Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net loss	$ (20,713)	$ (18,292)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation	595	429
Non-cash lease expense	31	103
Stock-based compensation	10,623	10,576
Accretion and short-term investment discount	(287)	(128)
Changes in operating assets and liabilities:
Accounts receivable	1,268	316
Inventories	(550)	(2,906)
Prepaid expenses and other current assets	649	1,031
Other assets	71	70
Accounts payable	218	(169)
Accrued liabilities	(334)	(267)
Deferred revenue	(702)	989
Other liabilities	(8)	(167)
Net cash used in operating activities	(9,139)	(8,415)
Cash flows from investing activities
Purchase of property and equipment	(366)	(2,378)
Purchases of short-term investments		(19,716)
Proceeds from maturity of short-term investments	20,131
Net cash provided by (used in) investing activities	19,765	(22,094)
Cash flows from financing activities
Proceeds from issuance of stock, net of issuance costs	81	220
Net cash provided by financing activities	81	220
Net increase (decrease) in cash, cash equivalents, and restricted cash	10,707	(30,289)
Cash, cash equivalents, and restricted cash at beginning of period	9,855	40,144
Cash, cash equivalents, and restricted cash at end of period	20,562	9,855
Supplemental disclosure of cash flow information:
Purchase of property and equipment included in accounts payable		313
Reconciliation of cash, cash equivalents, and restricted cash to balance sheet as of December 31st:
Cash and cash equivalents	19,818	8,586
Restricted cash - current	525	525
Restricted cash	219	744
Total cash, cash equivalents, and restricted cash	$ 20,562	$ 9,855