Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flow from operating activities:
Net loss	$ (14,210)	$ (7,247)
Adjustments to reconcile net loss to net cash used for operating activities:
Amortization	154	189
Depreciation	142	142
Bad debt provision	119	31
Stock-based compensation expense	2,077	516
Amortization of debt discount and debt costs	53	79
Loss on extinguishment of debt	341
Deferred tax expense	1
Change in fair value of convertible debentures	7,464	4,440
Changes in operating assets and liabilities:
Accounts receivable	3,201	(399)
Inventory	(737)	(671)
Prepaid and other current assets	(19)	51
Accounts payable	(569)	573
Accrued expenses	(1,650)	(184)
Deferred revenue	60	76
Total adjustments	10,637	4,843
Net cash used for operating activities	(3,573)	(2,404)
Cash flow from investing activities:
Additions to patents, technology and other	(6)	(7)
Additions to property and equipment	(180)	(136)
Net cash used for investing activities	(186)	(143)
Cash flow from financing activities:
Stock option exercises	100	1,395
Taxes paid related to restricted stock issuance		(12)
Principal payments of capital lease obligations		(6)
Principal repayment of debt financing	(4,638)	(800)
Repayment of credit line	(2,000)
Proceeds from debt financing	6,957
Debt issuance costs	(37)
Proceeds from issuance of common stock, net	12,289	9,352
Net cash provided by financing activities	12,671	9,929
Decrease in cash and equivalents	8,912	7,382
Cash and cash equivalents, beginning of period	15,313	12,185
Cash and cash equivalents, end of period	24,225	19,567
Supplemental disclosure of cash flow information:
Interest paid	127	335
Taxes paid	31	27
Issuance of stock upon conversion of debentures	21,164
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 69	$ 907