BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 1,779	$ 1,275
Trade accounts receivable, less allowance for doubtful accounts of $5 and $6 on December 31, 2016 and 2015, respectively	434	507
Inventories, net	772	662
Prepaid expenses and other current assets	442	247
Total current assets	3,427	2,691
Equipment and leasehold improvements, net	1,395	1,861
Other assets, net	20	22
Total assets	4,842	4,574
Current liabilities:
Current portion of capital lease obligations	107	94
Accounts payable	669	508
Accrued expenses	521	276
Total current liabilities	1,297	878
Long-term portion of capital lease obligations	110	144
Long-term deferred rent	466	519
Asset retirement obligations	178	172
Total long-term liabilities	754	835
Contingent liabilities
Stockholders' equity:
Preferred stock, $.01 par value, 24,088 shares authorized and no shares issued and outstanding
Common stock, $.01 par value, 42,000,000 and 35,000,000 shares authorized; 31,229,996 and 28,585,496 shares issued and outstanding on December 31, 2016 and December 31, 2015, respectively	312	286
Additional paid-in capital	97,359	96,172
Accumulated deficit	(94,880)	(93,597)
Total stockholders' equity	2,791	2,861
Total liabilities and stockholders' equity	$ 4,842	$ 4,574