Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 3,359	$ 3,526
Accounts receivable, net	3,186	4,528
Unbilled accounts receivable	224	406
Inventories	8,582	8,640
Prepaid expenses and other current assets	875	1,328
Total current assets	16,226	18,428
Equipment, furniture and leasehold improvements, net	8,921	8,553
Intangibles and other assets	269	326
Total assets	25,416	27,307
Current liabilities:
Accounts payable	2,024	1,714
Accrued compensation	1,634	1,557
Revolving credit facility, net		3,808
Common stock warrant liability	1,497	784
Other accrued expenses	1,827	719
Deferred revenue	38	765
Other current liabilities	427	469
Total current liabilities	7,447	9,816
Commitments and contingencies (Note 9)
Shareholders' equity:
Preferred stock, $.001 par value: authorized 10,000,000 shares: Series B Convertible Preferred stock, (liquidation preference of $5,659) stated value $1,000 per share, $.001 par value: 10,000 shares designated and 5,659 issued and outstanding as of December 31, 2018 and 2017
Common stock, $.001 par value: authorized 200,000,000 shares, issued 45,323,339 shares, outstanding 45,161,273 shares as of December 31, 2018 and issued 35,182,589 shares, outstanding 35,020,523 shares as of December 31, 2017	45	35
Additional paid-in capital	254,736	244,726
Accumulated deficit	(236,312)	(226,770)
Treasury stock, 162,066 shares as of December 31, 2018 and December 31, 2017	(500)	(500)
Total shareholders' equity	17,969	17,491
Total liabilities and shareholders' equity	$ 25,416	$ 27,307