CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2017	Jan. 03, 2016
Cash flows from operating activities:
Net loss	$ (14,131)	$ (19,148)	$ (17,848)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,373	1,332	1,409
Stock-based compensation	1,441	1,584	2,028
Write-down of inventories	232	296	229
Write-off of equipment	12	368	8
Changes in operating assets and liabilities:
Accounts receivable	(86)	762	(49)
Inventories	(1,774)	565	1,845
Other assets	103	305	300
Trade payables	(145)	(1,337)	260
Accrued liabilities	72	124	(94)
Deferred income	0	(26)	26
Other long-term liabilities	(35)	(84)	57
Net cash used in operating activities	(12,938)	(15,259)	(11,829)
Cash flows from investing activities:
Capital expenditures for property and equipment	(642)	(1,954)	(346)
Net cash used in investing activities	(642)	(1,954)	(346)
Cash flows from financing activities:
Payment of capital software lease obligations	(344)	(280)	(293)
Proceeds from line of credit	18,000	4,000	1,000
Repayment of line of credit	(18,000)	0	0
Proceeds from issuance of common stock	17,550	10,603	692
Stock issuance costs	(1,771)	(1,197)	0
Taxes paid related to net settlement of equity awards	(198)	(179)	(138)
Net cash provided by financing activities	15,237	12,947	1,261
Net increase (decrease) in cash and cash equivalents	1,657	(4,266)	(10,914)
Cash and cash equivalents at beginning of period	14,870	19,136	30,050
Cash and cash equivalents at end of period	16,527	14,870	19,136
Supplemental disclosures of cash flow information:
Interest paid	106	183	77
Income taxes paid	157	128	121
Supplemental schedule of non-cash investing and financing activities :
Capital software lease obligation to finance capital expenditures	654	209	489
Purchase of equipment included in accounts payable	$ 436	$ 0	$ 977