Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 6,667	$ 12,872
Accounts receivable, net of allowance for doubtful accounts of $13 and $22 as of September 30, 2022 and December 31, 2021	300	147
Prepaid expenses and other current assets	187	462
Total current assets	7,154	13,481
Property and equipment, net	189	182
Operating lease right-of-use asset, net	1,664	1,883
Other assets	172	172
Total assets	9,179	15,718
Current liabilities:
Accounts payable	887	507
Accrued expenses and other current liabilities	2,115	2,121
Deferred revenue	378	847
Operating lease liability - current	304	237
Total current liabilities	3,684	3,712
Operating lease liability - noncurrent	1,398	1,631
Total liabilities	5,082	5,343
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value, 25,000,000 shares authorized and no shares issued and outstanding as of September 30, 2022 and December 31, 2021	0	0
Common stock, $0.001 par value, 100,000,000 shares authorized, 17,841,927 and 16,871,265 shares issued and outstanding as of September 30, 2022 and December 31, 2021, respectively	18	17
Additional paid-in capital	141,655	139,055
Accumulated deficit	(137,576)	(128,697)
Total stockholders’ equity	4,097	10,375
Total liabilities and stockholders’ equity	$ 9,179	$ 15,718