{
  "patent_number": "US 10444502",
  "country": "US",
  "title": "How Two People's Body Movements Are Tracked in Augmented Reality",
  "original_title": "Method and apparatus for multiple user self-relative tracking for augmented reality systems using magnetic tracking",
  "summary": "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.",
  "what_it_does": "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.",
  "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.\""
  ],
  "filed": "2019-07-31",
  "granted": "2019-10-15",
  "expires": "2039-07-31",
  "status": "active",
  "holder": "Sixense Enterprises",
  "holder_url": "https://patentbrief.org/company/sixense-enterprises",
  "inventors": [
    {
      "name": "Alejandro Santiago Diaz",
      "url": "https://patentbrief.org/inventor/alejandro-santiago-diaz"
    },
    {
      "name": "Oded Y. Zur",
      "url": "https://patentbrief.org/inventor/oded-y-zur"
    },
    {
      "name": "Owen Walter Pedrotti",
      "url": "https://patentbrief.org/inventor/owen-walter-pedrotti"
    },
    {
      "name": "Amir Rubin",
      "url": "https://patentbrief.org/inventor/amir-rubin"
    }
  ],
  "times_cited": 0,
  "tags": [
    "consumer_electronics",
    "software",
    "telecommunications",
    "gaming",
    "ai_ml"
  ],
  "abstract": "A method and apparatus for self-relative body tracking in virtual reality systems using magnetic tracking is disclosed, which allows more accurate tracking of a user's body relative to the user's field of vision. A head-mounted magnetic tracking (HMMT) system is used, in which other parts of a user's body are tracked relative to the HMD on the user's head, rather than relative to a base station. This results in less distortion of the magnetic field used for tracking and thus allows for more accurate determination of the position and orientation of a user's body parts relative to the user's field of vision, so that a more accurate avatar may be presented on the HMD to the user. This allows the avatar of the user's body part to be shown in a location that corresponds closely to its physical position. In an alternative embodiment, multiple portions of the user's body may be tracked.",
  "url": "https://patentbrief.org/patent/us/10444502/method-and-apparatus-for-multiple-user-self-relative-tracking-for-augmented-real",
  "markdown_url": "https://patentbrief.org/patent/us/10444502/method-and-apparatus-for-multiple-user-self-relative-tracking-for-augmented-real/md",
  "google_patents_url": "https://patents.google.com/patent/US10444502",
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