CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities
Net loss	$ (9,019)	$ (1,207)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	316	371
Provision for inventory obsolescence	36	0
Gain on disposal of property and equipment, net	0	(1)
Stock based compensation	1,715	749
Change in fair value of derivative liabilities	0	(20)
Non-cash lease expense	53	0
Realized gain on short term investments	(164)	0
Provision for allowance for doubtful accounts	(157)	82
Changes in current assets and liabilities:
Trade receivables	(1,046)	(817)
Prepaid expenses	(841)	(72)
Inventories	(1,216)	(1,007)
Deposits and other assets	(321)	(23)
Accounts payable	218	1,162
Accrued severance and related	(319)	0
Accrued and other liabilities	604	(898)
Net cash used in operating activities	(10,141)	(1,681)
Cash flows from investing activities
Purchases of property and equipment	(922)	(332)
Purchases of marketable securities	(18,884)	0
Proceeds from maturities of marketable securities	80,726	0
Net cash provided by (used in) investing activities	60,920	(332)
Cash flows from financing activities
Proceeds from stock options/warrants exercised	115	0
Repayment of mortgage note payable	0	(120)
Net cash provided by (used in) financing activities	115	(120)
Net change in cash, cash equivalents and restricted cash	50,894	(2,133)
Cash, cash equivalents and restricted cash, beginning of period	16,466	10,668
Cash, cash equivalents and restricted cash, end of period	67,360	8,535
Cash paid for:
Interest	0	72
Non cash investing and financing activities:
Cashless exercise of stock options/warrants	662	0
Capitalization of lease	$ 394	$ 0