5. Commitments

Operating Lease

We rent office space under an operating lease that expires on March 31, 2019. The lease allows us to terminate the lease any time after March 31, 2017 without a penalty.

Future minimum annual operating lease payments are as follows:


Year ending December 31:
2018 (remaining)	$	97
2019		48

Total future operating lease payments	$	145

Rent expense was $48 for both the three months ended June 30, 2018 and 2017, and $100 and $87 during the six months ended June 30, 2018 and 2017, respectively.

Purchase Commitments

As of June 30, 2018 and December 31, 2017, we had commitments to suppliers for inventory purchases totaling $16.3 million and $9.0 million, respectively, of which $0.0 million and $0.4 million, respectively, was committed to Medtronic, a related party.