These consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. (U.S. GAAP). The consolidated financial statements include the Company’s accounts and those of its four wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated.

The chief operating decision maker for the Company is the Chief Executive Officer. The Chief Executive Officer reviews financial information presented on a consolidated basis, accompanied only by information about revenue by geographic region, for purposes of allocating resources and evaluating financial performance. The Company has one business activity and there are no segment managers who are held accountable for operations, operating results or plans for levels or components below the consolidated unit level, other than revenue. Accordingly, the Company has determined that it has a single reportable and operating segment structure. The Company and its Chief Executive Officer evaluate performance based primarily on revenue in the geographic locations in which the Company operates.

Until 2015, the Company had derived most of its revenue from sales to customers in Australia and Europe. In May 2015, the U.S. Food and Drug Administration (FDA) approved the Company’s premarket approval (PMA) application to market Senza in the United States and the Company launched sales in the United States in 2015. Revenue by geography is based on the billing address of the customer. The United States is the only country that accounts for 10% or more of the revenue during the periods presented:

	Years Ended December 31,
	2018			2017			2016
United States		83	%		81	%		76	%

Long-lived assets and operating income outside the United States are not material; therefore disclosures have been limited to revenue.

The Company’s consolidated financial statements are prepared in U.S. dollars (USD). Its foreign subsidiaries use their local currency as their functional currency and maintain their records in the local currency. Accordingly, the assets and liabilities of these subsidiaries are translated into USD using the current exchange rates in effect at the balance sheet date and equity accounts are translated into USD using historical rates. Revenues and expenses are translated using the monthly average exchange rates during the period when the transaction occurs. The resulting foreign currency translation adjustments from this process are recorded in accumulated other comprehensive income (loss) in the consolidated balance sheets. Unrealized foreign exchange gains and losses from the remeasurement of assets and liabilities denominated in currencies other than the functional currency of the reporting entity are recorded in other income (expense), net. The Company recorded net unrealized foreign currency transaction losses of $0.6 million during the year ended December 31, 2018, gains of $0.8 million during the year ended December 31, 2017 and losses of $1.6 million during the year ended December 31, 2016. Additionally, realized gains and losses resulting from transactions denominated in currencies other than the local currency are recorded in other income (expense), net. The Company recorded realized foreign currency transaction losses of $0.4 million during the year ended December 31, 2018, gains of $0.5 million during the year ended December 31, 2017 and gains of $0.7 million during the year ended December 31, 2016.

As the Company’s international operations grow, the effect of fluctuations in currency rates will become greater, and the Company will continue to reassess its approach to managing this risk. In addition, currency fluctuations or a weakening U.S. dollar can increase the costs of the Company’s international expansion. To date, the Company has not entered into any foreign currency hedging contracts. Based on its current international structure, the Company does not plan on engaging in hedging activities in the near future.

The preparation of financial statements in accordance with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Significant accounting estimates and management judgments reflected in the consolidated financial statements include items such as allowances for doubtful accounts; warranty obligations; stock-based compensation; depreciation and amortization lives; inventory valuation; valuation of investments and accounting for income taxes. Estimates are based on historical experience, where applicable, and other assumptions believed to be reasonable by management. Actual results may differ from those estimates under different assumptions or conditions.

Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash, cash equivalents and investments. The majority of the Company’s cash is held by one financial institution in the United States in excess of federally insured limits. The Company maintained investments in money market funds that were not federally insured during the years ended December 31, 2018 and 2017, and held cash in foreign banks of approximately $4.1 million and $4.5 million at December 31, 2018 and 2017, respectively, that was not federally insured. The Company has not experienced any losses on its deposits of cash and cash equivalents.

The Company’s convertible note hedge transactions, entered into in connection with the 2021 Notes, subject the Company to credit risk such that the counterparties may be unable to fulfill the terms of the transactions. The associated risk is mitigated by limiting the counterparties to major financial institutions.

In the international markets in which the Company participates, the Company uses both a direct sales force and distributors to sell its products, while in the United States the Company utilizes a direct sales force. The Company performs ongoing credit evaluations of some of its direct customers and distributors, does not require collateral, and maintains allowances for potential credit losses on customer accounts when deemed necessary.

There were no customers that accounted for 10% or more of the Company’s revenue for each of the years ended December 31, 2018, 2017 and 2016. Additionally, there were no customers that accounted for 10% or more of the Company’s accounts receivable balance as of December 31, 2018 and 2017.

The Company is subject to risks common to medical device companies including, but not limited to, new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations, product liability, uncertainty of market acceptance of products and the need to obtain additional financing. The Company is dependent on third party manufacturers and suppliers, in some cases sole- or single-source suppliers.

