Note 4 - Equity (Tables)

6 Months Ended

Jun. 30, 2023

Notes Tables

Share-based Payment Arrangement, Expensed, Amount [Table Text Block]

	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
General and administrative	$	379	$	350	$	748	$	711
Research and development		134		164		264		330
Total stock-based compensation expense	$	513	$	514	$	1,012	$	1,041