Krios Electrode Localization

Handheld Optical Measurement for Electrode Localization

The Polaris^® Krios handheld digitizing scanner integrates into OEM neurodiagnostic equipment to measure, identify, and map electrode positions (via attached markers) in EEG, MEG, NIRS, PSG, and ECG tests. The Polaris Krios is based on optical 3D measurement technology that scans up to 256 markers in less than 2 minutes to accuracy within 0.5 mm and repeatability of 0.1 mm. Real-time compensation for data variability ensures only actual markers are measured for mapping and registration purposes.

NDI’s extensive API library provides neurodiagnostic equipment manufacturers with seamless integration and management of this electrode measurement data; for example, recording and naming electrodes against a preset 10-20 electrode placement model. The Krios complements the workflow of existing neurodiagnostic systems by reducing the time and complexity of electrode registration and identification. The electrode setup process, which can be time-consuming and difficult for operators, now takes only minutes.

Krios Benefits

Benefits of the Polaris^® Krios to Neurodiagnostic OEMs and Operators

• Lightweight Ergonomic Scanner
  Operate the Krios with ease – its balanced one-hand grip, handy start/stop trigger button, color-coded LED status indicator lights, and audio cues maximize scanning efficiency.
• Integrated Touch Probe
  Improve the detection of obstructed electrodes and electrode positioning with one-touch localization and registration of fiducial points such as the nasion, inion, and preauricular points.
• No Marker Calculations
  Scan right away – self-calibrating markers attach to any sized or shaped electrode, in any order. No position calculations or sequencing are required. Marker positions are automatically mapped.
• Accurate and Reliable Data Collection
  Capture marker positions to accuracy within 0.5mm and a repeatability of 0.1mm. Only actual markers are measured for electrode mapping purposes.
• Automatic Registration Process
  Save significant electrode registration time – up to 256 markers can be scanned in less than 2 minutes. Markers are then automatically mapped and registered within the OEM’s neurofeedback software.

Krios Operation

How the Polaris^® Krios Works

The Polaris Krios is based on optical measurement technology; the scanner uses light reflected by markers to determine their position coordinates.

Attach each electrode (with prefixed marker) to the scalp or cap.	Scan the head with the Krios to localize each marker’s position. This localization process creates a digital point cloud (3D model) and rigid body of marker coordinates.	Probe anatomical features to establish fiducial (reference) points with respect to the rigid body, such as the nasion, inion, and preauricular points of the subject’s head.

Results

The rigid body is transformed from the Krios coordinate system to the subject coordinate system. Using the Krios software, operators can append notes to electrode positions. The final point cloud with all identified marker coordinates, fiducial points, and notes, is saved as a .CSV file for export to the neurofeedback software.  The point cloud can then be mapped to a pre-defined electrode configuration within the neurofeedback software.

Krios Specifications

Polaris^® Krios Technical Specifications