| In millions, except per share items | Jun-30-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 |
| | 10-Q | 8-K | 10-Q | 10-Q | 10-Q | 10-K/A | 10-Q | 10-Q |
| Net sales | | 24.2 | 23.3 | 22.8 | 24.8 | 25.8 | 24.4 | 23.6 |
| Net sales growth | | -6.3% | -4.6% | -3.4% | 15.0% | 27.1% | 14.9% | 23.6% |
| Cost of goods sold | | | 10.7 | 10.2 | 11.1 | 11.1 | 10.8 | 10.9 |
| Gross margin | | 13.2 | 12.6 | 12.6 | 13.7 | 14.7 | 13.6 | 12.8 |
| Gross margin | | 54.5% | 54.2% | 55.2% | 55.2% | 57.0% | 55.6% | 54.0% |
| |
| Operating expenses: | | | | | | | | |
| Research and development | | 6.1 | 4.6 | 4.9 | 5.0 | | 5.0 | 4.8 |
| Selling, general and administrative | | 7.9 | 5.9 | 6.2 | 6.3 | | 6.3 | 5.9 |
| Total operating expenses | | 14.0 | 14.2 | 14.7 | 15.0 | 15.0 | 15.2 | 14.6 |
| Operating income (loss) | | -0.7 | -1.9 | -2.5 | -1.6 | -0.6 | -2.6 | -2.8 |
| Operating margin | | -3.1% | -8.2% | -10.9% | -6.6% | -2.4% | -10.5% | -11.9% |
| |
| Non-operating income (loss): | | | | | | | | |
| Interest income | | 0.0 | 0.0 | 0.0 | 0.0 | | 0.0 | |
| Gain on sale of assets | | | | | 0.1 | | | |
| Foreign currency transaction gain (loss) | | 0.2 | 0.4 | 0.1 | -0.1 | 0.0 | 0.2 | 0.0 |
| Total non-operating income (loss) | | 0.4 | 0.3 | 0.0 | -0.2 | -0.1 | 0.0 | -0.5 |
| Income (loss) before income taxes | | | | -2.3 | -1.7 | -0.6 | | |
| Income tax (expense) benefit | | -0.7 | -0.6 | -0.5 | -0.4 | 0.0 | 0.0 | -0.2 |
| Net income (loss) | | -1.1 | -1.8 | -2.7 | -2.0 | -0.6 | -2.0 | -2.7 |
| |
| Basic earnings (loss) per share | | ($0.13) | ($0.21) | ($0.31) | ($0.23) | ($0.06) | | |
| Diluted earnings (loss) per share | | ($0.13) | ($0.21) | ($0.31) | ($0.23) | ($0.06) | | |
| |
| Weighted-average basic shares | | 6.6 | 6.5 | 6.4 | 8.6 | 8.5 | 8.5 | 8.4 |
| Weighted-average diluted shares | | 6.6 | 6.5 | 6.5 | 8.6 | 8.6 | 8.5 | 8.4 |