Note 15 - Common Stock Reserved for Issuance - Common Stock Reserved for Issuance (Details) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Outstanding stock options and RSUs (in dollars per share)	$ 13,130,144	$ 5,977,179
Shares reserved for future option grants and RSUs (in shares)	376,201	589,064
Total common stock reserved for issuance (in shares)	95,674,634	40,931,857
Lincoln Park [Member]
Total common stock reserved for issuance (in shares)	15,814,471	5,222,867
Madryn Noteholders [Member]
Total common stock reserved for issuance (in shares)	8,215,706	8,213,880
Non-Voting Preferred Stock [Member]
Shares reserved for conversion of future preferred share issuance (in shares)	1,209,245	1,209,245
Voting Preferred Stock [Member]
Shares reserved for conversion of future preferred share issuance (in shares)	9,150,000	0
Common Stock [Member]
Outstanding common stock warrants (in shares)	15,928,867	15,928,867
Preferred Stock [Member]
Preferred shares (in shares)	31,850,000	3,790,755