| In millions, except per share items | Jun-30-23 | Mar-31-23 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 |
| | 10-K | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K |
| Revenue | | | 0.7 | 0.9 | 0.9 | 0.8 | 0.4 | 0.3 |
| Revenue growth | | | 89.0% | 160.2% | 75.2% | 47.1% | -39.2% | -31.6% |
| Cost of revenue | | | 0.5 | 0.7 | 0.7 | 0.7 | 0.4 | 0.3 |
| Gross profit | | | 0.2 | 0.2 | 0.2 | 0.1 | 0.0 | 0.0 |
| Gross margin | | | 25.8% | 22.1% | 21.3% | 17.1% | 5.5% | 10.8% |
| |
| Operating expenses: | | | | | | | | |
| Selling, general and administrative | | | 6.2 | 6.0 | 6.0 | 6.2 | 5.2 | 4.7 |
| Research and development | | | 3.3 | 2.8 | 2.7 | 2.6 | 2.7 | 2.7 |
| Total operating expenses | | | 9.5 | 8.8 | 8.6 | 8.8 | 7.9 | 7.9 |
| Loss from operations | | | -9.3 | -8.6 | -8.4 | -8.6 | -7.9 | -7.9 |
| Operating margin | | | -1292.6% | -989.1% | -984.7% | -1060.6% | -2076.4% | -2368.3% |
| Other income and expense, net | | | 0.0 | 0.2 | 0.5 | 0.4 | 0.3 | 0.2 |
| Loss from operations before income taxes | | | -8.8 | -8.3 | -7.8 | -8.1 | -7.5 | -7.6 |
| Net loss | | | -8.8 | -8.3 | -7.8 | -8.1 | -7.5 | -7.6 |
| |
| Weighted average common shares outstanding: | | | | | | | | |
| Basic and diluted (in shares) | | | 24.8 | 24.5 | 29.6 | 33.8 | 25.9 | 15.9 |
| |
| Basic and diluted net loss per common share: | | | | | | | | |
| Net loss per common share (in dollars per share) | | | ($2.68) | ($2.67) | ($1.34) | ($0.15) | ($0.20) | ($0.43) |
| |
| Other comprehensive loss, net of tax: | | | | | | | | |
| Net loss | | | -8.8 | -8.3 | -7.8 | -8.1 | -7.5 | -7.6 |
| |
| Available-for-sale securities: | | | | | | | | |
| Total comprehensive loss | | | -10.3 | -9.5 | -8.6 | -8.3 | -7.6 | -7.6 |