Note 4 - Balance Sheet Details - Summary of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Disclosure Text Block [Abstract]
Prepaid insurance	$ 807	$ 540
Other receivables	20	150
Prepaid subscriptions and fees	205	215
Prepaid software licenses	54	78
Deferred equity issuance costs	81	0
Prepaid other	6	28
Prepaid expenses and other current assets	$ 1,173	$ 1,011