Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 2,838,000	$ 5,358,000
Accounts receivable, net of allowance for doubtful accounts of $14 and $9 at March 31, 2019 and December 31, 2018	287,000	274,000
Inventory	118,000	141,000
Prepaid expenses and other current assets	285,000	445,000
Total current assets	3,528,000	6,218,000
Property and equipment, net	175,000	145,000
Operating lease right-of-use asset, net	1,400,000
Other assets	54,000	54,000
Total assets	5,157,000	6,417,000
Current liabilities:
Accounts payable	1,139,000	1,020,000
Accrued expenses and other current liabilities	1,715,000	1,528,000
Operating lease liability - current	469,000
Total current liabilities	3,323,000	2,548,000
Operating lease liability - noncurrent	1,016,000
Deferred rent		77,000
Total liabilities	4,339,000	2,625,000
Stockholders’ equity:
Preferred stock, $0.001 par value, 25,000,000 shares authorized as of March 31, 2019 and December 31, 2018; no shares issued and outstanding as of March 31, 2019 and December 31, 2018
Common stock, $0.001 par value, 100,000,000 shares authorized as of March 31, 2019 and December 31, 2018; 43,631,684 and 43,611,240 shares issued and outstanding as of March 31, 2019 and December 31, 2018	44,000	43,000
Additional paid-in capital	90,800,000	90,110,000
Accumulated deficit	(90,026,000)	(86,361,000)
Total stockholders’ equity	818,000	3,792,000
Total liabilities and stockholders’ equity	$ 5,157,000	$ 6,417,000