Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 21,759	$ 20,994
Accounts receivable, net	4,505	6,573
Inventories	5,694	5,621
Prepaid expenses and other current assets	1,498	1,539
Total current assets	33,456	34,727
Property and equipment, net	13,834	13,366
Intangible assets, net	908	969
Goodwill	8,444	8,342
Other assets	167	167
Total assets	56,809	57,571
Liabilities, contingently redeemable preferred stock, and stockholders’ equity
Accounts payable	2,706	3,893
Accrued expenses and other	4,306	5,271
Deferred revenue	6,443	5,624
Current portion of long-term debt	508	204
Total current liabilities	13,963	14,992
Long-term debt, net of current portion	3,359	2,203
Other noncurrent liabilities	45	56
Total liabilities	17,367	17,251
Commitments and contingencies
Contingently redeemable series C preferred stock, 0.55 shares issued and outstanding (liquidation preference of $550)	550	550
Stockholders’ equity:
Preferred stock, $0.01 par value; 1,000 shares authorized Series B convertible preferred stock, 0.13 shares issued and outstanding (liquidation preference of $13)
Common stock $0.01 par value; 150,000 shares authorized; 12,257 issued and 10,844 outstanding at March 31, 2017 and December 31, 2016	123	123
Additional paid-in capital	290,971	290,636
Treasury stock (at cost), 1,413 shares at March 31, 2017 and December 31, 2016	(8,601)	(8,601)
Accumulated deficit	(238,801)	(237,360)
Accumulated other comprehensive loss	(4,800)	(5,028)
Total stockholders’ equity	38,892	39,770
Total liabilities, contingently redeemable preferred stock, and stockholders’ equity	$ 56,809	$ 57,571