STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (7,710)	$ (9,695)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	135	183
Stock-based compensation	555	711
Loss on sale of equipment	0	28
Bad debt expense	(2)	6
Changes in operating assets and liabilities:
Accounts receivable	20	(42)
Other assets	(4)	0
Prepaid expenses	(10)	(148)
Inventory	58	148
Accounts payable	(390)	206
Accrued expenses	(192)	(18)
Deferred revenue	(26)	44
Net cash used in operating activities	(7,566)	(8,577)
Cash flows from investing activities:
Proceeds received on sale of property and equipment	0	4
Purchase of property and equipment	(149)	(174)
Net cash used in investing activities	(149)	(170)
Cash flows from financing activities:
Proceeds from the issuance of common stock, net	5,407	4,228
Proceeds from the exercise of warrants	2,831	0
Proceeds from the issuance of notes payable	114	0
Repayments of notes payable	(6)	(5)
Repayments of finance lease obligations	0	(27)
Payment of employee withholding taxes related to share based awards	(11)	0
Net cash provided by financing activities	8,335	4,196
Increase (decrease) in cash and cash equivalents	620	(4,551)
Cash and cash equivalents, beginning of year	4,775	9,326
Cash and cash equivalents, end of year	5,395	4,775
Cash paid for:
Interest paid	4	1
Income taxes paid	0	0
Non-cash investing and financing activities:
Notes payable incurred for the purchase of certain equipment	$ 81	$ 0