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 |