CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 6,921	$ 6,053
Short-term investments		300
Accounts receivable	790	1,175
Inventories	713	968
Prepaid expenses and other	359	472
Total current assets	8,783	8,968
Property and equipment, net	86	197
Right-of-use lease asset, net	352	156
Other	17	78
Total assets	9,238	9,399
Current liabilities
Accounts payable	80	218
Deferred revenue		166
Short-term lease liability	201	166
PPP note payable, current	171
Accrued expenses and other	1,233	1,155
Total current liabilities	1,685	1,705
Convertible notes payable	3,092	2,858
PPP note payable	408
Long-term lease liability	152
Total liabilities	5,337	4,563
Commitments and contingencies (Note 4)
Stockholders’ equity
Preferred stock, $0.01 par value; 20,000 shares authorized; none issued and outstanding
Common stock, $0.001 par value; 120,000 shares authorized; 3,553 shares and 2,179 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively	3	2
Additional paid-in capital	245,488	243,281
Accumulated deficit	(241,590)	(238,447)
Total stockholders’ equity	3,901	4,836
Total liabilities and stockholders’ equity	$ 9,238	$ 9,399