Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 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
	March 31,
	2018		2017
	(in thousands)
	(unaudited)
U.S.
Services	$	21	$	—
Total U.S. revenue		21		—
Outside of U.S. ("OUS")
Systems		3,454		1,572
Instruments and accessories		1,111		277
Services		181		97
Total OUS revenue		4,746		1,946
Total
Systems		3,454		1,572
Instruments and accessories		1,111		277
Services		202		97
Total revenue	$	4,767	$	1,946