Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (2,429,000)	$ (7,301,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	38,000	704,000
Stock-based compensation expense	65,000	70,000
Gain from the sale of patents, property and equipment	(510,000)	0
Write-down of intangibles	134,000	0
Obsolete inventory	190,000	0
Changes in assets and liabilities:
Accounts receivable	344,000	(157,000)
Inventories	5,000	26,000
Prepaid expenses and other current assets	2,000	(86,000)
Accounts payable, accrued expenses and other current liabilities	(491,000)	(18,000)
Net cash used in operating activities	(2,652,000)	(6,762,000)
CASH FLOWS FROM INVESTING ACTIVITIES:
Net proceeds from the sale of patents, property and equipment	1,222,000	0
Net cash used in investing activities	1,222,000	0
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from the sale of common stock		1,421,000
Net proceeds from the exercise of warrants	2,479,000
Net cash provided by financing activities	2,479,000	1,421,000
Net increase (decrease) in cash and cash equivalents	1,049,000	(5,341,000)
Cash and cash equivalents at beginning of period	713,000	5,616,000
Cash and cash equivalents at end of period	1,762,000	$ 275,000
NONCASH INVESTING AND FINANCING ACTIVITIES:
Acquisition of preferred equity interest in real estate in exchange for common stock	$ 1,600,000