Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 15,109	$ 21,352
Accounts receivable, net of allowance for doubtful accounts of $1 and $2 at June 30, 2017 and December 31, 2016, respectively	142	74
Inventory	193	135
Short-term investments	1,796
Prepaid expenses	282	356
Total current assets	17,522	21,917
Property and equipment, net	180	111
Other assets	54	54
Total assets	17,756	22,082
Current liabilities:
Accounts payable	590	525
Accrued expenses and other current liabilities	864	848
Deferred revenue	153	71
Total current liabilities	1,607	1,444
Deferred rent	68	56
Total liabilities	1,675	1,500
Stockholders’ equity:
Preferred stock, $0.001 par value, 50,000,000 shares authorized, no shares issued and outstanding at June 30, 2017 and December 31, 2016
Common stock, $0.001 par value, 750,000,000 shares authorized at June 30, 2017 and December 31, 2016, 457,682,784 shares and 457,575,631 shares issued and outstanding at June 30, 2017 and December 31, 2016, respectively	458	458
Additional paid-in capital	81,586	80,266
Accumulated deficit	(65,963)	(60,142)
Total stockholders’ equity	16,081	20,582
Total liabilities and stockholders’ equity	$ 17,756	$ 22,082