Note 4 - Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2023

Notes Tables

Property, Plant and Equipment [Table Text Block]

	December 31,
	2023			2022
Leasehold improvements	$	2,519		$	2,519
Laboratory equipment		1,247			1,118
Furniture, fixtures and equipment		966			966
Software		272			289
Construction in progress		—			22
		5,004			4,914
Less: Accumulated depreciation and amortization		(3,476	)		(2,953	)
	$	1,528		$	1,961

Schedule of Finite-Lived Intangible Assets [Table Text Block]

	December 31,
	2023			2022
Acquired patents and licenses	$	7,985		$	7,985
Less: Accumulated amortization		(6,099	)		(5,434	)
	$	1,886		$	2,551

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

Years ending December 31:
2024	$	665
2025		665
2026		556
	$	1,886

Schedule of Accrued Liabilities [Table Text Block]

	December 31,
	2023		2022
Compensation expense	$	3,199	$	1,377
Director and officer liability insurance (Note 12)		—		571
Clinical trial fees and costs		84		64
Professional fees		343		318
Warranty		—		50
Other		188		215
	$	3,814	$	2,595