Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Jul. 01, 2017	Jul. 02, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (5,170,000)	$ (5,708,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,028,000	1,157,000
Stock-based compensation expense	201,000	519,000
Adjustments to fair value of warrant derivatives	(8,000)	(21,000)
Changes in assets and liabilities:
Accounts receivable	9,000	22,000
Inventories	6,000	59,000
Prepaid expenses and other current assets	(103,000)	(61,000)
Patents, licenses and purchased technology	71,000	(94,000)
Other assets	27,000	30,000
Accounts payable, accrued expenses and other current liabilities	(212,000)	3,000
Net cash used in operating activities	(4,151,000)	(4,052,000)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(39,000)
Net cash used in investing activities	(39,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from the exercise of outstanding warrants	200,000
Net cash provided by financing activities	200,000
Net decrease in cash and cash equivalents	(3,990,000)	(4,052,000)
Cash and cash equivalents at beginning of period	10,452,000	7,469,000
Cash and cash equivalents at end of period	$ 6,462,000	$ 3,417,000