Wrist SP Biotech v. Masimo: Pulse Oximeter Patent Case Transferred to C.D. California
Wrist SP Biotech, LLC asserted US11331015B2 against Masimo Corp.'s LNCS-NEO-L-3 Pulse Oximeter in the Western District of Texas. Within 125 days, the case was transferred to the Central District of California on a stipulated motion by both parties under 28 U.S.C. § 1404(a).
Patent Infringement Action Rerouted Before Any Merits Ruling
On August 25, 2023, Wrist SP Biotech, LLC filed a patent infringement action against Masimo Corp. in the United States District Court for the Western District of Texas (Case No. 6:23-cv-00632) before Judge Fred Biery. The asserted patent is US11331015B2 (application no. US16/569066), and the accused product is Masimo's LNCS-NEO-L-3 Pulse Oximeter. Plaintiff was represented by Joseph J. Zito and William P. Ramey III of Ramey LLP and Whitestone Law.
The case did not advance to any substantive merits ruling in Texas. Both parties jointly filed a Stipulated Motion to Transfer to the Central District of California and Extend Answer Deadline (Docket No. 13). The court granted the transfer pursuant to 28 U.S.C. § 1404(a), formally transferring the case to the U.S. District Court for the Central District of California. The answer deadline was extended to 21 days after the case was docketed in the transferee court, unless that court ordered otherwise.
The stipulated nature of the transfer — agreed by both parties — suggests the venue change was uncontested, though the specific reasons motivating the agreement are not disclosed in the available record. The case closed in Texas after just 125 days without any ruling on infringement, validity, or claim construction. Substantive proceedings, if any, will continue in the Central District of California.
See Complete Case & Patent Analysis →Filing to Case Transferred in 125 days
Case resolved by transfer in 125 days — before any merits ruling
US11331015B2 — Pulse Oximetry Monitoring Technology
Any organization developing, manufacturing, or commercializing pulse oximetry sensors, wearable health monitors, or patient monitoring systems should assess their exposure to US11331015B2. This patent has been asserted against a high-profile clinical device (Masimo's LNCS-NEO-L-3), suggesting the patent holder believes the claims extend broadly across sensor product lines. R&D teams building next-generation oximetry hardware or signal processing systems face the greatest risk if their designs fall within the asserted claim scope.
Official order — verbatim text
The court's transfer order is procedural in nature — it resolves only the question of venue and expressly does not adjudicate infringement, validity, or any other substantive patent issue. The stipulated character of the motion means both parties consented to the transfer, removing any adversarial venue dispute from the Texas docket. All merits questions under US11331015B2 remain open for resolution by the Central District of California.
What a 28 U.S.C. § 1404(a) transfer means for this case
A transfer under 28 U.S.C. § 1404(a) moves the entire civil action to a different federal district court 'in the interest of justice' or for the convenience of parties and witnesses. Crucially, it is not a dismissal — the case survives intact and continues in the transferee court. Here, both parties stipulated to the transfer, meaning the court did not need to weigh competing venue factors; it simply granted the agreed motion.
No merits decided in TexasCentral District of California: a major patent venue
The Central District of California is one of the busiest patent litigation venues in the United States, particularly for technology and consumer electronics disputes. Masimo Corp. is headquartered in Irvine, California, which falls within the Central District. This geographic connection to the defendant's home district is a common rationale for § 1404(a) transfers, though the specific reasons behind the stipulation are not stated in the available record.
Litigation continues in C.D. Cal.Wrist SP Biotech's claim survives — venue shifts, not dismissed
Because the case was transferred rather than dismissed, Wrist SP Biotech's infringement claim under US11331015B2 remains live. The plaintiff retains the right to pursue its case in the Central District of California. The extended answer deadline — 21 days after docketing in the transferee court — preserves the procedural timeline for both sides as the case is re-seated.
Claims still live in C.D. Cal.Masimo faces litigation in its home district
For Masimo Corp., the transfer to the Central District of California — proximate to its Irvine headquarters — may afford logistical advantages regarding witnesses, documents, and local counsel. However, the substantive infringement dispute over the LNCS-NEO-L-3 Pulse Oximeter and US11331015B2 remains unresolved. The extended answer deadline gives Masimo additional time to prepare its initial response in the new venue.
Merits dispute continuesFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Wrist SP Biotech, LLC | Company | /Search in Eureka ↗ |
| Defendant | Masimo, Corp. | Company | /Search in Eureka ↗ |
| Plaintiff counsel | Joseph J. Zito | Attorney | Counsel for Wrist SP Biotech, LLCSearch in Eureka ↗ |
| Plaintiff counsel | William P. Ramey , III | Attorney | Counsel for Wrist SP Biotech, LLCSearch in Eureka ↗ |
| Plaintiff law firm | Ramey LLP | Law Firm | Representing Wrist SP Biotech, LLCSearch in Eureka ↗ |
| Plaintiff law firm | Whitestone Law | Law Firm | Representing Wrist SP Biotech, LLCSearch in Eureka ↗ |
| Presiding judge | Judge Fred Biery | Judge | Texas Western District CourtSearch in Eureka ↗ |
R&D signals in the pulse oximetry & patient monitoring space
Forward-looking patent and innovation intelligence drawn from the Wrist SP Biotech v. Masimo dispute and the broader pulse oximetry technology landscape.