There can be no assurance that the Company’s products or services will continue to be accepted in the marketplace, nor can there be any assurance that any future products or services can be developed or manufactured at an acceptable cost and with appropriate performance characteristics, or that such products or services will be successfully marketed, if at all.

The Company expects to incur operating losses in the near term and may need to obtain additional financing. There can be no assurance that such financing will be available or will be at terms acceptable by the Company.

Carrying amounts of certain of the Company’s financial instruments, including cash equivalents, short term investments, accounts receivable, accounts payable and accrued liabilities approximate fair value due to their relatively short maturities.

The Company considers all highly liquid investments purchased with an original maturity of three months or less at the date of purchase to be cash equivalents. Cash and cash equivalents include money market funds in the amount of $15.6 million and $30.3 million as of December 31, 2018 and 2017, respectively. At December 31, 2018 and 2017, the Company’s cash equivalents were held in institutions in the United States and include deposits in a money market fund which were unrestricted as to withdrawal or use.

Restricted cash as of December 31, 2018 and 2017 includes certificates of deposit of $0.6 million representing collateral for the Company’s Redwood City, CA building lease pursuant to an agreement dated March 5, 2015. Restricted cash as of December 31, 2017 additionally includes certificates of deposit of $0.2 million collateralizing payment of charges related to the Company’s credit cards.

The Company classifies its investment securities as available-for-sale. The Company classifies these investment securities as short-term or long-term based on the nature of the investment, its maturity date and its availability for use in current operations. Those investments with original maturities greater than three months at the date of purchase and remaining maturities of less than 12 months are considered short-term investments. Those investments with remaining maturities greater than 12 months are also classified as short-term investments as management considers them to be available for current operations if needed. The Company’s investment securities are recorded at fair value based on the fair value hierarchy. Money market funds are classified within Level 1 of the fair value hierarchy, and commercial paper and corporate notes are classified within Level 2 of the fair value hierarchy. Unrealized gains and losses, deemed temporary in nature, are reported as a separate component of accumulated other comprehensive income (loss).

A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the corresponding establishment of a new cost basis for the security. Premiums (discounts) are amortized (accreted) over the life of the related security as an adjustment to yield using the straight-line interest method. Dividend and interest income are recognized when earned. Realized gains and losses are included in earnings and are derived using the specific identification method for determining the cost of securities sold.

Inventories are stated at the lower of cost to purchase or manufacture the inventory or the net realizable value of such inventory. Cost is determined using the standard cost method which approximates the first-in, first-out basis. Net realizable value is determined as the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. The Company regularly reviews inventory quantities in consideration of actual loss experiences, projected future demand, and remaining shelf life to record a provision for excess and obsolete inventory when appropriate.

The Company’s policy is to write down inventory that has become obsolete, inventory that has a cost basis in excess of its expected lower of cost or net realizable value, and inventory in excess of expected requirements. The estimate of excess quantities is judgmental and primarily dependent on the Company’s estimates of future demand for a particular product. If the estimate of future demand is inaccurate based on actual sales, the Company may increase the write down for excess inventory for that component and record a charge to inventory impairment in the accompanying consolidated statements of operations and comprehensive loss. The Company periodically evaluates the carrying value of inventory on hand for potential excess amount over demand using the same lower of cost or net realizable value approach as that has been used to value the inventory. The Company also periodically evaluates inventory quantities in consideration of actual loss experience. As a result of these evaluations, for the years ended December 31, 2018, 2017 and 2016, the Company recognized total write downs of $2.0 million, $4.0 million and $4.1 million for its inventories. The Company’s estimation of the future demand for a particular component of the Company’s products may vary and may result in changes in estimates in any particular period.

Shipping and handling costs are expensed as incurred and are included in cost of revenue.

The Company has revenue arrangements that generally consist of a single performance obligation, although, in some instances, revenue arrangements may consist of two performance obligations. The Company recognizes revenue at the point in time when it transfers control of promised goods to its customers. Revenue is measured as the amount of consideration it expects to receive in exchange for transferring goods.

The Company makes estimates of the collectability of accounts receivable. In doing so, the Company analyzes historical bad debt trends, customer credit worthiness, current economic trends and changes in customer payment patterns when evaluating the adequacy of the allowance for doubtful accounts.

The Company provides a limited one- to five-year warranty and warrants that its products will operate substantially in conformity with product specifications. The Company records an estimate for the provision for warranty claims in cost of revenue when the related revenues are recognized. This estimate is based on historical and anticipated rates of warranty claims, the cost per claim and the number of units sold. The Company regularly assesses the adequacy of its recorded warranty obligations and adjusts the amounts as necessary.

