Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Operating Activities
Net loss	$ (16,598)	$ (22,525)
Adjustments to reconcile net loss to net cash and cash equivalents used in operating activities:
Loss from sale of SurgiBot assets, net	0	97
Depreciation	570	563
Amortization of intangible assets	2,564	2,611
Amortization of debt discount and debt issuance costs	0	330
Amortization of short-term investment discount	0	(220)
Stock-based compensation	1,923	2,981
Interest expense on deferred consideration - MST acquisition	0	204
Deferred tax benefit	(697)	(610)
Change in fair value of warrant liabilities	155	106
Change in fair value of contingent consideration	1,056	998
Changes in operating assets and liabilities:
Accounts receivable	(340)	(129)
Inventories	(1,063)	(4,621)
Other current and long term assets	(76)	(2,663)
Accounts payable	509	286
Accrued expenses	(433)	(2,518)
Deferred revenue	83	(197)
Other long term liabilities	(130)	1,112
Net cash and cash equivalents used in operating activities	(12,477)	(24,195)
Investing Activities
Purchase of short-term investments	0	(10,894)
Proceeds from maturities of short-term investments	0	40,000
Purchase of property and equipment	(2)	(118)
Net cash and cash equivalents (used in) provided by investing activities	(2)	28,988
Financing Activities
Proceeds from issuance of common stock, preferred stock and warrants under 2020 financing, net of issuance costs	13,525	0
Proceeds from issuance of common stock and warrants, net of issuance costs	11,212	0
Taxes paid related to net share settlement of vesting of restricted stock units	(33)	(499)
Proceeds from exercise of stock options and warrants	0	236
Net cash and cash equivalents provided by (used in) financing activities	24,704	(263)
Effect of exchange rate changes on cash and cash equivalents	(51)	(58)
Net increase in cash, cash equivalents and restricted cash	12,174	4,472
Cash, cash equivalents and restricted cash, beginning of period	10,567	21,651	$ 21,651
Cash, cash equivalents and restricted cash, end of period	22,741	26,123	$ 10,567
Supplemental Disclosure for Cash Flow Information
Interest paid	0	750
Supplemental Schedule of Non-cash Investing and Financing Activities
Transfer of inventories to property and equipment	1,958	86
Exchange of common stock for Series B Warrants	2,470	0
Transfer of in-process research and development to intellectual property	2,425	0
Conversion of preferred stock to common stock	$ 30	$ 0