UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018
Cash flows from operating activities:
Net loss	$ (8,110)	$ (7,454)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	592	675
Stock-based compensation	1,742	911
Write-down of inventories	88	126
Write-off of equipment	2	5
Tax benefit from acquisition	(282)	0
Changes in operating assets and liabilities:
Accounts receivable	690	(1,266)
Inventories	247	(857)
Other assets	(150)	(95)
Trade payables	77	263
Accrued liabilities	(850)	172
Other long-term liabilities	(16)	47
Net cash used in operating activities	(5,970)	(7,473)
Cash flows from investing activities:
Capital expenditures for property and equipment	(523)	(95)
Cash received from business acquisition	20	0
Net cash used in investing activities	(503)	(95)
Cash flows from financing activities:
Payment of finance lease obligations	(194)	(236)
Proceeds from line of credit	20,000	12,000
Payment of line of credit	(20,000)	(12,000)
Proceeds from issuance of common stock	9,439	15,855
Stock issuance costs	(891)	(1,638)
Taxes for net issuance of stock awards	(193)	(125)
Net cash provided by financing activities	8,161	13,856
Net increase in cash, cash equivalents and restricted cash	1,688	6,288
Cash, cash equivalents and restricted cash at beginning of period	26,463	16,527
Cash, cash equivalents and restricted cash at end of period	$ 28,151	$ 22,815