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation of property and equipment, other than leasehold improvements, is computed using the straight-line method over the assets’ estimated useful lives of three to five years. Leasehold improvements are amortized on a straight-line basis over the shorter of the estimated useful life of the asset or the life of the lease. Upon retirement or sale, the cost and related accumulated depreciation are removed from the consolidated balance sheet and the resulting gain or loss is reflected in operations. Maintenance and repairs are charged to operations as incurred.

The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group might not be recoverable. When such an event occurs, management determines whether there has been impairment by comparing the anticipated undiscounted future net cash flows to the related asset group’s carrying value. If an asset is considered impaired, the asset is written down to fair value, which is determined based either on discounted cash flows or appraised value, depending on the nature of the asset. There were no impairment charges, or changes in estimated useful lives, recorded through December 31, 2018.

The Company records income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the Company’s consolidated financial statements or income tax returns. In estimating future tax consequences, expected future events other than enactments or changes in the tax law or rates are considered. Valuation allowances are provided when necessary to reduce deferred tax assets to the amount expected to be realized.

The Company operates in various tax jurisdictions and is subject to audit by various tax authorities. To date, taxes paid have been predominantly due to income taxes in foreign and state jurisdictions in which we conduct business. The Company provides for tax contingencies whenever it is deemed probable that a tax asset has been impaired or a tax liability has been incurred for events such as tax claims or changes in tax laws. Tax contingencies are based upon their technical merits, relative tax law, and the specific facts and circumstances as of each reporting period. Changes in facts and circumstances could result in material changes to the amounts recorded for such tax contingencies.

The Company records uncertain tax positions on the basis of a two-step process whereby (1) a determination is made as to whether it is more likely than not that the tax positions will be sustained based on the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold the Company recognizes the largest amount of tax benefit that is greater than 50% likely to be realized upon ultimate settlement with the related tax authority. The Company’s policy is to recognize interest and penalties related to income taxes as a component of income tax expense. No interest or penalties related to income taxes have been recognized in the statements of operations and comprehensive loss in 2018, 2017 and 2016.

On December 22, 2017, the 2017 Tax Cuts and Jobs Act (the 2017 Tax Act) was enacted into law. The Securities and Exchange Commission (SEC) staff previously issued Staff Accounting Bulletin No. 118 (SAB 118), Income Tax Accounting Implications of the Tax Cuts and Jobs Act, which allowed the Company to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. As of December 31, 2018, the SAB 118 measurement period has ended, and the Company has completed its accounting for the income tax effects of the 2017 Tax Act with immaterial adjustments to provisional estimates recorded in previous periods. The recorded impact for the effects of the 2017 Tax Act is based on the Company’s current knowledge, assumptions and interpretations of available guidance. The Company elected to account for Global Intangible Low-Tax Income (GILTI) as a current period expense when incurred. The Company will continue to monitor the issuance of additional regulatory or accounting guidance and record any necessary adjustments in the period for which additional guidance is issued.

Other comprehensive income (loss) represents all changes in stockholders’ equity except those resulting from distributions to stockholders. The Company’s unrealized gains on short-term available-for-sale investment securities and foreign currency translation adjustments represent the components of other comprehensive income (loss) that are excluded from the reported net loss and are presented in the consolidated statements of operations and comprehensive loss.

Research and development expenses, including new product development, regulatory compliance, and clinical research, are charged to operations as incurred in the consolidated statements of operations and comprehensive loss. Such costs include personnel-related costs, including stock-based compensation, supplies, services, depreciation, allocated facilities and information services, clinical trial and related clinical manufacturing expenses, fees paid to investigative sites, and other indirect costs.

The Company accounts for stock-based compensation arrangements with employees in accordance with Accounting Standards Codification (ASC) 718, Compensation—Stock Compensation. ASC 718 requires the recognition of compensation expense, using a fair value-based method, for costs related to all share-based payments including stock options.

In March 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-09, Stock Compensation (Topic 718): Improvements to Employee Shared-Based Payment Accounting, which the Company adopted on January 1, 2017. Under ASU 2016-09, entities are permitted to make an accounting policy election to either estimate forfeitures on share-based payment awards, as previously required, or to recognize forfeitures as they occur. The Company has elected to continue to estimate forfeitures expected to occur to determine the amount of compensation cost recognized in each period. ASU 2016-09 also requires that entities recognize, on a prospective basis, all excess tax benefits and tax deficiencies as income tax expense or benefit in the income statement as discrete items in the reporting period in which they occur. The adoption did not result in a cumulative-effect adjustment to accumulated deficit as of January 1, 2017 using the modified retrospective method. Additionally, under ASU 2016-09, excess tax benefits are classified as an operating activity in the statement of cash flows. The Company has elected the presentation of excess tax benefits in the statement of cash flows using the prospective transition method.

