Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities:
Net loss	$ (6,387,000)	$ (6,829,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Mark-down of inventory		641,000
Depreciation and amortization	848,000	802,000
Stock-based compensation	415,000	725,000
Impairment of long-lived assets	1,676,000
Loss on disposal of fixed assets	(2,000)
Changes in operating assets and liabilities:
Trade accounts receivable	(192,000)	(15,000)
Inventory	(55,000)	(269,000)
Prepaid expenses and other current assets	(48,000)	(22,000)
Accounts payable and accrued liabilities	109,000	31,000
Deferred revenue	(30,000)	6,000
Net cash used in operating activities	(3,666,000)	(4,930,000)
Investing Activities:
Purchases of property and equipment	(630,000)	(156,000)
Proceeds from disposal of fixed assets	272,000
Net cash used in investing activities	(358,000)	(156,000)
Financing Activities:
Proceeds from exercise of stock options	14,000	125,000
Net cash provided by financing activities	14,000	125,000
Net decrease in cash and restricted cash	(4,010,000)	(4,961,000)
Cash and restricted cash at beginning of period	35,234,000	41,314,000
Cash and restricted cash at end of period	$ 31,224,000	$ 36,353,000