Balance Sheet Components (Tables)

6 Months Ended

12 Months Ended

Jun. 30, 2015

Dec. 31, 2014

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Property and Equipment

Property and equipment consisted of the following (in thousands):

	June 30, 2015			December 31, 2014
	(Unaudited)
Prototype	$	6,451		$	6,342
Machinery and equipment		4,996			4,214
Leasehold improvements		1,274			1,270
Furniture and fixtures		322			263
Software		768			647
Property and equipment, gross		13,811			12,736
Less: accumulated depreciation and amortization		(10,313	)		(9,805	)
Property and equipment, net	$	3,498		$	2,931

Property and equipment consist of the following (in thousands):

	December 31,
	2013			2014
Prototype	$	6,053		$	6,342
Machine and equipment		2,714			4,214
Leasehold improvements		1,154			1,270
Furniture and fixtures		232			263
Software		595			647
Property and equipment, gross		10,748			12,736
Less: accumulated depreciation and amortization		(8,962	)		(9,805	)
Property and equipment, net	$	1,786		$	2,931

Summary of Intangible Assets

Intangible assets consisted of the following (in thousands):

	June 30, 2015			December 31, 2014
	(Unaudited)
Intangible assets—license cost	$	500		$	500
Accumulated amortization		(319	)		(236	)
Intangible assets, net	$	181		$	264

Intangible assets consist of the following (in thousands):

	December 31,
	2013			2014
Intangible assets—license cost	$	500		$	500
Accumulated amortization		(69	)		(236	)
Intangible assets, net	$	431		$	264

Summary of Estimated Future Amortization Expense

At June 30, 2015, the estimated future amortization expense of purchased intangible assets was as follows (in thousands):

Year Ending December 31,	Estimated Future Amortization Expense
The remainder of 2015	$	83
2016		98
Total amortization expense	$	181

The estimated future amortization expense of purchased intangible assets at December 31, 2014 was as follows (in thousands):

Year Ending December 31,	Estimated Future Amortization Expense
2015	$	167
2016		97
Total	$	264

Schedule of Accrued Liabilities

Accrued liabilities consisted of the following (in thousands):

	June 30, 2015		December 31, 2014
	(Unaudited)
Accrued payroll and related benefits	$	1,337	$	1,652
Accrued accounts payable		465		946
Sales tax and medical device excise tax payable		37		499
Accrued legal and accounting		744		901
Accrued interest		49		142
Accrued debt facility fee		1,509		—
Other		447		296
Total accrued liabilities	$	4,588	$	4,436

Accrued liabilities consist of the following (in thousands):

	December 31,
	2013		2014
Accrued payroll and related benefits	$	1,233	$	1,652
Accrued non-cancellable purchase commitments		1,502		—
Accrued accounts payable		517		946
Sales tax and medical device excise tax payable		98		499
Accrued legal and accounting		84		901
Accrued interest		78		142
Other		536		296
Total accrued liabilities	$	4,048	$	4,436

Schedule of Deferred Revenue

Deferred revenue consisted of the following (in thousands):

	June 30, 2015			December 31, 2014
	(Unaudited)
Deferred revenue:
Product	$	9,750		$	6,919
Services		80			442
Total deferred revenue		9,830			7,361
Less: current portion of deferred revenue		(9,830	)		(7,361	)
Noncurrent portion of deferred revenue	$	—		$	—

Deferred revenue consists of the following (in thousands):

	December 31,
	2013			2014
Deferred revenue:
Products	$	286		$	6,919
Service		267			442
Total deferred revenue		553			7,361
Less: current portion of deferred revenue		(425	)		(7,361	)
Noncurrent portion of deferred revenue	$	128		$	—