The Company’s determination of the fair value of stock options on the date of grant utilizes the Black-Scholes option-pricing model, and is impacted by its common stock price as well as changes in assumptions regarding a number of highly complex and subjective variables. These variables include, but are not limited to, the expected term that options will remain outstanding, the expected common stock price volatility over the term of the option awards, risk-free interest rates and expected dividends.

The fair value of stock options is recognized over the period during which an optionee is required to provide services in exchange for the option award, known as the requisite service period (usually the vesting period), on a straight-line basis. Stock-based compensation expense recognized at fair value includes the impact of estimated forfeitures. The Company estimates future forfeitures at the date of grant and revises the estimates, if necessary, in subsequent periods if actual forfeitures differ from those estimates.

The Company estimates the fair value of the rights to purchase shares by employees under the Employee Stock Purchase Plan using the Black-Scholes option pricing formula. The Employee Stock Purchase Plan provides for consecutive six-month offering periods and the Company uses its own historical volatility data in the valuation.

Equity instruments issued to non-employees are recorded at their fair value on the measurement date and are subject to periodic adjustments as the underlying equity instruments vest. The fair value of options granted to consultants is expensed when vested. The non-employee stock-based compensation expense was not material for all periods presented.

The Company accounts for stock-based compensation for the restricted stock units at their fair value, based on the closing market price of the Company’s common stock on the grant date. These costs are recognized on a straight-line basis over the requisite service period, which is generally the vesting term of four years.

The Company also issues stock options and restricted stock units with vesting based upon completion of performance goals. The fair value for these performance-based awards is recognized over the period during which the goals are to be achieved. Stock-based compensation expense recognized at fair value includes the impact of estimated probability that the goals would be achieved, which is assessed prior to the requisite service period for the specific goals.

Upon adoption of ASU 2016-09 as described above, excess tax benefits or deficiencies from share-based award activity are reflected in the consolidated statements of operations as a component of the provision for income taxes, whereas they were previously recognized as additional paid-in capital.

Basic net loss per common share is calculated by dividing net loss by the weighted-average number of common shares outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing net loss by the weighted-average number of common shares and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, restricted stock units and common stock options are considered to be potentially dilutive securities. Because the Company has reported a net loss in all periods presented, diluted net loss per common share is the same as basic net loss per common share for those periods.

In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). In July 2018, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842, Leases, which provides clarification to ASU 2016-02, and ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, which provides another transition method in addition to the existing transition method by allowing entities to initially apply the new leases standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption (the optional transition method). These ASU’s (collectively, the new lease standard) require an entity to recognize assets and liabilities for leases with lease terms of more than 12 months on the balance sheet. The Company plans to adopt the new standard on January 1, 2019 and elect the optional transition method. The Company will also elect the package of transitional practical expedients such that the Company will not need to reassess whether contracts are leases and will retain lease classification and initial direct costs for leases existing prior to the adoption of the new lease standard. The Company will also elect the hindsight practical expedient. The Company expects that the adoption of the new lease standard will have a material impact on its consolidated balance sheets, primarily related to the recognition of right-of-use assets of approximately $24.3 million to $25.3 million and the recognition of lease liabilities of approximately $25.7 million to $26.7 million. The Company does not expect the adoption of the new lease standard to have a material impact on its consolidated statements of operations

In March 2017, the FASB issued ASU No. 2017-08, Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities. This update shortens the premium amortization period for certain purchased callable debt securities held at a premium. ASU 2017-08 is effective for public entities for annual periods beginning after December 15, 2018. The Company has not determined the potential effects of the guidance on its consolidated financial statements.

In February 2018, the FASB issued ASU No. 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220). This update provides companies with the option to reclassify stranded tax effects caused by the 2017 Tax Cuts and Jobs Act (the 2017 Tax Act) from accumulated other comprehensive income to retained earnings. ASU 2018-02 is effective for public entities for annual periods beginning after December 15, 2018, with early adoption permitted. The Company has not determined the potential effects of the guidance on its consolidated financial statements.

In June 2018, the FASB issued ASU No. 2018-07, Compensation-Stock Compensation (Topic 718), Improvements to Nonemployee Share-based Payments. This ASU expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees and aligns the accounting for share-based payments for employees and nonemployees. ASU 2018-07 is effective for public entities for annual periods beginning after December 15, 2018, with early adoption permitted. The guidance should be applied to new awards granted after the date of adoption. The Company is currently evaluating the effect ASU 2018-07 will have on the consolidated financial statements.