| In millions, except per share items | Jun-30-23 | Mar-31-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 |
| | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q |
| Operating Activities: | | | | | | | | |
| Net income/(loss) | -3.4 | -1.8 | 0.0 | -12.1 | -6.8 | -6.1 | 0.0 | -8.4 |
| Adjustments to reconcile net income (loss) to cash used in operating activities: | | | | | | | | |
| Depreciation and amortization | 0.1 | 0.1 | | 0.1 | 0.0 | 0.0 | | 0.1 |
| Share-based compensation | 5.8 | 5.2 | | 3.8 | | | | |
| Accretion of debt discount | 1.8 | 1.2 | | 2.3 | 2.2 | 2.4 | | 0.9 |
| Loss on equity method investment | 0.0 | | | 0.0 | | 0.0 | | |
| Changes in operating assets and liabilities: | | | | | | | | |
| Accounts receivable | 0.8 | 0.4 | 0.0 | -0.1 | -0.8 | -0.5 | | 0.0 |
| Inventories | -0.1 | 0.1 | 0.0 | 0.0 | 0.0 | 0.1 | 0.0 | -0.1 |
| Prepaid expenses and other current assets | 1.3 | -0.1 | 0.7 | -0.2 | 0.3 | 0.1 | 0.3 | -0.5 |
| Accounts payable | 0.4 | 0.1 | | 0.2 | 0.3 | 0.1 | 0.0 | 0.0 |
| Related party payable | -0.1 | -0.1 | 0.0 | 0.1 | 0.1 | | 0.0 | -0.3 |
| Accrued interest | 0.1 | 0.2 | | 0.0 | 0.0 | 0.1 | | 0.3 |
| Accrued expenses | 0.1 | 0.6 | | 1.4 | 0.8 | 0.7 | 0.0 | -0.1 |
| Net cash used in operating activities | -11.7 | -12.7 | -10.5 | -11.1 | -10.6 | -10.2 | -9.4 | -7.6 |
| |
| Investing Activities: | | | | | | | | |
| Contributions to equity method investment | | | 0.1 | | | -0.1 | | |
| Payments on purchase of assets | -3.8 | 0.0 | 0.0 | 0.1 | 0.0 | -0.1 | 0.0 | -0.2 |
| Net cash used in investing activities | -4.0 | -0.2 | -0.3 | -0.3 | -0.4 | -0.4 | -0.3 | -0.2 |
| |
| Financing Activities: | | | | | | | | |
| Proceeds from issuance of Series 1B Preferred Stock | 0.9 | | | | | | | |
| Payment of convertible notes | -1.0 | -0.1 | | | | | | |
| Net cash used in financing activities | 16.1 | 16.1 | 16.3 | 10.0 | | | 15.5 | 11.0 |
| |
| Non-Cash Transactions: | | | | | | | | |
| Purchase of equipment not yet paid at end of period | | | 0.2 | 0.2 | 0.2 | | | |
| Supplemental disclosure of cash flow information: | | | | | | | | |
| Interest | 0.2 | | | | | | | |