Note 5 - Equity (Tables)

9 Months Ended

Sep. 30, 2023

Notes Tables

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

	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
General and administrative	$	346	$	378	$	1,094	$	1,089
Research and development		147		321		411		651
Total stock-based compensation expense	$	493	$	699	$	1,505	$	1,740