CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (3,455)	$ (2,488)
Adjustments to reconcile net loss to net cash used in operating activities:
Gain on investments held to maturity	(9)	0
Amortization of discounts on investments held to maturity	5	0
Depreciation and amortization	59	46
Stock-based compensation	1,061	1,131
Non-cash charge for settlement of dispute	0	300
Amortization of debt discount	0	20
(Gain) Loss on remeasurement of common stock warrant liability	(9)	2
Loss on extinguishment of unsecured promissory note	0	9
(Increase) decrease in current assets:
Accounts receivable	4	13
Prepaid expenses	90	0
Inventory	(54)	0
Deposits	(196)	0
Increase (decrease) in current liabilities:
Accounts payable	(166)	108
Accrued contract cancellation settlement	(1,000)	0
Accrued expenses	291	38
Deferred rent	5	0
Deferred revenues	0	(46)
Net cash used in operating activities	(3,374)	(867)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of securities held to maturity	(2,957)	0
Purchase of property and equipment	(130)	(7)
Net cash used in investing activities	(3,087)	(7)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds received on unissued shares of common stock	0	50
Proceeds from the issuance of series B convertible preferred stock	0	671
Proceeds from the issuance of notes payable	21	326
Repayments of notes payable	(6)	(2)
Repayments of notes payable, related parties	(10)	(35)
Repayments of capital lease obligations	(7)	(5)
Payment of deferred offering costs	0	(216)
Proceeds from exercise of stock options and warrants	0	195
Net cash (used in) provided by financing activities	(2)	984
NET CHANGE IN CASH	(6,463)	110
CASH AT BEGINNING OF PERIOD	11,826	141
CASH AT END OF PERIOD	5,363	251
SUPPLEMENTAL INFORMATION:
Interest paid	14	16
Income taxes paid	0	0
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Issuance of series B convertible preferred stock in connection with conversion of convertible notes and notes payable	0	16
Issuance of shares of common stock upon conversion of Series B convertible preferred stock	0	260
Debt discount on convertible notes	0	9
Original issue discount	$ 0	$ 179