Summary of Significant Accounting Policies	9 Months Ended
Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of presentation The accompanying financial statements have been prepared using accounting principles generally accepted in the United States of America (GAAP). Reverse Stock Split On October 14, 2021, the Company effected a 1-for-6.046 reverse stock split of its outstanding common stock and redeemable convertible preferred stock. Upon the effectiveness of the reverse stock split, all issued and outstanding shares of common stock options to purchase common stock, warrants, instruments convertible to shares, redeemable convertible preferred stock and related share data and per share amounts contained in the accompanying financial statements were retroactively revised to reflect this reverse stock split for all periods presented. The par value of the authorized stock was not adjusted as a result of the reverse stock split. Unaudited interim financial information The accompanying condensed balance sheet as of September 30, 2021, the condensed statements of operations, the condensed statements of redeemable convertible preferred stock and stockholders’ deficit and condensed statements of cash flows for the three and nine months ended September 30, 2020 and 2021 are unaudited. The unaudited interim condensed financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of September 30, 2021 and the results of its operations and its cash flows for the three and nine months ended September 30, 2020 and 2021. The financial data and other information disclosed in these notes related to the three and nine months ended September 30, 2020 and 2021 are also unaudited. The results for the three and nine months ended September 30, 2021 are not necessarily indicative of results to be expected for the year ending December 31, 2021, any other interim periods, or any future year or period. The balance sheet as of December 31, 2020 included herein was derived from the audited financial statements as of that date. Certain disclosures have been condensed or omitted from the interim condensed financial statements. These unaudited interim condensed financial statements should be read in conjunction with the audited annual financial statements and related notes. The significant accounting policies used in the preparation of the unaudited condensed financial statements for the three and nine months ended September 30, 2020 and 2021, are consistent with those discussed in Note 2 to the audited financial statements for the years ended December 31, 2019 and 2020 included in our audited financial statements and notes thereto for the year ended December 31, 2020, included in our prospectus dated October 21, 2021 filed with the U.S. Securities and Exchange Commission (SEC) pursuant to Rule 424(b)(4) under the Securities Act of 1933, as amended (the “Prospectus”).There have been no significant changes in the significant accounting policies or critical accounting estimates since December 31, 2020. Use of estimates The preparation of financial statements in conformity with GAAP 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. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions. Significant estimates and assumptions include accounts receivable allowances, inventory allowances, recoverability of long-term assets, valuation of equity instruments and equity-linked instruments, valuation of common stock, stock-based compensation, valuation of the redeemable convertible preferred stock warrant liability and derivative liabilities, valuation and estimated useful lives of intangible assets, deferred tax assets and related valuation allowances, and impact of contingencies. Fair value of financial instruments The carrying amounts of the Company’s financial instruments, including cash and cash equivalents, accounts receivable, accounts payable, and accrued liabilities, approximate their fair value due to the short-term nature of these assets and liabilities. Based on the borrowing rates currently available to the Company for debt with similar terms and consideration of default and credit risk, the carrying values of the term loans approximate their fair values. Refer to Note 4 for further details. Concentration of credit risk Financial instruments that potentially subject the Company to concentrations of risk consist principally of cash, cash equivalents and accounts receivable. The Company maintains its cash and cash equivalents balances with established financial institutions and, at times, such balances with any one financial institution may be in excess of the Federal Deposit Insurance Corporation (FDIC) insured limits. The Company earns revenue from sale of disposable devices and controllers to customers such as hospitals, ambulatory surgical centers and physician offices. The Company’s accounts receivable are derived from revenue earned from customers. The Company performs ongoing credit evaluations of its customers’ financial condition and generally requires no collateral from its customers. At September 30, 2021 and 2020, and for the periods then ended, no customer accounted for more than 10.0% of accounts receivable or revenue. Concentration of suppliers The Company purchases certain components of its products from a single or small number of suppliers. A change in or loss of these suppliers could cause a delay in filling customer orders and a possible loss of sales, which could adversely affect results of operations; however, management believes that suitable replacement suppliers could be obtained in such an event Deferred Offering Costs Deferred offering costs, consisting of legal, accounting and other fees and costs relating to the Company’s initial public offering (IPO), are capitalized and recorded on the balance sheet. As of September 30, 2021, $2.5 million of deferred offering costs were recorded on the balance sheet under Prepaid expenses and other current assets. The Company successfully completed its IPO in October 2021. Net loss per share attributable to common stockholders Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders, 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 the 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, redeemable convertible preferred stock, redeemable convertible preferred stock warrants, convertible notes, common stock subject to repurchase, and common stock options are considered to be potentially dilutive securities. Basic and diluted net loss attributable to common stockholders per share is presented in conformity with the two-class method required for participating securities as the redeemable convertible preferred stock is considered a participating security because it participates in dividends with common stock. The Company also considers the shares issued upon the early exercise of stock options subject to repurchase to be participating securities, because holders of such shares have non-forfeitable dividend rights in the event a dividend is paid on common stock. The holders of all series of redeemable convertible preferred stock do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders. Because the Company has reported a net loss for the nine months ended September 30, 2021 and 2020, diluted net loss per common share is the same as basic net loss per common share for the two periods presented.

