Note 5 — Debt

The following tables set forth a summary of the debt instruments and their changes during the three and nine months ended September 30, 2026 and 2025 (in thousands):

Convertible Notes

Convertible Loans Payable

As of September 30, 2026, the Company had issued $15.3 million in aggregate of Ascent PIPE Notes: approximately $12.2 million in 2025 (“2025 Ascent PIPE Notes”), $1.7 million in April 2026 (“Q2’26 Ascent PIPE Notes” or “April 2026 Ascent PIPE Notes”) and $1.4 million in August and September 2026 (“Q3’26 Ascent PIPE Notes”).

The 2025, Q2’26 and Q3’26 Ascent PIPE Notes bear interest at 10%, 12% and 7% per annum, respectively. Interest accrues on the outstanding unconverted principal balance, and a minimum interest amount equal to 10% of the original principal is fully earned at issuance, reduced by interest subsequently accrued. Cash payments are subject to a 5% fee. Upon an event of default, the interest rate on the 2025 and Q2’26 Ascent PIPE Notes increase to 24% per annum, while the Q3’26 Ascent PIPE Notes bear a default rate of 18%. In addition, a 10% late fee applies to overdue amounts on all Ascent PIPE Notes. The Q3’26 Ascent PIPE Notes are subject to monthly interest and principal payments, and can be made in either cash or shares. The 2025 Ascent PIPE Notes, the April 2026 Ascent PIPE Notes, and August Ascent PIPE Notes mature in January 2027, April 2027 and August 2027, respectively. The September Ascent PIPE Notes mature on the earlier of their one year anniversary from issuance date or the closing of the exercise of the Company’s G3 Call Option under the Option Agreement. See Note 7 for further details on the Option Agreement.

The Ascent PIPE Notes are convertible at the holder’s option at a conversion price equal to the lower of the applicable conversion price or 95% of the lowest daily volume-weighted average price (“VWAP”) of the Company’s common stock during the 10 trading days immediately preceding the applicable conversion date, subject to the applicable floor price and customary anti-dilution protections. The Ascent PIPE Notes may be prepaid upon 10 business days’ prior notice (absent an event of default), subject to Ascent’s conversion rights, and requires mandatory prepayment upon Subsequent Offerings, as defined by the PIPE Subscription Agreement. Conversion is subject to a beneficial ownership cap of 9.99%.

Amendment No. 4

On April 2, 2026, the Company entered into Amendment No. 4 to the PIPE Subscription Agreement and related Pledge Agreement with Ascent (“Amendment No. 4”). Under Amendment No. 4, the Company may, subject to the terms and conditions of the amended agreements, request additional funding through the issuance of convertible promissory notes with an aggregate principal amount of up to $12.2 million, which the investor may elect to purchase at its discretion. This financing capacity is separate from the $12.2 million of aggregate principal issued during 2025 and results in aggregate principal issuance capacity of approximately $24.4 million under the amended financing arrangement. Amendment No. 4 also revised the Pledge Agreement release condition so that it is satisfied upon payment in full, in cash or through conversion, of the $1.7 million of notes issued in the April 2026 additional closings. Mandatory prepayments received will be applied first to the April 2026 Ascent PIPE Notes and then to previously issued notes.

Ascent Warrant

As consideration for Ascent’s participation in the April 2, 2026 closing, Ascent earned a warrant to purchase 11,111 shares of common stock, as adjusted for the July and August Reverse Stock Splits. On April 20, 2026, in connection with the second April closing and a side letter under which Ascent waived certain defaults, the Company issued a replacement warrant (the “Ascent Warrant”) for 33,333 shares at an exercise price of $50.00 per share, as adjusted for the July and August Reverse Stock Splits. The Ascent Warrant is exercisable on a cash or cashless basis through April 20, 2031, and is subject to a 9.99% beneficial ownership limitation and customary anti-dilution adjustments. During the nine months ended September 30, 2026, the Company recognized aggregate financing costs of $2.2 million related to the Ascent Warrants, consisting of $0.8 million associated with the initial issuance of the warrants on April 2, 2026, and $1.4 million of incremental fair value resulting from the April 20, 2026 modification. These amounts were expensed as incurred within financing costs, net on the Company’s condensed consolidated statements of operations. See Note 9 for the inputs used to estimate the fair value of the warrant. The Company also granted Ascent demand and piggyback registration rights for the underlying shares. Ascent’s 120-day lock-up on the underlying shares expired on August 22, 2026.

