Certain prior period amounts have been reclassified to conform to the current period presentation as further described in Note 3. Discontinued Operations.

The financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). The preparation of the financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates. The Company’s financial statements are based upon a number of estimates including, but not limited to, allowance for credit losses, evaluation of impairment of assets, valuation of long-lived assets and their associated estimated useful lives, reserves for warranty costs, including product recalls, evaluation of probable loss contingencies and fair value of equity awards granted.

After the sale of the Dermatology Business in August 2021, the Company began operating its business in one segment which includes all activities related to the research, development and manufacture of the DABRA system. The chief operating decision-maker reviews the operating results on an aggregate basis and manages the operations as a single operating segment.

The Company considers all short-term, highly liquid investments with original maturities of three months or less to be cash equivalents. Cash equivalents primarily represent funds invested in readily available checking and money market accounts. The Company maintains deposits in financial institutions in excess of federally insured limits.

Fair value represents the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants and is a market-based measurement that should be determined based

on assumptions that market participants would use in pricing an asset or liability. A three-tier value hierarchy is used to identify inputs used in measuring fair value as follows:

Level 1 - Observable inputs that reflect quoted market prices (unadjusted) for identical assets or liabilities in active markets;

Level 2 - Inputs other than the quoted prices in active markets that are observable either directly or indirectly in the marketplace for identical or similar assets and liabilities; and

Level 3 - Unobservable inputs that are supported by little or no market data, which require the Company to develop its own assumptions.

Cash equivalents, trade accounts receivable and accounts payable are reported on the balance sheets at carrying value which approximates fair value due to the short-term maturities of these instruments.

Trade accounts receivable are presented net of allowances for credit losses. The Company sells its catheters directly to distributors or physicians and maintains an allowance for credit losses for balances that appear to have specific collection issues. The collection process is based on the age of the invoice and requires attempted contacts with the customer at specified intervals. Delinquent accounts receivable are charged against the allowance for credit losses once the Company has determined the amounts are uncollectible. The factors considered in reaching this determination are the apparent financial condition of the customer and the Company’s success in contacting and negotiating with the customer. If the financial condition of the Company’s customers were to deteriorate, resulting in an impairment of their ability to make payments, additional allowances may be required.

The following table shows the activity in the allowance for credit losses for the periods presented (in thousands):

	Year Ended December 31,
	2021		2020
Balance at beginning of year	$	84	$	305
Provision for credit losses		47		42
Deductions		—		(263	)
Balance at end of year	$	131	$	84

Inventories are stated at the lower of cost (first-in, first-out method) or net realizable value. Cost includes materials, labor and manufacturing overhead related to the purchase and production of inventories. The Company reduces the carrying value of inventories for those items that are potentially excess, obsolete or slow-moving based on changes in customer demand, technological developments or other economic factors. Although inventories are classified as current assets in the accompanying balance sheets, the Company anticipates that such inventories will be utilized beyond twelve months from December 31, 2021.

Catheters are manufactured in-house and each catheter is tested at various stages of the manufacturing process for adherence to quality standards. Catheters that do not meet functionality specification at each test point are destroyed and immediately written off, with the expense recorded in cost of revenues in the statements of operations. Once manufactured, completed catheters that pass quality assurance, are sent to a third-party for sterilization and sealed in a sterile container. Upon return from the third-party sterilizer, a sample of catheters from each batch are re-tested. If the sample tests are successful, the batch is accepted into finished goods inventory. If the sample tests are unsuccessful, the entire batch is written off, with the expense recorded in cost of revenues in the statement of operations.

Property and equipment are recorded at cost and depreciated on a straight-line basis over their estimated useful lives as follows:

Computer hardware and software		4-5 years
Furniture and fixtures		5 years
Machinery and equipment		5-10 years
Lasers		5 years
Automobiles		5 years

Leasehold improvements are depreciated over the shorter of the useful life of the leasehold improvement or the term of the underlying property’s lease.

The Company periodically reviews the residual values and estimated useful lives of each class of its property and equipment for ongoing reasonableness, considering long-term views on its intended use of each class of property and equipment and the planned level of improvements to maintain and enhance assets within those classes. Effective January 1, 2022, based on management’s revised assessment of average laser on-time utilization, the Company changed the estimated useful life of its lasers to eight years.

When assets are retired or otherwise disposed of, the cost and related accumulated depreciation are removed from the account balances and any resulting gain or loss is recognized in income for the period. The cost of repairs and maintenance is expensed as incurred, whereas significant betterments are capitalized.