Wrist SP Biotech's filing activity in oximetry monitoring
Wrist SP Biotech, LLC holds at least US11331015B2 in the pulse oximetry domain. Understanding the breadth of the entity's portfolio — including related continuations or family members — is critical for any company operating in patient monitoring. A portfolio review can reveal whether additional patents cover adjacent sensor, signal, or system technologies beyond the claims asserted in this action.
Portfolio breadth riskPatent filing trends in non-invasive pulse oximetry
Non-invasive pulse oximetry is a rapidly evolving field, with active filing by medical device OEMs and consumer wearable manufacturers. Filing trends around optical sensor design, motion artifact reduction, and multi-wavelength photoplethysmography (PPG) signal processing indicate where innovation and IP density are concentrating. Mapping these trends helps R&D teams identify crowded areas and emerging white space.
High filing activityMasimo's patent portfolio in physiological monitoring
Masimo Corp. is a prolific filer in the physiological monitoring space, with an extensive portfolio covering SET (Signal Extraction Technology), rainbow pulse oximetry, and multi-parameter patient monitoring. Understanding Masimo's own IP position is essential for competitors assessing freedom-to-operate and for evaluating whether Masimo may assert counterclaims as the case proceeds in C.D. California.
Masimo IP strengthAdjacent innovation gaps near US11331015B2 claim space
Enforcement activity around US11331015B2 highlights that certain pulse oximetry sensor architectures may carry assertion risk. R&D teams can use claim-mapping and white-space analysis to identify design-around pathways — particularly in alternative sensor geometries, signal processing algorithms, or wireless patient monitoring architectures — that sit adjacent to the asserted claims but outside their scope.
Design-around opportunitySimilar pulse oximetry patent cases in U.S. district courts
Explore comparable patent infringement actions involving pulse oximetry and patient monitoring technology litigated in the Western District of Texas and Central District of California.
What this transfer signals for the pulse oximetry IP landscape
A stipulated venue transfer within 125 days signals early strategic alignment — and defers all substantive patent risk to C.D. California.
Stipulated transfers in patent cases often precede negotiated outcomes
When both plaintiff and defendant jointly move to transfer venue before any claim construction or discovery, it typically signals that the parties are managing costs and convenience rather than immediately contesting on the merits. Competitors monitoring Masimo's patent exposure in pulse oximetry should track the C.D. California docket for any further developments on US11331015B2.
W.D. Texas remains a filing destination despite transfer risk
Wrist SP Biotech's initial choice of the Western District of Texas — a historically plaintiff-friendly patent venue — followed a recognizable playbook. The subsequent transfer to C.D. California shows that a defendant with strong jurisdictional ties to another district can negotiate a venue change even before answering, a dynamic relevant to any company assessing litigation risk in Texas.
Wrist v Masimo — key questions answered
Wrist SP Biotech, LLC filed a patent infringement action against Masimo Corp. in the Western District of Texas on August 25, 2023, asserting US11331015B2 against the Masimo LNCS-NEO-L-3 Pulse Oximeter. The case was transferred to the Central District of California on a stipulated motion by both parties under 28 U.S.C. § 1404(a) and closed in Texas on December 28, 2023 — 125 days after filing — with no merits ruling.
The transfer was ordered pursuant to 28 U.S.C. § 1404(a) on a joint stipulated motion filed by both parties (Docket No. 13). The specific reasons motivating the stipulation are not disclosed in the available Texas docket record. Masimo Corp. is headquartered in Irvine, California, which falls within the Central District of California, a fact that is consistent with convenience-based venue transfer rationales.
The single patent asserted is US11331015B2 (application number US16/569066), which relates to pulse oximetry monitoring technology. It was asserted against Masimo's LNCS-NEO-L-3 Pulse Oximeter. The case has been transferred to the Central District of California, where substantive proceedings on the patent's infringement and validity remain open.
No. A transfer under 28 U.S.C. § 1404(a) is not a dismissal. The infringement action survives intact and continues in the Central District of California. The Texas court's transfer order also extended Masimo's deadline to answer or otherwise respond to the complaint until 21 days after the case is docketed in the transferee court, unless the Central District orders otherwise.
The case signals active enforcement of US11331015B2 in the pulse oximetry domain against a leading clinical monitoring device manufacturer. Companies developing or sourcing pulse oximetry sensors or patient monitoring systems should evaluate their freedom-to-operate position against US11331015B2. The transferred case in C.D. California will be the venue to watch for claim construction rulings and any further developments on the merits.
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