UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2018	Apr. 02, 2017
Cash flows from operating activities:
Net loss	$ (3,970)	$ (3,565)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	339	355
Stock-based compensation	432	318
Write-down of inventories	42	104
Write-off of equipment	5	0
Changes in operating assets and liabilities:
Accounts receivable	(329)	(968)
Inventories	(33)	(948)
Other assets	(609)	183
Trade payables	(6)	267
Accrued liabilities	324	75
Deferred revenue	0	317
Other long-term liabilities	51	(4)
Net cash used in operating activities	(3,754)	(3,866)
Cash flows from investing activities:
Capital expenditures for property and equipment	(48)	(15)
Net cash used in investing activities	(48)	(15)
Cash flows from financing activities:
Payment of capital lease obligations	(123)	(122)
Proceeds from line of credit	6,000	0
Payment of line of credit	(6,000)	0
Proceeds from issuance of common stock	0	17,069
Stock issuance costs	0	(1,242)
Taxes for net issuance of stock awards	(41)	(20)
Net cash (used in) provided by financing activities	(164)	15,685
Net (decrease) increase in cash and cash equivalents	(3,966)	11,804
Cash and cash equivalents at beginning of period	16,527	14,870
Cash and cash equivalents at end of period	12,561	26,674
Supplemental schedule of non-cash investing and financing activities :
Capital lease obligation to finance capital expenditures	531	213
Purchase of equipment included in accounts payable	$ 38	$ 15