UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net loss	$ (12,381)	$ (10,714)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	900	980
Stock-based compensation	2,490	1,427
Write-down of inventories	80	206
Write-off of equipment	2	5
Tax benefit from acquisition	(282)
Changes in operating assets and liabilities:
Accounts receivable	950	(301)
Inventories	378	(736)
Other assets	304	(59)
Trade payables	(492)	(232)
Accrued liabilities and deferred revenue	(683)	562
Other long-term liabilities	(16)	33
Net cash used in operating activities	(8,750)	(8,829)
Cash flows from investing activities:
Capital expenditures for property and equipment	(599)	(112)
Cash received from business acquisition	20
Net cash used in investing activities	(579)	(112)
Cash flows from financing activities:
Payment of finance lease obligations	(283)	(329)
Proceeds from line of credit	32,000	21,000
Payment of line of credit	(32,000)	(18,000)
Proceeds from issuance of common stock	9,439	15,859
Stock issuance costs	(1,181)	(1,638)
Taxes for net issuance of stock awards	(287)	(259)
Net cash provided by financing activities	7,688	16,633
Net (decrease)/increase in cash, cash equivalents and restricted cash	(1,641)	7,692
Cash, cash equivalents and restricted cash at beginning of period	26,463	16,527
Cash, cash equivalents and restricted cash at end of period	$ 24,822	$ 24,219