Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating Activities
Net loss	$ (154,201,000)	$ (61,777,000)
Adjustments to reconcile net loss to net cash and cash equivalents used in operating activities:
Goodwill and in-process research and development impairment	86,881,000	0
Depreciation		2,420,000
Amortization of intangible assets	10,301,000	10,868,000
Amortization of debt discount and debt issuance costs	1,513,000	725,000
Amortization of short-term investment discount	(327,000)	(351,000)
Stock-based compensation	11,508,000	9,039,000
Inventory write-down related to restructuring	7,408,000	0
Inventory write-down	1,523,000	0
Bad debt expense	1,634,000	0
Interest expense on deferred consideration - MST acquisition	756,000	0
Deferred tax benefit	(3,224,000)	(3,377,000)
Loss on extinguishment of debt	1,006,000	1,400,000
Change in fair value of warrant liabilities	(2,248,000)	14,320,000
Change in fair value of contingent consideration	(9,553,000)	(1,011,000)
Reversal of transfer fee accrual	0	(2,994,000)
Changes in operating assets and liabilities, net of effect of acquisition:
Accounts receivable	6,083,000	(7,225,000)
Interest receivable	26,000	54,000
Inventories	(16,404,000)	(2,145,000)
Other current and long term assets	(655,000)	(325,000)
Accounts payable	(668,000)	767,000
Accrued expenses	(1,180,000)	2,134,000
Deferred revenue	(959,000)	825,000
Other long term liabilities	998,000	0
Net cash and cash equivalents used in operating activities	(73,484,000)	(48,493,000)
Investing Activities
Purchase of short-term investments	(12,883,000)	(55,439,000)
Proceeds from maturities of short-term investments	65,000,000	4,000,000
Payment for acquisition of a business	0	(5,800,000)
Purchase of property and equipment	(437,000)	(770,000)
Proceeds from sale of property and equipment	0	32,000
Net cash and cash equivalents provided by (used in) investing activities	67,645,000	(53,481,000)
Financing Activities
Payment of notes payable	(31,425,000)	(15,305,000)
Proceeds from issuance of debt and warrants, net of issuance costs	0	28,507,000
Payment of contingent consideration	0	(770,000)
Proceeds from issuance of common stock and warrants, net of issuance costs	25,777,000	279,000
Taxes paid related to net share settlement of vesting of restricted stock units	(499,000)	(1,662,000)
Proceeds from issuance of common stock related to sale of SurgiBot assets	0	3,000,000
Proceeds from exercise of stock options and warrants	538,000	12,403,000
Net cash and cash equivalents (used in) provided by financing activities	(5,609,000)	26,452,000
Effect of exchange rate changes on cash and cash equivalents	364,000	(433,000)
Net (decrease) increase in cash, cash equivalents and restricted cash	(11,084,000)	(75,955,000)
Cash, cash equivalents and restricted cash, beginning of period	21,651,000	97,606,000
Cash, cash equivalents and restricted cash, end of period	10,567,000	21,651,000
Supplemental Disclosure for Cash Flow Information
Interest paid	2,187,000	1,730,000
Supplemental Schedule of Non-cash Investing and Financing Activities
Transfer of inventories to property and equipment	486,000	2,160,000
Transfer of property and equipment to inventories	323,000	637,000
Reclass of warrant liability to common stock and additional paid-in capital	0	23,774,000
Cashless exercise of warrants	0	4,272,000
Issuance of common stock related to MST acquisition		8,300,000
Proceeds from sale of AutoLap assets exchanged for settlement of Company obligations	1,000,000	0
Deferred consideration - MST acquisition	0	5,962,000
AutoLap
Adjustments to reconcile net loss to net cash and cash equivalents used in operating activities:
Loss (gain) from sale of assets, net	(15,965,000)	0
Investing Activities
Proceeds related to sale of assets, net	15,965,000	0
SurgiBot System
Adjustments to reconcile net loss to net cash and cash equivalents used in operating activities:
Loss (gain) from sale of assets, net	97,000	(11,840,000)
Inventory write-down	1,500,000	0
Investing Activities
Proceeds related to sale of assets, net	$ 0	$ 4,496,000