How Two People's Body Movements Are Tracked in Augmented Reality
This patent describes a system for two users to accurately track their body parts, like a limb, relative to their own head-mounted display using magnetic fields, then display these virtual limbs in a shared augmented reality.
Original patent title: “Method and apparatus for multiple user self-relative tracking for augmented reality systems using magnetic tracking”
This patent describes a system for two users to accurately track their body parts, like a limb, relative to their own head-mounted display using magnetic fields, then display these virtual limbs in a shared augmented reality. Granted to Sixense Enterprises in 2019 with 14 claims, and it is expected to expire in 2039.
Coverage
What does this patent actually cover?
This system allows two users wearing head-mounted displays (HMDs) to see their own and each other's virtual limbs in an augmented reality (AR) environment. Each HMD has its own tracking system to know its absolute position in the real world (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1). For each user, a magnetic tracking system is used, with one magnetic coil attached to their HMD and another to a limb, like an arm or leg (Claim 1). A processor then figures out the limb's position relative to the HMD using the magnetic data. It combines this with the HMD's absolute position to know the limb's exact location in the real world. Finally, the system displays a virtual version of each user's limb on both HMDs, making it appear in the correct place within the shared AR experience (Claim 1). For example, two friends could be playing an AR game together, and each would see their own and the other's virtual arms moving correctly as they interact with virtual objects.
The gap
What does this patent NOT cover?
- Tracking systems that rely solely on a fixed base station to determine the position of body parts, rather than relative to the HMD.
- Systems that use optical cameras, inertial sensors, or other non-magnetic methods for tracking body parts.
- Single-user augmented reality experiences; this patent specifically claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more → a system for "two head-mounted displays" and "multiple user self-relative tracking."
- Virtual reality (VR) systems that replace the entire real world with a virtual one, as it focuses on displaying "augmented reality."
- Tracking of entire body skeletons or facial expressions, as the claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more → specifically refer to tracking a "limb."
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The core innovation is tracking a user's body parts, like a limb, relative to their own head-mounted display using magnetic fields, rather than relative to a fixed point in the room. This "self-relative" approach minimizes magnetic field distortions, allowing for a much more accurate representation of the user's virtual body in augmented reality.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
High-end augmented reality headsets with full-body tracking accessories
Collaborative AR applications for design or training
VR/AR gaming systems that track hands or feet for interaction
Professional simulation environments using magnetic trackers
Why it matters
The bigger picture
Accurate body tracking is crucial for creating believable and immersive augmented reality experiences, especially for interactions between multiple users. By tracking limbs relative to the HMD, this system aims to reduce errors caused by magnetic field distortions, which are common when tracking from a distant base station. This improved accuracy helps make virtual avatars feel more connected to the user's actual movements, enhancing shared AR applications in gaming, training, and collaborative work.
Filed
July 31, 2019
Granted
October 15, 2019
Market context
Who's building on this
Companies in this space
Companies like Meta (with its Quest line), Apple (with Vision Pro), Microsoft (with HoloLens), and HTC (with Vive XR Elite) are all heavily invested in developing advanced AR/VR systems that require precise body and limb tracking for immersive experiences. Sixense Enterprises Inc., the assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, also continues to develop magnetic tracking solutions for various applications.
Market impact
This type of self-relative tracking technology contributes to the ongoing improvement of user immersion and interaction fidelity in AR/VR. By enabling more accurate body representation, it supports the development of sophisticated multi-user AR applications for gaming, remote collaboration, and professional training, driving adoption in these emerging markets. It helps overcome a technical hurdle that previously limited the realism of virtual avatars in shared spaces.
Claim 1 — Plain English
What this patent covers
This system allows two users wearing head-mounted displays (HMDs) to see their own and each other's virtual limbs in an augmented reality (AR) environment. Each HMD has its own tracking system to know its absolute position in the real world (Claim 1). For each user, a magnetic tracking system is used, with one magnetic coil attached to their HMD and another to a limb, like an arm or leg (Claim 1). A processor then figures out the limb's position relative to the HMD using the magnetic data. It combines this with the HMD's absolute position to know the limb's exact location in the real world. Finally, the system displays a virtual version of each user's limb on both HMDs, making it appear in the correct place within the shared AR experience (Claim 1). For example, two friends could be playing an AR game together, and each would see their own and the other's virtual arms moving correctly as they interact with virtual objects.
The clever bit
The core innovation is tracking a user's body parts, like a limb, relative to their own head-mounted display using magnetic fields, rather than relative to a fixed point in the room. This "self-relative" approach minimizes magnetic field distortions, allowing for a much more accurate representation of the user's virtual body in augmented reality.
What it does not cover
- Tracking systems that rely solely on a fixed base station to determine the position of body parts, rather than relative to the HMD.
- Systems that use optical cameras, inertial sensors, or other non-magnetic methods for tracking body parts.
- Single-user augmented reality experiences; this patent specifically claims a system for "two head-mounted displays" and "multiple user self-relative tracking."
