Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2020

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	Lesser of lease term or 3 to 10 years

Summary of Revenue Disaggregated by Type and Geography

The following table presents revenue disaggregated by type and geography:

	Three Months Ended
	March 31,
	2020		2019
	(in thousands) (unaudited)
U.S.
Systems	$	30	$	—
Instruments and accessories	60		—
Services	69		133
Total U.S. revenue	159		133
Outside of U.S. ("OUS")
Systems	39		1,283
Instruments and accessories	113		546
Services	289		219
Total OUS revenue	441		2,048
Total
Systems	69		1,283
Instruments and accessories	173		546
Services	358		352
Total revenue	$	600	$	2,181