Optical and Electromagnetic Navigation
Technology Videos
Introductory Videos
Optical Navigation Technology
The Polaris family of optical trackers is used to track the position and orientation of surgical instruments in 3D space in real-time. These trackers use infrared light to detect reflective markers attached to the instruments and triangulate their positions. The tracking data is then processed by a host application, which displays the instruments’ locations and paths like how a GPS tracks a device’s location.
Electromagnetic Tracking Solutions
NDI’s Aurora® Electromagnetic tracking technology uses an electromagnetic field to accurately localize and track OEM medical instruments in 3D space. It provides real-time tracking of microsensors that can be embedded into rigid and flexible OEM medical instruments such as ultrasound probes, endoscopes, catheters, guidewires or even at the tip of a needle.
How Passive Marker Spheres Work
NDI pioneered the development of the passive marker sphere, which is attached to surgical instruments and acts as a location point in the OR. NDI Passive Spheres are used to calibrate the NDI Polaris tracker and optimize measurement performance.
Polaris Lyra® – Optical Navigation in Confined Spaces
Tracking 6D tool positions and orientations with low data latency, high update rate, and unparalleled accuracy, the Polaris Lyra® complements the workflow of many OEM applications used in spinal surgery, neurosurgery, and transcranial magnetic stimulation (TMS) procedures.
Optical Navigation in TMS Applications
High accuracy, a small footprint, and a short stand-off make the Polaris Lyra® a trusted choice for OEM solution providers providing real-time neuronavigation for Transcranial Magnetic Stimulation (TMS). The Polaris Lyra optical navigation technology allows clinicians to create personalized therapies with accurate repeatability.
Bronchoscopic diagnostics and Ablation with Aurora Electromagnetic Tracking Technology
The video describes the use of an endoscope with embedded sensors that is tracked by the Aurora electromagnetic tracking solution. The sensors relay position and orientation tracking data to the OEM host application, enabling the scope to be navigated to the treatment site using preoperative image sets.
Electromagnetic Tracking Technology in Interventional Cardiology Procedures
The video shows how the Window Field Generator establishes a measurement volume for tracking medical instruments. A sensor-guided guidewire is used to guide the instruments to the treatment site, and it is exchanged for a trans-septal needle and a sensorized mapping catheter for precise targeting and mapping of abnormal tissue.
MedTech Minutes: Global and Local Coordinate Systems
What Is a Measurement Volume?
A measurement volume isn’t everything the tracker can detect. It’s the smaller, characterized space where accuracy stays within specification. This explainer breaks down the distinction and why it matters for integration.
What Is a Local Coordinate System?
A local coordinate system lets you track relative to a reference you choose, not relative to the tracker itself. This explainer covers what it is, why it’s useful, and how it relates to the global coordinate system.
What Is a Global Coordinate System?
Before you can say where anything is, you need a frame to say it in. That’s the global coordinate system. This explainer covers what it is and where it comes from.
How Global and Local Coordinate Systems Are Defined
Global frames are locked in at manufacturing. Local frames are yours to define. This explainer shows how each is set, for both optical and electromagnetic tracking.
Why Tracking Needs Both Local and Global Coordinate Systems
A global frame tells you where something is. A local frame tells you how it’s oriented. Tracking needs both, and this explainer shows why, with two simple analogies.
How Coordinate Systems and Measurement Volume Relate
The measurement volume is a physical reality. Coordinate systems are just how you describe what’s inside it. This explainer untangles how the two relate, and where they don’t.
How Tracked Object Coordinates Are Reported
Tracking data comes down to two questions: where is the object, and how is it oriented? This explainer covers how those coordinates are reported, and why NDI often uses quaternions.
MedTech Minutes: Electromagnetic Systems
How Do NDI’s Electromagnetic Sensors Work
How does electromagnetic tracking actually work, and what happens inside the sensor? This short explainer breaks down how NDI’s electromagnetic sensors measure position and orientation in real time.
5DOF vs 6DOF EM Tracking: How to Choose
5DOF or 6DOF? The right choice comes down to sensor size, cost, and whether you need roll. This explainer walks through how NDI’s electromagnetic sensors handle both, and how to decide between them.
How to Reduce Measurement Distortion in EM Tracking
Distortion is the gap between where your sensor really is and where the tracker reports it. This explainer covers what causes measurement error in electromagnetic tracking, how to detect it, and how to reduce it.
What Is a Commutator? Reducing Distortion in EM Tracking
Run a sensor cable roughly two meters through a busy environment and it picks up interference along the way. The commutator is the component built to clean that up. This explainer covers what it is, how it works, and where to place it.
What Determines EM Tracking Accuracy?
EM tracking accuracy isn’t a single number. It depends on the sensor, the field generator, where you are in the tracking volume, and how you define accuracy in the first place. This explainer breaks down the factors that shape it.
MedTech Minutes: Optical Tools
What Is an Optical Tracking Tool?
An optical tracking tool is really just a rigid carrier for markers, and the markers are what the tracker actually sees. This explainer covers what makes up a tool and how it’s tracked.
Does Optical Tool Rigidity Matter?
Yes, and it’s not a nice-to-have. Rigidity is a core assumption behind how optical tracking computes a tool’s pose. This explainer covers why, and what it means for tool design.
Optical Tracking Tool Types Explained
Every optical tool comes down to its markers, and there are two families: active markers that emit light, and passive markers that reflect it. This explainer covers both, plus the wired-versus-wireless split.
Designing Optical Tracking Tools: What to Consider
Good optical tool design starts with two questions: what is the tool for, and which tracker will read it? Everything after that is trade-offs. This explainer walks through the key ones.
What Is Marker Geometry?
Marker geometry is how a tool’s markers are arranged, and it’s what lets the tracker tell one tool from another and work out its pose. This explainer covers how it works and why active and passive tools are designed differently.
What Are Referencing and Tool Digitization?
Referencing relates one coordinate frame to another. Tool digitization is how you build a new frame from points you capture. This explainer covers how both work.
What Is Tool Tip Offset?
You track the markers, but you care about the tip. Tool tip offset is the distance between them, and this explainer shows how you find it.
Absolute vs Reference Tracking: What’s the Difference?
Move your tracker mid-setup and every reported position shifts, unless you’re using reference tracking. This explainer covers the difference between absolute and reference tracking, and why NDI recommends the latter.