Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 4,820	$ 12,689
Accounts receivable, net of allowance for doubtful accounts of $6 and $6 at September 30, 2018 and December 31, 2017, respectively	170	95
Inventory	134	191
Prepaid expenses	224	340
Total current assets	5,348	13,315
Property and equipment, net	154	169
Other assets	54	54
Total assets	5,556	13,538
Current liabilities:
Accounts payable	1,102	902
Accrued expenses and other current liabilities	1,430	1,263
Deferred revenue		167
Total current liabilities	2,532	2,332
Deferred rent	80	81
Total liabilities	2,612	2,413
Stockholders’ equity:
Preferred stock, $0.001 par value, 25,000,000 shares authorized; no shares issued and outstanding as of September 30, 2018 and December 31, 2017
Common stock, $0.001 par value, 100,000,000 shares authorized as of September 30, 2018 and December 31, 2017 respectively; 38,277,908 and 38,218,660 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively	38	38
Additional paid-in capital	85,625	83,537
Accumulated deficit	(82,719)	(72,450)
Total stockholders’ equity	2,944	11,125
Total liabilities and stockholders’ equity	$ 5,556	$ 13,538