On April 29, 2026, the Company and Ascent amended the Ascent Warrant to eliminate its automatic conversion or assumption in fundamental transactions.

Amendment No. 5

On August 12, 2026, the Company and Ascent entered into Amendment No. 5 to the PIPE Subscription Agreement, which added a new form of Senior Secured Convertible Promissory Note for additional closings, revised the definition of “Note” accordingly, and reduced the exercise price of the Ascent Warrant to $4.28 per share (as adjusted for the August Reverse Stock Split). Except as modified by Amendment No. 5, all other terms remained in effect. See Note 9 for the fair value inputs and the accounting effect of the repriced warrant. The Company completed an additional closing on the same date, issuing a note with a principal amount of $0.7 million for cash proceeds of $0.7 million.

Share Exchange Agreement

On August 19, 2026, the Company and Ascent entered into a Share Exchange Agreement where all Ascent PIPE Notes issued through August 12, 2026, representing aggregate payable amounts of approximately $6.1 million at the time the agreement was signed, will be exchanged for Series A Non-Voting Preferred Stock at a rate of 0.93458 shares of Series A Preferred Stock for every $1,000. The exchange will be effective on the date the Company delivers a Call Notice to G3. See Note 7 for further details on the Company’s G3 Call Option.

The Company evaluated the impact of the Share Exchange Agreement on the outstanding Ascent PIPE Notes under ASC 470-50 and determined that the addition of a substantive conversion feature resulted in substantially different terms from the original notes. Accordingly, the Company accounted for the Share Exchange Agreement as a debt extinguishment and recognized a loss on extinguishment of debt of approximately $6.4 million during the three and nine months ended September 30, 2026.

September 2026 Closings

The Company completed two additional closings in September 2026 and issued notes with aggregate principal of approximately $0.7 million for aggregate cash proceeds of $0.6 million.

During the three and nine months ended September 30, 2026, the Company repaid zero and $1.0 million, respectively, of principal on the Ascent PIPE Notes. During the three and nine months ended September 30, 2025, the Company repaid $0.6 million of principal on the Ascent PIPE Notes. Ascent converted an aggregate of $5.2 million and $7.2 million of principal and accrued interest balance into 2,032,092 and 2,059,060 shares, respectively, of the Company’s common stock during the three and nine months ended September 30, 2026. The shares of common stock issued during the three and nine months ended September 30, 2026 had a total fair value of $7.2 million and $11.9 million, respectively, upon conversion. Ascent did not convert their principal for shares during the three and nine months ended September 30, 2025.

As of September 30, 2026, the convertible loans payable had a fair value of $2.6 million and it is classified under Convertible senior notes and loans payable at fair value on the condensed consolidated balance sheets, as the loan is due within 12 months from the balance sheet date. As of December 31, 2025, the convertible loans payable was fair valued at $7.9 million and was classified as long-term in the condensed consolidated balance sheets under convertible loans payable at fair value. As of September 30, 2026 and December 31, 2025, the Company had accrued interest of $0.2 million and $0.7 million on the convertible loans payable.

Tasly Convertible Note - Related Party

In June 2023, the Company entered into a short-term loan agreement with a related party for borrowings of up to $1.6 million, the full amount of which had been drawn by February 2024.

The loans bear interest at a rate of 12% per annum and originally matured on December 31, 2023. The original maturity date was extended to March 31, 2024, subject to the parties’ decision to extend thereafter. Upon an event of default, the interest rate increases to 24% per annum until the payment date. The lender has the option to convert the entire outstanding balance and accrued but unpaid interest under the Tasly Convertible Note into either (i) senior unsecured promissory notes on substantially the same terms as the outstanding Convertible Senior Notes, or (ii) the Company’s common stock at a conversion price of $14,400.00 per share, as adjusted for the Reverse Stock Splits.

