Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net loss	$ (4,311)	$ (4,476)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	4	17
Amortization of intangible assets	417	416
Noncash interest expense	58	104
Stock-based compensation	427	1,256
Bad debt expense	149	109
Warrant expense		130
Amortization of deferred debt issuance costs	47
Other noncash items	18	4
Change in operating assets and liabilities:
Accounts and other receivables	848	(3,111)
Finished goods inventory	60	(40)
Prepaid expenses and other current assets	(274)	(1,191)
Accounts payable and accrued liabilities	(865)	1,083
Warranty liability	173
Other	4
Net cash used in operating activities	(3,245)	(5,699)
Cash flows from financing activities:
Proceeds from issuance of subordinated convertible debentures		2,000
Proceeds from credit agreement, net of issuance costs	2,500
Payments of financing costs	(25)	(21)
Net cash provided by financing activities	2,475	1,979
Effect of currency exchange rate changes on cash and cash equivalents	(48)
Net decrease in cash, cash equivalents and restricted cash	(818)	(3,720)
Cash, cash equivalents and restricted cash at beginning of period	2,985	5,548
Cash, cash equivalents and restricted cash at end of period	2,167	1,828
Noncash investing and financing activities:
Fair value of warrants classified as debt issuance costs	$ 1,393
Conversion of common stock to convertible preferred stock		12
Conversion of convertible preferred share to common stock		1
Embedded derivative liability recorded as discount on subordinated convertible debentures		$ 481