Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Operating Activities:
Net loss	$ (13,840)	$ (16,598)	$ (20,171)	$ (22,525)	$ (30,438)	$ (42,696)
Adjustments to reconcile net loss to net cash and cash equivalents used in operating activities:
Loss from sale of SurgiBot assets, net	0		0		0	97
Depreciation					1,162	1,126
Amortization of intangible assets	2,619		2,585		5,183	5,196
Amortization of debt discount and debt issuance costs					0	622
Amortization of short-term investment discount					0	(300)
Stock-based compensation					3,856	6,336
Interest expense on deferred consideration - MST acquisition					0	387
Deferred tax benefit					(1,388)	(1,479)
Write down of inventory	0		800		0	761
Change in fair value of warrant liabilities	114		(2,528)		269	(2,422)
Change in fair value of contingent consideration	212		960		1,268	1,958
Changes in operating assets and liabilities:
Accounts receivable					(350)	2,808
Interest receivable					0	(4)
Inventories					(2,332)	(10,301)
Other current and long term assets					827	(3,689)
Accounts payable					(1,221)	2,499
Accrued expenses					(1,736)	(1,454)
Deferred revenue					22	(862)
Other long term liabilities					(258)	1,879
Net cash and cash equivalents used in operating activities					(25,136)	(39,538)
Investing Activities:
Purchase of short-term investments					0	(12,883)
Proceeds from maturities of short-term investments					0	55,000
Purchase of property and equipment					(3)	(189)
Net cash and cash equivalents (used in) provided by investing activities					(3)	41,928
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, net of issuance costs					11,212	0
Proceeds from notes payable, net of issuance costs					2,815	(30)
Taxes paid related to net share settlement of vesting of restricted stock units					(33)	(499)
Payment of contingent consideration					(74)	0
Proceeds from exercise of warrants					3,340	534
Net cash and cash equivalents provided by (used in) financing activities					30,785	5
Effect of exchange rate changes on cash and cash equivalents					17	(32)
Net increase in cash, cash equivalents and restricted cash					5,663	2,363
Cash, cash equivalents and restricted cash, beginning of period		$ 10,567		$ 21,651	10,567	21,651	$ 21,651
Cash, cash equivalents and restricted cash, end of period	$ 16,230		$ 24,014		16,230	24,014	$ 10,567
Supplemental Disclosure for Cash Flow Information:
Interest paid					0	1,528
Supplemental Schedule of Non-cash Investing and Financing Activities:
Transfer of inventories to property and equipment					3,403	415
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					$ 79	$ 0