| In millions, except per share items | Jun-30-17 | Jun-30-16 | Jun-30-15 | Jun-30-14 | Jun-30-13 | Jun-30-12 | Jun-30-11 | Jun-30-10 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Current assets: | | | | | | | | |
| Cash and cash equivalents | 6.0 | 3.6 | 8.3 | 25.6 | 6.4 | 8.5 | 7.8 | |
| Accounts receivable | 0.6 | 0.3 | 0.4 | 0.7 | 0.4 | 0.3 | 0.3 | |
| Inventories | 1.3 | 1.1 | 1.4 | 1.1 | 1.5 | 0.6 | 0.8 | |
| Prepaid expenses and other current assets | 0.2 | 0.3 | 0.3 | 0.3 | | 0.2 | 0.2 | |
| Total current assets | 8.1 | 14.4 | 23.4 | 42.6 | 14.5 | 15.7 | 10.7 | |
| Property and equipment, net | 0.7 | 1.2 | 1.9 | 2.5 | 3.2 | 2.3 | 0.7 | |
| Restricted cash | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | | | |
| Total assets | 8.9 | 15.7 | 29.3 | 47.6 | 17.8 | 18.1 | 11.5 | |
| |
| Current liabilities: | | | | | | | | |
| Accounts payable | 0.9 | 0.8 | 0.7 | 0.8 | 0.8 | 0.9 | 0.6 | |
| Accrued compensation | 0.5 | 0.7 | 0.4 | 0.9 | 0.6 | 0.4 | 0.5 | |
| Other accrued liabilities | 0.7 | 0.5 | 0.5 | 0.4 | 0.4 | 0.4 | 0.3 | |
| Current portion of deferred revenue | 0.6 | 0.6 | 0.4 | 0.4 | 0.4 | 0.7 | 0.7 | |
| Warrant liabilities | 8.6 | | | | | | | |
| Total current liabilities | 11.4 | 2.6 | 2.1 | 2.7 | 2.2 | 2.4 | 2.2 | |
| Deferred revenue, net of current portion | 2.3 | 2.5 | 2.1 | 1.6 | 1.6 | 1.7 | 0.4 | |
| Note payable, net of current portion | 3.5 | 3.1 | 2.8 | 3.1 | 2.8 | 2.5 | | |
| Other non-current liabilities | 0.1 | 0.2 | 0.2 | 0.0 | 0.2 | 0.2 | 0.1 | |
| Total liabilities | 17.3 | 8.4 | 7.2 | 7.4 | 6.8 | 6.8 | 2.6 | |
| |
| Commitments and contingencies (Note 8) | | | | | | | | |
| Redeemable convertible preferred stock Series B: 172 and 273 shares issued and outstanding at September 30, 2017 and June 30, 2017, respectively | | | | | | | | |
| Stockholders' deficit: | | | | | | | | |
| Preferred stock, $0.001 par value: 5,000,000 shares authorized; 250,000 shares designated as Series A; 8,000 shares designated as Series B; Convertible preferred stock Series A: 0 shares issued and outstanding at September 30, 2017 and June 30, 2017 | | | | | | | | |
| Common stock | 0.0 | 0.0 | 0.0 | 0.1 | 0.1 | 0.0 | 0.0 | |
| Additional paid-in capital | 215.0 | 196.4 | 195.2 | 194.0 | 165.1 | 149.3 | 133.3 | |
| Treasury stock at cost (6,622 shares at September 30, 2017 and June 30, 2017) | -0.6 | -0.6 | -0.6 | -0.6 | -0.6 | -0.6 | -0.6 | |
| |
| Accumulated other comprehensive loss | | | | | | | | |
| Accumulated deficit | -222.9 | -205.7 | -189.7 | -170.5 | -153.6 | -137.4 | -123.8 | |
| Total stockholders' deficit | -8.4 | 7.3 | 22.1 | 40.2 | 11.0 | 11.4 | 8.9 | |
| Total liabilities, redeemable convertible preferred stock and stockholders' deficit | 8.9 | 15.7 | 29.3 | 47.6 | 17.8 | 18.1 | 11.5 | |