Overview
Doug Wentzel focuses his practice on patent and trade secret litigation. Doug successfully represents clients in district courts across the country and before the International Trade Commission (ITC), Patent Trial and Appeal Board (PTAB), and Patent Office. Doug is adept at understanding complex technologies and has assisted clients in cases covering a broad spectrum of technologies, including wearable health devices, minimally invasive heart repair devices, respiratory therapy products, automotive shock absorbers, microdermabrasion systems, and more. Doug also has experience litigating design patents.
Among other client successes, Doug played an integral role in a high-profile ITC investigation resulting in an import ban of the Apple Watch, and in persuading both the PTAB and the Patent Office not to institute challenges to the patents underlying the import ban.
Doug is actively involved in the legal community and is a co-chair of the Young Lawyers Division of the Federal Bar Association’s Orange County Chapter.
Education
- University of Pennsylvania Law School (J.D., 2016), cum laude
- Drexel University (B.S. Civil Engineering, 2013), summa cum laude
Representative Experience
Masimo Corp. et al. v. Apple Inc., Case No. 8:20-cv-00048 (C.D. Cal.)
Doug Wentzel is a core member of the Knobbe Martens team representing Masimo and Cercacor Laboratories against Apple in various forums. Mr. Wentzel is deeply involved in handling Masimo’s patent liability and technical trade secret claims in a case pending in the Central District of California. After a November 2025 trial, the jury found Apple infringed Masimo’s patent and awarded more than $634 million in damages.
Apple Inc. v. Masimo Corp. et al., Case Nos. 1:22-cv-01377 and -01378 (D. Del)
Mr. Wentzel is a key member of the Knobbe Martens team representing Masimo in a case pending in the District of Delaware, where Masimo asserts patent infringement, antitrust, and false advertising claims against Apple.
Apple Inc. v. Masimo Corp., Case Nos. IPR2022-01271 through -01276 (USPTO)
Successfully defended Masimo against Apple’s six petitions for inter partes review of the Masimo pulse oximetry patents that formed the basis of the ITC exclusion order banning the import of certain Apple watches. The Patent Office declined to institute all six IPR petitions.
In re Certain Light-Based Physiological Measurement Devices and Components Thereof, Inv. No. 337-TA-1276 (ITC)
Successfully represented Masimo against Apple in ITC investigation relating to infringement of Masimo’s patented pulse oximetry technology. Obtained exclusion order and cease and desist order banning Apple from importing and selling certain Apple Watches.
Fisher & Paykel Healthcare Ltd. v. Flexicare Inc., Case No. 8:19-cv-00835 (C.D. Cal.)
Successfully represented Fisher & Paykel Healthcare in asserting multiple patents relating to respiratory care products. Obtained summary judgment of patent infringement. Achieved favorable case-dispositive settlement before trial.
In re Certain Sleep Disordered Breathing Treatment Systems and Components Thereof, Inv. No. 337-TA-1022 (ITC)
Successfully represented Fisher & Paykel Healthcare in ITC investigation relating to alleged infringement of patents on patient interfaces for sleep apnea therapy. After obtaining a favorable evidentiary ruling for Fisher & Paykel Healthcare, patentee unilaterally withdrew its complaint and terminated the investigation.
Recognition
Awards & Honors
- Recognized as a Rising Star in Managing IP‘s “IP Stars” guide (2023-2026)
- Recognized in the “Best Lawyers 2026 Guide: Ones to Watch” for Intellectual Property Litigation, Patent Litigation, and Patent Law in Best Lawyers in America (2025)
News & Insights
Articles
Co-author, “35 U.S.C. § 325(d) Petition Practice in Ex Parte Reexaminations,” Reuters Westlaw, October 2024.
Co-author, “Tips for Patent Prosecutors from Litigators: Enhancing Litigation Outcomes,” IP Watchdog, August 2024.
Stays Pending Inter Partes Review: Not in the Eastern District of Texas, 98 J. Pat. & Trademark Off. Soc’y 120 (2016)
Uber & Alice: Could One Patent Really Take Down this Ridesharing Giant?, 98 J. Pat. & Trademark Off. Soc’y 86 (2016)
Editor and Contributor, KnobbeMedical.com Blog
- AI & the FDA
- Developments in Patent Disputes Between Apple and Alivecor
- Apple Watch Found to Infringe AliveCor ECG Patents
- Medical device innovations and IP: A strategy is everything.
- BioNTech to Ship Modular mRNA Vaccine Factory to Rwanda
- AI and Cancer Diagnostics
- Federal Circuit Reverses District Court’s Decision Based on On-Sale Bar (Junker v. Medical Components, Inc.)
- FDA Seeks $7.2 Billion Budget for 2024
- FDA: Approval for Novel Medical Devices Remains a High Priority, Despite COVID-19
- FDA Breakthrough Device Designation for Biology-Guided Radiotherapy (‘BgRT’) Device
- Alpha Tau Receives FDA Breakthrough Device Designation for Alpha DaRT Treatment of GBM
- Medical Device Trade Secret Not Publicly Disclosed via Patenting, Displaying, and Selling Covered Product, 7th Cir. Affirms
- FDA Taking Steps to Prevent Future Medical Device Shortages
- Boston Scientific To Acquire Blood Clot Removal Tech Company Devoro Medical
- Stryker to Acquire Surgical Smoke Evacuator Company SafeAir
- Materialise Receives First-Ever 510(k) Clearance for Anatomical Model 3D Printing Software
- FDA Issues Final Guidance on Software as a Medical Device
- Testing of Jenex TherOZap™ Device Set to Begin
Editor and Contributor, Knobbe Martens Litigation Blog
- Federal Circuit Sheds Light on “Skilled Searcher” Standard for IPR Estoppel
- Invisible but Invalidating: Undisclosed Functionality Still Triggers On-Sale Bar
- How Ignoring Disclosed Structure Can Derail a Means-Plus-Function Case
- Words Matter: “Identical” Does Not Mean “Identical to a Portion Of”
- Sunkist Squeezes Out a Win and Kisses Kist Goodbye!
- Patent Claims Applying Machine Learning Methods to New Environment Do Not Withstand § 101 Scrutiny
- Equitable Estoppel: Misleading Silence Not Enough Unless It Was Relied on and Caused Prejudice
- The Board Must Provide Reasoned Explanation When Discarding Material, Unrebutted Evidence
- Where Method Claim Steps Are Connected by “And,” a Covered Method Must Perform Each Step
- Every Word Counts: Specification Naming Conventions Can Limit Claim Scope
- A Patent Must Describe What Is Claimed, Not What Infringes
- “Quotation” Letter Found to Constitute Offer Invalidating Patents
- Resolving Claim Construction Dispute at 12(b)(6) Stage May Be Error if Specification Indicates Claim Term Does Not Have its Plain Meaning
- Combining Abstract Ideas Does Not Make Them Less Abstract
- An Expert Witness Need Not Have Been a Posita at the Time of the Invention
- Skinny Labeling May Not Be Enough to Avoid Induced Infringement Allegations
- Unclean Hands and Inequitable Conduct: Dishonesty Is Not the Best Policy
- Claimed Ranges Overlapping the Prior Art Can Lead To Short Patent Shelf-Life
- Exhibit Combustion: Disavowing Contradictory Statements Contained in Complaint Exhibits
- The Patent Ineligibility of Digital Imaging Processing Method Claims
- Incorporation by Reference: Patent Portfolio Builder or Destroyer?
- “Filtering” Appropriate Claim Construction Reasoning
- In Re Oath Holdings Inc.
- Result-Oriented Claims Based on Natural Laws Held Invalid Under § 101
