Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018
Operating activities:
Net loss	$ (5,467)	$ (6,883)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	354	395
Change in fair value of earn-out liability	127	55
Stock-based compensation	1,240	843
Provision for doubtful accounts	25
Changes in operating assets and liabilities:
Accounts receivable	973	721
Inventories	(207)	282
Prepaid expenses and other current assets	(47)	(153)
Other long-term assets	3	(30)
Accounts payable	(320)	519
Accrued compensation	(811)	(67)
Accrued expenses	(505)	145
Accrued warranty	(284)	(809)
Deferred revenue	(242)	(204)
Other long-term liabilities		133
Net cash used in operating activities	(5,161)	(5,053)
Investing activities:
Acquisition of property and equipment	(111)	(374)
Payment on earn-out liability	(199)	(186)
Net cash used in investing activities	(310)	(560)
Financing activities:
Proceeds from stock option exercises		62
Taxes paid related to net share settlements of equity awards	(101)	(152)
Net cash provided by financing activities	(101)	(90)
Effect of foreign exchange rate changes	11	41
Net decrease in cash and cash equivalents	(5,561)	(5,662)
Cash and cash equivalents, beginning of period	21,194	21,707
Cash and cash equivalents, end of period	15,633	16,045
Supplemental disclosure of cash flow information:
Cash paid during the period for income taxes	19	9
Supplemental disclosure of non-cash activities:
Transfer of inventory to property and equipment	$ 26	$ 6