Clean Alert Innovations Sues Sensirion Holding Over an Air Filter Clogging Detector Patent, Seeking Past Damages Only.

The complaint

The case is Clean Alert Innovations, LLC v. Sensirion Holding AG, No. 2:26-cv-00797 (E.D. Tex., Marshall Division), a six page complaint for patent infringement filed September 8, 2026, ECF No. 1, with the patent and a claim chart attached as exhibits. The docket shows the case assigned to District Judge Rodney Gilstrap on September 8. The complaint describes Clean Alert as a Delaware limited liability company based in Wilmington, Delaware, and Sensirion Holding AG as a Swiss corporation based in Stäfa, Switzerland. It alleges, on information and belief, that a Swiss affiliate develops, manufactures, and exports the accused products and that a U.S. subsidiary with a place of business in Chicago imports, offers, and sells them in the United States, including in the district.

Jurisdiction and venue

The complaint alleges, on information and belief, that Sensirion placed the accused products into the stream of commerce through subsidiaries, distributors, and resellers expecting them to reach customers in the district, and pleads in the alternative personal jurisdiction under Federal Rule of Civil Procedure 4(k)(2). It pleads venue under 28 U.S.C. 1391(c)(3) because Sensirion is a foreign corporation.

What the patent covers

U.S. Patent 7,178,410, Clogging Detector for Air Filter, issued February 20, 2007; the complaint says the application was filed March 21, 2005 and alleges the patent expired on May 13, 2025, so it seeks damages for past infringement only. The asserted claim, method claim 12, covers monitoring the degree of gas filter clogging by positioning a gas flow sensor in a stream of gas, determining a reference gas flow rate through a clean filter, computing an alarm threshold as a fraction of that reference level, setting the threshold, monitoring the current flow rate during normal operation, comparing it with the threshold, and producing an indicative signal when the current flow rate crosses the threshold. The complaint alleges Clean Alert is the assignee of all right, title, and interest in the patent.

The accused products

The complaint alleges that Sensirion directly infringed method claim 12 in the district by performing and using the method with the Sensirion SDP800 series differential pressure sensors and the products identified in its claim chart, and by having its employees in the United States test and use them. The chart, Exhibit 2, compares claim 12 with the SDP800 sensor's filter monitoring function, citing Sensirion web pages. The complaint alleges, on information and belief, that numerous other infringing devices were made, used, sold, imported, and offered for sale by Sensirion or its customers.

The relief sought

Clean Alert asks for judgments that the patent is valid and enforceable and that Sensirion directly infringed it, an accounting, damages for past infringement under 35 U.S.C. 284 with interest, a finding that the case is exceptional under 35 U.S.C. 285 with attorneys' fees, costs, and other relief. It demands a jury trial.

What to watch next

The docket shows a summons issued to Sensirion Holding AG on September 8, 2026. Watch for service on the Swiss defendant and an answer or Rule 12 motion. The case can end at any time, including by settlement or voluntary dismissal.