Note 2 - Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2022

Notes Tables

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	December 31,
	2022		2021
Total potentially dilutive common shares as of:
Stock options to purchase common stock (Note 13)		6,301,500		6,301,500
Series C Convertible Preferred Stock and related accrued dividends (Note 9)		524,736		524,736
Series D Convertible Preferred Stock (Note 10)		3,628,576		3,628,576
Total potentially dilutive common shares		10,454,812		10,454,812

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

	December 31,
	2022			2021
Customer A		21	%		22	%
Customer B		14	%		19	%
Customer C		14	%		13	%
Customer D		15	%		11	%

	December 31,
	2022			2021
Supplier A		53	%		29	%
Supplier B		13	%		16	%
Supplier C		12	%		19	%
Supplier D		11	%		*
Supplier E		*			10	%