Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating activities:
Net loss	$ (11,571)	$ (11,907)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	84	82
Reduction in the carrying amount of right-of-use assets	327	295
Share-based compensation	1,030	1,183
Loss on disposal of property and equipment	(4)	(0)
Changes in operating assets and liabilities:
Accounts receivable	(138)	54
Prepaid expenses and other current assets	(5)	(163)
Accounts payable	184	4
Accrued expenses and other current liabilities	482	416
Deferred revenue	(341)	(506)
Operating lease liability	(316)	(237)
Net cash used in operating activities	(9,974)	(10,561)
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of property and equipment	(12)	(70)
Net cash used in investing activities	(12)	(70)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from sales of common stock	4,388	5,540
Issuance costs of sale of common stock	662	418
Net cash provided by financing activities	3,726	5,122
Net change in cash and cash equivalents	(6,260)	(5,509)
Cash and cash equivalents at beginning of year	7,363	12,872
Cash and cash equivalents at end of year	1,103	7,363
Supplemental disclosure of noncash investing and financing activities:
Unpaid issuance costs of common stock	195	172
Issuance of restricted stock units in lieu of cash bonus obligations	$ 564	$ 401