CONDENSED UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jul. 03, 2016	Jun. 28, 2015
Cash flows from operating activities:
Net loss	$ (10,667)	$ (7,916)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	631	727
Shares issued to third parties for services provided	78	0
Stock-based compensation	923	988
Write-down of inventories	235	13
Write-off of equipment	312	0
Changes in operating assets and liabilities:
Accounts receivable	116	(45)
Inventories	325	1,938
Other assets	357	409
Trade payables	(1,816)	(533)
Accrued liabilities and deferred revenue	(43)	617
Other long-term liabilities	(13)	79
Net cash used in operating activities	(9,562)	(3,723)
Cash flows from investing activities:
Capital expenditures for property and equipment	(1,513)	(163)
Net cash used in investing activities	(1,513)	(163)
Cash flows from financing activities:
Payment of debt and capital lease obligations	(238)	(158)
Proceeds from line of credit	2,000	0
Proceeds from issuance of common stock	10,344	409
Stock issuance costs	(1,197)	0
Net cash provided by financing activities	10,909	251
Net decrease in cash and cash equivalents	(166)	(3,635)
Cash and cash equivalents at beginning of period	19,136	30,050
Cash and cash equivalents at end of period	18,970	26,415
Supplemental schedule of non-cash investing and financing activities :
Capital lease obligation to finance capital expenditures	251	258
Purchase of equipment included in accounts payable	$ 8	$ 36