Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (3,771)	$ (17,410)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	762	1,651
Depreciation and amortization	455	701
Impairment of assets held for sale	54
Amortization of intangible assets		47
Bad debt expense		97
Inventory write-off		391
Change in fair value of common stock warrant liability	(5,105)	4,027
Inducement loss on sale of liability classified warrants		5,197
Loss on restructuring and other charges		425
(Gain) Loss on sale of property and equipment	(2)	7
Changes in operating assets and liabilities:
Accounts receivable	256	(598)
Inventory		119
Prepaid expenses and other current assets	(393)	(1,639)
Operating lease right-of-use assets	292	328
Other assets/liabilities, net		245
Accounts payable and accrued expenses	1,702	138
Other current liabilities	(1)	(15)
Deferred revenue	(52)	39
Operating lease liabilities	(238)	(360)
Net cash used in operating activities	(6,041)	(6,610)
CASH FLOWS FROM (USED IN) INVESTING ACTIVITIES
Purchase of property and equipment	(31)	(12)
Proceeds from sale of property and equipment	7	10
Net cash used in investing activities	(24)	(2)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from insurance financing arrangements	1,027	1,028
Principal payments on term note payable and financing arrangements	(10)	(9)
Principal payments on financing leases	(116)	(135)
Net proceeds from the sale of common stock, warrants and pre-funded warrants		9,884
Proceeds from the sale of warrants		1,002
Proceeds from warrants exercised		6,671
Proceeds from pre-funded warrants exercised		8
Proceeds from the sale of warrants and preferred stock net of issuance costs	4,814
Cash paid for tax withholdings related to net share settlement	(127)	(125)
Proceeds from stock options exercised		3
Net cash provided by financing activities	5,588	18,327
Net increase (decrease) in cash and cash equivalents, including cash classified within assets held for sale	(477)	11,715
Less: net increase in cash and cash equivalents classified within assets held for sale	175
Net increase (decrease) in cash and cash equivalents	(652)	11,715
Cash and cash equivalents - beginning of period	19,375	25,522
Cash and cash equivalents - end of period	18,723	37,237
Supplemental cash flow information:
Cash paid for interest	16	31
Supplemental schedule of non-cash investing and financing activities:
Fair value of placement agent warrants issued in connection with offering	144	838
Reclassification of warrant liability to stockholders’ equity upon exercise of warrant		8,964
Conversion of Series A and Series B preferred stock into common stock	16
Allocation of financing to warrant liability	3,129	8,629
Deferred and accrued offering costs	104	500
Reclassification of assets held for sale	3,163
Reclassification of liabilities held for sale	$ 215