The Company elected to apply the fair value option to account for the Tasly Convertible Note and as such, no features of the Tasly Convertible Note are bifurcated and separately accounted for. The fair value of the Tasly Convertible Note, inclusive of accrued interest was $2.7 million and $2.3 million as of September 30, 2026 and December 31, 2025, respectively. There was accrued interest of $1.1 million and $0.7 million as of September 30, 2026 and December 31, 2025, respectively, on the Tasly Convertible Note.

The Tasly Convertible Note is recorded under convertible and promissory notes payable to related parties on the condensed consolidated balance sheets.

Convertible Promissory Note – Related Party

In connection with the Business Combination, the Company assumed a convertible working capital promissory note issued by Northview to NVAC, the sponsor of Northview (the “Sponsor”). The related party convertible promissory note is non-interest bearing and became convertible on the Closing Date. As originally issued, the Sponsor could convert all or a portion of the unpaid principal into warrants at $7,500.00 per warrant. On March 20, 2026, the maturity date was extended from January 11, 2026 to December 31, 2026.

The Company elected to apply the fair value option to account for the convertible promissory note and as such, no features of the convertible promissory note are bifurcated and separately accounted for.

On April 24, 2026, the Company and NVAC entered into a Note Modification and Conversion Agreement that established the outstanding principal balance at $1.9 million, retained the December 31, 2026 maturity date, and provided NVAC the option to convert the outstanding principal into shares of the Company’s common stock. On April 29, 2026, the parties entered into Amendment No. 1, which restricted issuance of conversion shares above 19.99% of the Company’s issued and outstanding common stock absent stockholder approval. An earlier April 6, 2026 amendment updated the conversion price and concurrently approved the potential conversion of the entire outstanding principal balance of $1.9 million was rescinded on April 7, 2026, and no shares were issued for that amendment. The Company’s stockholders approved issuances of the Company common stock for the conversion of the note above the 19.99% limit on June 23, 2026, which terminated the restriction.

On July 31, 2026, the Company and NVAC entered into Amendment No. 2, which (i) increased the beneficial ownership limitation to 49.9% of the Company’s outstanding common stock following conversion, (ii) set the conversion price at $4.24 per share, the closing price on July 31, 2026, as adjusted for the August Reverse Stock Split, and (iii) provided that shares issuable on conversion equal 122% of the principal converted divided by the conversion price. On August 12, 2026, the Company and NVAC entered into Amendment No. 3, which set the conversion price at the higher of (i) $4.28 per share, as adjusted for the August Reverse Stock Split, and (ii) the closing price on the trading day before the conversion notice.

The Company evaluated Amendments No. 2 and No. 3 under ASC 470-50 and determined that each represented an extinguishment, because the change in fair value of the embedded conversion feature exceeded 10% of the carrying amount of the note immediately before the amendment. Accordingly, the Company recognized an aggregate of $1.5 million in losses on extinguishment for the note during the three and nine months ended September 30, 2026.

On August 12, 2026, NVAC converted $1.1 million of principal into 301,991 shares of the Company’s common stock at a conversion price of $4.28 per share. The Company accounted for the transaction as a contractual conversion under ASC 470-20. Immediately prior to the conversion, the Company remeasured the NVAC convertible promissory note to fair value in connection with Amendment No. 3. Upon conversion, the Company derecognized the note’s carrying amount attributable to the converted portion, with a corresponding increase to common stock and additional paid-in capital. No additional gain or loss was recognized upon conversion. Approximately $0.8 million of principal outstanding following the conversion and it continues to be measured under the fair value option.

As of September 30, 2026 and December 31, 2025, the convertible promissory note fair value of $1.0 million and $1.9 million, respectively, was classified under convertible and promissory notes payable to related parties on the condensed consolidated balance sheets.

