Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2020

Summary Of Significant Accounting Policies [Line Items]

Summary of Cash and Cash Equivalents and Restricted Cash

Restricted cash serves as collateral for the Company’s corporate credit card program. The following table reconciles cash and restricted cash in the condensed consolidated balance sheets to the totals shown on the condensed consolidated statements of cash flows (in thousands):

	June 30, 2020		December 31, 2019
	(unaudited)
Cash and cash equivalents	$	24,295	$	9,452
Restricted cash		150		150
Total cash, cash equivalents and restricted cash	$	24,445	$	9,602

Summary of Disaggregation of Revenue

The following table sets forth the Company’s revenue for disposables and systems/service for the three and six months ended June 30, 2020 and 2019 (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
	(unaudited)				(unaudited)
Disposables	$	1,122	$	730	$	2,179	$	1,512
Systems		—		—	$	520		—
Service/Other		12		4		18		9
Total	$	1,134	$	734	$	2,717	$	1,521

Summary of Revenue from External Customers by Geographic Areas

The following table provides revenue by geographic location for the three and six months ended June 30, 2020 and 2019 (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
	(unaudited)				(unaudited)
United States	$	559	$	221	$	1,328	$	456
Europe		575		513		1,389		1,065
Total Revenue	$	1,134	$	734	$	2,717	$	1,521

Summary of Fair Value, Liabilities Measured on Recurring Basis

The following tables classify the Company’s financial assets and liabilities measured at fair value on a recurring basis into the fair value hierarchy as of June 30, 2020 and December 31, 2019 (in thousands):

	Fair Value Measured at June 30, 2020 (unaudited)
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value at June 30, 2020
Assets included in:
Cash and cash equivalents
Money market securities	$	21,544	$	—	$	—	$	21,544
Marketable securities at fair value
U.S. treasury securities		—		5,037		—		5,037
Total fair value	$	21,544	$	5,037	$	—	$	26,581
Liabilities included in:
Contingent consideration	$	—	$	—	$	7,500	$	7,500
Common and preferred stock warrant liability		—		—		10,791		10,791
Total fair value	$	—	$	—	$	18,291	$	18,291
	Fair Value Measured at December 31, 2019
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value at December 31, 2019
Assets included in:
Cash and cash equivalents
Money market securities	$	8,901	$	—	$	—	$	8,901
Marketable securities at fair value
Corporate debt securities		—		28,224		—		28,224
Asset-backed securities		—		17,121		—		17,121
U.S. treasury securities		—		5,032		—		5,032
Commercial paper		—		11,974		—		11,974
Total fair value	$	8,901	$	62,351	$	—	$	71,252
Liabilities included in:
Contingent consideration	$	—	$	—	$	13,900	$	13,900
Common and preferred stock warrant liability		—		—		8,919		8,919
Total fair value	$	—	$	—	$	22,819	$	22,819

Summary of Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation

The following table presents changes in Level 3 liabilities measured at fair value for the six months ended June 30, 2020 (in thousands):

	Common and Preferred Stock Warrant Liability		Contingent Consideration			Total
Balance, December 31, 2019	$	8,919	$	13,900		$	22,819
Payment of contingent consideration		—		(2,619	)		(2,619	)
Issuance of preferred stock for contingent consideration		—		(2,197	)		(2,197	)
Change in fair value		1,872		(1,584	)		288
Balance, June 30, 2020 (unaudited)	$	10,791	$	7,500		$	18,291

Weighted-average unobservable inputs to measure contingent consideration

The weighted-average (in aggregate) significant unobservable inputs (Level 3 inputs) used in measuring the common and preferred stock warrant liabilities as of June 30, 2020 and December 31, 2019 were as follows:

	June 30, 2020	December 31, 2019
	(unaudited)
Risk-free interest rate	0.15% - 0.18%	1.59% - 1.60%
Expected dividend yield	—	—
Contractual term in years	0.2 - 0.5	0.7 - 1.0
Expected volatility	67.0% - 123.0%	60.0% - 110.5%

Weighted-average unobservable inputs to measure contingent consideration

The weighted-average (in aggregate) significant unobservable inputs (Level 3 inputs) used in measuring the contingent consideration from the acquisition of Rhythm Xience as of June 30, 2020 and December 31, 2019 were as follows:

	June 30, 2020	December 31, 2019
	(unaudited)
Risk-free interest rate	0.20%	1.60%
Expected term in years	1.0 - 2.0	1.0 - 2.0
Expected volatility	18.3%	11.8%