Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2018

Accounting Policies [Abstract]

Summary of Estimated Lives of Assets

Depreciation is recorded using the straight-line method over the estimated useful lives of the assets as follows:

Machinery, manufacturing and demonstration equipment	3-5 years
Computer equipment	3 years
Furniture	5 years
Leasehold improvements	Lesserof lease term or 3 to 10 years

Summary of Revenue Disaggregated by Types and Geography

The following table presents revenue disaggregated by types and geography:

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2018		2017		2018		2017
	(in thousands)				(in thousands)
	(unaudited)				(unaudited)
U.S.
Systems	$	875	$	—	$	875	$	—
Instruments and accessories		409		—		409		—
Services		28		—		49		—
Total U.S. revenue		1,312		—		1,333		—
Outside of U.S. ("OUS")
Systems		3,782		1,400		7,236		2,972
Instruments and accessories		1,101		34		2,212		311
Services		194		150		375		247
Total OUS revenue		5,077		1,584		9,823		3,530
Total
Systems		4,657		1,400		8,111		2,972
Instruments and accessories		1,510		34		2,621		311
Services		222		150		424		247
Total revenue	$	6,389	$	1,584	$	11,156	$	3,530