The Company periodically reviews its long-lived assets for impairment when certain events or changes in circumstances indicate that the carrying value of the long-lived assets may not be recoverable. Should the sum of the undiscounted expected future net cash flows be less than the carrying value, the Company would recognize an impairment loss at that date. There were no impairment charges for the years ended December 31, 2021 or 2020.

Products are warrantied against defects in material and workmanship when properly used for their intended purpose and appropriately maintained. Accordingly, the Company generally replaces catheters that kink or fail to calibrate. The product warranty liability is determined based on historical information such as past experience, product failure rates or number of units repaired, estimated cost of material and labor. The product warranty liability also includes the estimated costs of a product recall.

The warranty accrual is included in accrued expenses in the accompanying balance sheets. Warranty expenses are included in cost of revenues in the accompanying statements of operations. Changes in estimates to previously established warranty accruals result from current period updates to assumptions regarding repair and product recall costs and are included in current period warranty expense.

The Company generates revenue from the sales of products and services. Product sales consist of the sales of catheters for use with the DABRA laser system. The Company has paused selling commercial product and is only selling catheters for use in the atherectomy clinical trial. The Company’s sales agreements generally do not include right-of-return provisions for any form of consideration, including partial refund or credit against amounts owed to the Company. Services and other revenues primarily consist of billable services, including fees related to DABRA laser commercial usage agreements.

The Company accounts for a contract with a customer when it has a legally enforceable contract with the customer, the arrangement identifies the rights of the parties, the contract has commercial substance, and the Company determines it is probable that it will collect the contract consideration. The Company recognizes revenue when control of the promised goods or services transfers to customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. Taxes collected from customers relating to goods or services and remitted to governmental authorities are excluded from revenue.

When engaged in commercial sales, the Company enters into a DABRA laser commercial usage agreement or DABRA laser placement acknowledgement with each customer that is supplied a DABRA laser, collectively the “usage agreement”, which provides for specific terms of continued use of the DABRA laser, including a nominal periodic fee. The terms of a usage agreement typically allow the Company to place a DABRA laser at a customer’s specified location without a specified contract term. Under the usage agreement terms, the Company retains all ownership rights to the DABRA laser and is permitted to request the return of the equipment within 10 business days of notification. While the laser periodic fees are nominal, the usage agreement provides the Company the exclusive rights to supply related single-use catheters to the customer which aggregate the majority of the product sales revenue. There are no specified minimum purchase commitments for the catheters.

The Company recognizes revenue associated with the usage agreements and catheter supply arrangements in accordance with Financial Accounting Standards Board “Revenue from Contracts with Customers (Topic 606),” (“Topic 606”) since (i) the contract primarily includes variable payments, (ii) the catheters are priced at their standalone selling price, and (iii) the laser equipment is insignificant in the context of the contract. Revenue is recognized when the performance obligation is satisfied which is generally upon shipment of the catheter.

In certain markets outside the U.S., the Company sells products and provides services to customers through distributors that specialize in medical device products. The terms of sales transactions through distributors are generally consistent with the terms of direct sales to customers. The Company accounts for these transactions in accordance with the Company’s revenue recognition policy described herein.

Shipping and handling charged to customers are included in net product sales. Shipping and handling costs are included in selling, general and administrative expenses in the accompanying statements of operations.

Major components of research and development costs include personnel expenses, stock-based compensation, consulting, supplies and clinical trial expenses. Research and development expenses are charged to operations in the period they are incurred.

The Company expenses patent costs, including related legal costs, as incurred and records such costs as selling, general and administrative expenses in the accompanying statements of operations.

The Company records stock-based compensation expense associated with stock options, restricted stock awards (“RSAs”) and restricted stock units (“RSUs”) issued to employees, members of the Company’s board of directors and consultants in accordance with the authoritative guidance for stock-based compensation. The Company evaluates whether an award should be classified and accounted for as a liability award or equity award for all stock-based compensation awards granted. The cost of an award of an equity instrument is measured at the grant date, based on the estimated fair value of the award using the Black-Scholes option pricing valuation model, or Black-Scholes model, which incorporates various assumptions including expected term, volatility and risk-free interest rate, and is recognized as expense on a straight-line basis over the requisite service period of the award. Share-based compensation for an award with a performance condition is recognized when the achievement of such performance condition is determined to be probable. If the outcome of such performance condition is not determined to be probable or is not met, no compensation expense is recognized, and any previously recognized compensation expense is reversed. Forfeitures are recognized as a reduction of stock-based compensation expense as they occur.

The Company accounts for income taxes using the asset and liability method. Under this method, deferred tax assets and liabilities are determined based on differences between the financial reporting and tax basis of assets and liabilities and are measured using enacted tax rates and laws that are expected to be in effect when the differences reverse. Any resulting net deferred tax assets are evaluated for recoverability and, accordingly, a valuation allowance is provided when it is more likely than not that all or some portion of the deferred tax asset will not be realized.