- Virtual reality (VR) systems that replace the entire real world with a virtual one, as it focuses on displaying "augmented reality."
- Tracking of entire body skeletons or facial expressions, as the claims specifically refer to tracking a "limb."
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
PatentBrief Score
Impact Score
Limited data
Citation count
0/40
No citations yet
Claim breadth
9/20
Moderate scope
Recency
10/20
Granted 5–10 years ago
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$23K – $72K
Midpoint $45K · 12.9 yr remaining · industry ×1.5
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
The original legal language
Original claims
14 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Diaz, A. S., Zur, O. Y., Pedrotti, O. W., & Rubin, A. (2019). How Two People's Body Movements Are Tracked in Augmented Reality (U.S. Patent No. 10,444,502). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/10444502/method-and-apparatus-for-multiple-user-self-relative-tracking-for-augmented-real
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
Embed
Add this patent to your site
Drop this plain-English patent card into any blog post or article — free, no signup. It always links back to the full breakdown here.
<div data-patentlens-widget data-patent-number="US10444502"></div> <script src="https://patentbrief.org/embed.js" async></script>
Stay in the loop
Get a weekly digest of new patents.
One email per week. No spam. Unsubscribe anytime.
Keep exploring
Related patents you should know
US 4683195 · 1987
How to Make Billions of Copies of a DNA Segment
This patent describes the Polymerase Chain Reaction (PCR), a method to rapidly create many copies of a specific piece of DNA or RNA, enabling its detection and analysis.
Cetus Corp
US 8697359 · 2014
How to Edit Genes in Human Cells Using an Engineered CRISPR System
This patent describes an engineered CRISPR-Cas9 system for precisely cutting DNA in eukaryotic cells to change how genes work, opening the door for gene editing in complex organisms.
Massachusetts Institute of Technology
US 7657849 · 2010
How the iPhone's Slide-to-Unlock Gesture Works
Apple's 2010 patent describes unlocking a device by dragging a specific graphical image across the touchscreen along a predefined path, a gesture that became iconic with the original iPhone.
Apple Inc
US 4733665 · 1988
How Doctors Implant a Permanent Stent Using a Balloon
This patent describes the method for placing a permanent, expandable wire mesh tube inside a blood vessel or other body tube using a balloon-tipped catheter to widen it and keep it open.
Expandable Grafts Partnership
US 4965188 · 1990
How to Make Many Copies of a DNA Piece with Heat
This patent describes the Polymerase Chain Reaction (PCR) method, a technique to make millions of copies of a specific DNA segment using a heat-resistant enzyme and repeated temperature changes.
Cetus Corp
US 4235871 · 1980
How to Encapsulate Active Materials in Lipid Bubbles Efficiently
This patent describes a method for trapping biologically active substances inside tiny, multi-layered fat bubbles called liposomes, using a specific water-in-oil emulsion and gel-forming process to improve how much material gets captured.
Individual
Semantically similar
You might also find these interesting
US 12386177 · 2025 · Disney Enterprises
How Disney's Compact AR Display Uses Special Mirrors
US 20210117042 · Apple
How Devices Detect Touch Using Heat Signatures
US 10878237 · 2020 · Seeing Machines
How Eye Tracking Systems Adapt When They Can't See Eye Glints
US 12008152 · 2024 · Snap Inc
How Snap's AR Tech Measures Distance for Virtual Button Presses
More to explore
More in Consumer Electronics
US 7657849 · 2010 · Apple Inc
How the iPhone's Slide-to-Unlock Gesture Works
US 7479949 · 2009 · Apple Inc
How Touchscreens Understand Your Finger Swipes and Scrolls
US 4528643 · 1985 · FPDC Inc
How Stores Make Custom Products On-Demand with Remote Approval
US 7469381 · 2008 · Apple Inc
How Touchscreens Show and Snap Back When You Scroll Past an Edge
New to patents?
Common Questions
Frequently Asked Questions
What does How Two People's Body Movements Are Tracked in Augmented Reality cover?
This patent describes a system for two users to accurately track their body parts, like a limb, relative to their own head-mounted display using magnetic fields, then display these virtual limbs in a shared augmented reality.
Who owns patent US 10444502?
Sixense Enterprises owns this patent, granted in 2019.
When does this patent expire?
This patent is expected to expire on July 31, 2039, when the invention enters the public domain.
What problem does this patent solve?
Accurate body tracking is crucial for creating believable and immersive augmented reality experiences, especially for interactions between multiple users. By tracking limbs relative to the HMD, this system aims to reduce errors caused by magnetic field distortions, which are common when tracking from a distant base station. This improved accuracy helps make virtual avatars feel more connected to the user's actual movements, enhancing shared AR applications in gaming, training, and collaborative work.
What does this patent NOT cover?
Tracking systems that rely solely on a fixed base station to determine the position of body parts, rather than relative to the HMD.
Patent monitoring