The complaint

The case is HeartLung Corporation v. SimonMed Imaging Management, LLC, No. 3:26-cv-06085-DMS-BJW (S.D. Cal.), filed October 25, 2026, before Judge Dana M. Sabraw. HeartLung Corporation is a Delaware corporation based in Houston, Texas. It develops AutoBMD, which the complaint describes as an FDA-cleared CT-based bone-density analysis product (K213760). The accused defendants are SimonMed Imaging Management, LLC; Health Diagnostics of California, A Professional Corporation; SimonMed Imaging, LLC; and Cascaid Health, Inc., together with Does 1 through 20. BDI, Inc. and the Lundquist Institute for Biomedical Innovation are joined as nominal defendants under Federal Rule of Civil Procedure 19; HeartLung asserts no infringement claim and no monetary relief against them. Venue is pleaded under 28 U.S.C. 1400(b) based on alleged acts at SimonMed's La Jolla facility in San Diego, California. The complaint is signed by Naveen Madala of Madala Law.

Standing and joinder

The complaint alleges that the Lundquist Institute, formerly the Los Angeles Biomedical Research Institute (LA BioMed), is the record owner of both patents and that the chain of rights runs Lundquist to BDI to HeartLung. According to the complaint, BDI granted HeartLung a royalty-bearing, exclusive, worldwide license or sublicense under both patents by a May 14, 2021 agreement. HeartLung pleads BDI's own upstream rights from BDI's representations and from Lundquist's written description of BDI as its exclusive licensee, and says it has not been given the Lundquist-BDI agreement. HeartLung alleges that BDI and Lundquist dispute whether its grant conveys a unilateral right to sue, that both refused written requests to join or consent to joinder on October 2, 2026, and that joinder is required so the Court can adjudicate the patent rights with all interest holders present. In the alternative, it asks the Court to realign Lundquist as an involuntary plaintiff. HeartLung also has a pending Los Angeles Superior Court action against BDI, Case No. 23STCV20656, filed in August 2023 over the same license agreement.

The complaint also alleges that BDI's counsel wrote in July 2026 that BDI provides software and related services that SimonMed may access under agreements between BDI and SimonMed, and that BDI later described SimonMed as its customer and declined to produce those agreements. HeartLung alleges, on information and belief, that any BDI-SimonMed agreement postdates its May 14, 2021 exclusive grant, and that any such grant exceeded BDI's retained rights and does not authorize the accused conduct.

The patents

Both patents are titled "Method for Thoracic Vertebral Bone Density Measurement by Thoracic Quantitative Computed Tomography." U.S. Patent 9,119,590 issued September 1, 2015, and U.S. Patent 10,695,022 issued June 30, 2020, as a continuation in the same family. USPTO assignment records show one recorded assignment for each patent, from the inventors to the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center (Reel/Frame 026122/0206, recorded April 13, 2011, for the '590 patent, and Reel/Frame 041377/0499, recorded February 24, 2017, for the '022 patent). HeartLung asserts at least method claim 1 of each patent as a representative claim and does not assert the system or machine-readable-medium claims in this pleading.

U.S. Patent 9,119,590 covers a method for determining bone mineral density using phantomless quantitative computed tomography. Claim 1 covers obtaining CT image data representing a heart from a scan performed without a calibration phantom, calculating bone mineral density at three consecutive thoracic spine levels by identifying a first spine level at the site of origin of the left main coronary artery, and determining a thoracic trabecular bone mineral density measurement from those calculations.

U.S. Patent 10,695,022 covers a related phantomless quantitative CT method. Claim 1 covers obtaining CT image data representing a heart, calculating BMD at two or more spine levels starting from the left main coronary artery origin using Hounsfield Unit values, and determining a thoracic trabecular BMD measurement that is normalized to an MDCT BMD using a translation formula with two different constants, without a calibration phantom.

The accused workflow

HeartLung's pre-suit investigation centers on a May 2026 coronary artery calcium examination obtained at SimonMed's La Jolla facility, followed by a SimonMed/Cascaid Health patient-facing bone-density result derived from that examination. The complaint alleges that the result reported a bone-density classification and a T-score, displayed coronal and sagittal vertebral CT images, and was delivered through Cascaid Health's web portal, and that HeartLung's pre-suit investigation indicates no calibration phantom was used.

On information and belief, the accused workflow analyzes thoracic vertebral levels within the cardiac image volume, measures CT attenuation in trabecular bone, and generates a quantitative bone-density output and T-score. HeartLung alleges, also on information and belief, that SimonMed and Cascaid perform the method together or through vendors SimonMed directs and controls, and, in the alternative, that SimonMed induces Cascaid or other vendors under 35 U.S.C. 271(b). The complaint alleges that SimonMed dealt with HeartLung for more than a year over AutoBMD, including a signed contract transmitted to HeartLung on February 1, 2025, then paused and declined to continue the project around April 2025 after HeartLung's counsel raised concerns about a proposed reimbursement-contingent payment structure.

According to the complaint, HeartLung sent SimonMed a cease-and-desist letter on June 3, 2026 identifying both patents and the accused workflow, copied to Cascaid, and a final notice on June 15, 2026. The complaint alleges that SimonMed's continued infringement after the June 3 notice has been willful. Counts I and II allege direct infringement of the '590 and '022 patents by SimonMed and Cascaid under 35 U.S.C. 271(a). Count III alleges induced infringement by the three SimonMed entities under section 271(b), pleaded in the alternative.

The relief sought

HeartLung asks for a judgment that SimonMed and Cascaid infringed both patents and that the SimonMed entities induced infringement, a permanent injunction under 35 U.S.C. 283, damages including lost profits or a reasonable royalty under 35 U.S.C. 284, an accounting, enhanced damages up to three times for willful infringement, an exceptional-case finding and attorneys' fees under 35 U.S.C. 285, joinder of BDI and Lundquist under Rule 19 with adjudication of patent rights among HeartLung, BDI, and Lundquist, including a determination that no BDI grant to any accused defendant authorizes the accused conduct, interest and costs, and preservation and, where appropriate, expedited production of technical and commercial evidence. It demands a jury trial. No infringement judgment or monetary relief is sought against BDI or Lundquist.

What to watch next

Watch for responses on Rule 19 joinder of BDI and the Lundquist Institute, service and answers or Rule 12 motions by the SimonMed defendants and Cascaid, and any motion practice over HeartLung's standing or the BDI-SimonMed agreements.