The Company accounts for uncertainty in income taxes using a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining whether it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon ultimate settlement. An uncertain tax position is considered effectively settled on completion of an examination by a taxing authority if certain other conditions are satisfied. Should the Company incur interest and penalties relating to tax uncertainties, such amounts would be classified as a component of interest expense and other expense, respectively.

Credit risk represents the accounting loss that would be recognized at the reporting date if counterparties failed completely to perform as contracted. Concentrations of credit risk that arise from financial instruments exist for groups of customers or counterparties when they have similar economic characteristics that would cause their ability to meet contractual obligations to be similarly affected by changes in economic or other conditions described below.

Financial instruments, which potentially subject the Company to concentration of credit risk, consist of cash equivalent balances maintained in excess of Federal Depository Insurance Corporation limits, and accounts receivable which have no collateral or security. The Company monitors the financial condition of the banks in which it currently has deposits. The Company has not experienced any significant losses in this respect and believes that it is not exposed to any significant related risk.

Exposure to losses on accounts receivable is dependent upon the individual customer’s financial condition. The Company monitors its exposure to credit losses and reserves for those accounts receivable that it deems to be not collectible.

For the years ended December 31, 2021 and 2020, we had three and four individual customers, respectively, that represented greater than 10% of total net revenues. One individual customer represented greater than 10% of accounts receivable at each of December 31, 2021 and 2020.

The Company recognized revenue on laser sales at the point in time that control transferred to the customer. Control of the product typically transferred upon shipment.

The Company typically provided a 12-month warranty with the purchase of its laser systems. Customers could extend the warranty period through the purchase of extended warranty service contracts. Extended warranty service contracts were sold with contract terms ranging from 12 to 60 months and covered periods after the end of the initial 12-month warranty period. The warranty provided the customer with maintenance services in addition to the assurance that the laser product complied with agreed-upon specifications. Therefore, the warranty service was treated as a separate performance obligation from the laser system. Warranty services were a stand-ready obligation, and the Company recognized revenue on a straight-line basis over the service contract term. Warranty service revenue was included in service and other revenue in the statements of operations.

Certain of the Company’s contracts with customers contained multiple performance obligations. For these contracts, the Company accounted for individual products and services as separate performance obligations if they are distinct, which was if (i) a product or service is separately identifiable from other items in the arrangement and (ii) the customer can benefit from the product or service on its own or with other readily available resources. The transaction price was allocated to the separate performance obligations on a relative standalone selling price basis. The Company determined standalone selling prices based on observable prices of products or services sold separately in comparable circumstances to similar customers.

For multi-year warranty service contracts in which there was a difference between the cash selling price and the consideration in the contract and a significant amount of time between the payment, which was due up-front, and delivery of the services (greater than one year), the Company recorded an adjustment for significant financing to reflect the time value of money. The Company recognized revenue associated with the cash selling price and interest expense using the effective interest method as the Company satisfied its performance obligation(s). The amount of interest expense the Company recognized over the contract term was based on the contract liability balance, which increased for the accrual of interest and decreased as services are provided.

For services contracts that had an original duration of one year or less, the Company used the practical expedient applicable to such contracts and did not adjust the transaction price for the time value of money.

As part of the Company’s adoption of Topic 606, the Company elected to use the following practical expedients:

The Company capitalized costs to obtain contracts that were considered incremental and recoverable, such as sales commissions. The capitalized costs were amortized to selling, general and administrative expense over the estimated period of benefit of the asset, which was the contract term. The Company elected to use the practical expedient to expense the costs to obtain a contract when the amortization period was less than one year.

The Company also derived income pursuant to product operating lease agreements for its Pharos laser systems, prior to the sale of the Dermatology Business. Consequently, the Company retained title to the equipment. Depreciation expense on these leased lasers was recorded to cost of revenues on a straight-line basis. The costs to maintain these leased lasers were charged to cost of revenues as incurred.

These lease arrangements contained one lease component (the laser) and one nonlease component (warranty service) for which the Company elected the practical expedient to not separate the nonlease component from the lease component. The Company accounted for the combined lease component as an operating lease and recognized lease income on a straight-line basis over the lease term.

As an emerging growth company, the Company may elect to adopt new or revised accounting standards when they become effective for non-public companies, which typically is later than public companies must adopt the standards. The Company has elected to take advantage of the extended transition period afforded by the JOBS Act and, as a result, will comply with new or revised accounting standards on the relevant dates on which adoption of such standards is required for non-public companies.