Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 3,515	$ 3,359
Accounts receivable, net	3,966	3,186
Unbilled accounts receivable	155	224
Inventories	8,832	8,582
Prepaid expenses and other current assets	1,130	875
Total current assets	17,598	16,226
Equipment, furniture and leasehold improvements, net	8,100	8,921
Operating lease right-of-use assets	3,729
Intangibles and other assets	160	269
Total assets	29,587	25,416
Current liabilities:
Accounts payable	1,302	2,024
Accrued compensation	1,778	1,634
Revolving credit facility, net	2,891
Common stock warrant liability	23	1,497
Other accrued expenses	1,401	1,827
Deferred revenue	277	38
Operating lease liability - current	775
Other current liabilities	342	427
Total current liabilities	8,789	7,447
Finance lease liability-long term	24
Operating lease liability-long term	3,067
Total liabilities	11,880	7,447
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, 2019 and 2018.
Common stock, $.001 par value: authorized 200,000,000 shares, issued 50,250,378 shares, outstanding 50,088,312 shares as of December 31, 2019 and issued 45,323,339 shares, outstanding 45,161,273 shares as of December 31, 2018.	50	45
Additional paid-in capital	258,767	254,736
Accumulated deficit	(240,610)	(236,312)
Treasury stock, 162,066 shares as of December 31, 2019 and 2018	(500)	(500)
Total shareholders' equity	17,707	17,969
Total liabilities and shareholders' equity	$ 29,587	$ 25,416