| In millions, except per share items | Jun-30-23 | Mar-31-23 | Dec-31-22 | Sep-30-22 | Sep-05-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 |
| | 10-Q | 10-Q | 10-K | 10-Q | 8-K | 10-Q | 10-Q | 10-K |
| ASSETS | | | | | | | | |
| Current assets | | | | | | | | |
| Cash and cash equivalents | 2.7 | 5.2 | 3.5 | 6.3 | 6.3 | 9.0 | 10.8 | 13.0 |
| Accounts receivable, net | 0.0 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
| Inventory, net | 1.0 | 0.9 | | 0.8 | 0.8 | 0.8 | 0.4 | |
| Deferred offering costs | 0.1 | 0.0 | | 0.1 | | | | |
| Prepaid expenses and other current assets | 0.3 | 0.3 | | 0.3 | 0.3 | 0.4 | 0.6 | |
| Total current assets | 4.0 | 6.5 | 5.3 | 7.6 | 7.6 | 10.4 | 12.0 | 14.3 |
| Property and equipment, net | 0.1 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Right-of-use assets, operating lease | 0.4 | 0.5 | | 0.6 | | 0.6 | 0.6 | |
| Other assets | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Total assets | 4.6 | 7.1 | 5.9 | 8.2 | 8.2 | 11.0 | 12.7 | 15.0 |
| |
| LIABILITIES AND STOCKHOLDERS' EQUITY | | | | | | | | |
| Current liabilities | | | | | | | | |
| Accounts payable | 0.8 | 1.1 | 1.3 | 1.6 | 1.6 | 1.9 | 0.6 | 0.8 |
| Other accrued expenses | 0.1 | 0.3 | | 0.3 | 0.3 | 0.3 | 0.3 | |
| Operating lease liability, current | 0.2 | 0.2 | | 0.2 | | 0.2 | 0.2 | |
| Total current liabilities | 1.2 | 1.6 | 1.9 | 2.0 | 2.0 | 2.4 | 1.1 | 1.2 |
| Operating lease liability | 0.3 | 0.3 | | 0.4 | | 0.5 | 0.5 | |
| Total liabilities | 1.4 | 1.9 | 2.2 | 2.4 | 2.4 | 2.8 | 1.6 | 1.8 |
| |
| Commitments and contingencies (See Note 5) | | | | | | | | |
| Stockholders' equity | | | | | | | | |
| Common stock | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Additional paid in capital | 37.0 | 37.0 | 33.3 | 33.2 | 33.2 | 33.0 | 32.9 | 32.8 |
| Accumulated deficit | -33.9 | -31.8 | -29.6 | -27.4 | -27.4 | -24.8 | -21.8 | -19.5 |
| Total stockholders' equity | 3.2 | 5.2 | 3.6 | 5.8 | 5.8 | 8.2 | 11.1 | 13.3 |
| Total liabilities and stockholders' equity | 4.6 | 7.1 | 5.9 | 8.2 | 8.2 | 11.0 | 12.7 | 15.0 |