stock-based compensation, net of forfeitures	228	187
Changes in operating assets and liabilities:
Accounts receivable	(334)	966
Employee retention credit receivable	(1,677)	0
Inventory	(24)	(135)
Prepaid expenses, other current assets and other non-current assets	367	114
Accounts payable	524	383
Accrued liabilities and other non-current liabilities	(1,728)	(21)
Net cash (used in) provided by operating activities	(2,664)	17
Investing Activities
Purchases of equipment and patents	(204)	(103)
Purchases of debt securities	(11,107)	(9,685)
Maturities of debt securities	7,000	1,500
Net cash used in investing activities	(4,311)	(8,288)
Financing Activities
Taxes paid on behalf of award participants	(95)	0
Proceeds from exercise of stock options	0	42
Net cash (used in) provided by financing activities	(95)	42
Effect of exchange rate fluctuations on cash	(104)	35
Net decrease in cash and cash equivalents	(7,174)	(8,194)
Cash and cash equivalents at beginning of period	17,578	23,328
Cash and cash equivalents at end of period	$ 10,404	$ 15,134