Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
ASSETS
Cash and cash equivalents	$ 5,708	$ 6,937
Accounts receivable, net of allowance for doubtful accounts ($50 and $51 at March 31, 2020 and December 31, 2019, respectively)	952	1,066
Inventory, net of allowance for excess and obsolete inventory and lower of cost or estimated net realizable value adjustments ($230 and $247 at March 31, 2020 and December 31, 2019, respectively)	552	492
Prepaid expenses and other current assets	662	886
Total current assets	7,874	9,381
Operating lease right-of-use assets	1,028	1,252
Property and equipment, net	97	110
Other assets	476	477
TOTAL ASSETS	9,475	11,220
LIABILITIES AND STOCKHOLDERS' (DEFICIT) EQUITY
Accounts payable	602	331
Accrued liabilities	1,326	1,778
Deferred revenue	559
Operating lease liability	774	930
Notes payable, related party	1,250	1,202
Convertible note	954	1,409
Embedded derivative liability	1	3
Warrant liability	17	34
Total current liabilities	5,483	5,687
Operating lease liabilities-non-current	406	505
Warrant liability	3,935	4,055
Total liabilities	9,824	10,247
Stockholders' (deficit) equity:
Preferred stock: 5,000 shares authorized; none issued and outstanding at March 31, 2020 and December 31, 2019
Common stock, $0.01 par value; 50,000 shares authorized; 28,239 and 27,938 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively	282	279
Additional paid-in capital	125,975	125,718
Accumulated deficit	(126,606)	(125,024)
Total stockholders' (deficit) equity	(349)	973
TOTAL LIABILITIES AND STOCKHOLDERS' (DEFICIT) EQUITY	$ 9,475	$ 11,220