Junior Convertible Notes

The annual effective interest rate for the junior convertible notes was estimated between 12.54% to 53.28% for the nine months ended September 30, 2025. Interest expense for the three and nine months ended September 30, 2025 was $0.1 million and $1.2 million, respectively. The junior convertible notes were converted into 373 shares of the Company’s common stock based on $19.6 million of principal and accrued interest during the three and nine months ended September 30, 2025, as adjusted for the Reverse Stock Splits. As of September 30, 2026, the Company does not have an outstanding balance of junior convertible notes.

Convertible Senior Notes

As of September 30, 2026, the Company does not have an outstanding balance of convertible senior notes. During the three and nine months ended September 30, 2026, the Company settled less than $0.1 million of principal and accrued interest with the issuance of 42.835 shares of Series A Non-Voting Convertible Preferred Stock. The fair value of shares issued was determined to be less than $0.1 million, resulting in the recognition of less than a $0.1 million gain on extinguishment of debt during the three and nine months ended September 30, 2026.

The annual effective interest rate of convertible senior notes was estimated between 0% to 12.15% for the nine months ended September 30, 2025. The annual effective interest rate on the convertible senior notes for the three and nine months ended September 30, 2026 was not meaningful due to the immaterial outstanding balance.

The interest expense for the three and nine months ended September 30, 2026 was not material. Interest expense for the three and nine months ended September 30, 2025 was $0.1 million and $1.3 million, respectively.

Promissory Notes

The carrying value of the promissory notes as of September 30, 2026 and December 31, 2025 was $0.4 million and $1.0 million, respectively, representing past due amounts because the maturity dates of the promissory notes has passed. During the three and nine months ended September 30, 2026, the Company settled $0.7 million of principal and accrued interest, of which $0.4 million was held by a related party, with the issuance of 623.851 shares of Series A Non-Voting Convertible Preferred Stock. The fair value of shares issued was determined to be $0.3 million, resulting in the recognition of $0.4 million in gain on extinguishment of debt during the three and nine months ended September 30, 2026. The Company determined that the settlement represented a transaction with the related party in its capacity as a creditor rather than as a shareholder and, accordingly, recognized the resulting gain on extinguishment of debt in earnings rather than as a capital contribution within stockholders’ equity (deficit).

As of September 30, 2026 and December 31, 2025, outstanding balance of promissory notes due to related parties was zero and $0.4 million, respectively, and are classified under convertible and promissory notes payable to related parties and the remainder is classified under promissory notes on the condensed consolidated balance sheets. Interest expense on the Company’s promissory notes was less than $0.1 million for three and nine months ended September 30, 2026 and 2025.

Paycheck Protection Program (“PPP”) Loan

The Company applied for forgiveness of the 2nd PPP Loan in December 2025 and was notified in February 2026 that the loan had been forgiven. The Company recognized a gain on the extinguishment of the 2nd PPP Loan of $1.4 million within gain on extinguishment of debt in the condensed consolidated statements of operations during the nine months ended September 30, 2026. Interest expense on the PPP loan for the nine months ended September 30, 2026 was not material. Interest expense on the PPP loan for the three and nine months ended September 30, 2025 was not material.

Director and Officer (D&O) Insurance Financing Loan

During the nine months ended September 30, 2026, the Company made aggregate payments of $0.3 million against the obligation and recognized approximately $0.3 million of insurance expense and an immaterial amount of interest expense. As of September 30, 2026 and December 31, 2025, the remaining financing obligation was $0 and $0.3 million, respectively, which is recorded under promissory notes and other on the Company’s condensed consolidated balance sheets.

Summary of Outstanding Borrowings

As of September 30, 2026, the Company had outstanding borrowings with aggregate carrying amounts of approximately $6.8 million, all of which were classified as current liabilities. Certain of the Company’s borrowings are measured at fair value under the fair value option, and their carrying amounts may differ from the contractual principal and interest payable upon maturity or settlement. The contractual maturity dates, interest provisions, conversion features, and other significant terms of the Company’s outstanding borrowing arrangements are described above.