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2021

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of presentation

The accompanying financial statements have been prepared using accounting principles generally accepted in the United States of America (GAAP).

Reverse Stock Split

On October 14, 2021, the Company effected a 1-for-6.046 reverse stock split of its outstanding common stock and redeemable convertible preferred stock. Upon the effectiveness of the reverse stock split, all issued and outstanding shares of common stock options to purchase common stock, warrants, instruments convertible to shares, redeemable convertible preferred stock and related share data and per share amounts contained in the accompanying financial statements were retroactively revised to reflect this reverse stock split for all periods presented. The par value of the authorized stock was not adjusted as a result of the reverse stock split.

Unaudited interim financial information

The accompanying condensed balance sheet as of September 30, 2021, the condensed statements of operations, the condensed statements of redeemable convertible preferred stock and stockholders’ deficit and condensed statements of cash flows for the three and nine months ended September 30, 2020 and 2021 are unaudited. The unaudited interim condensed financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of September 30, 2021 and the results of its operations and its cash flows for the three and nine months ended September 30, 2020 and 2021. The financial data and other information disclosed in these notes related to the three and nine months ended September 30, 2020 and 2021 are also unaudited. The results for the three and nine months ended September 30, 2021 are not necessarily indicative of results to be expected for the year ending December 31, 2021, any other interim periods, or any future year or period. The balance sheet as of December 31, 2020 included herein was derived from the audited financial statements as of that date. Certain disclosures have been condensed or omitted from the interim condensed financial statements. These unaudited interim condensed financial statements should be read in conjunction with the audited annual financial statements and related notes. The significant accounting policies used in the preparation of the unaudited condensed financial statements for the three and nine months ended September 30, 2020 and 2021, are consistent with those discussed in Note 2 to the audited financial statements for the years ended December 31, 2019 and 2020 included in our audited financial statements and notes thereto for the year ended December 31, 2020, included in our prospectus dated October 21, 2021 filed with the U.S. Securities and Exchange Commission (SEC) pursuant to Rule 424(b)(4) under the Securities Act of 1933,

as amended (the “Prospectus”).There have been no significant changes in the significant accounting policies or critical accounting estimates since December 31, 2020.

Use of estimates

The preparation of financial statements in conformity with GAAP 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. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions.

Significant estimates and assumptions include accounts receivable allowances, inventory allowances, recoverability of long-term assets, valuation of equity instruments and equity-linked instruments, valuation of common stock, stock-based compensation, valuation of the redeemable convertible preferred stock warrant liability and derivative liabilities, valuation and estimated useful lives of intangible assets, deferred tax assets and related valuation allowances, and impact of contingencies.

Fair value of financial instruments

The carrying amounts of the Company’s financial instruments, including cash and cash equivalents, accounts receivable, accounts payable, and accrued liabilities, approximate their fair value due to the short-term nature of these assets and liabilities. Based on the borrowing rates currently available to the Company for debt with similar terms and consideration of default and credit risk, the carrying values of the term loans approximate their fair values. Refer to Note 4 for further details.

Concentration of credit risk

Financial instruments that potentially subject the Company to concentrations of risk consist principally of cash, cash equivalents and accounts receivable. The Company maintains its cash and cash equivalents balances with established financial institutions and, at times, such balances with any one financial institution may be in excess of the Federal Deposit Insurance Corporation (FDIC) insured limits.

The Company earns revenue from sale of disposable devices and controllers to customers such as hospitals, ambulatory surgical centers and physician offices. The Company’s accounts receivable are derived from revenue earned from customers. The Company performs ongoing credit evaluations of its customers’ financial condition and generally requires no collateral from its customers. At September 30, 2021 and 2020, and for the periods then ended, no customer accounted for more than 10.0% of accounts receivable or revenue.

Concentration of suppliers

The Company purchases certain components of its products from a single or small number of suppliers. A change in or loss of these suppliers could cause a delay in filling customer orders and a possible loss of sales, which could adversely affect results of operations; however, management believes that suitable replacement suppliers could be obtained in such an event

Deferred Offering Costs

Deferred offering costs, consisting of legal, accounting and other fees and costs relating to the Company’s initial public offering (IPO), are capitalized and recorded on the balance sheet. As of September 30, 2021, $2.5 million of deferred offering costs were recorded on the balance sheet under Prepaid expenses and other current assets. The Company successfully completed its IPO in October 2021.

Net loss per share attributable to common stockholders

Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders, 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 the 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, redeemable convertible preferred stock, redeemable convertible preferred stock warrants, convertible notes, common stock subject to repurchase, and common stock options are considered to be potentially dilutive securities. Basic and diluted net loss attributable to common stockholders per share is presented in conformity with the two-class method required for participating securities as the redeemable convertible preferred stock is considered a participating security because it participates in dividends with common stock. The Company also considers the shares issued upon the early exercise of stock options subject to repurchase to be participating securities, because holders of such shares have non-forfeitable dividend rights in the event a dividend is paid on common stock. The holders of all series of redeemable convertible preferred stock do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders. Because the Company has reported a net loss for the nine months ended

September 30, 2021 and 2020, diluted net loss per common share is the same as basic net loss per common share for the two periods presented.